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r0638c44 r6e991d6 11 11 %% Created On : Wed Apr 6 14:53:29 2016 12 12 %% Last Modified By : Peter A. Buhr 13 %% Last Modified On : T ue May 3 08:05:33201614 %% Update Count : 24613 %% Last Modified On : Thu Apr 21 08:15:37 2016 14 %% Update Count : 131 15 15 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 16 16 17 17 % requires tex packages: texlive-base texlive-latex-base tex-common texlive-humanities texlive-latex-extra texlive-fonts-recommended 18 19 % inline code ©...© (copyright symbol) emacs: C-q M-)20 % red highlighting ®...® (registered trademark sumbol) emacs: C-q M-.21 % latex escape §...§ (section symbol) emacs: C-q M-'22 % keyword escape ¶...¶ (pilcrow symbol) emacs: C-q M-^23 % math escape $...$ (dollar symbol)24 18 25 19 \documentclass[openright,twoside]{article} … … 180 174 \CC~\cite{c++,ANSI14:C++} is an example of a similar project; 181 175 however, it largely extended the language, and did not address existing problems.\footnote{% 182 Two important existing problems addressed were changing the type of character literals from ©int© to ©char© and enumerator from ©int©to the type of its enumerators.}176 Two important existing problems addressed were changing the type of character literals from \lstinline@int@ to \lstinline@char@ and enumerator from \lstinline@int@ to the type of its enumerators.} 183 177 Fortran~\cite{Fortran08}, Ada~\cite{Ada12}, and Cobol~\cite{Cobol14} are examples of programming languages that took an evolutionary approach, where modern language features are added and problems fixed within the framework of the existing language. 184 178 Java~\cite{Java8}, Go~\cite{Go}, Rust~\cite{Rust} and D~\cite{D} are examples of the revolutionary approach for modernizing C/\CC, resulting in a new language rather than an extension of the descendent. … … 205 199 206 200 However, it is necessary to differentiate between C and \CFA code because of name overloading, as for \CC. 207 For example, the C math-library provides the following routines for computing the absolute value of the basic type: ©abs©, ©labs©, ©llabs©, ©fabs©, ©fabsf©, ©fabsl©, ©cabsf©, ©cabs©, and ©cabsl©.208 Whereas, \CFA wraps each of these routines into one with the common name ©abs©.201 For example, the C math-library provides the following routines for computing the absolute value of the basic type: \lstinline@abs@, \lstinline@labs@, \lstinline@llabs@, \lstinline@fabs@, \lstinline@fabsf@, \lstinline@fabsl@, \lstinline@cabsf@, \lstinline@cabs@, and \lstinline@cabsl@. 202 Whereas, \CFA wraps each of these routines into one with the common name \lstinline@abs@. 209 203 \begin{lstlisting} 210 204 char abs( char ); … … 221 215 long double _Complex abs( long double _Complex ); 222 216 \end{lstlisting} 223 The problem is the name clash between the library routine ©abs© and the \CFA names ©abs©.224 Hence, names appearing in an ©extern "C"©block have \newterm{C linkage}.217 The problem is the name clash between the library routine \lstinline@abs@ and the \CFA names \lstinline@abs@. 218 Hence, names appearing in an \lstinline@extern "C"@ block have \newterm{C linkage}. 225 219 Then overloading polymorphism uses a mechanism called \newterm{name mangling} to create unique names that are different from C names, which are not mangled. 226 220 Hence, there is the same need as in \CC, to know if a name is a C or \CFA name, so it can be correctly formed. 227 221 There is no way around this problem, other than C's approach of creating unique names for each pairing of operation and type. 228 222 This example strongly illustrates a core idea in \CFA: \emph{the power of a name}. 229 The name `` ©abs©'' evokes the notion of absolute value, and many mathematical types provide the notion of absolute value.230 Hence, knowing the name ©abs©should be sufficient to apply it to any type where it is applicable.223 The name ``\lstinline@abs@'' evokes the notion of absolute value, and many mathematical types provide the notion of absolute value. 224 Hence, knowing the name \lstinline@abs@ should be sufficient to apply it to any type where it is applicable. 231 225 The time savings and safety of using one name uniformly versus $N$ unique names should not be underestimated. 232 226 233 227 234 \section[Compiling CFA Program]{Compiling \CFA Program} 235 236 The command ©cfa© is used to compile \CFA program(s). 237 This command works like the GNU ©gcc©\index{gcc} command, e.g.: 238 \begin{lstlisting} 239 cfa§\indexc{cfa}\index{compilation!cfa@©cfa©}§ [ gcc-options ] C/§\CFA§-files [ assembler/loader-files ] 240 \end{lstlisting} 241 By default, \CFA programs having the following ©gcc© flags turned on: 228 \section{Compiling \CFA Program} 229 230 The command \lstinline@cfa@ is used to compile \CFA program(s). 231 This command works like the GNU \lstinline@gcc@\index{gcc} command, e.g.: 232 \begin{lstlisting} 233 cfa [ gcc-options ] C/@{\CFA}@-files [ assembler/loader-files ] 234 \end{lstlisting} 235 \index{cfa@\lstinline$cfa$}\index{compilation!cfa@\lstinline$cfa$} 236 By default, \CFA programs having the following \lstinline@gcc@ flags turned on: 242 237 \begin{description} 243 \item\hspace*{-4pt}\Indexc{-std=gnu99}\index{compilation option!-std=gnu99@{©-std=gnu99©}} 238 \item 239 \hspace*{-4pt}\lstinline@-std=gnu99@ 240 \index{-std=gnu99@{\lstinline$-std=gnu99$}}\index{compilation option!-std=gnu99@{\lstinline$-std=gnu99$}} 244 241 The 1999 C standard plus GNU extensions. 245 \item\hspace*{-4pt}\Indexc{-fgnu89-¶inline¶}\index{compilation option!-fgnu89-inline@{©-fgnu89-¶inline¶©}} 242 \item 243 \hspace*{-4pt}\lstinline@-fgnu89-inline@ 244 \index{-fgnu89-inline@{\lstinline$-fgnu89-inline$}}\index{compilation option!-fgnu89-inline@{\lstinline$-fgnu89-inline$}} 246 245 Use the traditional GNU semantics for inline routines in C99 mode. 247 246 \end{description} 248 247 The following new \CFA option is available: 249 248 \begin{description} 250 \item\hspace*{-4pt}\Indexc{-CFA}\index{compilation option!-CFA@{©-CFA©}} 249 \item 250 \hspace*{-4pt}\lstinline@-CFA@ 251 \index{-CFA@{\lstinline$-CFA$}}\index{compilation option!-CFA@{\lstinline$-CFA$}} 251 252 Only the C preprocessor and the \CFA translator steps are performed and the transformed program is written to standard output, which makes it possible to examine the code generated by the \CFA translator. 252 253 \end{description} … … 254 255 The following preprocessor variables are available: 255 256 \begin{description} 256 \item\hspace*{-4pt}\Indexc{__CFA__}\index{preprocessor variables!__CFA__@{©__CFA__©}} 257 \item 258 \hspace*{-4pt}\lstinline$__CFA__$ 259 \index{__CFA__@{\lstinline$__CFA__$}}\index{preprocessor variables!__CFA__@{\lstinline$__CFA__$}} 257 260 is always available during preprocessing and its value is the current major \Index{version number} of \CFA.\footnote{ 258 261 The C preprocessor allows only integer values in a preprocessor variable so a value like ``\Version'' is not allowed. 259 262 Hence, the need to have three variables for the major, minor and patch version number.} 260 263 261 \item\hspace*{-4pt}\Indexc{__CFA_MINOR__}\index{preprocessor variables!__CFA_MINOR__@{©__CFA_MINOR__©}} 264 \item 265 \hspace*{-4pt}\lstinline$__CFA_MINOR__$ 266 \index{__CFA_MINOR__@{\lstinline$__CFA_MINOR__$}}\index{preprocessor variables!__CFA_MINOR__@{\lstinline$__CFA_MINOR__$}} 262 267 is always available during preprocessing and its value is the current minor \Index{version number} of \CFA. 263 268 264 \item\hspace*{-4pt}\Indexc{__CFA_PATCH__}\index{preprocessor variables!__CFA_PATCH__@©__CFA_PATCH__©} 269 \item 270 \hspace*{-4pt}\lstinline$__CFA_PATCH__$ 271 \index{__CFA_PATCH__@%(__CFA_PATCH__%)}\index{preprocessor variables!__CFA_PATCH__@%(__CFA_PATCH__%)} 265 272 is always available during preprocessing and its value is the current patch \Index{version number} of \CFA. 266 273 267 \item\hspace*{-4pt}\Indexc{__CFORALL__}\index{preprocessor variables!__CFORALL__@©__CFORALL__©} 274 \item 275 \hspace*{-4pt}\lstinline$__CFORALL__$ 276 \index{__CFORALL__@%(__CFORALL__%)}\index{preprocessor variables!__CFORALL__@%(__CFORALL__%)} 268 277 is always available during preprocessing and it has no value. 269 278 \end{description} … … 273 282 \begin{lstlisting} 274 283 #ifndef __CFORALL__ 275 #include <stdio.h> // C header file284 #include <stdio.h> // C header file 276 285 #else 277 #include <fstream> // §\CFA{}§header file286 #include <fstream> // @\CFA{}@ header file 278 287 #endif 279 288 \end{lstlisting} 280 which conditionally includes the correct header file, if the program is compiled using ©gcc© or ©cfa©.289 which conditionally includes the correct header file, if the program is compiled using \lstinline@gcc@ or \lstinline@cfa@. 281 290 282 291 … … 285 294 Numeric constants are extended to allow \Index{underscore}s within constants\index{constant!underscore}, e.g.: 286 295 \begin{lstlisting} 287 2 ®_®147®_®483®_®648; // decimal constant296 2`_`147`_`483`_`648; // decimal constant 288 297 56_ul; // decimal unsigned long constant 289 298 0_377; // octal constant … … 299 308 \begin{enumerate} 300 309 \item 301 A sequence of underscores is disallowed, e.g., ©12__34©is invalid.310 A sequence of underscores is disallowed, e.g., \lstinline@12__34@ is invalid. 302 311 \item 303 312 Underscores may only appear within a sequence of digits (regardless of the digit radix). 304 In other words, an underscore cannot start or end a sequence of digits, e.g., ©_1©, ©1_© and ©_1_©are invalid (actually, the 1st and 3rd examples are identifier names).313 In other words, an underscore cannot start or end a sequence of digits, e.g., \lstinline@_1@, \lstinline@1_@ and \lstinline@_1_@ are invalid (actually, the 1st and 3rd examples are identifier names). 305 314 \item 306 315 A numeric prefix may end with an underscore; 307 316 a numeric infix may begin and/or end with an underscore; 308 317 a numeric suffix may begin with an underscore. 309 For example, the octal ©0© or hexadecimal ©0x© prefix may end with an underscore ©0_377© or ©0x_ff©;310 the exponent infix ©E© may start or end with an underscore ©1.0_E10©, ©1.0E_10© or ©1.0_E_10©;311 the type suffixes ©U©, ©L©, etc. may start with an underscore ©1_U©, ©1_ll© or ©1.0E10_f©.318 For example, the octal \lstinline@0@ or hexadecimal \lstinline@0x@ prefix may end with an underscore \lstinline@0_377@ or \lstinline@0x_ff@; 319 the exponent infix \lstinline@E@ may start or end with an underscore \lstinline@1.0_E10@, \lstinline@1.0E_10@ or \lstinline@1.0_E_10@; 320 the type suffixes \lstinline@U@, \lstinline@L@, etc. may start with an underscore \lstinline@1_U@, \lstinline@1_ll@ or \lstinline@1.0E10_f@. 312 321 \end{enumerate} 313 322 It is significantly easier to read and enter long constants when they are broken up into smaller groupings (most cultures use comma or period among digits for the same purpose). … … 344 353 C and the new \CFA declarations may appear together in the same program block, but cannot be mixed within a specific declaration. 345 354 346 In \CFA declarations, the same tokens are used as in C: the character ©*© is used to indicate a pointer, square brackets ©[©\,©]© are used to represent an array, and parentheses ©()©are used to indicate a routine parameter.355 In \CFA declarations, the same tokens are used as in C: the character \lstinline@*@ is used to indicate a pointer, square brackets \lstinline@[@\,\lstinline@]@ are used to represent an array, and parentheses \lstinline@()@ are used to indicate a routine parameter. 347 356 However, unlike C, \CFA type declaration tokens are specified from left to right and the entire type specification is distributed across all variables in the declaration list. 348 For instance, variables ©x© and ©y©of type pointer to integer are defined in \CFA as follows:357 For instance, variables \lstinline@x@ and \lstinline@y@ of type pointer to integer are defined in \CFA as follows: 349 358 \begin{quote2} 350 359 \begin{tabular}{@{}l@{\hspace{30pt}}l@{}} 351 360 \multicolumn{1}{c@{\hspace{30pt}}}{\textbf{\CFA}} & \multicolumn{1}{c}{\textbf{C}} \\ 352 361 \begin{lstlisting} 353 ®* int x, y;® 362 `* int x, y;` 354 363 \end{lstlisting} 355 364 & … … 398 407 \end{quote2} 399 408 400 All type qualifiers, i.e., ©const© and ©volatile©, are used in the normal way with the new declarations but appear left to right, e.g.:409 All type qualifiers, i.e., \lstinline@const@ and \lstinline@volatile@, are used in the normal way with the new declarations but appear left to right, e.g.: 401 410 \begin{quote2} 402 411 \begin{tabular}{@{}l@{\hspace{30pt}}l@{\hspace{20pt}}l@{}} … … 418 427 \end{tabular} 419 428 \end{quote2} 420 All declaration qualifiers, i.e., ©extern©, ©static©, etc., are used in the normal way with the new declarations but can only appear at the start of a \CFA routine declaration,\footnote{\label{StorageClassSpecifier}429 All declaration qualifiers, i.e., \lstinline@extern@, \lstinline@static@, etc., are used in the normal way with the new declarations but can only appear at the start of a \CFA routine declaration,\footnote{\label{StorageClassSpecifier} 421 430 The placement of a storage-class specifier other than at the beginning of the declaration specifiers in a declaration is an obsolescent feature.~\cite[\S~6.11.5(1)]{C11}} e.g.: 422 431 \begin{quote2} … … 440 449 \end{quote2} 441 450 442 Unsupported are K\&R C declarations where the base type defaults to ©int©, if no type is specified\footnote{451 Unsupported are K\&R C declarations where the base type defaults to \lstinline@int@, if no type is specified\footnote{ 443 452 At least one type specifier shall be given in the declaration specifiers in each declaration, and in the specifier-qualifier list in each structure declaration and type name~\cite[\S~6.7.2(2)]{C11}}, 444 453 e.g.: … … 457 466 \section{Type Operators} 458 467 459 The new declaration syntax can be used in other contexts where types are required, e.g., casts and the pseudo-routine ©sizeof©:468 The new declaration syntax can be used in other contexts where types are required, e.g., casts and the pseudo-routine \lstinline@sizeof@: 460 469 \begin{quote2} 461 470 \begin{tabular}{@{}l@{\hspace{30pt}}l@{}} … … 479 488 The point of the new syntax is to allow returning multiple values from a routine~\cite{CLU,Galletly96}, e.g.: 480 489 \begin{lstlisting} 481 ®[ int o1, int o2, char o3 ]®f( int i1, char i2, char i3 ) {482 §\emph{routine body}§483 } 484 \end{lstlisting} 485 where routine ©f©has three output (return values) and three input parameters.490 `[ int o1, int o2, char o3 ]` f( int i1, char i2, char i3 ) { 491 @\emph{routine body}@ 492 } 493 \end{lstlisting} 494 where routine \lstinline@f@ has three output (return values) and three input parameters. 486 495 Existing C syntax cannot be extended with multiple return types because it is impossible to embed a single routine name within multiple return type specifications. 487 496 488 In detail, the brackets, ©[]©, enclose the result type, where each return value is named and that name is a local variable of the particular return type.\footnote{497 In detail, the brackets, \lstinline@[]@, enclose the result type, where each return value is named and that name is a local variable of the particular return type.\footnote{ 489 498 Michael Tiemann, with help from Doug Lea, provided named return values in g++, circa 1989.} 490 499 The value of each local return variable is automatically returned at routine termination. 491 500 Declaration qualifiers can only appear at the start of a routine definition, e.g.: 492 501 \begin{lstlisting} 493 extern [ int x ] g( int y ) { §\,§}502 extern [ int x ] g( int y ) {@\,@} 494 503 \end{lstlisting} 495 504 Lastly, if there are no output parameters or input parameters, the brackets and/or parentheses must still be specified; 496 505 in both cases the type is assumed to be void as opposed to old style C defaults of int return type and unknown parameter types, respectively, as in: 497 506 \begin{lstlisting} 498 [ §\,§] g();// no input or output parameters507 [@\,@] g(@\,@); // no input or output parameters 499 508 [ void ] g( void ); // no input or output parameters 500 509 \end{lstlisting} … … 510 519 int (*f(x))[ 5 ] int x; {} 511 520 \end{lstlisting} 512 The string `` ©int (*f(x))[ 5 ]©'' declares a K\&R style routine of type returning a pointer to an array of 5 integers, while the string ``©[ 5 ] int x©'' declares a \CFA style parameter x of type array of 5 integers.513 Since the strings overlap starting with the open bracket, ©[©, there is an ambiguous interpretation for the string.521 The string ``\lstinline@int (*f(x))[ 5 ]@'' declares a K\&R style routine of type returning a pointer to an array of 5 integers, while the string ``\lstinline@[ 5 ] int x@'' declares a \CFA style parameter x of type array of 5 integers. 522 Since the strings overlap starting with the open bracket, \lstinline@[@, there is an ambiguous interpretation for the string. 514 523 As well, \CFA-style declarations cannot be used to declare parameters for C-style routine-definitions because of the following ambiguity: 515 524 \begin{lstlisting} … … 517 526 int f( int (* foo) ); // foo is redefined as a parameter name 518 527 \end{lstlisting} 519 The string `` ©int (* foo)©'' declares a C-style named-parameter of type pointer to an integer (the parenthesis are superfluous), while the same string declares a \CFA style unnamed parameter of type routine returning integer with unnamed parameter of type pointer to foo.520 The redefinition of a type name in a parameter list is the only context in C where the character ©*©can appear to the left of a type name, and \CFA relies on all type modifier characters appearing to the right of the type name.528 The string ``\lstinline@int (* foo)@'' declares a C-style named-parameter of type pointer to an integer (the parenthesis are superfluous), while the same string declares a \CFA style unnamed parameter of type routine returning integer with unnamed parameter of type pointer to foo. 529 The redefinition of a type name in a parameter list is the only context in C where the character \lstinline@*@ can appear to the left of a type name, and \CFA relies on all type modifier characters appearing to the right of the type name. 521 530 The inability to use \CFA declarations in these two contexts is probably a blessing because it precludes programmers from arbitrarily switching between declarations forms within a declaration contexts. 522 531 … … 537 546 \subsection{Returning Values} 538 547 539 Named return values handle the case where it is necessary to define a local variable whose value is then returned in a ©return©statement, as in:548 Named return values handle the case where it is necessary to define a local variable whose value is then returned in a \lstinline@return@ statement, as in: 540 549 \begin{lstlisting} 541 550 int f() { … … 545 554 } 546 555 \end{lstlisting} 547 Because the value in the return variable is automatically returned when a \CFA routine terminates, the ©return©statement \emph{does not} contain an expression, as in:548 \begin{lstlisting} 549 ®[ int x ]®f() {556 Because the value in the return variable is automatically returned when a \CFA routine terminates, the \lstinline@return@ statement \emph{does not} contain an expression, as in: 557 \begin{lstlisting} 558 `[ int x ]` f() { 550 559 ... x = 0; ... x = y; ... 551 ®return;®// implicitly return x552 } 553 \end{lstlisting} 554 When the return is encountered, the current value of ©x©is returned to the calling routine.555 As well, ``falling off the end'' of a routine without a ©return©statement is permitted, as in:560 `return;` // implicitly return x 561 } 562 \end{lstlisting} 563 When the return is encountered, the current value of \lstinline@x@ is returned to the calling routine. 564 As well, ``falling off the end'' of a routine without a \lstinline@return@ statement is permitted, as in: 556 565 \begin{lstlisting} 557 566 [ int x ] f() { … … 559 568 } // implicitly return x 560 569 \end{lstlisting} 561 In this case, the current value of ©x© is returned to the calling routine just as if a ©return©had been encountered.570 In this case, the current value of \lstinline@x@ is returned to the calling routine just as if a \lstinline@return@ had been encountered. 562 571 563 572 … … 772 781 \subsection{Type Nesting} 773 782 774 \CFA allows \Index{type nesting}, and type qualification of the nested types, where as C hoists\index{type hoisting} (refactors) nested types into the enclosing scope and has no type qualification.783 \CFA allows \Index{type nesting}, and type qualification of the nested types, where as C hoists\index{type!hoisting} (refactors) nested types into the enclosing scope and has no type qualification. 775 784 \begin{quote2} 776 785 \begin{tabular}{@{}l@{\hspace{30pt}}l|l@{}} … … 827 836 828 837 int fred() { 829 s.t.c = ®S.®R; // type qualification830 struct ®S.®T t = { ®S.®R, 1, 2 };831 enum ®S.®C c;832 union ®S.T.®U u;838 s.t.c = `S.`R; // type qualification 839 struct `S.`T t = { `S.`R, 1, 2 }; 840 enum `S.`C c; 841 union `S.T.`U u; 833 842 } 834 843 \end{lstlisting} 835 844 \end{tabular} 836 845 \end{quote2} 837 In the left example in C, types ©C©, ©U© and ©T© are implicitly hoisted outside of type ©S©into the containing block scope.838 In the right example in \CFA, the types are not hoisted and accessed using the field-selection operator `` ©.©'' for type qualification, as does Java, rather than the \CC type-selection operator ``©::©''.846 In the left example in C, types \lstinline@C@, \lstinline@U@ and \lstinline@T@ are implicitly hoisted outside of type \lstinline@S@ into the containing block scope. 847 In the right example in \CFA, the types are not hoisted and accessed using the field-selection operator ``\lstinline@.@'' for type qualification, as does Java, rather than the \CC type-selection operator ``\lstinline@::@''. 839 848 840 849 … … 854 863 qsort( ia, size ); // sort ascending order using builtin ?<? 855 864 { 856 ®int ?<?( int x, int y ) { return x > y; }®// nested routine865 `int ?<?( int x, int y ) { return x > y; }` // nested routine 857 866 qsort( ia, size ); // sort descending order by local redefinition 858 867 } … … 861 870 Nested routines are not first-class, meaning a nested routine cannot be returned if it has references to variables in its enclosing blocks; 862 871 the only exception is references to the external block of the translation unit, as these variables persist for the duration of the program. 863 The following program in undefined in \CFA (and ©gcc©\index{gcc})872 The following program in undefined in \CFA (and \lstinline@gcc@\index{gcc}) 864 873 \begin{lstlisting} 865 874 [* [int]( int )] foo() { // int (*foo())( int ) 866 int ®i®= 7;875 int `i` = 7; 867 876 int bar( int p ) { 868 ®i®+= 1; // dependent on local variable869 sout | ®i®| endl;877 `i` += 1; // dependent on local variable 878 sout | `i` | endl; 870 879 } 871 880 return bar; // undefined because of local dependence … … 888 897 The general syntax of a tuple is: 889 898 \begin{lstlisting} 890 [ §\emph{exprlist}§]891 \end{lstlisting} 892 where ©$\emph{exprlist}$©is a list of one or more expressions separated by commas.893 The brackets, ©[]©, allow differentiating between tuples and expressions containing the C comma operator.899 [ $\emph{exprlist}$ ] 900 \end{lstlisting} 901 where \lstinline@$\emph{exprlist}$@ is a list of one or more expressions separated by commas. 902 The brackets, \lstinline$[]$, allow differentiating between tuples and expressions containing the C comma operator. 894 903 The following are examples of tuples: 895 904 \begin{lstlisting} … … 898 907 [ v+w, x*y, 3.14159, f() ] 899 908 \end{lstlisting} 900 Tuples are permitted to contain sub-tuples (i.e., nesting), such as ©[ [ 14, 21 ], 9 ]©, which is a 2-element tuple whose first element is itself a tuple.909 Tuples are permitted to contain sub-tuples (i.e., nesting), such as \lstinline@[ [ 14, 21 ], 9 ]@, which is a 2-element tuple whose first element is itself a tuple. 901 910 Note, a tuple is not a record (structure); 902 911 a record denotes a single value with substructure, whereas a tuple is multiple values with no substructure (see flattening coercion in Section 12.1). … … 908 917 The general syntax of a tuple type is: 909 918 \begin{lstlisting} 910 [ §\emph{typelist}§]911 \end{lstlisting} 912 where ©$\emph{typelist}$©is a list of one or more legal \CFA or C type specifications separated by commas, which may include other tuple type specifications.919 [ @\emph{typelist}@ ] 920 \end{lstlisting} 921 where \lstinline@$\emph{typelist}$@ is a list of one or more legal \CFA or C type specifications separated by commas, which may include other tuple type specifications. 913 922 Examples of tuple types include: 914 923 \begin{lstlisting} … … 918 927 [ * [ 5 ] int, * * char, * [ [ int, int ] ] (int, int) ] 919 928 \end{lstlisting} 920 Like tuples, tuple types may be nested, such as ©[ [ int, int ], int ]©, which is a 2-element tuple type whose first element is itself a tuple type.929 Like tuples, tuple types may be nested, such as \lstinline@[ [ int, int ], int ]@, which is a 2-element tuple type whose first element is itself a tuple type. 921 930 922 931 Examples of declarations using tuple types are: … … 954 963 tuple does not have structure like a record; a tuple is simply converted into a list of components. 955 964 \begin{rationale} 956 The present implementation of \CFA does not support nested routine calls when the inner routine returns multiple values; i.e., a statement such as ©g( f() )©is not supported.965 The present implementation of \CFA does not support nested routine calls when the inner routine returns multiple values; i.e., a statement such as \lstinline@g( f() )@ is not supported. 957 966 Using a temporary variable to store the results of the inner routine and then passing this variable to the outer routine works, however. 958 967 \end{rationale} … … 983 992 \begin{rationale} 984 993 Unfortunately, C's syntax for subscripts precluded treating them as tuples. 985 The C subscript list has the form ©[i][j]...© and not ©[i, j, ...]©.986 Therefore, there is no syntactic way for a routine returning multiple values to specify the different subscript values, e.g., ©f[g()]©always means a single subscript value because there is only one set of brackets.987 Fixing this requires a major change to C because the syntactic form ©M[i, j, k]© already has a particular meaning: ©i, j, k©is a comma expression.994 The C subscript list has the form \lstinline@[i][j]...@ and not \lstinline@i, j, ...]@. 995 Therefore, there is no syntactic way for a routine returning multiple values to specify the different subscript values, e.g., \lstinline@f[g()]@ always means a single subscript value because there is only one set of brackets. 996 Fixing this requires a major change to C because the syntactic form \lstinline@M[i, j, k]@ already has a particular meaning: \lstinline@i, j, k@ is a comma expression. 988 997 \end{rationale} 989 998 … … 1004 1013 [ a, b, c, d ] = w 1005 1014 \end{lstlisting} 1006 ©w©is implicitly opened to yield a tuple of four values, which are then assigned individually.1015 \lstinline@w@ is implicitly opened to yield a tuple of four values, which are then assigned individually. 1007 1016 1008 1017 A \newterm{flattening coercion} coerces a nested tuple, i.e., a tuple with one or more components, which are themselves tuples, into a flattened tuple, which is a tuple whose components are not tuples, as in: … … 1012 1021 First the right-hand tuple is flattened and then the values are assigned individually. 1013 1022 Flattening is also performed on tuple types. 1014 For example, the type ©[ int, [ int, int ], int ]© can be coerced, using flattening, into the type ©[ int, int, int, int ]©.1023 For example, the type \lstinline@[ int, [ int, int ], int ]@ can be coerced, using flattening, into the type \lstinline@[ int, int, int, int ]@. 1015 1024 1016 1025 A \newterm{structuring coercion} is the opposite of flattening; 1017 1026 a tuple is structured into a more complex nested tuple. 1018 For example, structuring the tuple ©[ 1, 2, 3, 4 ]© into the tuple ©[ 1, [ 2, 3 ], 4 ]© or the tuple type ©[ int, int, int, int ]© into the tuple type ©[ int, [ int, int ], int ]©.1027 For example, structuring the tuple \lstinline@[ 1, 2, 3, 4 ]@ into the tuple \lstinline@[ 1, [ 2, 3 ], 4 ]@ or the tuple type \lstinline@[ int, int, int, int ]@ into the tuple type \lstinline@[ int, [ int, int ], int ]@. 1019 1028 In the following example, the last assignment illustrates all the tuple coercions: 1020 1029 \begin{lstlisting} … … 1024 1033 \end{lstlisting} 1025 1034 Starting on the right-hand tuple in the last assignment statement, w is opened, producing a tuple of four values; 1026 therefore, the right-hand tuple is now the tuple ©[ [ 1, 2, 3, 4 ], 5 ]©.1027 This tuple is then flattened, yielding ©[ 1, 2, 3, 4, 5 ]©, which is structured into ©[ 1, [ 2, 3, 4, 5 ] ]©to match the tuple type of the left-hand side.1028 The tuple ©[ 2, 3, 4, 5 ]©is then closed to create a tuple value.1029 Finally, ©x© is assigned ©1© and ©w©is assigned the tuple value using multiple assignment (see Section 14).1035 therefore, the right-hand tuple is now the tuple \lstinline@[ [ 1, 2, 3, 4 ], 5 ]@. 1036 This tuple is then flattened, yielding \lstinline@[ 1, 2, 3, 4, 5 ]@, which is structured into \lstinline@[ 1, [ 2, 3, 4, 5 ] ]@ to match the tuple type of the left-hand side. 1037 The tuple \lstinline@[ 2, 3, 4, 5 ]@ is then closed to create a tuple value. 1038 Finally, \lstinline@x@ is assigned \lstinline@1@ and \lstinline@w@ is assigned the tuple value using multiple assignment (see Section 14). 1030 1039 \begin{rationale} 1031 1040 A possible additional language extension is to use the structuring coercion for tuples to initialize a complex record with a tuple. … … 1038 1047 Mass assignment has the following form: 1039 1048 \begin{lstlisting} 1040 [ §\emph{lvalue}§, ..., §\emph{lvalue}§ ] = §\emph{expr}§;1041 \end{lstlisting} 1042 The left-hand side is a tuple of \ emph{lvalues}, which is a list of expressions each yielding an address, i.e., any data object that can appear on the left-hand side of a conventional assignment statement.1043 ©$\emph{expr}$©is any standard arithmetic expression.1049 [ @\emph{lvalue}@, ..., @\emph{lvalue}@ ] = @\emph{expr}@; 1050 \end{lstlisting} 1051 The left-hand side is a tuple of \lstinline@$\emph{lvalues}$@, which is a list of expressions each yielding an address, i.e., any data object that can appear on the left-hand side of a conventional assignment statement. 1052 \lstinline@$\emph{expr}$@ is any standard arithmetic expression. 1044 1053 Clearly, the types of the entities being assigned must be type compatible with the value of the expression. 1045 1054 … … 1067 1076 *a1 = t; *a2 = t; *a3 = t; 1068 1077 \end{lstlisting} 1069 The temporary ©t©is necessary to store the value of the expression to eliminate conversion issues.1078 The temporary \lstinline@t@ is necessary to store the value of the expression to eliminate conversion issues. 1070 1079 The temporaries for the addresses are needed so that locations on the left-hand side do not change as the values are assigned. 1071 In this case, ©y[i]© uses the previous value of ©i©and not the new value set at the beginning of the mass assignment.1080 In this case, \lstinline@y[i]@ uses the previous value of \lstinline@i@ and not the new value set at the beginning of the mass assignment. 1072 1081 1073 1082 … … 1077 1086 Multiple assignment has the following form: 1078 1087 \begin{lstlisting} 1079 [ §\emph{lvalue}§, . . ., §\emph{lvalue}§ ] = [ §\emph{expr}§, . . ., §\emph{expr}§];1080 \end{lstlisting} 1081 The left-hand side is a tuple of \ emph{lvalues}, and the right-hand side is a tuple of \emph{expr}s.1082 Each \ emph{expr} appearing on the righthand side of a multiple assignment statement is assigned to the corresponding \emph{lvalues}on the left-hand side of the statement using parallel semantics for each assignment.1088 [ @\emph{lvalue}@, . . ., @\emph{lvalue}@ ] = [ @\emph{expr}@, . . ., @\emph{expr}@ ]; 1089 \end{lstlisting} 1090 The left-hand side is a tuple of \lstinline@$\emph{lvalues}$@, and the right-hand side is a tuple of \lstinline@$\emph{expr}$@s. 1091 Each \lstinline@$\emph{expr}$@ appearing on the righthand side of a multiple assignment statement is assigned to the corresponding \lstinline@$\emph{lvalues}$@ on the left-hand side of the statement using parallel semantics for each assignment. 1083 1092 An example of multiple assignment is: 1084 1093 \begin{lstlisting} 1085 1094 [ x, y, z ] = [ 1, 2, 3 ]; 1086 1095 \end{lstlisting} 1087 Here, the values ©1©, ©2© and ©3© are assigned, respectively, to the variables ©x©, ©y© and ©z©.1096 Here, the values \lstinline@1@, \lstinline@2@ and \lstinline@3@ are assigned, respectively, to the variables \lstinline@x@, \lstinline@y@ and \lstinline@z@. 1088 1097 A more complex example is: 1089 1098 \begin{lstlisting} 1090 1099 [ i, y[ i ], z ] = [ 1, i, a + b ]; 1091 1100 \end{lstlisting} 1092 Here, the values ©1©, ©i© and ©a + b© are assigned to the variables ©i©, ©y[i]© and ©z©, respectively.1101 Here, the values \lstinline@1@, \lstinline@i@ and \lstinline@a + b@ are assigned to the variables \lstinline@i@, \lstinline@y[i]@ and \lstinline@z@, respectively. 1093 1102 Note, the parallel semantics of 1094 1103 multiple assignment ensures: … … 1096 1105 [ x, y ] = [ y, x ]; 1097 1106 \end{lstlisting} 1098 correctly interchanges (swaps) the values stored in ©x© and ©y©.1107 correctly interchanges (swaps) the values stored in \lstinline@x@ and \lstinline@y@. 1099 1108 The following cases are errors: 1100 1109 \begin{lstlisting} … … 1117 1126 Cascade assignment has the following form: 1118 1127 \begin{lstlisting} 1119 §\emph{tuple}§ = §\emph{tuple}§ = ... = §\emph{tuple}§;1128 @\emph{tuple}@ = @\emph{tuple}@ = ... = @\emph{tuple}@; 1120 1129 \end{lstlisting} 1121 1130 and it has the same parallel semantics as for mass and multiple assignment. … … 1135 1144 Its general form is: 1136 1145 \begin{lstlisting} 1137 §\emph{expr}§ . [ §\emph{fieldlist}§]1138 §\emph{expr}§ -> [ §\emph{fieldlist}§]1139 \end{lstlisting} 1140 \ emph{expr} is any expression yielding a value of type record, e.g., ©struct©, ©union©.1141 Each element of \ emph{ fieldlist} is an element of the record specified by \emph{expr}.1146 @\emph{expr}@ . [ @\emph{fieldlist}@ ] 1147 @\emph{expr}@ -> [ @\emph{fieldlist}@ ] 1148 \end{lstlisting} 1149 \lstinline@$\emph{expr}$@ is any expression yielding a value of type record, e.g., \lstinline@struct@, \lstinline@union@. 1150 Each element of \lstinline@$\emph{ fieldlist}$@ is an element of the record specified by \lstinline@$\emph{expr}$@. 1142 1151 A record-field tuple may be used anywhere a tuple can be used. An example of the use of a record-field tuple is 1143 1152 the following: … … 1154 1163 also, it is unnecessary to specify all the fields of a struct in a multiple record-field tuple. 1155 1164 1156 If a field of a ©struct© is itself another ©struct©, multiple fields of this subrecord can be specified using a nested record-field tuple, as in the following example:1165 If a field of a \lstinline@struct@ is itself another \lstinline@struct@, multiple fields of this subrecord can be specified using a nested record-field tuple, as in the following example: 1157 1166 \begin{lstlisting} 1158 1167 struct inner { … … 1171 1180 \section{Labelled Break/Continue} 1172 1181 1173 While C provides ©break© and ©continue©statements for altering control flow, both are restricted to one level of nesting for a particular control structure.1174 Unfortunately, this restriction forces programmers to use ©goto©to achieve the equivalent for more than one level of nesting.1175 To prevent having to make this switch, the ©break© and ©continue©are extended with a target label to support static multi-level exit~\cite{Buhr85,Java}.1176 For the labelled ©break©, it is possible to specify which control structure is the target for exit, as in:1182 While C provides \lstinline@break@ and \lstinline@continue@ statements for altering control flow, both are restricted to one level of nesting for a particular control structure. 1183 Unfortunately, this restriction forces programmers to use \lstinline@goto@ to achieve the equivalent for more than one level of nesting. 1184 To prevent having to make this switch, the \lstinline@break@ and \lstinline@continue@ are extended with a target label to support static multi-level exit~\cite{Buhr85,Java}. 1185 For the labelled \lstinline@break@, it is possible to specify which control structure is the target for exit, as in: 1177 1186 \begin{quote2} 1178 1187 \begin{tabular}{@{}l@{\hspace{30pt}}l@{}} 1179 1188 \multicolumn{1}{c@{\hspace{30pt}}}{\textbf{\CFA}} & \multicolumn{1}{c}{\textbf{C}} \\ 1180 1189 \begin{lstlisting} 1181 ®L1:®for ( ... ) {1182 ®L2:®for ( ... ) {1183 ®L3:®for ( ... ) {1184 ... break ®L1®; ...1185 ... break ®L2®; ...1186 ... break ®L3®; // or break1190 `L1:` for ( ... ) { 1191 `L2:` for ( ... ) { 1192 `L3:` for ( ... ) { 1193 ... break `L1`; ... 1194 ... break `L2`; ... 1195 ... break `L3`; // or break 1187 1196 } 1188 1197 } … … 1204 1213 \end{quote2} 1205 1214 The inner most loop has three exit points, which cause termination of one or more of the three nested loops, respectively. 1206 For the labelled ©continue©, it is possible to specify which control structure is the target for the next loop iteration, as in:1215 For the labelled \lstinline@continue@, it is possible to specify which control structure is the target for the next loop iteration, as in: 1207 1216 \begin{quote2} 1208 1217 \begin{tabular}{@{}l@{\hspace{30pt}}l@{}} 1209 1218 \multicolumn{1}{c@{\hspace{30pt}}}{\textbf{\CFA}} & \multicolumn{1}{c}{\textbf{C}} \\ 1210 1219 \begin{lstlisting} 1211 ®L1®: for ( ... ) {1212 ®L2®: for ( ... ) {1213 ®L3®: for ( ... ) {1214 ... continue ®L1®; ...1215 ... continue ®L2®; ...1216 ... continue ®L3®; ...1220 `L1`: for ( ... ) { 1221 `L2`: for ( ... ) { 1222 `L3`: for ( ... ) { 1223 ... continue `L1`; ... 1224 ... continue `L2`; ... 1225 ... continue `L3`; ... 1217 1226 1218 1227 } … … 1240 1249 \end{quote2} 1241 1250 The inner most loop has three restart points, which cause the next loop iteration to begin, respectively. 1242 For both ©break© and ©continue©, the target label must be directly associated with a ©for©, ©while© or ©do©statement;1243 for ©break©, the target label can also be associated with a ©switch©statement.1244 Both ©break© and ©continue© with target labels are simply a ©goto©restricted in the following ways:1251 For both \lstinline@break@ and \lstinline@continue@, the target label must be directly associated with a \lstinline@for@, \lstinline@while@ or \lstinline@do@ statement; 1252 for \lstinline@break@, the target label can also be associated with a \lstinline@switch@ statement. 1253 Both \lstinline@break@ and \lstinline@continue@ with target labels are simply a \lstinline@goto@ restricted in the following ways: 1245 1254 \begin{itemize} 1246 1255 \item … … 1251 1260 Since they always transfers out of containing control structures, they cannot be used to branch into a control structure. 1252 1261 \end{itemize} 1253 The advantage of the labelled ©break©/©continue© is that it allows static multi-level exits without having to use the ©goto©statement and ties control flow to the target control structure rather than an arbitrary point in a program.1262 The advantage of the labelled \lstinline@break@/\lstinline@continue@ is that it allows static multi-level exits without having to use the \lstinline@goto@ statement and ties control flow to the target control structure rather than an arbitrary point in a program. 1254 1263 Furthermore, the location of the label at the beginning of the target control structure informs the reader that complex control-flow is occurring in the body of the control structure. 1255 With ©goto©, the label at the end of the control structure fails to convey this important clue early enough to the reader.1264 With \lstinline@goto@, the label at the end of the control structure fails to convey this important clue early enough to the reader. 1256 1265 Finally, using an explicit target for the transfer instead of an implicit target allows new nested loop or switch constructs to be added or removed without affecting other constructs. 1257 The implicit targets of the current ©break© and ©continue©, i.e., the closest enclosing loop or ©switch©, change as certain constructs are added or removed.1266 The implicit targets of the current \lstinline@break@ and \lstinline@continue@, i.e., the closest enclosing loop or \lstinline@switch@, change as certain constructs are added or removed. 1258 1267 1259 1268 1260 1269 \section{Switch Statement} 1261 1270 1262 C allows a number of questionable forms for the ©switch©statement:1271 C allows a number of questionable forms for the \lstinline@switch@ statement: 1263 1272 \begin{enumerate} 1264 1273 \item 1265 By default, the end of a ©case©clause\footnote{1266 In this section, the term \emph{case clause} refers to either a ©case© or ©default©clause.}1267 \emph{falls through} to the next ©case© clause in the ©switch©statement;1268 to exit a ©switch© statement from a ©case© clause requires explicitly terminating the clause with a transfer statement, most commonly ©break©, as in:1274 By default, the end of a \lstinline@case@ clause\footnote{ 1275 In this section, the term \emph{case clause} refers to either a \lstinline@case@ or \lstinline@default@ clause.} 1276 \emph{falls through} to the next \lstinline@case@ clause in the \lstinline@switch@ statement; 1277 to exit a \lstinline@switch@ statement from a \lstinline@case@ clause requires explicitly terminating the clause with a transfer statement, most commonly \lstinline@break@, as in: 1269 1278 \begin{lstlisting} 1270 1279 switch ( i ) { … … 1291 1300 \end{lstlisting} 1292 1301 In this example, case 2 is always done if case 3 is done. 1293 This control flow is difficult to simulate with if statements or a ©switch©statement without fall-through as code must be duplicated or placed in a separate routine.1302 This control flow is difficult to simulate with if statements or a \lstinline@switch@ statement without fall-through as code must be duplicated or placed in a separate routine. 1294 1303 C also uses fall-through to handle multiple case-values resulting in the same action, as in: 1295 1304 \begin{lstlisting} … … 1304 1313 \end{lstlisting} 1305 1314 However, this situation is handled in other languages without fall-through by allowing a list of case values. 1306 While fall-through itself is not a problem, the problem occurs when fall-through is the ©default©, as this semantics is not intuitive to most programmers and is different from virtually all other programming languages with a ©switch©statement.1307 Hence, ©default© fall-through semantics results in a large number of programming errors as programmers often forget the ©break© statement at the end of a ©case©clause, resulting in inadvertent fall-through.1308 1309 \item 1310 It is possible to place ©case© clauses on statements nested \emph{within} the body of the ©switch©statement, as in:1315 While fall-through itself is not a problem, the problem occurs when fall-through is the \lstinline@default@, as this semantics is not intuitive to most programmers and is different from virtually all other programming languages with a \lstinline@switch@ statement. 1316 Hence, \lstinline@default@ fall-through semantics results in a large number of programming errors as programmers often forget the \lstinline@break@ statement at the end of a \lstinline@case@ clause, resulting in inadvertent fall-through. 1317 1318 \item 1319 It is possible to place \lstinline@case@ clauses on statements nested \emph{within} the body of the \lstinline@switch@ statement, as in: 1311 1320 \begin{lstlisting} 1312 1321 switch ( i ) { … … 1349 1358 } 1350 1359 \end{lstlisting} 1351 which unrolls a loop N times (N = 8 above) and uses the ©switch©statement to deal with any iterations not a multiple of N.1360 which unrolls a loop N times (N = 8 above) and uses the \lstinline@switch@ statement to deal with any iterations not a multiple of N. 1352 1361 While efficient, this sort of special purpose usage is questionable: 1353 1362 \begin{quote} … … 1356 1365 \end{quote} 1357 1366 \item 1358 It is possible to place the ©default© clause anywhere in the list of labelled clauses for a ©switch©statement, rather than only at the end.1359 Virtually all programming languages with a ©switch© statement require the ©default©clause to appear last in the case-clause list.1360 The logic for this semantics is that after checking all the ©case© clauses without success, the ©default©clause is selected;1361 hence, physically placing the ©default© clause at the end of the ©case©clause list matches with this semantics.1362 This physical placement can be compared to the physical placement of an ©else© clause at the end of a series of connected ©if©/©else©statements.1363 1364 \item 1365 It is possible to place unreachable code at the start of a ©switch©statement, as in:1367 It is possible to place the \lstinline@default@ clause anywhere in the list of labelled clauses for a \lstinline@switch@ statement, rather than only at the end. 1368 Virtually all programming languages with a \lstinline@switch@ statement require the \lstinline@default@ clause to appear last in the case-clause list. 1369 The logic for this semantics is that after checking all the \lstinline@case@ clauses without success, the \lstinline@default@ clause is selected; 1370 hence, physically placing the \lstinline@default@ clause at the end of the \lstinline@case@ clause list matches with this semantics. 1371 This physical placement can be compared to the physical placement of an \lstinline@else@ clause at the end of a series of connected \lstinline@if@/\lstinline@else@ statements. 1372 1373 \item 1374 It is possible to place unreachable code at the start of a \lstinline@switch@ statement, as in: 1366 1375 \begin{lstlisting} 1367 1376 switch ( x ) { … … 1373 1382 } 1374 1383 \end{lstlisting} 1375 While the declaration of the local variable ©y© is useful and its scope is across all ©case©clauses, the initialization for such a variable is defined to never be executed because control always transfers over it.1376 Furthermore, any statements before the first ©case© clause can only be executed if labelled and transfered to using a ©goto©, either from outside or inside of the ©switch©.1384 While the declaration of the local variable \lstinline@y@ is useful and its scope is across all \lstinline@case@ clauses, the initialization for such a variable is defined to never be executed because control always transfers over it. 1385 Furthermore, any statements before the first \lstinline@case@ clause can only be executed if labelled and transfered to using a \lstinline@goto@, either from outside or inside of the \lstinline@switch@. 1377 1386 As mentioned, transfer into control structures should be forbidden. 1378 Transfers from within the ©switch© body using a ©goto©are equally unpalatable.1387 Transfers from within the \lstinline@switch@ body using a \lstinline@goto@ are equally unpalatable. 1379 1388 \end{enumerate} 1380 1389 Before discussing potential language changes to deal with these problems, it is worth observing that in a typical C program: 1381 1390 \begin{itemize} 1382 1391 \item 1383 the number of ©switch©statements is small,1384 \item 1385 most ©switch©statements are well formed (i.e., no Duff's device),1386 \item 1387 the ©default©clause is usually written as the last case-clause,1388 \item 1389 and there is only a medium amount of fall-through from one ©case©clause to the next, and most of these result from a list of case values executing common code, rather than a sequence of case actions that compound.1392 the number of \lstinline@switch@ statements is small, 1393 \item 1394 most \lstinline@switch@ statements are well formed (i.e., no Duff's device), 1395 \item 1396 the \lstinline@default@ clause is usually written as the last case-clause, 1397 \item 1398 and there is only a medium amount of fall-through from one \lstinline@case@ clause to the next, and most of these result from a list of case values executing common code, rather than a sequence of case actions that compound. 1390 1399 \end{itemize} 1391 1400 These observations should help to put the effects of suggested changes into perspective. … … 1393 1402 \begin{enumerate} 1394 1403 \item 1395 Eliminating the ©default©fall-through problem has the greatest potential for affecting existing code.1396 However, even if fall-through is removed, most ©switch© statements would continue to work because of the explicit transfers already present at the end of each ©case© clause, and the common placement of the ©default©clause at the end of the case list.1397 In addition, the above grammar provides for the most common use of fall-through, i.e., a list of ©case©clauses executing common code, e.g.:1404 Eliminating the \lstinline@default@ fall-through problem has the greatest potential for affecting existing code. 1405 However, even if fall-through is removed, most \lstinline@switch@ statements would continue to work because of the explicit transfers already present at the end of each \lstinline@case@ clause, and the common placement of the \lstinline@default@ clause at the end of the case list. 1406 In addition, the above grammar provides for the most common use of fall-through, i.e., a list of \lstinline@case@ clauses executing common code, e.g.: 1398 1407 \begin{lstlisting} 1399 1408 case 1: case 2: case 3: ... 1400 1409 \end{lstlisting} 1401 1410 Nevertheless, reversing the default action would have a non-trivial effect on case actions that compound, such as the above example of processing shell arguments. 1402 Therefore, to preserve backwards compatibility, it is necessary to introduce a new kind of ©switch© statement, called ©choose©, with no fall-through semantics.1403 The ©choose© statement is identical to the new ©switch© statement, except there is no implicit fall-through between case-clauses and the ©break© statement applies to the enclosing loop construct (as for the continue statement in a ©switch©statement).1411 Therefore, to preserve backwards compatibility, it is necessary to introduce a new kind of \lstinline@switch@ statement, called \lstinline@choose@, with no fall-through semantics. 1412 The \lstinline@choose@ statement is identical to the new \lstinline@switch@ statement, except there is no implicit fall-through between case-clauses and the \lstinline@break@ statement applies to the enclosing loop construct (as for the continue statement in a \lstinline@switch@ statement). 1404 1413 It is still possible to fall-through if a case-clause ends with the new keyword fallthru, e.g.: 1405 1414 \begin{lstlisting} … … 1417 1426 \item 1418 1427 Eliminating Duff's device is straightforward and only invalidates a small amount of very questionable code. 1419 The solution is to allow ©case© clauses to only appear at the same nesting level as the ©switch© body, as is done in most other programming languages with ©switch©statements.1420 \item 1421 The issue of ©default© at locations other than at the end of the cause clause can be solved by using good programming style, and there are a few reasonable situations involving fall-through where the ©default©clause may appear is locations other than at the end.1428 The solution is to allow \lstinline@case@ clauses to only appear at the same nesting level as the \lstinline@switch@ body, as is done in most other programming languages with \lstinline@switch@ statements. 1429 \item 1430 The issue of \lstinline@default@ at locations other than at the end of the cause clause can be solved by using good programming style, and there are a few reasonable situations involving fall-through where the \lstinline@default@ clause may appear is locations other than at the end. 1422 1431 Therefore, no language change is made for this issue. 1423 1432 \item 1424 Dealing with unreachable code at the start of a ©switch© statement is solved by defining the declaration-list, including any associated initialization, at the start of a ©switch© statement body to be executed before the transfer to the appropriate ©case©clause.1433 Dealing with unreachable code at the start of a \lstinline@switch@ statement is solved by defining the declaration-list, including any associated initialization, at the start of a \lstinline@switch@ statement body to be executed before the transfer to the appropriate \lstinline@case@ clause. 1425 1434 This semantics is the same as for declarations at the start of a loop body, which are executed before each iteration of the loop body. 1426 As well, this grammar does not allow statements to appear before the first ©case©clause.1435 As well, this grammar does not allow statements to appear before the first \lstinline@case@ clause. 1427 1436 The change is compatible for declarations with initialization in this context because existing code cannot assume the initialization has occurred. 1428 1437 The change is incompatible for statements, but any existing code using it is highly questionable, as in: … … 1434 1443 } 1435 1444 \end{lstlisting} 1436 The statement after the ©switch©can never be executed unless it is labelled.1437 If it is labelled, it must be transfered to from outside or inside the ©switch©statement, neither of which is acceptable control flow.1445 The statement after the \lstinline@switch@ can never be executed unless it is labelled. 1446 If it is labelled, it must be transfered to from outside or inside the \lstinline@switch@ statement, neither of which is acceptable control flow. 1438 1447 \end{enumerate} 1439 1448 … … 1441 1450 \section{Case Clause} 1442 1451 1443 C restricts the ©case© clause of a ©switch©statement to a single value.1444 For multiple ©case© clauses associated with the same statement, it is necessary to have multiple ©case©clauses rather than multiple values.1445 Requiring a ©case©clause for each value does not seem to be in the spirit of brevity normally associated with C.1446 Therefore, the ©case©clause is extended with a list of values, as in:1452 C restricts the \lstinline@case@ clause of a \lstinline@switch@ statement to a single value. 1453 For multiple \lstinline@case@ clauses associated with the same statement, it is necessary to have multiple \lstinline@case@ clauses rather than multiple values. 1454 Requiring a \lstinline@case@ clause for each value does not seem to be in the spirit of brevity normally associated with C. 1455 Therefore, the \lstinline@case@ clause is extended with a list of values, as in: 1447 1456 \begin{quote2} 1448 1457 \begin{tabular}{@{}l@{\hspace{30pt}}l@{\hspace{20pt}}l@{}} … … 1450 1459 \begin{lstlisting} 1451 1460 switch ( i ) { 1452 ®case 1, 3, 5®:1461 `case 1, 3, 5`: 1453 1462 ... 1454 ®case 2, 4, 6®:1463 `case 2, 4, 6`: 1455 1464 ... 1456 1465 } … … 1482 1491 \begin{lstlisting} 1483 1492 switch ( i ) { 1484 ®case 1~5:®1493 `case 1~5:` 1485 1494 ... 1486 ®case 10~15:®1495 `case 10~15:` 1487 1496 ... 1488 1497 } … … 1739 1748 1740 1749 The syntax for using references in \CFA is the same as \CC with the exception of reference initialization. 1741 Use ©&©to specify a reference, and access references just like regular objects, not like pointers (use dot notation to access fields).1750 Use \lstinline@&@ to specify a reference, and access references just like regular objects, not like pointers (use dot notation to access fields). 1742 1751 When initializing a reference, \CFA uses a different syntax which differentiates reference initialization from assignment to a reference. 1743 The ©&©is used on both sides of the expression to clarify that the address of the reference is being set to the address of the variable to which it refers.1752 The \lstinline@&@ is used on both sides of the expression to clarify that the address of the reference is being set to the address of the variable to which it refers. 1744 1753 1745 1754 \begin{figure} … … 1814 1823 In \CFA, as in C, all scalar types can be incremented and 1815 1824 decremented, which is defined in terms of adding or subtracting 1. 1816 The operations ©&&©, ©||©, and ©!© can be applied to any scalar arguments and are defined in terms of comparison against 0 (ex. ©(a && b)© becomes ©(a != 0 && b != 0)©).1825 The operations \lstinline@&&@, \lstinline@||@, and \lstinline@!@ can be applied to any scalar arguments and are defined in terms of comparison against 0 (ex. \lstinline@(a && b)@ becomes \lstinline@(a != 0 && b != 0)@). 1817 1826 1818 1827 In C, the integer constants 0 and 1 suffice because the integer promotion rules can convert them to any … … 1823 1832 polymorphic parameters, and user-defined pointer-like types may need a null value. 1824 1833 Defining special 1825 constants for a user-defined type is more efficient than defining a conversion to the type from ©_Bool©.1834 constants for a user-defined type is more efficient than defining a conversion to the type from \lstinline@_Bool@. 1826 1835 1827 1836 Why just 0 and 1? Why not other integers? No other integers have special status in C. … … 1906 1915 \begin{tabular}[t]{ll} 1907 1916 %identifier & operation \\ \hline 1908 ©?[?]©& subscripting \impl{?[?]}\\1909 ©?()©& function call \impl{?()}\\1910 ©?++©& postfix increment \impl{?++}\\1911 ©?--©& postfix decrement \impl{?--}\\1912 ©++?©& prefix increment \impl{++?}\\1913 ©--?©& prefix decrement \impl{--?}\\1914 ©*?©& dereference \impl{*?}\\1915 ©+?©& unary plus \impl{+?}\\1916 ©-?©& arithmetic negation \impl{-?}\\1917 ©~?©& bitwise negation \impl{~?}\\1918 ©!?©& logical complement \impl{"!?}\\1919 ©?*?©& multiplication \impl{?*?}\\1920 ©?/?©& division \impl{?/?}\\1917 \lstinline@?[?]@ & subscripting \impl{?[?]}\\ 1918 \lstinline@?()@ & function call \impl{?()}\\ 1919 \lstinline@?++@ & postfix increment \impl{?++}\\ 1920 \lstinline@?--@ & postfix decrement \impl{?--}\\ 1921 \lstinline@++?@ & prefix increment \impl{++?}\\ 1922 \lstinline@--?@ & prefix decrement \impl{--?}\\ 1923 \lstinline@*?@ & dereference \impl{*?}\\ 1924 \lstinline@+?@ & unary plus \impl{+?}\\ 1925 \lstinline@-?@ & arithmetic negation \impl{-?}\\ 1926 \lstinline@~?@ & bitwise negation \impl{~?}\\ 1927 \lstinline@!?@ & logical complement \impl{"!?}\\ 1928 \lstinline@?*?@ & multiplication \impl{?*?}\\ 1929 \lstinline@?/?@ & division \impl{?/?}\\ 1921 1930 \end{tabular}\hfil 1922 1931 \begin{tabular}[t]{ll} 1923 1932 %identifier & operation \\ \hline 1924 ©?%?©& remainder \impl{?%?}\\1925 ©?+?©& addition \impl{?+?}\\1926 ©?-?©& subtraction \impl{?-?}\\1927 ©?<<?©& left shift \impl{?<<?}\\1928 ©?>>?©& right shift \impl{?>>?}\\1929 ©?<?©& less than \impl{?<?}\\1930 ©?<=?©& less than or equal \impl{?<=?}\\1931 ©?>=?©& greater than or equal \impl{?>=?}\\1932 ©?>?©& greater than \impl{?>?}\\1933 ©?==?©& equality \impl{?==?}\\1934 ©?!=?©& inequality \impl{?"!=?}\\1935 ©?&?©& bitwise AND \impl{?&?}\\1933 \lstinline@?%?@ & remainder \impl{?%?}\\ 1934 \lstinline@?+?@ & addition \impl{?+?}\\ 1935 \lstinline@?-?@ & subtraction \impl{?-?}\\ 1936 \lstinline@?<<?@ & left shift \impl{?<<?}\\ 1937 \lstinline@?>>?@ & right shift \impl{?>>?}\\ 1938 \lstinline@?<?@ & less than \impl{?<?}\\ 1939 \lstinline@?<=?@ & less than or equal \impl{?<=?}\\ 1940 \lstinline@?>=?@ & greater than or equal \impl{?>=?}\\ 1941 \lstinline@?>?@ & greater than \impl{?>?}\\ 1942 \lstinline@?==?@ & equality \impl{?==?}\\ 1943 \lstinline@?!=?@ & inequality \impl{?"!=?}\\ 1944 \lstinline@?&?@ & bitwise AND \impl{?&?}\\ 1936 1945 \end{tabular}\hfil 1937 1946 \begin{tabular}[t]{ll} 1938 1947 %identifier & operation \\ \hline 1939 ©?^?©& exclusive OR \impl{?^?}\\1940 ©?|?©& inclusive OR \impl{?"|?}\\1941 ©?=?©& simple assignment \impl{?=?}\\1942 ©?*=?©& multiplication assignment \impl{?*=?}\\1943 ©?/=?©& division assignment \impl{?/=?}\\1944 ©?%=?©& remainder assignment \impl{?%=?}\\1945 ©?+=?©& addition assignment \impl{?+=?}\\1946 ©?-=?©& subtraction assignment \impl{?-=?}\\1947 ©?<<=?©& left-shift assignment \impl{?<<=?}\\1948 ©?>>=?©& right-shift assignment \impl{?>>=?}\\1949 ©?&=?©& bitwise AND assignment \impl{?&=?}\\1950 ©?^=?©& exclusive OR assignment \impl{?^=?}\\1951 ©?|=?©& inclusive OR assignment \impl{?"|=?}\\1948 \lstinline@?^?@ & exclusive OR \impl{?^?}\\ 1949 \lstinline@?|?@ & inclusive OR \impl{?"|?}\\ 1950 \lstinline@?=?@ & simple assignment \impl{?=?}\\ 1951 \lstinline@?*=?@ & multiplication assignment \impl{?*=?}\\ 1952 \lstinline@?/=?@ & division assignment \impl{?/=?}\\ 1953 \lstinline@?%=?@ & remainder assignment \impl{?%=?}\\ 1954 \lstinline@?+=?@ & addition assignment \impl{?+=?}\\ 1955 \lstinline@?-=?@ & subtraction assignment \impl{?-=?}\\ 1956 \lstinline@?<<=?@ & left-shift assignment \impl{?<<=?}\\ 1957 \lstinline@?>>=?@ & right-shift assignment \impl{?>>=?}\\ 1958 \lstinline@?&=?@ & bitwise AND assignment \impl{?&=?}\\ 1959 \lstinline@?^=?@ & exclusive OR assignment \impl{?^=?}\\ 1960 \lstinline@?|=?@ & inclusive OR assignment \impl{?"|=?}\\ 1952 1961 \end{tabular} 1953 1962 \hfil … … 1958 1967 These identifiers are defined such that the question marks in the name identify the location of the operands. 1959 1968 These operands represent the parameters to the functions, and define how the operands are mapped to the function call. 1960 For example, ©a + b© becomes ©?+?(a, b)©.1969 For example, \lstinline@a + b@ becomes \lstinline@?+?(a, b)@. 1961 1970 1962 1971 In the example below, a new type, myComplex, is defined with an overloaded constructor, + operator, and string operator. … … 2001 2010 \begin{quote2} 2002 2011 \begin{tabular}{@{}l@{\hspace{30pt}}ll@{}} 2003 \multicolumn{1}{c@{\hspace{30pt}}}{\textbf{\CC}} & \multicolumn{1}{c}{ ©gcc©}\index{gcc} \\2012 \multicolumn{1}{c@{\hspace{30pt}}}{\textbf{\CC}} & \multicolumn{1}{c}{\lstinline@gcc@}\index{gcc} \\ 2004 2013 \begin{lstlisting} 2005 2014 … … 2032 2041 \end{itemize} 2033 2042 2034 In \CFA, ©typedef©provides a mechanism to alias long type names with short ones, both globally and locally, but not eliminate the use of the short name.2035 ©gcc© provides ©typeof©to declare a secondary variable from a primary variable.2043 In \CFA, \lstinline@typedef@ provides a mechanism to alias long type names with short ones, both globally and locally, but not eliminate the use of the short name. 2044 \lstinline@gcc@ provides \lstinline@typeof@ to declare a secondary variable from a primary variable. 2036 2045 \CFA also relies heavily on the specification of the left-hand side of assignment for type inferencing, so in many cases it is crucial to specify the type of the left-hand side to select the correct type of the right-hand expression. 2037 2046 Only for overloaded routines with the same return type is variable type-inferencing possible. 2038 Finally, ©auto©presents the programming problem of tracking down a type when the type is actually needed.2047 Finally, \lstinline@auto@ presents the programming problem of tracking down a type when the type is actually needed. 2039 2048 For example, given 2040 2049 \begin{lstlisting} 2041 auto j = ®...®2042 \end{lstlisting} 2043 and the need to write a routine to compute using ©j©2044 \begin{lstlisting} 2045 void rtn( ®...®parm );2050 auto j = `...` 2051 \end{lstlisting} 2052 and the need to write a routine to compute using \lstinline@j@ 2053 \begin{lstlisting} 2054 void rtn( `...` parm ); 2046 2055 rtn( j ); 2047 2056 \end{lstlisting} 2048 A programmer must work backwards to determine the type of ©j©'s initialization expression, reconstructing the possibly long generic type-name.2057 A programmer must work backwards to determine the type of \lstinline@j@'s initialization expression, reconstructing the possibly long generic type-name. 2049 2058 In this situation, having the type name or a short alias is very useful. 2050 2059 … … 2054 2063 At some point, a programmer wants the type of the variable to remain constant and the expression to be in error when it changes. 2055 2064 2056 Given ©typedef© and ©typeof©in \CFA, and the strong need to use the type of left-hand side in inferencing, auto type-inferencing is not supported at this time.2065 Given \lstinline@typedef@ and \lstinline@typeof@ in \CFA, and the strong need to use the type of left-hand side in inferencing, auto type-inferencing is not supported at this time. 2057 2066 Should a significant need arise, this feature can be revisited. 2058 2067 … … 2356 2365 } s; 2357 2366 \end{lstlisting} 2358 The problem occurs in accesing these fields using the selection operation `` ©.©'':2367 The problem occurs in accesing these fields using the selection operation ``\lstinline@.@'': 2359 2368 \begin{lstlisting} 2360 2369 s.0 = 0; // ambiguity with floating constant .0 … … 2363 2372 To make this work, a space is required after the field selection: 2364 2373 \begin{lstlisting} 2365 ®s.§\textvisiblespace§0®= 0;2366 ®s.§\textvisiblespace§1®= 1;2374 `s.@\textvisiblespace@0` = 0; 2375 `s.@\textvisiblespace@1` = 1; 2367 2376 \end{lstlisting} 2368 2377 While this sytact is awkward, it is unlikely many programers will name fields of a structure 0 or 1. 2369 Like the \CC lexical problem with closing template-syntax, e.g, ©Foo<Bar<int®>>®©, this issue can be solved with a more powerful lexer/parser.2370 2371 There are several ambiguous cases with operator identifiers, e.g., ©int *?*?()©, where the string ©*?*?© can be lexed as ©*©/©?*?© or ©*?©/©*?©.2372 Since it is common practise to put a unary operator juxtaposed to an identifier, e.g., ©*i©, users will be annoyed if they cannot do this with respect to operator identifiers.2378 Like the \CC lexical problem with closing template-syntax, e.g, \lstinline@Foo<Bar<int`>>`@, this issue can be solved with a more powerful lexer/parser. 2379 2380 There are several ambiguous cases with operator identifiers, e.g., \lstinline@int *?*?()@, where the string \lstinline@*?*?@ can be lexed as \lstinline@*@/\lstinline@?*?@ or \lstinline@*?@/\lstinline@*?@. 2381 Since it is common practise to put a unary operator juxtaposed to an identifier, e.g., \lstinline@*i@, users will be annoyed if they cannot do this with respect to operator identifiers. 2373 2382 Even with this special hack, there are 5 general cases that cannot be handled. 2374 The first case is for the function-call identifier ©?()©:2375 \begin{lstlisting} 2376 int * §\textvisiblespace§?()(); // declaration: space required after '*'2377 * §\textvisiblespace§?()(); // expression: space required after '*'2378 \end{lstlisting} 2379 Without the space, the string ©*?()©is ambiguous without N character look ahead;2380 it requires scanning ahead to determine if there is a ©'('©, which is the start of an argument/parameter list.2383 The first case is for the function-call identifier \lstinline@?()@: 2384 \begin{lstlisting} 2385 int *@\textvisiblespace@?()(); // declaration: space required after '*' 2386 *@\textvisiblespace@?()(); // expression: space required after '*' 2387 \end{lstlisting} 2388 Without the space, the string \lstinline@*?()@ is ambiguous without N character look ahead; 2389 it requires scanning ahead to determine if there is a \lstinline@'('@, which is the start of an argument/parameter list. 2381 2390 2382 2391 The 4 remaining cases occur in expressions: 2383 2392 \begin{lstlisting} 2384 i++ §\textvisiblespace§?i:0; // space required before '?'2385 i-- §\textvisiblespace§?i:0; // space required before '?'2386 i §\textvisiblespace§?++i:0; // space required after '?'2387 i §\textvisiblespace§?--i:0; // space required after '?'2388 \end{lstlisting} 2389 In the first two cases, the string ©i++?© is ambiguous, where this string can be lexed as ©i© / ©++?© or ©i++© / ©?©;2390 it requires scanning ahead to determine if there is a ©'('©, which is the start of an argument list.2391 In the second two cases, the string ©?++x© is ambiguous, where this string can be lexed as ©?++© / ©x© or ©?© / y©++x©;2392 it requires scanning ahead to determine if there is a ©'('©, which is the start of an argument list.2393 i++@\textvisiblespace@?i:0; // space required before '?' 2394 i--@\textvisiblespace@?i:0; // space required before '?' 2395 i@\textvisiblespace@?++i:0; // space required after '?' 2396 i@\textvisiblespace@?--i:0; // space required after '?' 2397 \end{lstlisting} 2398 In the first two cases, the string \lstinline@i++?@ is ambiguous, where this string can be lexed as \lstinline@i@ / \lstinline@++?@ or \lstinline@i++@ / \lstinline@?@; 2399 it requires scanning ahead to determine if there is a \lstinline@'('@, which is the start of an argument list. 2400 In the second two cases, the string \lstinline@?++x@ is ambiguous, where this string can be lexed as \lstinline@?++@ / \lstinline@x@ or \lstinline@?@ / y\lstinline@++x@; 2401 it requires scanning ahead to determine if there is a \lstinline@'('@, which is the start of an argument list. 2393 2402 2394 2403 … … 3316 3325 3317 3326 3318 \subsection [Comparing Key Features of CFA]{Comparing Key Features of \CFA}3327 \subsection{Comparing Key Features of \CFA} 3319 3328 3320 3329 … … 3690 3699 3691 3700 \begin{comment} 3692 \subsubsection{Modules /Packages}3701 \subsubsection{Modules/Packages} 3693 3702 3694 3703 \begin{lstlisting} … … 3932 3941 3933 3942 3934 \subsubsection [C++]{\CC}3943 \subsubsection{\CC} 3935 3944 3936 3945 \CC is a general-purpose programming language. … … 4006 4015 \begin{enumerate} 4007 4016 \item 4008 Change type of character literal ©int© to ©char©.4017 Change type of character literal \lstinline@int@ to \lstinline@char@. 4009 4018 This change allows overloading differentiation argument type matching, e.g.: 4010 4019 \begin{lstlisting} … … 4023 4032 4024 4033 \item 4025 Change: String literals made ©const©\\4026 The type of a string literal is changed from ©array of char© to ©array of const char©.4027 The type of a wide string literal is changed from ©array of wchar_t© to ©array of const wchar_t©. \\4034 Change: String literals made \lstinline@const@ \\ 4035 The type of a string literal is changed from \lstinline@array of char@ to \lstinline@array of const char@. 4036 The type of a wide string literal is changed from \lstinline@array of wchar_t@ to \lstinline@array of const wchar_t@. \\ 4028 4037 Rationale: This avoids calling an inappropriate overloaded function, which might expect to be able to modify its argument. 4029 4038 Effect on original feature: Change to semantics of well-defined feature. \\ 4030 Difficulty of converting: Simple syntactic transformation, because string literals can be converted to ©char*;©(4.2).4039 Difficulty of converting: Simple syntactic transformation, because string literals can be converted to \lstinline@char*;@ (4.2). 4031 4040 The most common cases are handled by a new but deprecated standard conversion: 4032 4041 \begin{lstlisting} … … 4067 4076 4068 4077 \CFA is C \emph{incompatible} on this issue, and provides semantics similar to \CC. 4069 Nested types are not hoisted and can be referenced using the field selection operator `` ©.©'', unlike the \CC scope-resolution operator ``©::©''.4078 Nested types are not hoisted and can be referenced using the field selection operator ``\lstinline@.@'', unlike the \CC scope-resolution operator ``\lstinline@::@''. 4070 4079 Given that nested types in C are equivalent to not using them, i.e., they are essentially useless, it is unlikely there are any realistic usages that break because of this incompatibility. 4080 4071 4081 4072 4082 \item … … 4080 4090 struct Y yy; // valid C, invalid C++ 4081 4091 \end{lstlisting} 4082 Rationale: C++ classes have member functions which require that classes establish scopes. 4083 The C rule would leave classes as an incomplete scope mechanism which would prevent C++ programmers from maintaining locality within a class. A coherent set of scope rules for C++ based on the C rule would be very complicated and C++ programmers would be unable to predict reliably the meanings of nontrivial examples involving nested or local functions. 4084 Effect on original feature: Change of semantics of welldefined feature. 4085 Difficulty of converting: Semantic transformation. To make the struct type name visible in the scope of the enclosing struct, the struct tag could be declared in the scope of the enclosing struct, before the enclosing struct is defined. Example: 4092 Rationale: C++ classes have member functions which require that classes establish scopes. The C rule 4093 would leave classes as an incomplete scope mechanism which would prevent C++ programmers from maintaining 4094 locality within a class. A coherent set of scope rules for C++ based on the C rule would be very 4095 complicated and C++ programmers would be unable to predict reliably the meanings of nontrivial examples 4096 involving nested or local functions. 4097 Effect on original feature: Change of semantics of welldefined 4098 feature. 4099 Difficulty of converting: Semantic transformation. To make the struct type name visible in the scope of 4100 the enclosing struct, the struct tag could be declared in the scope of the enclosing struct, before the enclosing 4101 struct is defined. Example: 4086 4102 \begin{lstlisting} 4087 4103 struct Y; // struct Y and struct X are at the same scope … … 4090 4106 }; 4091 4107 \end{lstlisting} 4092 All the definitions of C struct types enclosed in other struct definitions and accessed outside the scope of the enclosing struct could be exported to the scope of the enclosing struct. 4093 Note: this is a consequence of the difference in scope rules, which is documented in 3.3. 4108 All the definitions of C struct types enclosed in other struct definitions and accessed outside the scope of 4109 the enclosing struct could be exported to the scope of the enclosing struct. Note: this is a consequence of 4110 the difference in scope rules, which is documented in 3.3. 4094 4111 How widely used: Seldom. 4095 4112 \end{enumerate} … … 4107 4124 \begin{lstlisting} 4108 4125 int x = 0, y = 1, z = 2; 4109 ®sout® ®|® x ®|® y ®|® z ®| endl®;4126 `sout` `|` x `|` y `|` z `| endl`; 4110 4127 \end{lstlisting} 4111 4128 & … … 4116 4133 \end{tabular} 4117 4134 \end{quote2} 4118 The \CFA form is half as many characters, and is similar to \Index{Python}I/O with respect to implicit separators.4135 The \CFA form is half as many characters, and is similar to Python I/O with respect to implicit separators. 4119 4136 4120 4137 The logical-or operator is used because it is the lowest-priority overloadable operator, other than assignment. … … 4143 4160 A seperator does not appear at the start or end of a line. 4144 4161 \begin{lstlisting}[belowskip=0pt] 4145 sout |1 | 2 | 3 | endl;4162 sout 1 | 2 | 3 | endl; 4146 4163 \end{lstlisting} 4147 4164 \begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt] … … 4162 4179 which is a local mechanism to disable insertion of the separator character. 4163 4180 \item 4164 A seperator does not appear before a C string starting with the (extended) \Index{ASCII}\index{ASCII!extended} characters: \lstinline[mathescape=off]@([{$£¥¡¿«@4181 A seperator does not appear before a C string starting with the \Index{extended ASCII}\index{ASCII} characters: \lstinline[mathescape=off]@([{$£¥¿«@ 4165 4182 %$ 4166 4183 \begin{lstlisting}[mathescape=off] 4167 sout | "x (" | 1 | "x [" | 2 | "x {" | 3 | "x $" | 4 | "x £" | 5 | "x ¥" | 6 | "x ¡" | 7 | "x ¿" | 8 | "x «" | 9| endl;4184 sout | "x (" | 1 | "x [" | 2 | "x {" | 3 | "x $" | 4 | "x £" | 5 | "x ¥" | 6 | "x ¿" | 7 | "x «" | 8 | endl; 4168 4185 \end{lstlisting} 4169 4186 %$ 4170 4187 \begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt] 4171 x (1 x [2 x {3 x $4 x £5 x ¥6 x ¡7 x ¿8 x «94188 x (1 x [2 x {3 x $4 x £5 x ¥6 x ¿7 x «8 4172 4189 \end{lstlisting} 4173 4190 %$ 4174 4191 \item 4175 A seperator does not appear after a C string ending with the (extended) \Index{ASCII}\index{ASCII!extended} characters: ©,.:;!?)]}%¢»©4192 A seperator does not appear after a C string ending with the extended ASCII characters: \lstinline@,.:;!?)]}%¢»@ 4176 4193 \begin{lstlisting}[belowskip=0pt] 4177 4194 sout | 1 | ", x" | 2 | ". x" | 3 | ": x" | 4 | "; x" | 5 | "! x" | 6 | "? x" | 7 | ") x" | 8 | "] x" | 9 | "} x" 4178 | 10 | "% x" | 11 | "¢ x" | 12 |"» x" | endl;4195 | 10 | "% x" | 11 | L"¢ x" | 12 | L"» x" | endl; 4179 4196 \end{lstlisting} 4180 4197 \begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt] … … 4182 4199 \end{lstlisting} 4183 4200 \item 4184 A seperator does not appear before or after a C string begining/ending with the \Index{ASCII} quote or whitespace characters: \lstinline[showspaces=true]@`'" \t\v\f\r\n@4201 A seperator does not appear before or after a C string begining/ending with the characters: \lstinline@\f\n\r\t\v\`'"@ 4185 4202 \begin{lstlisting}[belowskip=0pt] 4186 sout | "x`" | 1 | "`x'" | 2 | "'x\"" | 3 | "\"x" | "x " | 4 | " x" | "x\t" | 1 | "\tx" | endl; 4187 \end{lstlisting} 4188 \begin{lstlisting}[mathescape=off,showspaces=true,showtabs=true,aboveskip=0pt,belowskip=0pt] 4189 x`1`x'2'x"3"x x 4 x x 1 x 4203 sout | "x '" | 1 | "' x \`" | 2 | "\` x \"" | 3 | "\" x" | endl; 4204 \end{lstlisting} 4205 \begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt] 4206 x '1' x \`2\` x "3" x 4207 \end{lstlisting} 4208 \begin{lstlisting}[showtabs=true,aboveskip=0pt] 4209 sout | "x\t" | 1 | "\tx" | endl; 4210 x 1 x 4190 4211 \end{lstlisting} 4191 4212 \end{enumerate} … … 4219 4240 \end{lstlisting} 4220 4241 \begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt] 4221 1 2 34242 1 2 3 4222 4243 \end{lstlisting} 4223 4244 \begin{lstlisting}[mathescape=off,aboveskip=0pt,aboveskip=0pt,belowskip=0pt] … … 4230 4251 \end{lstlisting} 4231 4252 %$ 4232 \begin{comment} 4253 \VRef[Figure]{f:ExampleIO} shows an example of input and output I/O in \CFA. 4254 4255 \begin{figure} 4256 \begin{lstlisting}[mathescape=off] 4233 4257 #include <fstream> 4234 4258 4235 4259 int main() { 4236 int x = 3, y = 5, z = 7; 4237 sout | x * 3 | y + 1 | z << 2 | x == y | (x | y) | (x || y) | (x > z ? 1 : 2) | endl; 4238 sout | 1 | 2 | 3 | endl; 4239 sout | '1' | '2' | '3' | endl; 4240 sout | 1 | "" | 2 | "" | 3 | endl; 4241 sout | "x (" | 1 | "x [" | 2 | "x {" | 3 | "x $" | 4 | "x £" | 5 | "x ¥" | 6 | "x ¡" | 7 | "x ¿" | 8 | "x «" | 9 | endl; 4242 sout | 1 | ", x" | 2 | ". x" | 3 | ": x" | 4 | "; x" | 5 | "! x" | 6 | "? x" | 7 | ") x" | 8 | "] x" | 9 | "} x" 4243 | 10 | "% x" | 11 | "¢ x" | 12 | "» x" | endl; 4244 sout | "x`" | 1 | "`x'" | 2 | "'x\"" | 3 | "\"x" | "x " | 4 | " x" | "x\t" | 1 | "\tx" | endl; 4245 sout | sepOn | 1 | 2 | 3 | sepOn | endl; // separator at start of line 4246 sout | 1 | sepOff | 2 | 3 | endl; // turn off implicit separator temporarily 4247 sout | sepDisable | 1 | 2 | 3 | endl; // turn off implicit separation, affects all subsequent prints 4248 sout | 1 | sepOn | 2 | 3 | endl; // turn on implicit separator temporarily 4249 sout | sepEnable | 1 | 2 | 3 | endl; // turn on implicit separation, affects all subsequent prints 4250 sepSet( sout, ", $" ); // change separator from " " to ", $" 4251 sout | 1 | 2 | 3 | endl; 4252 4253 } 4254 4255 // Local Variables: // 4256 // tab-width: 4 // 4257 // End: // 4258 \end{comment} 4259 %$ 4260 char c; // basic types 4261 short int si; 4262 unsigned short int usi; 4263 int i; 4264 unsigned int ui; 4265 long int li; 4266 unsigned long int uli; 4267 long long int lli; 4268 unsigned long long int ulli; 4269 float f; 4270 double d; 4271 long double ld; 4272 float _Complex fc; 4273 double _Complex dc; 4274 long double _Complex ldc; 4275 char s1[10], s2[10]; 4276 4277 ifstream in; // create / open file 4278 open( &in, "input.data", "r" ); 4279 4280 &in | &c // character 4281 | &si | &usi | &i | &ui | &li | &uli | &lli | &ulli // integral 4282 | &f | &d | &ld // floating point 4283 | &fc | &dc | &ldc // floating-point complex 4284 | cstr( s1 ) | cstr( s2, 10 ); // C string, length unchecked and checked 4285 4286 sout | c | ' ' | endl // character 4287 | si | usi | i | ui | li | uli | lli | ulli | endl // integral 4288 | f | d | ld | endl // floating point 4289 | fc | dc | ldc | endl; // complex 4290 sout | endl; 4291 sout | f | "" | d | "" | ld | endl // floating point without separator 4292 | sepDisable | fc | dc | ldc | sepEnable | endl // complex without separator 4293 | sepOn | s1 | sepOff | s2 | endl // local separator removal 4294 | s1 | "" | s2 | endl; // C string withou separator 4295 sout | endl; 4296 sepSet( sout, ", $" ); // change separator, maximum of 15 characters 4297 sout | f | d | ld | endl // floating point without separator 4298 | fc | dc | ldc | endl // complex without separator 4299 | s1 | s2 | endl; 4300 } 4301 4302 $ cat input.data 4303 A 1 2 3 4 5 6 7 8 1.1 1.2 1.3 1.1+2.3 1.1-2.3 1.1-2.3 abc xyz 4304 $ a.out 4305 A 4306 1 2 3 4 5 6 7 8 4307 1.1 1.2 1.3 4308 1.1+2.3i 1.1-2.3i 1.1-2.3i 4309 4310 1.11.21.3 4311 1.1+2.3i1.1-2.3i1.1-2.3i 4312 abcxyz 4313 abcxyz 4314 4315 1.1, $1.2, $1.3 4316 1.1+2.3i, $1.1-2.3i, $1.1-2.3i 4317 abc, $xyz 4318 \end{lstlisting} 4319 \caption{Example I/O} 4320 \label{f:ExampleIO} 4321 \end{figure} 4260 4322 4261 4323 … … 4269 4331 4270 4332 \begin{lstlisting} 4271 forall( otype T ) T * malloc( void ); §\indexc{malloc}§4333 forall( otype T ) T * malloc( void ); 4272 4334 forall( otype T ) T * malloc( char fill ); 4273 4335 forall( otype T ) T * malloc( T * ptr, size_t size ); 4274 4336 forall( otype T ) T * malloc( T * ptr, size_t size, unsigned char fill ); 4275 forall( otype T ) T * calloc( size_t nmemb );§\indexc{calloc}§4276 forall( otype T ) T * realloc( T * ptr, size_t size ); §\indexc{ato}§4337 forall( otype T ) T * calloc( size_t size ); 4338 forall( otype T ) T * realloc( T * ptr, size_t size ); 4277 4339 forall( otype T ) T * realloc( T * ptr, size_t size, unsigned char fill ); 4278 4340 4279 forall( otype T ) T * aligned_alloc( size_t alignment ); §\indexc{ato}§4341 forall( otype T ) T * aligned_alloc( size_t alignment ); 4280 4342 forall( otype T ) T * memalign( size_t alignment ); // deprecated 4281 4343 forall( otype T ) int posix_memalign( T ** ptr, size_t alignment ); … … 4286 4348 4287 4349 4288 \subsection{ato /strto}4289 4290 \begin{lstlisting} 4291 int ato( const char * ptr ); §\indexc{ato}§4350 \subsection{ato/strto} 4351 4352 \begin{lstlisting} 4353 int ato( const char * ptr ); 4292 4354 unsigned int ato( const char * ptr ); 4293 4355 long int ato( const char * ptr ); … … 4317 4379 4318 4380 4319 \subsection{bsearch /qsort}4381 \subsection{bsearch/qsort} 4320 4382 4321 4383 \begin{lstlisting} 4322 4384 forall( otype T | { int ?<?( T, T ); } ) 4323 T * bsearch( const T key, const T * arr, size_t dimension ); §\indexc{bsearch}§4385 T * bsearch( const T key, const T * arr, size_t dimension ); 4324 4386 4325 4387 forall( otype T | { int ?<?( T, T ); } ) 4326 void qsort( const T * arr, size_t dimension ); §\indexc{qsort}§4388 void qsort( const T * arr, size_t dimension ); 4327 4389 \end{lstlisting} 4328 4390 … … 4331 4393 4332 4394 \begin{lstlisting} 4333 char abs( char );§\indexc{abs}§ 4334 int abs( int ); 4395 char abs( char ); 4396 extern "C" { 4397 int abs( int ); // use default C routine for int 4398 } // extern "C" 4335 4399 long int abs( long int ); 4336 4400 long long int abs( long long int ); … … 4338 4402 double abs( double ); 4339 4403 long double abs( long double ); 4340 float abs( float _Complex ); 4341 double abs( double _Complex ); 4342 long double abs( long double _Complex ); 4404 float _Complex abs( float _Complex ); 4405 double _Complex abs( double _Complex ); 4406 long double _Complex abs( long double _Complex ); 4407 \end{lstlisting} 4408 4409 4410 \subsection{floor/ceil} 4411 4412 \begin{lstlisting} 4413 float floor( float ); 4414 extern "C" { 4415 double floor( double ); // use C routine for double 4416 } // extern "C" 4417 long double floor( long double ); 4418 4419 float ceil( float ); 4420 extern "C" { 4421 double ceil( double ); // use C routine for double 4422 } // extern "C" 4423 long double ceil( long double ); 4343 4424 \end{lstlisting} 4344 4425 … … 4347 4428 4348 4429 \begin{lstlisting} 4349 void rand48seed( long int s ); §\indexc{rand48seed}§4350 char rand48(); §\indexc{rand48}§4430 void rand48seed( long int s ); 4431 char rand48(); 4351 4432 int rand48(); 4352 4433 unsigned int rand48(); … … 4361 4442 4362 4443 4363 \subsection{min / max /swap}4444 \subsection{min/max/swap} 4364 4445 4365 4446 \begin{lstlisting} 4366 4447 forall( otype T | { int ?<?( T, T ); } ) 4367 T min( const T t1, const T t2 ); §\indexc{min}§4448 T min( const T t1, const T t2 ); 4368 4449 4369 4450 forall( otype T | { int ?>?( T, T ); } ) 4370 T max( const T t1, const T t2 ); §\indexc{max}§4451 T max( const T t1, const T t2 ); 4371 4452 4372 4453 forall( otype T ) 4373 void swap( T * t1, T * t2 );§\indexc{swap}§ 4374 \end{lstlisting} 4375 4376 4377 \section{Math Library} 4378 \label{s:Math Library} 4379 4380 The goal of the \CFA math-library is to wrap many of the existing C math library-routines that are explicitly polymorphic into implicitly polymorphic versions. 4381 4382 4383 \subsection{General} 4384 4385 \begin{lstlisting} 4386 float fabs( float );§\indexc{fabs}§ 4387 double fabs( double ); 4388 long double fabs( long double ); 4389 float cabs( float _Complex ); 4390 double cabs( double _Complex ); 4391 long double cabs( long double _Complex ); 4392 4393 float ?%?( float, float );§\indexc{fmod}§ 4394 float fmod( float, float ); 4395 double ?%?( double, double ); 4396 double fmod( double, double ); 4397 long double ?%?( long double, long double ); 4398 long double fmod( long double, long double ); 4399 4400 float remainder( float, float );§\indexc{remainder}§ 4401 double remainder( double, double ); 4402 long double remainder( long double, long double ); 4403 4404 [ int, float ] remquo( float, float );§\indexc{remquo}§ 4405 float remquo( float, float, int * ); 4406 [ int, double ] remquo( double, double ); 4407 double remquo( double, double, int * ); 4408 [ int, long double ] remquo( long double, long double ); 4409 long double remquo( long double, long double, int * ); 4410 4411 [ int, float ] div( float, float ); // alternative name for remquo 4412 float div( float, float, int * );§\indexc{div}§ 4413 [ int, double ] div( double, double ); 4414 double div( double, double, int * ); 4415 [ int, long double ] div( long double, long double ); 4416 long double div( long double, long double, int * ); 4417 4418 float fma( float, float, float );§\indexc{fma}§ 4419 double fma( double, double, double ); 4420 long double fma( long double, long double, long double ); 4421 4422 float fdim( float, float );§\indexc{fdim}§ 4423 double fdim( double, double ); 4424 long double fdim( long double, long double ); 4425 4426 float nan( const char * );§\indexc{nan}§ 4427 double nan( const char * ); 4428 long double nan( const char * ); 4429 \end{lstlisting} 4430 4431 4432 \subsection{Exponential} 4433 4434 \begin{lstlisting} 4435 float exp( float );§\indexc{exp}§ 4436 double exp( double ); 4437 long double exp( long double ); 4438 float _Complex exp( float _Complex ); 4439 double _Complex exp( double _Complex ); 4440 long double _Complex exp( long double _Complex ); 4441 4442 float exp2( float );§\indexc{exp2}§ 4443 double exp2( double ); 4444 long double exp2( long double ); 4445 float _Complex exp2( float _Complex ); 4446 double _Complex exp2( double _Complex ); 4447 long double _Complex exp2( long double _Complex ); 4448 4449 float expm1( float );§\indexc{expm1}§ 4450 double expm1( double ); 4451 long double expm1( long double ); 4452 4453 float log( float );§\indexc{log}§ 4454 double log( double ); 4455 long double log( long double ); 4456 float _Complex log( float _Complex ); 4457 double _Complex log( double _Complex ); 4458 long double _Complex log( long double _Complex ); 4459 4460 float log2( float );§\indexc{log2}§ 4461 double log2( double ); 4462 long double log2( long double ); 4463 float _Complex log2( float _Complex ); 4464 double _Complex log2( double _Complex ); 4465 long double _Complex log2( long double _Complex ); 4466 4467 float log10( float );§\indexc{log10}§ 4468 double log10( double ); 4469 long double log10( long double ); 4470 float _Complex log10( float _Complex ); 4471 double _Complex log10( double _Complex ); 4472 long double _Complex log10( long double _Complex ); 4473 4474 float log1p( float );§\indexc{log1p}§ 4475 double log1p( double ); 4476 long double log1p( long double ); 4477 4478 int ilogb( float );§\indexc{ilogb}§ 4479 int ilogb( double ); 4480 int ilogb( long double ); 4481 4482 float logb( float );§\indexc{logb}§ 4483 double logb( double ); 4484 long double logb( long double ); 4485 \end{lstlisting} 4486 4487 4488 \subsection{Power} 4489 4490 \begin{lstlisting} 4491 float sqrt( float );§\indexc{sqrt}§ 4492 double sqrt( double ); 4493 long double sqrt( long double ); 4494 float _Complex sqrt( float _Complex ); 4495 double _Complex sqrt( double _Complex ); 4496 long double _Complex sqrt( long double _Complex ); 4497 4498 float cbrt( float );§\indexc{cbrt}§ 4499 double cbrt( double ); 4500 long double cbrt( long double ); 4501 4502 float hypot( float, float );§\indexc{hypot}§ 4503 double hypot( double, double ); 4504 long double hypot( long double, long double ); 4505 4506 float pow( float, float );§\indexc{pow}§ 4507 double pow( double, double ); 4508 long double pow( long double, long double ); 4509 float _Complex pow( float _Complex, float _Complex ); 4510 double _Complex pow( double _Complex, double _Complex ); 4511 long double _Complex pow( long double _Complex, long double _Complex ); 4512 \end{lstlisting} 4513 4514 4515 \subsection{Trigonometric} 4516 4517 \begin{lstlisting} 4518 float sin( float );§\indexc{sin}§ 4519 double sin( double ); 4520 long double sin( long double ); 4521 float _Complex sin( float _Complex ); 4522 double _Complex sin( double _Complex ); 4523 long double _Complex sin( long double _Complex ); 4524 4525 float cos( float );§\indexc{cos}§ 4526 double cos( double ); 4527 long double cos( long double ); 4528 float _Complex cos( float _Complex ); 4529 double _Complex cos( double _Complex ); 4530 long double _Complex cos( long double _Complex ); 4531 4532 float tan( float );§\indexc{tan}§ 4533 double tan( double ); 4534 long double tan( long double ); 4535 float _Complex tan( float _Complex ); 4536 double _Complex tan( double _Complex ); 4537 long double _Complex tan( long double _Complex ); 4538 4539 float asin( float );§\indexc{asin}§ 4540 double asin( double ); 4541 long double asin( long double ); 4542 float _Complex asin( float _Complex ); 4543 double _Complex asin( double _Complex ); 4544 long double _Complex asin( long double _Complex ); 4545 4546 float acos( float );§\indexc{acos}§ 4547 double acos( double ); 4548 long double acos( long double ); 4549 float _Complex acos( float _Complex ); 4550 double _Complex acos( double _Complex ); 4551 long double _Complex acos( long double _Complex ); 4552 4553 float atan( float );§\indexc{atan}§ 4554 double atan( double ); 4555 long double atan( long double ); 4556 float _Complex atan( float _Complex ); 4557 double _Complex atan( double _Complex ); 4558 long double _Complex atan( long double _Complex ); 4559 4560 float atan2( float, float );§\indexc{atan2}§ 4561 double atan2( double, double ); 4562 long double atan2( long double, long double ); 4563 4564 float atan( float, float ); // alternative name for atan2 4565 double atan( double, double );§\indexc{atan}§ 4566 long double atan( long double, long double ); 4567 \end{lstlisting} 4568 4569 4570 \subsection{Hyperbolic} 4571 4572 \begin{lstlisting} 4573 float sinh( float );§\indexc{sinh}§ 4574 double sinh( double ); 4575 long double sinh( long double ); 4576 float _Complex sinh( float _Complex ); 4577 double _Complex sinh( double _Complex ); 4578 long double _Complex sinh( long double _Complex ); 4579 4580 float cosh( float );§\indexc{cosh}§ 4581 double cosh( double ); 4582 long double cosh( long double ); 4583 float _Complex cosh( float _Complex ); 4584 double _Complex cosh( double _Complex ); 4585 long double _Complex cosh( long double _Complex ); 4586 4587 float tanh( float );§\indexc{tanh}§ 4588 double tanh( double ); 4589 long double tanh( long double ); 4590 float _Complex tanh( float _Complex ); 4591 double _Complex tanh( double _Complex ); 4592 long double _Complex tanh( long double _Complex ); 4593 4594 float asinh( float );§\indexc{asinh}§ 4595 double asinh( double ); 4596 long double asinh( long double ); 4597 float _Complex asinh( float _Complex ); 4598 double _Complex asinh( double _Complex ); 4599 long double _Complex asinh( long double _Complex ); 4600 4601 float acosh( float );§\indexc{acosh}§ 4602 double acosh( double ); 4603 long double acosh( long double ); 4604 float _Complex acosh( float _Complex ); 4605 double _Complex acosh( double _Complex ); 4606 long double _Complex acosh( long double _Complex ); 4607 4608 float atanh( float );§\indexc{atanh}§ 4609 double atanh( double ); 4610 long double atanh( long double ); 4611 float _Complex atanh( float _Complex ); 4612 double _Complex atanh( double _Complex ); 4613 long double _Complex atanh( long double _Complex ); 4614 \end{lstlisting} 4615 4616 4617 \subsection{Error / Gamma} 4618 4619 \begin{lstlisting} 4620 float erf( float );§\indexc{erf}§ 4621 double erf( double ); 4622 long double erf( long double ); 4623 float _Complex erf( float _Complex ); 4624 double _Complex erf( double _Complex ); 4625 long double _Complex erf( long double _Complex ); 4626 4627 float erfc( float );§\indexc{erfc}§ 4628 double erfc( double ); 4629 long double erfc( long double ); 4630 float _Complex erfc( float _Complex ); 4631 double _Complex erfc( double _Complex ); 4632 long double _Complex erfc( long double _Complex ); 4633 4634 float lgamma( float );§\indexc{lgamma}§ 4635 double lgamma( double ); 4636 long double lgamma( long double ); 4637 float lgamma( float, int * ); 4638 double lgamma( double, int * ); 4639 long double lgamma( long double, int * ); 4640 4641 float tgamma( float );§\indexc{tgamma}§ 4642 double tgamma( double ); 4643 long double tgamma( long double ); 4644 \end{lstlisting} 4645 4646 4647 \subsection{Nearest Integer} 4648 4649 \begin{lstlisting} 4650 float floor( float );§\indexc{floor}§ 4651 double floor( double ); 4652 long double floor( long double ); 4653 4654 float ceil( float );§\indexc{ceil}§ 4655 double ceil( double ); 4656 long double ceil( long double ); 4657 4658 float trunc( float );§\indexc{trunc}§ 4659 double trunc( double ); 4660 long double trunc( long double ); 4661 4662 float rint( float );§\indexc{rint}§ 4663 long double rint( long double ); 4664 long int rint( float ); 4665 long int rint( double ); 4666 long int rint( long double ); 4667 long long int rint( float ); 4668 long long int rint( double ); 4669 long long int rint( long double ); 4670 4671 long int lrint( float );§\indexc{lrint}§ 4672 long int lrint( double ); 4673 long int lrint( long double ); 4674 long long int llrint( float ); 4675 long long int llrint( double ); 4676 long long int llrint( long double ); 4677 4678 float nearbyint( float );§\indexc{nearbyint}§ 4679 double nearbyint( double ); 4680 long double nearbyint( long double ); 4681 4682 float round( float );§\indexc{round}§ 4683 long double round( long double ); 4684 long int round( float ); 4685 long int round( double ); 4686 long int round( long double ); 4687 long long int round( float ); 4688 long long int round( double ); 4689 long long int round( long double ); 4690 4691 long int lround( float );§\indexc{lround}§ 4692 long int lround( double ); 4693 long int lround( long double ); 4694 long long int llround( float ); 4695 long long int llround( double ); 4696 long long int llround( long double ); 4697 \end{lstlisting} 4698 4699 4700 \subsection{Manipulation} 4701 4702 \begin{lstlisting} 4703 float copysign( float, float );§\indexc{copysign}§ 4704 double copysign( double, double ); 4705 long double copysign( long double, long double ); 4706 4707 float frexp( float, int * );§\indexc{frexp}§ 4708 double frexp( double, int * ); 4709 long double frexp( long double, int * ); 4710 4711 float ldexp( float, int );§\indexc{ldexp}§ 4712 double ldexp( double, int ); 4713 long double ldexp( long double, int ); 4714 4715 [ float, float ] modf( float );§\indexc{modf}§ 4716 float modf( float, float * ); 4717 [ double, double ] modf( double ); 4718 double modf( double, double * ); 4719 [ long double, long double ] modf( long double ); 4720 long double modf( long double, long double * ); 4721 4722 float nextafter( float, float );§\indexc{nextafter}§ 4723 double nextafter( double, double ); 4724 long double nextafter( long double, long double ); 4725 4726 float nexttoward( float, long double );§\indexc{nexttoward}§ 4727 double nexttoward( double, long double ); 4728 long double nexttoward( long double, long double ); 4729 4730 float scalbn( float, int );§\indexc{scalbn}§ 4731 double scalbn( double, int ); 4732 long double scalbn( long double, int ); 4733 4734 float scalbln( float, long int );§\indexc{scalbln}§ 4735 double scalbln( double, long int ); 4736 long double scalbln( long double, long int ); 4454 void swap( T * t1, T * t2 ); 4737 4455 \end{lstlisting} 4738 4456 … … 4746 4464 \begin{lstlisting} 4747 4465 // implementation 4748 struct Rational { §\indexc{Rational}§4466 struct Rational { 4749 4467 long int numerator, denominator; // invariant: denominator > 0 4750 4468 }; // Rational
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