Changeset a14187f for doc/user


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Timestamp:
Aug 3, 2016, 11:33:36 AM (9 years ago)
Author:
Aaron Moss <a3moss@…>
Branches:
ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, ctor, deferred_resn, demangler, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, memory, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, with_gc
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e93bc13
Parents:
ac43954 (diff), aea7168 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
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Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

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  • doc/user/user.tex

    rac43954 ra14187f  
    1111%% Created On       : Wed Apr  6 14:53:29 2016
    1212%% Last Modified By : Peter A. Buhr
    13 %% Last Modified On : Wed Jul 13 08:14:39 2016
    14 %% Update Count     : 1247
     13%% Last Modified On : Tue Aug  2 17:39:02 2016
     14%% Update Count     : 1286
    1515%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    1616
    … …  
    211211however, it largely extended the language, and did not address many existing problems.\footnote{%
    212212Two 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.}
    213 \Index*{Fortran}~\cite{Fortran08}, \Index*{Ada}~\cite{Ada12}, and \Index*{Cobol}~\cite{Cobol14} are examples of programming languages that took an evolutionary approach, where modern language features (e.g., objects, concurrency) are added and problems fixed within the framework of the existing language.
     213\Index*{Fortran}~\cite{Fortran08}, \Index*{Ada}~\cite{Ada12}, and \Index*{Cobol}~\cite{Cobol14} are examples of programming languages that took an evolutionary approach, where modern language features (\eg objects, concurrency) are added and problems fixed within the framework of the existing language.
    214214\Index*{Java}~\cite{Java8}, \Index*{Go}~\cite{Go}, \Index*{Rust}~\cite{Rust} and \Index*{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.
    215215These languages have different syntax and semantics from C, and do not interoperate directly with C, largely because of garbage collection.
    … …  
    226226
    227227\section{Interoperability}
     228\label{s:Interoperability}
    228229
    229230\CFA is designed to integrate well with existing C programs and libraries.
    … …  
    265266\section[Compiling CFA Program]{Compiling \CFA Program}
    266267
    267 The command ©cfa© is used to compile \CFA program(s), and is based on the GNU \Indexc{gcc} command, e.g.:
     268The command ©cfa© is used to compile \CFA program(s), and is based on the GNU \Indexc{gcc} command, \eg:
    268269\begin{lstlisting}
    269270cfa§\indexc{cfa}\index{compilation!cfa@©cfa©}§ [ gcc-options ] C/§\CFA§-files [ assembler/loader-files ]
    … …  
    314315The \CFA compilation message is printed at the beginning of a compilation.
    315316\textbf{This option is the default.}
     317
     318\item
     319\Indexc{-no-include-std}\index{compilation option!-no-include-std@©-no-include-std©}
     320Do not supply ©extern "C"© wrappers for \Celeven standard include files (see~\VRef{s:StandardHeaders}).
     321\textbf{This option is \emph{not} the default.}
    316322\end{description}
    317323
    … …  
    350356\section{Underscores in Constants}
    351357
    352 Numeric constants are extended to allow \Index{underscore}s within constants\index{constant!underscore}, e.g.:
     358Numeric constants are extended to allow \Index{underscore}s within constants\index{constant!underscore}, \eg:
    353359\begin{lstlisting}
    3543602®_®147®_®483®_®648;                    §\C{// decimal constant}§
    … …  
    366372\begin{enumerate}
    367373\item
    368 A sequence of underscores is disallowed, e.g., ©12__34© is invalid.
     374A sequence of underscores is disallowed, \eg ©12__34© is invalid.
    369375\item
    370376Underscores may only appear within a sequence of digits (regardless of the digit radix).
    371 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).
     377In other words, an underscore cannot start or end a sequence of digits, \eg ©_1©, ©1_© and ©_1_© are invalid (actually, the 1st and 3rd examples are identifier names).
    372378\item
    373379A numeric prefix may end with an underscore;
    … …  
    498504\end{quote2}
    499505
    500 All type qualifiers, e.g., ©const©, ©volatile©, etc., are used in the normal way with the new declarations and also appear left to right, e.g.:
     506All type qualifiers, \eg ©const©, ©volatile©, etc., are used in the normal way with the new declarations and also appear left to right, \eg:
    501507\begin{quote2}
    502508\begin{tabular}{@{}l@{\hspace{1em}}l@{\hspace{1em}}l@{}}
    … …  
    518524\end{tabular}
    519525\end{quote2}
    520 All declaration qualifiers, e.g., ©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}
    521 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.:
     526All declaration qualifiers, \eg ©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}
     527The 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}} \eg:
    522528\begin{quote2}
    523529\begin{tabular}{@{}l@{\hspace{3em}}l@{\hspace{2em}}l@{}}
    … …  
    542548Unsupported are K\&R C declarations where the base type defaults to ©int©, if no type is specified,\footnote{
    543549At 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}}
    544 e.g.:
     550\eg:
    545551\begin{lstlisting}
    546552x;                                                              §\C{// int x}§
    … …  
    612618A \Index{pointer}/\Index{reference} is a generalization of a variable name, i.e., a mutable address that can point to more than one memory location during its lifetime.
    613619(Similarly, an integer variable can contain multiple integer literals during its lifetime versus an integer constant representing a single literal during its lifetime and may not occupy storage as the literal is embedded directly into instructions.)
    614 Hence, a pointer occupies memory to store its current address, and the pointer's value is loaded by dereferencing, e.g.:
     620Hence, a pointer occupies memory to store its current address, and the pointer's value is loaded by dereferencing, \eg:
    615621\begin{quote2}
    616622\begin{tabular}{@{}ll@{}}
    … …  
    669675Except for auto-dereferencing by the compiler, this reference example is the same as the previous pointer example.
    670676Hence, a reference behaves like the variable name for the current variable it is pointing-to.
    671 The simplest way to understand a reference is to imagine the compiler inserting a dereference operator before the reference variable for each reference qualifier in a declaration, e.g.:
     677The simplest way to understand a reference is to imagine the compiler inserting a dereference operator before the reference variable for each reference qualifier in a declaration, \eg:
    672678\begin{lstlisting}
    673679r2 = ((r1 + r2) * (r3 - r1)) / (r3 - 15);
    … …  
    677683®*®r2 = ((®*®r1 + ®*®r2) ®*® (®**®r3 - ®*®r1)) / (®**®r3 - 15);
    678684\end{lstlisting}
    679 When a reference operation appears beside a dereference operation, e.g., ©&*©, they cancel out.\footnote{
     685When a reference operation appears beside a dereference operation, \eg ©&*©, they cancel out.\footnote{
    680686The unary ©&© operator yields the address of its operand.
    681687If the operand has type ``type'', the result has type ``pointer to type''.
    … …  
    721727®&®crc = &cx;                                   §\C{// error, cannot change crc}§
    722728\end{lstlisting}
    723 Hence, for type ©& const©, there is no pointer assignment, so ©&rc = &x© is disallowed, and \emph{the address value cannot be ©0© unless an arbitrary pointer is assigned to the reference}, e.g.:
     729Hence, for type ©& const©, there is no pointer assignment, so ©&rc = &x© is disallowed, and \emph{the address value cannot be ©0© unless an arbitrary pointer is assigned to the reference}, \eg:
    724730\begin{lstlisting}
    725731int & const r = *0;                             §\C{// where 0 is the int * zero}§
    726732\end{lstlisting}
    727733Otherwise, the compiler is managing the addresses for type ©& const© not the programmer, and by a programming discipline of only using references with references, address errors can be prevented.
     734Finally, the position of the ©const© qualifier \emph{after} the pointer/reference qualifier causes confuse for C programmers.
     735The ©const© qualifier cannot be moved before the pointer/reference qualifier for C style-declarations;
     736\CFA-style declarations attempt to address this issue:
     737\begin{quote2}
     738\begin{tabular}{@{}l@{\hspace{3em}}l@{}}
     739\multicolumn{1}{c@{\hspace{3em}}}{\textbf{\CFA}}        & \multicolumn{1}{c}{\textbf{C}}        \\
     740\begin{lstlisting}
     741®const® * ®const® * const int ccp;
     742®const® & ®const® & const int ccr;
     743\end{lstlisting}
     744&
     745\begin{lstlisting}
     746const int * ®const® * ®const® ccp;
     747
     748\end{lstlisting}
     749\end{tabular}
     750\end{quote2}
     751where the \CFA declaration is read left-to-right (see \VRef{s:Declarations}).
    728752
    729753\Index{Initialization} is different than \Index{assignment} because initialization occurs on the empty (uninitialized) storage on an object, while assignment occurs on possibly initialized storage of an object.
    … …  
    785809\section{Type Operators}
    786810
    787 The new declaration syntax can be used in other contexts where types are required, e.g., casts and the pseudo-routine ©sizeof©:
     811The new declaration syntax can be used in other contexts where types are required, \eg casts and the pseudo-routine ©sizeof©:
    788812\begin{quote2}
    789813\begin{tabular}{@{}l@{\hspace{3em}}l@{}}
    … …  
    805829
    806830\CFA also supports a new syntax for routine definition, as well as ISO C and K\&R routine syntax.
    807 The point of the new syntax is to allow returning multiple values from a routine~\cite{Galletly96,CLU}, e.g.:
     831The point of the new syntax is to allow returning multiple values from a routine~\cite{Galletly96,CLU}, \eg:
    808832\begin{lstlisting}
    809833®[ int o1, int o2, char o3 ]® f( int i1, char i2, char i3 ) {
    … …  
    817841\Index*{Michael Tiemann}, with help from \Index*{Doug Lea}, provided named return values in g++, circa 1989.}
    818842The value of each local return variable is automatically returned at routine termination.
    819 Declaration qualifiers can only appear at the start of a routine definition, e.g.:
     843Declaration qualifiers can only appear at the start of a routine definition, \eg:
    820844\begin{lstlisting}
    821845®extern® [ int x ] g( int y ) {§\,§}
    … …  
    849873The 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.
    850874
    851 C-style declarations can be used to declare parameters for \CFA style routine definitions, e.g.:
     875C-style declarations can be used to declare parameters for \CFA style routine definitions, \eg:
    852876\begin{lstlisting}
    853877[ int ] f( * int, int * );              §\C{// returns an integer, accepts 2 pointers to integers}§
    … …  
    898922
    899923The syntax of the new routine prototype declaration follows directly from the new routine definition syntax;
    900 as well, parameter names are optional, e.g.:
     924as well, parameter names are optional, \eg:
    901925\begin{lstlisting}
    902926[ int x ] f ();                                 §\C{// returning int with no parameters}§
    … …  
    906930\end{lstlisting}
    907931This syntax allows a prototype declaration to be created by cutting and pasting source text from the routine definition header (or vice versa).
    908 It is possible to declare multiple routine-prototypes in a single declaration, but the entire type specification is distributed across \emph{all} routine names in the declaration list (see~\VRef{s:Declarations}), e.g.:
     932It is possible to declare multiple routine-prototypes in a single declaration, but the entire type specification is distributed across \emph{all} routine names in the declaration list (see~\VRef{s:Declarations}), \eg:
    909933\begin{quote2}
    910934\begin{tabular}{@{}l@{\hspace{3em}}l@{}}
    … …  
    919943\end{tabular}
    920944\end{quote2}
    921 Declaration qualifiers can only appear at the start of a \CFA routine declaration,\footref{StorageClassSpecifier} e.g.:
     945Declaration qualifiers can only appear at the start of a \CFA routine declaration,\footref{StorageClassSpecifier} \eg:
    922946\begin{lstlisting}
    923947extern [ int ] f (int);
    … …  
    928952\section{Routine Pointers}
    929953
    930 The syntax for pointers to \CFA routines specifies the pointer name on the right, e.g.:
     954The syntax for pointers to \CFA routines specifies the pointer name on the right, \eg:
    931955\begin{lstlisting}
    932956* [ int x ] () fp;                      §\C{// pointer to routine returning int with no parameters}§
    … …  
    10461070p( /* positional */, /* named */, . . . );
    10471071\end{lstlisting}
    1048 While it is possible to implement both approaches, the first possibly is more complex than the second, e.g.:
     1072While it is possible to implement both approaches, the first possibly is more complex than the second, \eg:
    10491073\begin{lstlisting}
    10501074p( int x, int y, int z, . . . );
    … …  
    10561080In the second call, the named arguments separate the positional and ellipse arguments, making it trivial to read the call.
    10571081
    1058 The problem is exacerbated with default arguments, e.g.:
     1082The problem is exacerbated with default arguments, \eg:
    10591083\begin{lstlisting}
    10601084void p( int x, int y = 2, int z = 3. . . );
    … …  
    12641288
    12651289As mentioned, tuples can appear in contexts requiring a list of value, such as an argument list of a routine call.
    1266 In unambiguous situations, the tuple brackets may be omitted, e.g., a tuple that appears as an argument may have its
     1290In unambiguous situations, the tuple brackets may be omitted, \eg a tuple that appears as an argument may have its
    12671291square brackets omitted for convenience; therefore, the following routine invocations are equivalent:
    12681292\begin{lstlisting}
    … …  
    13031327
    13041328Type qualifiers, i.e., const and volatile, may modify a tuple type.
    1305 The meaning is the same as for a type qualifier modifying an aggregate type [Int99, x 6.5.2.3(7),x 6.7.3(11)], i.e., the qualifier is distributed across all of the types in the tuple, e.g.:
     1329The meaning is the same as for a type qualifier modifying an aggregate type [Int99, x 6.5.2.3(7),x 6.7.3(11)], i.e., the qualifier is distributed across all of the types in the tuple, \eg:
    13061330\begin{lstlisting}
    13071331const volatile [ int, float, const int ] x;
    … …  
    13111335[ const volatile int, const volatile float, const volatile int ] x;
    13121336\end{lstlisting}
    1313 Declaration qualifiers can only appear at the start of a \CFA tuple declaration4, e.g.:
     1337Declaration qualifiers can only appear at the start of a \CFA tuple declaration4, \eg:
    13141338\begin{lstlisting}
    13151339extern [ int, int ] w1;
    … …  
    13191343Unfortunately, C's syntax for subscripts precluded treating them as tuples.
    13201344The C subscript list has the form ©[i][j]...© and not ©[i, j, ...]©.
    1321 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.
     1345Therefore, there is no syntactic way for a routine returning multiple values to specify the different subscript values, \eg ©f[g()]© always means a single subscript value because there is only one set of brackets.
    13221346Fixing 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.
    13231347\end{rationale}
    … …  
    13801404Clearly, the types of the entities being assigned must be type compatible with the value of the expression.
    13811405
    1382 Mass assignment has parallel semantics, e.g., the statement:
     1406Mass assignment has parallel semantics, \eg the statement:
    13831407\begin{lstlisting}
    13841408[ x, y, z ] = 1.5;
    … …  
    14691493\section{Unnamed Structure Fields}
    14701494
    1471 C requires each field of a structure to have a name, except for a bit field associated with a basic type, e.g.:
     1495C requires each field of a structure to have a name, except for a bit field associated with a basic type, \eg:
    14721496\begin{lstlisting}
    14731497struct {
    1474         int f1;                 // named field
    1475         int f2 : 4;             // named field with bit field size
    1476         int : 3;                // unnamed field for basic type with bit field size
    1477         int ;                   // disallowed, unnamed field
    1478         int *;                  // disallowed, unnamed field
    1479         int (*)(int);   // disallowed, unnamed field
     1498        int f1;                                 §\C{// named field}§
     1499        int f2 : 4;                             §\C{// named field with bit field size}§
     1500        int : 3;                                §\C{// unnamed field for basic type with bit field size}§
     1501        int ;                                   §\C{// disallowed, unnamed field}§
     1502        int *;                                  §\C{// disallowed, unnamed field}§
     1503        int (*)(int);                   §\C{// disallowed, unnamed field}§
    14801504};
    14811505\end{lstlisting}
    14821506This requirement is relaxed by making the field name optional for all field declarations; therefore, all the field declarations in the example are allowed.
    14831507As for unnamed bit fields, an unnamed field is used for padding a structure to a particular size.
    1484 A list of unnamed fields is also supported, e.g.:
     1508A list of unnamed fields is also supported, \eg:
    14851509\begin{lstlisting}
    14861510struct {
    1487         int , , ;               // 3 unnamed fields
     1511        int , , ;                               §\C{// 3 unnamed fields}§
    14881512}
    14891513\end{lstlisting}
    … …  
    14981522§\emph{expr}§ -> [ §\emph{fieldlist}§ ]
    14991523\end{lstlisting}
    1500 \emph{expr} is any expression yielding a value of type record, e.g., ©struct©, ©union©.
     1524\emph{expr} is any expression yielding a value of type record, \eg ©struct©, ©union©.
    15011525Each element of \emph{ fieldlist} is an element of the record specified by \emph{expr}.
    15021526A record-field tuple may be used anywhere a tuple can be used. An example of the use of a record-field tuple is
    … …  
    17601784}
    17611785\end{lstlisting}
    1762 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.
    1763 Furthermore, any statements before the first ©case© clause can only be executed if labelled and transferred to using a ©goto©, either from outside or inside of the ©switch©.
    1764 As mentioned, transfer into control structures should be forbidden;
    1765 transfers from within the ©switch© body using a ©goto© are equally unpalatable.
    1766 As well, the declaration of ©z© is cannot occur after the ©case© because a label can only be attached to a statement, and without a fall through to case 3, ©z© is uninitialized.
     1786While the declaration of the local variable ©y© is useful with a scope across all ©case© clauses, the initialization for such a variable is defined to never be executed because control always transfers over it.
     1787Furthermore, any statements before the first ©case© clause can only be executed if labelled and transferred to using a ©goto©, either from outside or inside of the ©switch©, both of which are problematic.
     1788As well, the declaration of ©z© cannot occur after the ©case© because a label can only be attached to a statement, and without a fall through to case 3, ©z© is uninitialized.
     1789The key observation is that the ©switch© statement branches into control structure, i.e., there are multiple entry points into its statement body.
    17671790\end{enumerate}
    17681791
    … …  
    17781801and 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.
    17791802\end{itemize}
    1780 These observations help to put the suggested changes to the ©switch© into perspective.
     1803These observations help to put the \CFA changes to the ©switch© into perspective.
    17811804\begin{enumerate}
    17821805\item
    17831806Eliminating default fall-through has the greatest potential for affecting existing code.
    1784 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, the common placement of the ©default© clause at the end of the case list, and the most common use of fall-through, i.e., a list of ©case© clauses executing common code, e.g.:
    1785 \begin{lstlisting}
     1807However, 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, the common placement of the ©default© clause at the end of the case list, and the most common use of fall-through, i.e., a list of ©case© clauses executing common code, \eg:
     1808 \begin{lstlisting}
    17861809case 1:  case 2:  case 3: ...
    17871810\end{lstlisting}
    17881811still work.
    17891812Nevertheless, reversing the default action would have a non-trivial effect on case actions that compound, such as the above example of processing shell arguments.
    1790 Therefore, to preserve backwards compatibility, it is necessary to introduce a new kind of ©switch© statement, called ©choose©, with no implicit fall-through semantics and an explicit fall-through if the last statement of a case-clause ends with the new keyword ©fallthru©, e.g.:
     1813<<<<<<< HEAD
     1814Therefore, to preserve backwards compatibility, it is necessary to introduce a new kind of ©switch© statement, called ©choose©, with no implicit fall-through semantics and an explicit fall-through if the last statement of a case-clause ends with the new keyword ©fallthru©, \eg:
     1815=======
     1816Therefore, to preserve backwards compatibility, it is necessary to introduce a new kind of ©switch© statement, called ©choose©, with no implicit fall-through semantics and an explicit fall-through if the last statement of a case-clause ends with the new keyword ©fallthrough©/©fallthru©, e.g.:
     1817>>>>>>> 080615890f586cb9954c252b55cab47f52c25758
    17911818\begin{lstlisting}
    17921819®choose® ( i ) {
    … …  
    18151842Therefore, no change is made for this issue.
    18161843\item
    1817 Dealing with unreachable code in a ©switch©/©choose© body is solved by restricting declarations and associated initialization to the start of statement body, which is executed \emph{before} the transfer to the appropriate ©case© clause.\footnote{
    1818 Essentially, these declarations are hoisted before the statement and both declarations and statement are surrounded by a compound statement.} and precluding statements before the first ©case© clause.
    1819 Further declaration in the statement body are disallowed.
     1844Dealing with unreachable code in a ©switch©/©choose© body is solved by restricting declarations and associated initialization to the start of statement body, which is executed \emph{before} the transfer to the appropriate ©case© clause\footnote{
     1845Essentially, these declarations are hoisted before the ©switch©/©choose© statement and both declarations and statement are surrounded by a compound statement.} and precluding statements before the first ©case© clause.
     1846Further declarations at the same nesting level as the statement body are disallowed to ensure every transfer into the body is sound.
    18201847\begin{lstlisting}
    18211848switch ( x ) {
    1822         ®int i = 0;®                            §\C{// allowed}§
     1849        ®int i = 0;®                            §\C{// allowed only at start}§
    18231850  case 0:
    18241851        ...
    1825         ®int i = 0;®                            §\C{// disallowed}§
     1852        ®int j = 0;®                            §\C{// disallowed}§
    18261853  case 1:
    18271854    {
    1828                 ®int i = 0;®                    §\C{// allowed in any compound statement}§
     1855                ®int k = 0;®                    §\C{// allowed at different nesting levels}§
    18291856                ...
    18301857        }
    … …  
    27072734Like the \Index*[C++]{\CC} lexical problem with closing template-syntax, e.g, ©Foo<Bar<int®>>®©, this issue can be solved with a more powerful lexer/parser.
    27082735
    2709 There are several ambiguous cases with operator identifiers, e.g., ©int *?*?()©, where the string ©*?*?© can be lexed as ©*©/©?*?© or ©*?©/©*?©.
    2710 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.
     2736There are several ambiguous cases with operator identifiers, \eg ©int *?*?()©, where the string ©*?*?© can be lexed as ©*©/©?*?© or ©*?©/©*?©.
     2737Since it is common practise to put a unary operator juxtaposed to an identifier, \eg ©*i©, users will be annoyed if they cannot do this with respect to operator identifiers.
    27112738Even with this special hack, there are 5 general cases that cannot be handled.
    27122739The first case is for the function-call identifier ©?()©:
    … …  
    27732800This means that a function requiring mutual exclusion could block if the lock is already held by another thread.
    27742801Blocking on a monitor lock does not block the kernel thread, it simply blocks the user thread, which yields its kernel thread while waiting to obtain the lock.
    2775 If multiple mutex parameters are specified, they will be locked in parameter order (i.e. first parameter is locked first) and unlocked in the
     2802If multiple mutex parameters are specified, they will be locked in parameter order (\ie first parameter is locked first) and unlocked in the
    27762803reverse order.
    27772804\begin{lstlisting}
    … …  
    43424369
    43434370
     4371\section{New Keywords}
     4372\label{s:NewKeywords}
     4373
     4374\begin{quote2}
     4375\begin{tabular}{ll}
     4376©catch©                 & ©lvalue©              \\
     4377©catchResume©   &                               \\
     4378©choose©                & ©otype©               \\
     4379                                &                               \\
     4380©disable©               & ©throw©               \\
     4381©dtype©                 & ©throwResume© \\
     4382                                & ©trait©               \\
     4383©enable©                & ©try©                 \\
     4384                                &                               \\
     4385©fallthrough©                                   \\
     4386©fallthru©                                              \\
     4387©finally©                                               \\
     4388©forall©                                                \\
     4389©ftype©                                                 \\
     4390\end{tabular}
     4391\end{quote2}
     4392
     4393
     4394\section{Standard Headers}
     4395\label{s:StandardHeaders}
     4396
     4397C prescribes the following standard header-files:
     4398\begin{quote2}
     4399\begin{minipage}{\linewidth}
     4400\begin{tabular}{lll}
     4401assert.h        & math.h                & stdlib.h              \\
     4402complex.h       & setjmp.h              & stdnoreturn.h \\
     4403ctype.h         & signal.h              & string.h              \\
     4404errno.h         & stdalign.h    & tgmath.h              \\
     4405fenv.h          & stdarg.h              & threads.h             \\
     4406float.h         & stdatomic.h   & time.h                \\
     4407inttypes.h      & stdbool.h             & uchar.h               \\
     4408iso646.h        & stddef.h              & wchar.h               \\
     4409limits.h        & stdint.h              & wctype.h              \\
     4410locale.h        & stdio.h               & unistd.h\footnote{\CFA extension}
     4411\end{tabular}
     4412\end{minipage}
     4413\end{quote2}
     4414For the prescribed head-files, \CFA implicit wraps their includes in an ©extern "C"©;
     4415hence, names in these include files are not mangled\index{mangling!name} (see~\VRef{s:Interoperability}).
     4416All other C header files must be explicitly wrapped in ©extern "C"© to prevent name mangling.
     4417
     4418
    43444419\section{Incompatible}
    43454420
    … …  
    43494424\item
    43504425\begin{description}
    4351 \item[Change:] add new keywords \\
     4426\item[Change:] add new keywords (see~\VRef{s:NewKeywords}) \\
    43524427New keywords are added to \CFA.
    43534428\item[Rationale:] keywords added to implement new semantics of \CFA.
    … …  
    44474522\begin{description}
    44484523\item[Change:] have ©struct© introduce a scope for nested types
    4449 In C, the name of the nested types belongs to the same scope as the name of the outermost enclosing 
     4524In C, the name of the nested types belongs to the same scope as the name of the outermost enclosing
    44504525Example:
    44514526\begin{lstlisting}
    … …  
    44714546\CFA is C \emph{incompatible} on this issue, and provides semantics similar to \Index*[C++]{\CC}.
    44724547Nested types are not hoisted and can be referenced using the field selection operator ``©.©'', unlike the \CC scope-resolution operator ``©::©''.
    4473 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.
     4548Given that nested types in C are equivalent to not using them, \ie they are essentially useless, it is unlikely there are any realistic usages that break because of this incompatibility.
    44744549\end{description}
    44754550
    … …  
    45704645%$
    45714646\begin{lstlisting}[mathescape=off]
    4572 sout | "x (" | 1 | "x [" | 2 | "x {" | 3 | "x $" | 4 | "x £" | 5 | "x ¥" | 6 | "x ¡" | 7 | "x ¿" | 8 | "x «" | 9 | endl;
     4647sout | "x (" | 1 | "x [" | 2 | "x {" | 3 | "x $" | 4 | "x £" | 5 | "x ¥" | 6 | "x ¡" | 7
     4648         | "x ¿" | 8 | "x «" | 9 | endl;
    45734649\end{lstlisting}
    45744650%$
    … …  
    45804656A seperator does not appear after a C string ending with the (extended) \Index{ASCII}\index{ASCII!extended} characters: ©,.:;!?)]}%¢»©
    45814657\begin{lstlisting}[belowskip=0pt]
    4582 sout | 1 | ", x" | 2 | ". x" | 3 | ": x" | 4 | "; x" | 5 | "! x" | 6 | "? x" | 7 | ") x" | 8 | "] x" | 9 | "} x"
    4583          | 10 | "% x" | 11 | "¢ x" | 12 | "» x" | endl;
     4658sout | 1 | ", x" | 2 | ". x" | 3 | ": x" | 4 | "; x" | 5 | "! x" | 6 | "? x" | 7
     4659         | ") x" | 8 | "] x" | 9 | "} x" | 10 | "% x" | 11 | "¢ x" | 12 | "» x" | endl;
    45844660\end{lstlisting}
    45854661\begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt]
    … …  
    45974673The following \CC-style \Index{manipulator}s allow further control over implicit seperation.
    45984674\begin{lstlisting}[mathescape=off,belowskip=0pt]
    4599 sout | sepOn | 1 | 2 | 3 | sepOn | endl;        // separator at start of line
     4675sout | sepOn | 1 | 2 | 3 | sepOn | endl;        §\C{// separator at start of line}§
    46004676\end{lstlisting}
    46014677\begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt]
    … …  
    46034679\end{lstlisting}
    46044680\begin{lstlisting}[mathescape=off,aboveskip=0pt,belowskip=0pt]
    4605 sout | 1 | sepOff | 2 | 3 | endl;                       // turn off implicit separator temporarily
     4681sout | 1 | sepOff | 2 | 3 | endl;                       §\C{// turn off implicit separator temporarily}§
    46064682\end{lstlisting}
    46074683\begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt]
    … …  
    46094685\end{lstlisting}
    46104686\begin{lstlisting}[mathescape=off,aboveskip=0pt,belowskip=0pt]
    4611 sout | sepDisable | 1 | 2 | 3 | endl;           // turn off implicit separation, affects all subsequent prints
     4687sout | sepDisable | 1 | 2 | 3 | endl;           §\C{// turn off implicit separation, affects all subsequent prints}§
    46124688\end{lstlisting}
    46134689\begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt]
    … …  
    46154691\end{lstlisting}
    46164692\begin{lstlisting}[mathescape=off,aboveskip=0pt,belowskip=0pt]
    4617 sout | 1 | sepOn | 2 | 3 | endl;                        // turn on implicit separator temporarily
     4693sout | 1 | sepOn | 2 | 3 | endl;                        §\C{// turn on implicit separator temporarily}§
    46184694\end{lstlisting}
    46194695\begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt]
    … …  
    46214697\end{lstlisting}
    46224698\begin{lstlisting}[mathescape=off,aboveskip=0pt,belowskip=0pt]
    4623 sout | sepEnable | 1 | 2 | 3 | endl;            // turn on implicit separation, affects all subsequent prints
     4699sout | sepEnable | 1 | 2 | 3 | endl;            §\C{// turn on implicit separation, affects all subsequent prints}§
    46244700\end{lstlisting}
    46254701\begin{lstlisting}[mathescape=off,showspaces=true,aboveskip=0pt,belowskip=0pt]
    … …  
    46274703\end{lstlisting}
    46284704\begin{lstlisting}[mathescape=off,aboveskip=0pt,aboveskip=0pt,belowskip=0pt]
    4629 sepSet( sout, ", $" );                                          // change separator from " " to ", $"
     4705sepSet( sout, ", $" );                                          §\C{// change separator from " " to ", \$"}§
    46304706sout | 1 | 2 | 3 | endl;
    46314707\end{lstlisting}
    … …  
    51625238\label{s:RationalNumbers}
    51635239
    5164 Rational numbers are numbers written as a ratio, i.e., as a fraction, where the numerator (top number) and the denominator (bottom number) are whole numbers.
     5240Rational numbers are numbers written as a ratio, \ie as a fraction, where the numerator (top number) and the denominator (bottom number) are whole numbers.
    51655241When creating and computing with rational numbers, results are constantly reduced to keep the numerator and denominator as small as possible.
    51665242
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