Changeset c45170a


Ignore:
Timestamp:
Aug 1, 2016, 9:00:59 AM (5 years ago)
Author:
Peter A. Buhr <pabuhr@…>
Branches:
aaron-thesis, arm-eh, cleanup-dtors, ctor, deferred_resn, demangler, jacob/cs343-translation, jenkins-sandbox, master, memory, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, resolv-new, with_gc
Children:
182fe1e
Parents:
057b34f
Message:

update switch documentation and LaTeX macros

Location:
doc
Files:
2 edited

Legend:

Unmodified
Added
Removed
  • doc/LaTeXmacros/common.tex

    r057b34f rc45170a  
    1111%% Created On       : Sat Apr  9 10:06:17 2016
    1212%% Last Modified By : Peter A. Buhr
    13 %% Last Modified On : Tue Jul 12 20:37:57 2016
    14 %% Update Count     : 206
     13%% Last Modified On : Mon Aug  1 08:57:17 2016
     14%% Update Count     : 223
    1515%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    1616
     
    1919\setlength{\textheight}{9in}
    2020%\oddsidemargin 0.0in
    21 \renewcommand{\topfraction}{0.8}        % float must be greater than X of the page before it is forced onto its own page
    22 \renewcommand{\bottomfraction}{0.8}     % float must be greater than X of the page before it is forced onto its own page
     21\renewcommand{\topfraction}{0.8}                % float must be greater than X of the page before it is forced onto its own page
     22\renewcommand{\bottomfraction}{0.8}             % float must be greater than X of the page before it is forced onto its own page
    2323\renewcommand{\floatpagefraction}{0.8}  % float must be greater than X of the page before it is forced onto its own page
    24 \renewcommand{\textfraction}{0.0}       % the entire page maybe devoted to floats with no text on the page at all
    25 
    26 \lefthyphenmin=4
     24\renewcommand{\textfraction}{0.0}               % the entire page maybe devoted to floats with no text on the page at all
     25
     26\lefthyphenmin=4                                                % hyphen only after 4 characters
    2727\righthyphenmin=4
    2828
     
    3838% Names used in the document.
    3939
    40 \newcommand{\CFA}{C$\mathbf\forall$\xspace}              % set language symbolic name
    41 \newcommand{\CFL}{Cforall\xspace}                        % set language text name
     40\newcommand{\CFA}{C$\mathbf\forall$\xspace} % set language symbolic name
     41\newcommand{\CFL}{Cforall\xspace}               % set language text name
    4242\newcommand{\CC}{\rm C\kern-.1em\hbox{+\kern-.25em+}\xspace} % CC symbolic name
    4343\newcommand{\CCeleven}{\rm C\kern-.1em\hbox{+\kern-.25em+}11\xspace} % C++11 symbolic name
    44 \def\c11{ISO/IEC C} % C11 name (cannot have numbers in latex command name)
     44\def\c11{ISO/IEC C}                                             % C11 name (cannot have numbers in latex command name)
    4545
    4646%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
     
    5252\setlength{\parindentlnth}{\parindent}
    5353
    54 \newlength{\gcolumnposn}
     54\newlength{\gcolumnposn}                                % temporary hack because lstlisting does handle tabs correctly
    5555\newlength{\columnposn}
    5656\setlength{\gcolumnposn}{2.5in}
     
    6363%\patchcmd{\lsthk@TextStyle}{\let\lst@DefEsc\@empty}{}{}{\errmessage{failed to patch}}
    6464
    65 \usepackage{pslatex}                                                                    % reduce size of san serif font
    66 \usepackage{relsize}                                    % must be after change to small or selects old size
     65\usepackage{pslatex}                                    % reduce size of san serif font
     66\usepackage{relsize}                                    % must be after change to small or selects old size
    6767
    6868% reduce size of chapter/section titles
     
    120120
    121121% inline text and lowercase index: \Index{inline and lowercase index text}
     122\newcommand{\Index}{\@ifstar\@sIndex\@Index}
    122123% inline text and as-in index: \Index[as-is index text]{inline text}
     124\newcommand{\@Index}[2][\@empty]{\lowercase{\def\temp{#2}}#2\ifx#1\@empty\index{\temp}\else\index{#1@{\protect#2}}\fi}
    123125% inline text but index with different as-is text: \Index[index text]{inline text}
    124 \newcommand{\Index}{\@ifstar\@sIndex\@Index}
    125 \newcommand{\@Index}[2][\@empty]{\lowercase{\def\temp{#2}}#2\ifx#1\@empty\index{\temp}\else\index{#1@{\protect#2}}\fi}
    126126\newcommand{\@sIndex}[2][\@empty]{#2\ifx#1\@empty\index{#2}\else\index{#1@{\protect#2}}\fi}
    127127
    128 % cannot use ©
     128% inline text and code index (cannot use ©)
    129129\newcommand{\Indexc}[1]{\lstinline$#1$\index{#1@\lstinline$#1$}}
     130% code index (cannot use ©)
    130131\newcommand{\indexc}[1]{\index{#1@\lstinline$#1$}}
    131132
     
    137138\newcommand{\@newterm}[2][\@empty]{\lowercase{\def\temp{#2}}{\newtermFontInline{#2}}\ifx#1\@empty\index{\temp}\else\index{#1@{\protect#2}}\fi}
    138139\newcommand{\@snewterm}[2][\@empty]{{\newtermFontInline{#2}}\ifx#1\@empty\index{#2}\else\index{#1@{\protect#2}}\fi}
     140
     141% Latin abbreviation
     142\newcommand{\abbrevFont}{\textit}       % set empty for no italics
     143\newcommand*{\eg}{%
     144        \@ifnextchar{,}{\abbrevFont{e}.\abbrevFont{g}.}%
     145                {\@ifnextchar{:}{\abbrevFont{e}.\abbrevFont{g}.}%
     146                        {\abbrevFont{e}.\abbrevFont{g}.,\xspace}}%
     147}%
     148\newcommand*{\ie}{%
     149        \@ifnextchar{,}{\abbrevFont{i}.\abbrevFont{e}.}%
     150                {\@ifnextchar{:}{\abbrevFont{i}.\abbrevFont{e}.}%
     151                        {\abbrevFont{i}.\abbrevFont{e}.,\xspace}}%
     152}%
     153\newcommand*{\etc}{%
     154        \@ifnextchar{.}{\abbrevFont{etc}}%
     155        {\abbrevFont{etc}.\xspace}%
     156}%
    139157\makeatother
    140158
     
    145163        \endlist
    146164}% quote2
     165
    147166\newenvironment{rationale}{%
    148167  \begin{quote2}\noindent$\Box$\enspace
     
    188207\newcommand{\VPageref}[2][page]{\ifx#1\@empty\else{#1}\nobreakspace\fi\pageref{#2}}
    189208
    190 % Go programming language
     209% Go programming language: https://github.com/julienc91/listings-golang/blob/master/listings-golang.sty
    191210\lstdefinelanguage{Golang}{
    192211        morekeywords=[1]{package,import,func,type,struct,return,defer,panic, recover,select,var,const,iota,},%
     
    204223}
    205224
    206 % CFA programming language, based on ANSI C
     225% CFA programming language, based on ANSI C (with some gcc additions)
    207226\lstdefinelanguage{CFA}[ANSI]{C}{
    208227        morekeywords={_Alignas,_Alignof,__alignof,__alignof__,asm,__asm,__asm__,_At,_Atomic,__attribute,__attribute__,auto,
     
    215234language=CFA,
    216235columns=fullflexible,
    217 basicstyle=\linespread{0.9}\sf,
    218 stringstyle=\tt,
    219 tabsize=4,
    220 xleftmargin=\parindentlnth,
    221 extendedchars=true,
    222 escapechar=§,
    223 mathescape=true,
    224 keepspaces=true,
    225 showstringspaces=false,
    226 showlines=true,
    227 aboveskip=4pt,
     236basicstyle=\linespread{0.9}\sf,                 % reduce line spacing and use sanserif font
     237stringstyle=\tt,                                                % use typewriter font
     238tabsize=4,                                                              % 4 space tabbing
     239xleftmargin=\parindentlnth,                             % indent code to paragraph indentation
     240extendedchars=true,                                             % allow ASCII characters in the range 128-255
     241escapechar=§,                                                   % escape to latex in CFA code
     242mathescape=true,                                                % allow $...$ LaTeX math escapes in code
     243%keepspaces=true,                                               %
     244showstringspaces=false,                                 % do not show spaces with cup
     245showlines=true,                                                 % show blank lines at end of code
     246aboveskip=4pt,                                                  % spacing above/below code block
    228247belowskip=3pt,
    229 moredelim=**[is][\color{red}]{®}{®}, % red highlighting
    230 moredelim=**[is][\color{blue}]{ß}{ß}, % blue highlighting
     248moredelim=**[is][\color{red}]{®}{®},    % red highlighting
     249moredelim=**[is][\color{blue}]{ß}{ß},   % blue highlighting
    231250moredelim=**[is][\color{OliveGreen}]{¢}{¢}, % green highlighting
    232251moredelim=[is][\lstset{keywords={}}]{¶}{¶}, % temporarily turn off keywords
     
    242261\renewcommand\thebibliography[1]{
    243262  \Oldthebibliography{#1}
    244   \setlength{\parskip}{0pt}                     % reduce vertical spacing between references
     263  \setlength{\parskip}{0pt}                             % reduce vertical spacing between references
    245264  \setlength{\itemsep}{5pt plus 0.3ex}
    246265}%
    247 
    248 \newcommand*{\eg}{\textit{e.g}.\@\xspace}
    249 \newcommand*{\ie}{\textit{i.e}.\@\xspace}
    250 
    251 \makeatletter
    252 \newcommand*{\etc}{%
    253     \@ifnextchar{.}%
    254         {\textit{etc}}%
    255         {\textit{etc}.\@\xspace}%
    256 }
    257 \makeatother
    258266
    259267% Local Variables: %
  • doc/user/user.tex

    r057b34f rc45170a  
    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 : Mon Aug  1 08:43:49 2016
     14%% Update Count     : 1270
    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.
     
    265265\section[Compiling CFA Program]{Compiling \CFA Program}
    266266
    267 The command ©cfa© is used to compile \CFA program(s), and is based on the GNU \Indexc{gcc} command, e.g.:
     267The command ©cfa© is used to compile \CFA program(s), and is based on the GNU \Indexc{gcc} command, \eg:
    268268\begin{lstlisting}
    269269cfa§\indexc{cfa}\index{compilation!cfa@©cfa©}§ [ gcc-options ] C/§\CFA§-files [ assembler/loader-files ]
     
    350350\section{Underscores in Constants}
    351351
    352 Numeric constants are extended to allow \Index{underscore}s within constants\index{constant!underscore}, e.g.:
     352Numeric constants are extended to allow \Index{underscore}s within constants\index{constant!underscore}, \eg:
    353353\begin{lstlisting}
    3543542®_®147®_®483®_®648;                    §\C{// decimal constant}§
     
    366366\begin{enumerate}
    367367\item
    368 A sequence of underscores is disallowed, e.g., ©12__34© is invalid.
     368A sequence of underscores is disallowed, \eg ©12__34© is invalid.
    369369\item
    370370Underscores 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).
     371In 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).
    372372\item
    373373A numeric prefix may end with an underscore;
     
    498498\end{quote2}
    499499
    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.:
     500All type qualifiers, \eg ©const©, ©volatile©, etc., are used in the normal way with the new declarations and also appear left to right, \eg:
    501501\begin{quote2}
    502502\begin{tabular}{@{}l@{\hspace{1em}}l@{\hspace{1em}}l@{}}
     
    518518\end{tabular}
    519519\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.:
     520All 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}
     521The 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:
    522522\begin{quote2}
    523523\begin{tabular}{@{}l@{\hspace{3em}}l@{\hspace{2em}}l@{}}
     
    542542Unsupported are K\&R C declarations where the base type defaults to ©int©, if no type is specified,\footnote{
    543543At 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.:
     544\eg:
    545545\begin{lstlisting}
    546546x;                                                              §\C{// int x}§
     
    612612A \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.
    613613(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.:
     614Hence, a pointer occupies memory to store its current address, and the pointer's value is loaded by dereferencing, \eg:
    615615\begin{quote2}
    616616\begin{tabular}{@{}ll@{}}
     
    669669Except for auto-dereferencing by the compiler, this reference example is the same as the previous pointer example.
    670670Hence, 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.:
     671The 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:
    672672\begin{lstlisting}
    673673r2 = ((r1 + r2) * (r3 - r1)) / (r3 - 15);
     
    677677®*®r2 = ((®*®r1 + ®*®r2) ®*® (®**®r3 - ®*®r1)) / (®**®r3 - 15);
    678678\end{lstlisting}
    679 When a reference operation appears beside a dereference operation, e.g., ©&*©, they cancel out.\footnote{
     679When a reference operation appears beside a dereference operation, \eg ©&*©, they cancel out.\footnote{
    680680The unary ©&© operator yields the address of its operand.
    681681If the operand has type ``type'', the result has type ``pointer to type''.
     
    721721®&®crc = &cx;                                   §\C{// error, cannot change crc}§
    722722\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.:
     723Hence, 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:
    724724\begin{lstlisting}
    725725int & const r = *0;                             §\C{// where 0 is the int * zero}§
    726726\end{lstlisting}
    727727Otherwise, 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.
     728Finally, the position of the ©const© qualifier \emph{after} the pointer/reference qualifier causes confuse for C programmers.
     729The ©const© qualifier cannot be moved before the pointer/reference qualifier for C style-declarations;
     730\CFA-style declarations attempt to address this issue:
     731\begin{quote2}
     732\begin{tabular}{@{}l@{\hspace{3em}}l@{}}
     733\multicolumn{1}{c@{\hspace{3em}}}{\textbf{\CFA}}        & \multicolumn{1}{c}{\textbf{C}}        \\
     734\begin{lstlisting}
     735®const® * ®const® * const int ccp;
     736®const® & ®const® & const int ccr;
     737\end{lstlisting}
     738&
     739\begin{lstlisting}
     740const int * ®const® * ®const® ccp;
     741
     742\end{lstlisting}
     743\end{tabular}
     744\end{quote2}
     745where the \CFA declaration is read left-to-right (see \VRef{s:Declarations}).
    728746
    729747\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.
     
    785803\section{Type Operators}
    786804
    787 The new declaration syntax can be used in other contexts where types are required, e.g., casts and the pseudo-routine ©sizeof©:
     805The new declaration syntax can be used in other contexts where types are required, \eg casts and the pseudo-routine ©sizeof©:
    788806\begin{quote2}
    789807\begin{tabular}{@{}l@{\hspace{3em}}l@{}}
     
    805823
    806824\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.:
     825The point of the new syntax is to allow returning multiple values from a routine~\cite{Galletly96,CLU}, \eg:
    808826\begin{lstlisting}
    809827®[ int o1, int o2, char o3 ]® f( int i1, char i2, char i3 ) {
     
    817835\Index*{Michael Tiemann}, with help from \Index*{Doug Lea}, provided named return values in g++, circa 1989.}
    818836The 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.:
     837Declaration qualifiers can only appear at the start of a routine definition, \eg:
    820838\begin{lstlisting}
    821839®extern® [ int x ] g( int y ) {§\,§}
     
    849867The 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.
    850868
    851 C-style declarations can be used to declare parameters for \CFA style routine definitions, e.g.:
     869C-style declarations can be used to declare parameters for \CFA style routine definitions, \eg:
    852870\begin{lstlisting}
    853871[ int ] f( * int, int * );              §\C{// returns an integer, accepts 2 pointers to integers}§
     
    898916
    899917The syntax of the new routine prototype declaration follows directly from the new routine definition syntax;
    900 as well, parameter names are optional, e.g.:
     918as well, parameter names are optional, \eg:
    901919\begin{lstlisting}
    902920[ int x ] f ();                                 §\C{// returning int with no parameters}§
     
    906924\end{lstlisting}
    907925This 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.:
     926It 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:
    909927\begin{quote2}
    910928\begin{tabular}{@{}l@{\hspace{3em}}l@{}}
     
    919937\end{tabular}
    920938\end{quote2}
    921 Declaration qualifiers can only appear at the start of a \CFA routine declaration,\footref{StorageClassSpecifier} e.g.:
     939Declaration qualifiers can only appear at the start of a \CFA routine declaration,\footref{StorageClassSpecifier} \eg:
    922940\begin{lstlisting}
    923941extern [ int ] f (int);
     
    928946\section{Routine Pointers}
    929947
    930 The syntax for pointers to \CFA routines specifies the pointer name on the right, e.g.:
     948The syntax for pointers to \CFA routines specifies the pointer name on the right, \eg:
    931949\begin{lstlisting}
    932950* [ int x ] () fp;                      §\C{// pointer to routine returning int with no parameters}§
     
    10461064p( /* positional */, /* named */, . . . );
    10471065\end{lstlisting}
    1048 While it is possible to implement both approaches, the first possibly is more complex than the second, e.g.:
     1066While it is possible to implement both approaches, the first possibly is more complex than the second, \eg:
    10491067\begin{lstlisting}
    10501068p( int x, int y, int z, . . . );
     
    10561074In the second call, the named arguments separate the positional and ellipse arguments, making it trivial to read the call.
    10571075
    1058 The problem is exacerbated with default arguments, e.g.:
     1076The problem is exacerbated with default arguments, \eg:
    10591077\begin{lstlisting}
    10601078void p( int x, int y = 2, int z = 3. . . );
     
    12641282
    12651283As 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
     1284In unambiguous situations, the tuple brackets may be omitted, \eg a tuple that appears as an argument may have its
    12671285square brackets omitted for convenience; therefore, the following routine invocations are equivalent:
    12681286\begin{lstlisting}
     
    13031321
    13041322Type 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.:
     1323The 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:
    13061324\begin{lstlisting}
    13071325const volatile [ int, float, const int ] x;
     
    13111329[ const volatile int, const volatile float, const volatile int ] x;
    13121330\end{lstlisting}
    1313 Declaration qualifiers can only appear at the start of a \CFA tuple declaration4, e.g.:
     1331Declaration qualifiers can only appear at the start of a \CFA tuple declaration4, \eg:
    13141332\begin{lstlisting}
    13151333extern [ int, int ] w1;
     
    13191337Unfortunately, C's syntax for subscripts precluded treating them as tuples.
    13201338The 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.
     1339Therefore, 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.
    13221340Fixing 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.
    13231341\end{rationale}
     
    13801398Clearly, the types of the entities being assigned must be type compatible with the value of the expression.
    13811399
    1382 Mass assignment has parallel semantics, e.g., the statement:
     1400Mass assignment has parallel semantics, \eg the statement:
    13831401\begin{lstlisting}
    13841402[ x, y, z ] = 1.5;
     
    14691487\section{Unnamed Structure Fields}
    14701488
    1471 C requires each field of a structure to have a name, except for a bit field associated with a basic type, e.g.:
     1489C requires each field of a structure to have a name, except for a bit field associated with a basic type, \eg:
    14721490\begin{lstlisting}
    14731491struct {
    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
     1492        int f1;                                 §\C{// named field}§
     1493        int f2 : 4;                             §\C{// named field with bit field size}§
     1494        int : 3;                                §\C{// unnamed field for basic type with bit field size}§
     1495        int ;                                   §\C{// disallowed, unnamed field}§
     1496        int *;                                  §\C{// disallowed, unnamed field}§
     1497        int (*)(int);                   §\C{// disallowed, unnamed field}§
    14801498};
    14811499\end{lstlisting}
    14821500This requirement is relaxed by making the field name optional for all field declarations; therefore, all the field declarations in the example are allowed.
    14831501As 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.:
     1502A list of unnamed fields is also supported, \eg:
    14851503\begin{lstlisting}
    14861504struct {
    1487         int , , ;               // 3 unnamed fields
     1505        int , , ;                               §\C{// 3 unnamed fields}§
    14881506}
    14891507\end{lstlisting}
     
    14981516§\emph{expr}§ -> [ §\emph{fieldlist}§ ]
    14991517\end{lstlisting}
    1500 \emph{expr} is any expression yielding a value of type record, e.g., ©struct©, ©union©.
     1518\emph{expr} is any expression yielding a value of type record, \eg ©struct©, ©union©.
    15011519Each element of \emph{ fieldlist} is an element of the record specified by \emph{expr}.
    15021520A record-field tuple may be used anywhere a tuple can be used. An example of the use of a record-field tuple is
     
    17601778}
    17611779\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.
     1780While 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.
     1781Furthermore, 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.
     1782As 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.
     1783The key observation is that the ©switch© statement branches into control structure, i.e., there are multiple entry points into its statement body.
    17671784\end{enumerate}
    17681785
     
    17821799\item
    17831800Eliminating 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}
     1801However, 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:
     1802 \begin{lstlisting}
    17861803case 1:  case 2:  case 3: ...
    17871804\end{lstlisting}
    17881805still work.
    17891806Nevertheless, 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.:
     1807Therefore, 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:
    17911808\begin{lstlisting}
    17921809®choose® ( i ) {
     
    18151832Therefore, no change is made for this issue.
    18161833\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.
     1834Dealing 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{
     1835Essentially, 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.
     1836Further declarations at the same nesting level as the statement body are disallowed to ensure every transfer into the body is sound.
    18201837\begin{lstlisting}
    18211838switch ( x ) {
    1822         ®int i = 0;®                            §\C{// allowed
     1839        ®int i = 0;®                            §\C{// allowed only at start
    18231840  case 0:
    18241841        ...
    1825         ®int i = 0;®                            §\C{// disallowed}§
     1842        ®int j = 0;®                            §\C{// disallowed}§
    18261843  case 1:
    18271844    {
    1828                 ®int i = 0;®                    §\C{// allowed in any compound statement
     1845                ®int k = 0;®                    §\C{// allowed at different nesting levels
    18291846                ...
    18301847        }
     
    27072724Like 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.
    27082725
    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.
     2726There are several ambiguous cases with operator identifiers, \eg ©int *?*?()©, where the string ©*?*?© can be lexed as ©*©/©?*?© or ©*?©/©*?©.
     2727Since 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.
    27112728Even with this special hack, there are 5 general cases that cannot be handled.
    27122729The first case is for the function-call identifier ©?()©:
     
    27732790This means that a function requiring mutual exclusion could block if the lock is already held by another thread.
    27742791Blocking 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
     2792If multiple mutex parameters are specified, they will be locked in parameter order (\ie first parameter is locked first) and unlocked in the
    27762793reverse order.
    27772794\begin{lstlisting}
     
    44714488\CFA is C \emph{incompatible} on this issue, and provides semantics similar to \Index*[C++]{\CC}.
    44724489Nested 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.
     4490Given 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.
    44744491\end{description}
    44754492
     
    51625179\label{s:RationalNumbers}
    51635180
    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.
     5181Rational numbers are numbers written as a ratio, \ie as a fraction, where the numerator (top number) and the denominator (bottom number) are whole numbers.
    51655182When creating and computing with rational numbers, results are constantly reduced to keep the numerator and denominator as small as possible.
    51665183
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