mirror of
https://github.com/lua/lua
synced 2024-11-23 13:19:57 +03:00
"locale" support + better uniformity in formating
This commit is contained in:
Roberto Ierusalimschy
parent
7820a47184
commit
d56e3a6481
97
manual.tex
97
manual.tex
@ -1,8 +1,7 @@
|
||||
% $Id: manual.tex,v 2.8 1997/06/27 22:38:49 roberto Exp roberto $
|
||||
% $Id: manual.tex,v 2.9 1997/07/01 17:41:34 roberto Exp roberto $
|
||||
|
||||
\documentstyle[fullpage,11pt,bnf]{article}
|
||||
|
||||
\newcommand{\rw}[1]{{\bf #1}}
|
||||
\newcommand{\See}[1]{Section~\ref{#1}}
|
||||
\newcommand{\see}[1]{(see \See{#1})}
|
||||
\newcommand{\M}[1]{\emph{#1}}
|
||||
@ -39,7 +38,7 @@ Waldemar Celes
|
||||
\tecgraf\ --- Computer Science Department --- PUC-Rio
|
||||
}
|
||||
|
||||
\date{\small \verb$Date: 1997/06/27 22:38:49 $}
|
||||
\date{\small \verb$Date: 1997/07/01 17:41:34 $}
|
||||
|
||||
\maketitle
|
||||
|
||||
@ -167,14 +166,14 @@ Before the first assignment, the value of a global variable is \nil;
|
||||
this default can be changed \see{tag-method}.
|
||||
|
||||
The unit of execution of Lua is called a \Def{chunk}.
|
||||
The syntax%
|
||||
\footnote{As usual, \rep{\emph{a}} means 0 or more \emph{a}'s,
|
||||
\opt{\emph{a}} means an optional \emph{a} and \oneormore{\emph{a}} means
|
||||
one or more \emph{a}'s.}
|
||||
for chunks is:
|
||||
The syntax for chunks is:
|
||||
\begin{Produc}
|
||||
\produc{chunk}{\rep{stat \Or function} \opt{ret}}
|
||||
\end{Produc}%
|
||||
(As usual, \rep{\emph{a}} means 0 or more \emph{a}'s,
|
||||
\opt{\emph{a}} means an optional \emph{a} and \oneormore{\emph{a}} means
|
||||
one or more \emph{a}'s.)
|
||||
|
||||
A chunk may contain statements and function definitions,
|
||||
and may be in a file or in a string inside the host program.
|
||||
A chunk may optionally end with a \verb|return| statement \see{return}.
|
||||
@ -182,10 +181,10 @@ When a chunk is executed, first all its functions and statements are compiled,
|
||||
then the statements are executed in sequential order.
|
||||
All modifications a chunk effects on the global environment persist
|
||||
after its end.
|
||||
Those include modifications to global variables and definitions
|
||||
of new functions%
|
||||
\footnote{Actually, a function definition is an
|
||||
assignment to a global variable \see{TypesSec}.}.
|
||||
Those include modifications to global variables
|
||||
and definitions of new functions
|
||||
(actually, a function definition is an
|
||||
assignment to a global variable \see{TypesSec}).
|
||||
|
||||
Chunks may be pre-compiled into binary form;
|
||||
see program \IndexVerb{luac} for details.
|
||||
@ -207,7 +206,9 @@ There are six \Index{basic types} in Lua: \Def{nil}, \Def{number},
|
||||
\emph{Nil} is the type of the value \nil,
|
||||
whose main property is to be different from any other value.
|
||||
\emph{Number} represents real (floating-point) numbers,
|
||||
while \emph{string} has the usual meaning.
|
||||
while \emph{string} has the usual meaning;
|
||||
notice that Lua is \Index{eight-bit clean},
|
||||
so strings can have ISO characters.
|
||||
The function \verb|type| returns a string describing the type
|
||||
of a given value \see{pdf-type}.
|
||||
|
||||
@ -275,9 +276,11 @@ This section describes the lexis, the syntax and the semantics of Lua.
|
||||
|
||||
\subsection{Lexical Conventions} \label{lexical}
|
||||
|
||||
Lua is a case-sensitive language.
|
||||
\Index{Identifiers} can be any string of letters, digits, and underscores,
|
||||
not beginning with a digit.
|
||||
The definition of letter depends on the current locale:
|
||||
Any character considered alphabetic by the current locale
|
||||
can be used in an identifier.
|
||||
The following words are reserved, and cannot be used as identifiers:
|
||||
\index{reserved words}
|
||||
\begin{verbatim}
|
||||
@ -286,6 +289,9 @@ The following words are reserved, and cannot be used as identifiers:
|
||||
nil not or repeat
|
||||
return then until while
|
||||
\end{verbatim}
|
||||
Lua is a case-sensitive language:
|
||||
\T{and} is a reserved word, but \T{And} and \T{\'and}
|
||||
(if the locale permits) are two other different identifiers.
|
||||
|
||||
The following strings denote other \Index{tokens}:
|
||||
\begin{verbatim}
|
||||
@ -307,9 +313,9 @@ other quoted strings.
|
||||
\Index{Comments} start anywhere outside a string with a
|
||||
double hyphen (\verb|--|) and run until the end of the line.
|
||||
Moreover,
|
||||
the first line of a chunk file is skipped if it starts with \verb|#|%
|
||||
\footnote{This facility allows the use of Lua as a script interpreter
|
||||
in Unix systems \see{lua-sa}.}.
|
||||
the first line of a chunk file is skipped if it starts with \verb|#|.
|
||||
This facility allows the use of Lua as a script interpreter
|
||||
in Unix systems \see{lua-sa}.
|
||||
|
||||
\Index{Numerical constants} may be written with an optional decimal part,
|
||||
and an optional decimal exponent.
|
||||
@ -325,9 +331,9 @@ The \verb|$| can be followed by any of the following directives:
|
||||
\begin{description}
|
||||
\item[\T{debug}] --- turn on some debugging facilities \see{pragma}.
|
||||
\item[\T{nodebug}] --- turn off some debugging facilities \see{pragma}.
|
||||
\item[{\tt if \M{cond}}] --- starts a conditional part.
|
||||
\item[\T{if \M{cond}}] --- starts a conditional part.
|
||||
If \M{cond} is false, then this part is skipped by the lexical analyzer.
|
||||
\item[{\tt ifnot \M{cond}}] --- starts a conditional part.
|
||||
\item[\T{ifnot \M{cond}}] --- starts a conditional part.
|
||||
If \M{cond} is true, then this part is skipped by the lexical analyzer.
|
||||
\item[\T{end}] --- ends a conditional part.
|
||||
\item[\T{else}] --- starts an ``else'' conditional part,
|
||||
@ -439,9 +445,9 @@ an assignment \verb|x = val|, where \verb|x| is a global variable,
|
||||
is equivalent to a call \verb|setglobal('x', val)|;
|
||||
an assignment \verb|t[i] = val| is equivalent to
|
||||
\verb|settable_event(t, i, val)|.
|
||||
See \See{tag-method} for a description of these functions%
|
||||
\footnote{Function \verb|setglobal| is pre-defined in Lua.
|
||||
Function \T{settable\_event} is used only for explanatory purposes.}.
|
||||
See \See{tag-method} for a description of these functions.
|
||||
(Function \verb|setglobal| is pre-defined in Lua.
|
||||
Function \T{settable\_event} is used only for explanatory purposes.)
|
||||
|
||||
The syntax \verb|var.NAME| is just syntactic sugar for
|
||||
\verb|var["NAME"]|:
|
||||
@ -515,9 +521,9 @@ An access to a global variable \verb|x| is equivalent to a
|
||||
call \verb|getglobal('x')|;
|
||||
an access to an indexed variable \verb|t[i]| is equivalent to
|
||||
a call \verb|gettable_event(t, i)|.
|
||||
See \See{tag-method} for a description of these functions%
|
||||
\footnote{Function \verb|getglobal| is pre-defined in Lua.
|
||||
Function \T{gettable\_event} is used only for explanatory purposes.}.
|
||||
See \See{tag-method} for a description of these functions.
|
||||
(Function \verb|getglobal| is pre-defined in Lua.
|
||||
Function \T{gettable\_event} is used only for explanatory purposes.)
|
||||
|
||||
The non-terminal \M{exp1} is used to indicate that the values
|
||||
returned by an expression must be adjusted to one single value:
|
||||
@ -563,9 +569,6 @@ If both arguments are numbers, then they are compared as such.
|
||||
Otherwise, if both arguments are strings,
|
||||
their values are compared using lexicographical order.
|
||||
Otherwise, the ``order'' tag method is called \see{tag-method}.
|
||||
%Note that the conversion rules of Section~\ref{coercion}
|
||||
%do apply to order operators.
|
||||
%Thus, \verb|"2">"12"| evaluates to true.
|
||||
|
||||
\subsubsection{Logical Operators}
|
||||
Like control structures, all logical operators
|
||||
@ -643,7 +646,7 @@ is essentially equivalent to:
|
||||
The form \emph{ffieldlist1} initializes other fields in a table:
|
||||
\begin{Produc}
|
||||
\produc{ffieldlist1}{ffield \rep{\ter{,} ffield} \opt{\ter{,}}}
|
||||
\produc{ffield}{\ter{[} exp \ter{]} \ter {=} exp \Or name \ter{=} exp}
|
||||
\produc{ffield}{\ter{[} exp \ter{]} \ter{=} exp \Or name \ter{=} exp}
|
||||
\end{Produc}%
|
||||
For example:
|
||||
\begin{verbatim}
|
||||
@ -1322,7 +1325,7 @@ The use of explicit nested blocks is strongly encouraged.
|
||||
|
||||
\subsection{Executing Lua Code}
|
||||
A host program can execute Lua chunks written in a file or in a string
|
||||
using the following functions:%
|
||||
using the following functions:
|
||||
\Deffunc{lua_dofile}\Deffunc{lua_dostring}
|
||||
\begin{verbatim}
|
||||
int lua_dofile (char *filename);
|
||||
@ -1967,7 +1970,7 @@ The following combinations are allowed in describing a character class:
|
||||
\item[\T{\%U}] --- represents all non upper case letter characters.
|
||||
\item[\T{\%w}] --- represents all alphanumeric characters.
|
||||
\item[\T{\%W}] --- represents all non alphanumeric characters.
|
||||
\item[{\tt \%\M{x}}] (where \M{x} is any non alphanumeric character) ---
|
||||
\item[\T{\%\M{x}}] (where \M{x} is any non alphanumeric character) ---
|
||||
represents the character \M{x}.
|
||||
This is the standard way to escape the magic characters \verb|()%.[*-?|.
|
||||
\item[\T{[char-set]}] ---
|
||||
@ -1976,17 +1979,21 @@ characters in char-set.
|
||||
To include a \verb|]| in char-set, it must be the first character.
|
||||
A range of characters may be specified by
|
||||
separating the end characters of the range with a \verb|-|;
|
||||
e.g., \verb|A-Z| specifies the upper case characters.
|
||||
e.g., \verb|A-Z| specifies the English upper case characters.
|
||||
If \verb|-| appears as the first or last character of char-set,
|
||||
then it represents itself.
|
||||
All classes \verb|%|\emph{x} described above can also be used as
|
||||
components in a char-set.
|
||||
All other characters in char-set represent themselves.
|
||||
\item[{\tt [\^{ }char-set]}] ---
|
||||
\item[\T{[\^{ }char-set]}] ---
|
||||
represents the complement of char-set,
|
||||
where char-set is interpreted as above.
|
||||
\end{description}
|
||||
|
||||
The definitions of letter, space, etc depend on the current locale.
|
||||
In particular, the class \verb|[a-z]| may not be equivalent to \verb|%l|.
|
||||
The second form should be preferred for more portable programs.
|
||||
|
||||
\paragraph{Pattern Item:}
|
||||
a \Def{pattern item} may be:
|
||||
\begin{itemize}
|
||||
@ -2006,11 +2013,11 @@ these repetition items will always match the shortest possible sequence.
|
||||
a single character class followed by \verb|?|,
|
||||
which matches 0 or 1 occurrence of a character in the class;
|
||||
\item
|
||||
{\tt \%\M{n}}, for \M{n} between 1 and 9;
|
||||
\T{\%\M{n}}, for \M{n} between 1 and 9;
|
||||
such item matches a sub-string equal to the n-th captured string
|
||||
(see below);
|
||||
\item
|
||||
{\tt \%b\M{xy}}, where \M{x} and \M{y} are two distinct characters;
|
||||
\T{\%b\M{xy}}, where \M{x} and \M{y} are two distinct characters;
|
||||
such item matches strings that start with \M{x}, end with \M{y},
|
||||
and where the \M{x} and \M{y} are \emph{balanced}.
|
||||
That means that, if one reads the string from left to write,
|
||||
@ -2039,6 +2046,7 @@ stored as the first capture (and therefore has number 1);
|
||||
the character matching \verb|.| is captured with number 2,
|
||||
and the part matching \verb|%s*| has number 3.
|
||||
|
||||
|
||||
\subsection{Mathematical Functions} \label{mathlib}
|
||||
|
||||
This library is an interface to some functions of the standard C math library.
|
||||
@ -2101,8 +2109,6 @@ When called with a file name, it opens the named file,
|
||||
sets its handle as the value of \verb|_INPUT|,
|
||||
and returns this value.
|
||||
It does not close the current input file.
|
||||
%When called with a file handle returned by a previous call,
|
||||
%it simply assigns it to \verb|_INPUT|.
|
||||
When called without parameters,
|
||||
it closes the \verb|_INPUT| file,
|
||||
and restores \verb|stdin| as the value of \verb|_INPUT|.
|
||||
@ -2130,8 +2136,6 @@ and returns this value.
|
||||
It does not close the current output file.
|
||||
Notice that, if the file already exists,
|
||||
then it will be \emph{completely erased} with this operation.
|
||||
%When called with a file handle returned by a previous call,
|
||||
%it restores the file as the current output.
|
||||
When called without parameters,
|
||||
this function closes the \verb|_OUTPUT| file,
|
||||
and restores \verb|stdout| as the value of \verb|_OUTPUT|.
|
||||
@ -2203,15 +2207,13 @@ from the input if it belongs to the class;
|
||||
it never fails.
|
||||
A character class followed by \verb|*| reads until a character that
|
||||
does not belong to the class, or end of file;
|
||||
since it can match a sequence of zero characters, it never fails.%
|
||||
\footnote{
|
||||
since it can match a sequence of zero characters, it never fails.
|
||||
Notice that the behavior of read patterns is different from
|
||||
the regular pattern matching behavior,
|
||||
where a \verb|*| expands to the maximum length \emph{such that}
|
||||
the rest of the pattern does not fail.
|
||||
With the read pattern behavior
|
||||
there is no need for backtracking the reading.
|
||||
}
|
||||
|
||||
A pattern item may contain sub-patterns enclosed in curly brackets,
|
||||
that describe \Def{skips}.
|
||||
@ -2270,6 +2272,17 @@ This function is equivalent to the C function \verb|system|.
|
||||
It passes \verb|command| to be executed by an operating system shell.
|
||||
It returns an error code, which is system-dependent.
|
||||
|
||||
\subsubsection*{\ff \T{setlocale (locale [, category])}}\Deffunc{setlocale}
|
||||
|
||||
This function is an interface to the ANSI C function \verb|setlocale|.
|
||||
\verb|locale| is a string specifing a locale;
|
||||
\verb|category| is a number describing which category to change:
|
||||
0 is \verb|LC_ALL|, 1 is \verb|LC_COLLATE|, 2 is \verb|LC_CTYPE|,
|
||||
3 is \verb|LC_MONETARY|, 4 is \verb|LC_NUMERIC|, and 5 is \verb|LC_TIME|;
|
||||
the default category is \verb|LC_ALL|.
|
||||
The function returns the name of the new locale,
|
||||
or \nil\ if the request cannot be honored.
|
||||
|
||||
|
||||
\section{The Debugger Interface} \label{debugI}
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user