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new fallback "getglobal".

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modifications to generate an index (not automatically yet).
This commit is contained in:
Roberto Ierusalimschy 1996-01-30 10:55:10 -02:00
parent 84df3ac267
commit b1c02c7f00
1 changed files with 20 additions and 8 deletions
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28
manual.tex
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@ -1,4 +1,4 @@
% $Id: $
% $Id: manual.tex,v 1.2 1996/01/29 17:08:23 roberto Exp roberto $
\documentstyle[A4,11pt,bnf]{article}
@ -13,7 +13,7 @@
\newcommand{\Def}[1]{{\em #1}\index{#1}}
\newcommand{\Deffunc}[1]{\index{{\tt #1}}}
%\makeindex
\begin{document}
@ -32,7 +32,7 @@ Waldemar Celes Filho
Departamento de Inform\'atica --- PUC-Rio
}
\date{November, 1995}
\date{\small \verb$Date: 1996/01/29 17:08:23 $}
\maketitle
@ -44,8 +44,6 @@ as a configuration language for any program that needs one.
This document describes version 2.2 of the Lua programming language and the
API that allows interaction between Lua programs and its host C program.
It also presents some examples of using the main features of the system.
{\em Lua manual: \verb$Date$, \verb$Revision$}
\end{abstract}
\vspace{4ex}
@ -649,6 +647,12 @@ not present in a table.
It receives as arguments the table and the index.
Its return value is the final result of the indexing operation.
The default function returns nil.
\item[``getglobal'']\index{index getglobal}
called when Lua tries to retrieve the value of a global variable
which has a nil value (or which has not been initialized).
It receives as argument the name of the variable.
Its return value is the final result of the expression.
The default function returns nil.
\item[``gettable'']\index{gettable fallback}
called when Lua tries to index a non table value.
It receives as arguments the non table value and the index.
@ -751,7 +755,8 @@ executes the ``file'' {\tt stdin}.
\subsection{Converting Values between C and Lua} \label{valuesCLua}
Because Lua has no static type system,
all values passed between Lua and C have type \IndexVerb{lua\_Object},
all values passed between Lua and C have type
\verb'lua_Object'\Deffunc{lua_Object},
which works like an abstract type in C that can hold any Lua value.
Lua has automatic memory management, and garbage collection.
@ -832,7 +837,8 @@ otherwise, the function returns 0 (the null pointer).
The reverse process, that is, passing a specific C value to Lua,
is done by using the following functions:
\Deffunc{lua_pushnumber}\Deffunc{lua_pushstring}\Deffunc{lua_pushliteral}
\Deffunc{lua_pushcfunction}\Deffunc{lua_pushusertag}\Deffunc{lua_pushuserdata}
\Deffunc{lua_pushcfunction}\Deffunc{lua_pushusertag}
\Deffunc{lua_pushuserdata}
\begin{verbatim}
void lua_pushnumber (double n);
void lua_pushstring (char *s);
@ -1040,7 +1046,8 @@ lua_Object lua_getparam (int number);
\end{verbatim}
where \verb'number' starts with 1 to get the first argument.
When called with a number larger than the actual number of arguments,
this function returns \IndexVerb{LUA\_NOOBJECT}.
this function returns
\verb'LUA_NOOBJECT'\Deffunc{LUA_NOOBJECT}.
In this way, it is possible to write functions that work with
a variable number of parameters.
@ -1781,4 +1788,9 @@ Special care should be taken with macros like
\verb'lua_getindexed' and \verb'lua_getfield'.
\end{itemize}
\newcommand{\indexentry}[2]{\item {#1} #2}
\begin{theindex}
\input{manual.idx}
\end{theindex}
\end{document}