commit 3aa500b524793cf79de78c373a618d708bf22004
parent f1861ee210a9ccab5b694d97cb9434fda841ba0d
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 11 May 1999 17:46:06 -0300
new pattern item '+'
Diffstat:
| M | manual.tex | | | 49 | +++++++++++++++++++++++++++++-------------------- |
1 file changed, 29 insertions(+), 20 deletions(-)
diff --git a/manual.tex b/manual.tex
@@ -1,4 +1,4 @@
-% $Id: manual.tex,v 1.30 1999/04/14 20:47:12 roberto Exp roberto $
+% $Id: manual.tex,v 1.31 1999/05/05 19:21:57 roberto Exp roberto $
\documentclass[11pt]{article}
\usepackage{fullpage,bnf}
@@ -41,7 +41,7 @@ Waldemar Celes
\tecgraf\ --- Computer Science Department --- PUC-Rio
}
-\date{{\small \tt\$Date: 1999/04/14 20:47:12 $ $}}
+\date{{\small \tt\$Date: 1999/05/05 19:21:57 $ $}}
\maketitle
@@ -1719,9 +1719,9 @@ equivalent to the Lua code:
lua_pushnumber(4); /* 3rd argument */
lua_callfunction(lua_getglobal("f")); /* call Lua function */
lua_pushobject(lua_getresult(1)); /* push first result of the call */
- lua_setglobal("a"); /* sets global variable 'a' */
- lua_pushobject(lua_getresult(2)); /* push second result of the call */
- lua_setglobal("b"); /* sets global variable 'b' */
+ lua_setglobal("a"); /* set global variable 'a' */
+ lua_pushobject(lua_getresult(2)); /* push second result of the call */
+ lua_setglobal("b"); /* set global variable 'b' */
\end{verbatim}
Some special Lua functions have exclusive interfaces.
@@ -2459,27 +2459,27 @@ For instance, when \verb|n| is 1 only the first occurrence of
Here are some examples:
\begin{verbatim}
- x = gsub("hello world", "(%w%w*)", "%1 %1")
+ x = gsub("hello world", "(%w+)", "%1 %1")
--> x="hello hello world world"
- x = gsub("hello world", "(%w%w*)", "%1 %1", 1)
+ x = gsub("hello world", "(%w+)", "%1 %1", 1)
--> x="hello hello world"
- x = gsub("hello world from Lua", "(%w%w*)%s*(%w%w*)", "%2 %1")
+ x = gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1")
--> x="world hello Lua from"
- x = gsub("home = $HOME, user = $USER", "$(%w%w*)", getenv)
+ x = gsub("home = $HOME, user = $USER", "%$(%w+)", getenv)
--> x="home = /home/roberto, user = roberto" (for instance)
- x = gsub("4+5 = $return 4+5$", "$(.-)%$", dostring)
+ x = gsub("4+5 = $return 4+5$", "%$(.-)%$", dostring)
--> x="4+5 = 9"
- local t = {name="lua", version="3.1"}
- x = gsub("$name - $version", "$(%w%w*)", function (v) return %t[v] end)
- --> x="lua - 3.1"
+ local t = {name="lua", version="3.2"}
+ x = gsub("$name - $version", "%$(%w+)", function (v) return %t[v] end)
+ --> x="lua - 3.2"
t = {n=0}
- gsub("first second word", "(%w%w*)", function (w) tinsert(%t, w) end)
+ gsub("first second word", "(%w+)", function (w) tinsert(%t, w) end)
--> t={"first", "second", "word"; n=3}
\end{verbatim}
@@ -2491,7 +2491,7 @@ a \Def{character class} is used to represent a set of characters.
The following combinations are allowed in describing a character class:
\begin{description}
\item[\emph{x}] (where \emph{x} is any character not in the list
-\verb|()%.[]*-?|)
+\verb|^$()%.[]*+-?|)
--- represents the character \emph{x} itself.
\item[\T{.}] --- (a dot) represents all characters.
\item[\T{\%a}] --- represents all letters.
@@ -2507,6 +2507,8 @@ The following combinations are allowed in describing a character class:
\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|()%.[]*-?|.
+It is strongly recommended that any control character (even the non magic),
+when used to represent itself in a pattern, should be preceded by a \verb|%|.
\item[\T{[char-set]}] ---
Represents the class which is the union of all
characters in char-set.
@@ -2533,7 +2535,7 @@ 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:
+a \Def{pattern item} may be
\begin{itemize}
\item
a single character class,
@@ -2541,12 +2543,16 @@ which matches any single character in the class;
\item
a single character class followed by \verb|*|,
which matches 0 or more repetitions of characters in the class.
-These repetition items will always match the longest possible sequence.
+These repetition items will always match the longest possible sequence;
+\item
+a single character class followed by \verb|+|,
+which matches 1 or more repetitions of characters in the class.
+These repetition items will always match the longest possible sequence;
\item
a single character class followed by \verb|-|,
which also matches 0 or more repetitions of characters in the class.
Unlike \verb|*|,
-these repetition items will always match the shortest possible sequence.
+these repetition items will always match the shortest possible sequence;
\item
a single character class followed by \verb|?|,
which matches 0 or 1 occurrence of a character in the class;
@@ -2804,7 +2810,7 @@ it uses a default pattern that reads the next line
A \Def{read pattern} is a sequence of read pattern items.
An item may be a single character class
-or a character class followed by \verb|?| or by \verb|*|.
+or a character class followed by \verb|?|, by \verb|*|, or by \verb|+|.
A single character class reads the next character from the input
if it belongs to the class, otherwise it fails.
A character class followed by \verb|?| reads the next character
@@ -2813,6 +2819,9 @@ 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.
+A character class followed by \verb|+| reads until a character that
+does not belong to the class, or end of file;
+it fails if it cannot read at least one character.
Note that the behavior of read patterns is slightly different from
the regular pattern matching behavior,
where a \verb|*| expands to the maximum length \emph{such that}
@@ -2838,7 +2847,7 @@ It is equivalent to the pattern \verb|".*"|.
\item[``*w''] returns the next word
(maximal sequence of non white-space characters),
skipping spaces if necessary, or \nil\ on end of file.
-It is equivalent to the pattern \verb|"{%s*}%S%S*"|.
+It is equivalent to the pattern \verb|"{%s*}%S+"|.
\end{description}
\subsubsection*{\ff \T{write ([filehandle, ] value1, ...)}}\Deffunc{write}
