ratatoskr-messenger/zwgc/substitute.h

46 lines
1.8 KiB
C

/* This file is part of the Project Athena Zephyr Notification System.
* It is one of the source files comprising zwgc, the Zephyr WindowGram
* client.
*
* Created by: Marc Horowitz <marc@athena.mit.edu>
*
* $Id$
*
* Copyright (c) 1989 by the Massachusetts Institute of Technology.
* For copying and distribution information, see the file
* "mit-copyright.h".
*/
#include <zephyr/mit-copyright.h>
#ifndef substitute_MODULE
#define substitute_MODULE
#include "new_string.h"
/*
* string substitute(string (*lookup)(string); string text)
* Effects: returns the result of expanding all variable
* references in text using lookup. Example:
* "test $foo.$bar baz" would be translated to
* "text <foo>.<bar> baz" where "<foo>" is the value of
* lookup("foo") and "<bar>" is the value of lookup("bar").
* Variables are case sensitive and have the form
* {identifier_char}+ where identifier_char is defined
* in lexer.h by is_identifier_char. $(foo) and
* ${foo} are alternate forms for $foo. In particular,
* ${foo}bar is a reference to foo followed by "bar" while
* $foobar is a reference to foobar. Incomplete variable
* references like $(foo bar are displayed as if they
* were not variable references. To allow quoting, "$$"
* is translated to "$". Only the first
* MAX_IDENTIFIER_LENGTH characters of an identifier are
* significant. The strings returned by lookup are not
* modified in any way or freed.
*/
extern string substitute(string (*)(string), string);
#endif