/*=gfunc string_substitute
*
* what: multiple global replacements
* general_use:
*
* exparg: source, string to transform
* exparg: match, substring or substring list to be replaced
* exparg: repl, replacement strings or substrings
*
* doc: @code{match} and @code{repl} may be either a single string or
* a list of strings. Either way, they must have the same structure
* and number of elements. For example, to replace all amphersands,
* less than and greater than characters, do something like this:
*
* @example
* (string-substitute source
* (list "&" "<" ">")
* (list "&" "<" ">"))
* @end example
=*/
SCM
ag_scm_string_substitute(SCM str, SCM Match, SCM Repl)
{
char const * text;
ssize_t len;
SCM res;
if (! AG_SCM_STRING_P(str))
return SCM_UNDEFINED;
text = scm_i_string_chars(str);
len = (ssize_t)AG_SCM_STRLEN(str);
if (AG_SCM_STRING_P(Match))
do_substitution(text, len, Match, Repl, (char **)&text, &len);
else
do_multi_subs((char **)&text, &len, Match, Repl);
res = AG_SCM_STR2SCM(text, (size_t)len);
return res;
}
/*=gfunc string_substitute
*
* what: multiple global replacements
* general_use:
*
* exparg: source, string to transform
* exparg: match, substring or substring list to be replaced
* exparg: repl, replacement strings or substrings
*
* doc: @code{match} and @code{repl} may be either a single string or
* a list of strings. Either way, they must have the same structure
* and number of elements. For example, to replace all amphersands,
* less than and greater than characters, do something like this:
*
* @example
* (string-substitute source
* (list "&" "<" ">")
* (list "&" "<" ">"))
* @end example
=*/
SCM
ag_scm_string_substitute(SCM Str, SCM Match, SCM Repl)
{
char const * pzStr;
ssize_t len;
SCM res;
if (! AG_SCM_STRING_P(Str))
return SCM_UNDEFINED;
pzStr = AG_SCM_CHARS(Str);
len = AG_SCM_STRLEN(Str);
if (AG_SCM_STRING_P(Match))
do_substitution(pzStr, len, Match, Repl, (char**)&pzStr, &len);
else
do_multi_subs((char**)&pzStr, &len, Match, Repl);
res = AG_SCM_STR2SCM(pzStr, len);
return res;
}
/*
* Recursive routine. It calls itself for list values and calls
* "do_substitution" for string values. Each substitution will
* be done in the order found in the tree walk of list values.
* The "match" and "repl" trees *must* be identical in structure.
*/
LOCAL void
do_multi_subs(char ** ppzStr, ssize_t * pStrLen, SCM match, SCM repl)
{
char * pzStr = *ppzStr;
char * pzNxt = pzStr;
/*
* Loop for as long as our list has more entries
*/
while (! scm_is_null(match)) {
/*
* "CAR" is the current value, "CDR" is rest of list
*/
SCM matchCar = SCM_CAR(match);
SCM replCar = SCM_CAR(repl);
match = SCM_CDR(match);
repl = SCM_CDR(repl);
if (AG_SCM_STRING_P(matchCar)) {
do_substitution(pzStr, *pStrLen, matchCar, replCar,
&pzNxt, pStrLen);
// coverity[use_after_free] -- invalid alias analysis
pzStr = pzNxt;
}
else if (AG_SCM_LIST_P(matchCar))
do_multi_subs(&pzStr, pStrLen, matchCar, replCar);
else
/*
* Whatever it is it is not part of what we would expect. Bail.
*/
break;
}
*ppzStr = pzStr;
}