Name: Anonymous 2008-10-02 19:21
Sup /prog/-riders
In this thread we post beautiful code. They can be from your job, school, whatever.
Here's a recursive regex parser with support for character classes, $ and & anchors, and the . and * metachars.
In this thread we post beautiful code. They can be from your job, school, whatever.
Here's a recursive regex parser with support for character classes, $ and & anchors, and the . and * metachars.
int matchhere(char* regexp, char* text);
int matchstar(int c, char* regexp, char* text)
{
do {
if (matchhere(regexp, text))
return 1;
} while (*text != '\0' && (*text++ == c || c == '.'));
return 0;
}
int matchhere(char* regexp, char* text)
{
if (regexp[0] == '\0')
return 1;
if (regexp[1] == '*')
return matchstar(regexp[0], regexp+2, text);
if (regexp[0] == '$' && regexp[1] == '\0')
return *text == '\0';
if (*text != '\0' && (regexp[0] == '.' || regexp[0] == *text))
return matchhere(regexp+1, text+1);
return 0;
}
int match(char* regexp, char* text)
{
if (regexp[0] == '^')
return matchhere(regexp+1, text);
do {
if (matchhere(regexp, text))
return 1;
} while (*text++ != '\0');
return 0;
}