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Updated regex escapes
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@orangeduck
orangeduck committed Nov 10, 2013
1 parent 51faac5 commit 0e8d286
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Showing 3 changed files with 72 additions and 76 deletions.
136 changes: 61 additions & 75 deletions mpc.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1400,7 +1400,7 @@ mpc_parser_t* mpc_failf(const char* fmt, ...) {
va_end(va);

buffer = realloc(buffer, strlen(buffer) + 1);

p->data.fail.m = buffer;
return p;

}
Expand Down Expand Up @@ -1905,101 +1905,92 @@ static mpc_val_t* mpc_re_fold_many(mpc_val_t* t, mpc_val_t* x) {
return mpc_also(t, x, free, mpcf_strfold);
}

static mpc_parser_t* mpc_re_escape_char(char c, int range) {
switch (c) {
case 'a': return mpc_char('\a');
case 'f': return mpc_char('\f');
case 'n': return mpc_char('\n');
case 't': return mpc_char('\t');
case 'v': return mpc_char('\v');
case 'A': return mpc_also(mpc_eoi(), mpc_lift(mpcf_lift_emptystr), free, mpcf_snd);
case 'b': if (range) { mpc_char('\b'); } else { return mpc_failf("In Regex '\\b' escape character unsupported!"); }
case 'B': return mpc_failf("In Regex '\\B' escape character unsupported!");
case 'd': return mpc_digit();
case 'D': return mpc_not_else(mpc_digit(), free, mpcf_lift_emptystr);
case 's': return mpc_space();
case 'S': return mpc_not_else(mpc_space(), free, mpcf_lift_emptystr);
case 'w': return mpc_alphanum();
case 'W': return mpc_not_else(mpc_alphanum(), free, mpcf_lift_emptystr);
case 'Z': return mpc_also(mpc_soi(), mpc_lift(mpcf_lift_emptystr), free, mpcf_snd);
default: return NULL;
}
}

static mpc_val_t* mpc_re_escape(mpc_val_t* x) {

char* s = mpcf_unescape(x);
char* s = x;
mpc_parser_t* p;

/* Regex Special Characters */
if (s[0] == '.') { free(s); return mpc_any(); }
if (s[0] == '$') { free(s); return mpc_also(mpc_eoi(), mpc_lift(mpcf_lift_emptystr), free, mpcf_snd); }
if (s[0] == '^') { free(s); return mpc_also(mpc_soi(), mpc_lift(mpcf_lift_emptystr), free, mpcf_snd); }
if (s[0] == '$') { free(s); return mpc_also(mpc_eoi(), mpc_lift(mpcf_lift_emptystr), free, mpcf_snd); }

/* Extra Regex Escapes */
/* Regex Escape */
if (s[0] == '\\') {

if (s[1] == 'd') { free(s); return mpc_digit(); }
if (s[1] == 'D') { free(s); return mpc_not_else(mpc_digit(), free, mpcf_lift_emptystr); }
if (s[1] == 's') { free(s); return mpc_space(); }
if (s[1] == 'S') { free(s); return mpc_not_else(mpc_space(), free, mpcf_lift_emptystr); }
if (s[1] == 'w') { free(s); return mpc_alphanum(); }
if (s[1] == 'W') { free(s); return mpc_not_else(mpc_alphanum(), free, mpcf_lift_emptystr); }
if (s[1] == 'Z') { free(s); return mpc_eoi(); }

p = mpc_char(s[1]);
p = mpc_re_escape_char(s[1], 0);
p = (p == NULL) ? mpc_char(s[1]) : p;
free(s);
return p;

} else {
p = mpc_char(s[0]);
free(s); return p;
}

/* Regex Standard */
p = mpc_char(s[0]);
free(s);
return p;
}

static mpc_val_t* mpcf_unescape_rechars(mpc_val_t* x);

static mpc_val_t* mpc_re_range(mpc_val_t* x) {

char* unescaped = mpcf_unescape_rechars(x);

printf("###%s###\n", unescaped);

char* s = unescaped;
int i;

char* s = x;
int i = 0;
int comp = 0;
char* range;
char start, end;
char buff[2];
mpc_parser_t* p;

/* TODO: Print Escaped String */
if (*s == '\0') { free(unescaped); return mpc_failf("Invalid Regex Range Specifier '%s'", s); }

if (*s == '^') {
comp = 1;
s++;
}
mpc_parser_t* q = NULL;
mpc_parser_t* p = mpc_failf("Invalid Range Specifier");

/* TODO: Print Escaped String */
if (*s == '\0') { free(unescaped); return mpc_failf("Invalid Regex Range Specifier '%s'", s); }
if (s[0] == '\0') { free(x); return p; }
if (s[0] == '^' &&
s[1] == '\0') { free(x); return p; }

range = calloc(1, 1);
if (s[0] == '^') { comp = 1;}

while (*s) {

if (*s == '-') {

start = *(s-1);
end = *(s+1);

if (end == '\0') { break; }
if (end < start) { s++; continue; }

range = realloc(range, strlen(range) + 1 + (end-start));

for (i = 0; i < (end-start); i++) {
buff[0] = start+i+1; buff[1] = '\0';
strcat(range, buff);
}

s++;
for (i = comp; i < strlen(s); i++){

/* Regex Range Escape */
if (s[i] == '\\') {
q = mpc_re_escape_char(s[i+1], 1);
q = (q == NULL) ? mpc_char(s[i+1]) : q;
p = mpc_else(p, q);
i++;
}

else {
range = realloc(range, strlen(range) + 2);
buff[0] = *s; buff[1] = '\0';
strcat(range, buff);
/* Regex Range...Range */
else if (s[i] == '-') {
if (s[i+1] == '\0' || i == 0) {
p = mpc_else(p, mpc_char('-'));
} else {
p = mpc_else(p, mpc_range(s[i-1]+1, s[i+1]-1));
}
}

/* Regex Range Normal */
else { p = mpc_else(p, mpc_char(s[i])); }

s++;
}

p = (comp ? mpc_noneof(range) : mpc_oneof(range));

free(range);
free(unescaped);
return p;
free(x);
return comp ? mpc_not_else(p, free, mpcf_lift_emptystr) : p;
}

static mpc_val_t* mpc_re_lift(void) {
Expand Down Expand Up @@ -2110,7 +2101,7 @@ static char mpc_escape_input_c[] = {
'\t', '\v', '\\', '\'', '\"', '\0'};

static char* mpc_escape_output_c[] = {
"\\a", "\\b", "\\f", "\\n", "\\r", "\\t",
"\\a", "\\b", "\\f", "\\n", "\\r", "\\t",
"\\v", "\\\\", "\\'", "\\\"", "\\0", NULL};

static char mpc_escape_input_raw_re[] = { '/' };
Expand Down Expand Up @@ -2214,10 +2205,6 @@ mpc_val_t* mpcf_unescape_regex(mpc_val_t* x) {
mpc_val_t* y = mpcf_unescape_new(x, mpc_escape_input_raw_re, mpc_escape_output_raw_re);
free(x);
return y;
}

mpc_val_t* mpcf_unescape_regexchars(mpc_val_t* x) {

}

mpc_val_t* mpcf_strcrop(mpc_val_t* x) {
Expand Down Expand Up @@ -2815,7 +2802,6 @@ static mpc_val_t* mpca_grammar_apply_char(mpc_val_t* x) {

static mpc_val_t* mpca_grammar_apply_regex(mpc_val_t* x) {
char* y = mpcf_unescape_regex(x);
printf("||%s||\n", y);
mpc_parser_t* p = mpc_tok(mpc_re(y));
free(y);
return mpca_tag(mpc_apply(p, mpcf_apply_str_ast), "regex");
Expand Down
1 change: 0 additions & 1 deletion mpc.h
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Original file line number Diff line number Diff line change
Expand Up @@ -208,7 +208,6 @@ mpc_val_t* mpcf_float(mpc_val_t* x);
mpc_val_t* mpcf_escape(mpc_val_t* x);
mpc_val_t* mpcf_unescape(mpc_val_t* x);
mpc_val_t* mpcf_unescape_regex(mpc_val_t* x);
mpc_val_t* mpcf_unescape_regexchars(mpc_val_t* x);

mpc_val_t* mpcf_strcrop(mpc_val_t* x);

Expand Down
11 changes: 11 additions & 0 deletions mpc_optimise.h
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Original file line number Diff line number Diff line change
@@ -0,0 +1,11 @@
/*
** Just Some Ideas:
**
** - Predictive Optimisation. Check all first character of all possible roots. If no conflict then predictive.
** - Or Optimisation. Check if any terminal parses are _ored_ together. If so condence into single large range.
** - Not Optimisation. Similar to the above. Convert _nots_ into positive cases by inverting full range of characters.
** - Also Optimisation. Two Character parsers together can be condensed to a single string parser.
** - Lookup Optimisation. Finite State Machine Parser.
** -
**
*/

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