/*
* Typechecking of lenses
*/
static struct value *disjoint_check(struct info *info, const char *msg,
struct regexp *r1, struct regexp *r2) {
struct fa *fa1 = NULL;
struct fa *fa2 = NULL;
struct fa *fa = NULL;
struct value *exn = NULL;
exn = regexp_to_fa(r1, &fa1);
if (exn != NULL)
goto done;
exn = regexp_to_fa(r2, &fa2);
if (exn != NULL)
goto done;
fa = fa_intersect(fa1, fa2);
if (! fa_is_basic(fa, FA_EMPTY)) {
size_t xmpl_len;
char *xmpl;
fa_example(fa, &xmpl, &xmpl_len);
exn = make_exn_value(ref(info),
"overlapping lenses in %s", msg);
exn_printf_line(exn, "Example matched by both: '%s'", xmpl);
free(xmpl);
}
done:
fa_free(fa);
fa_free(fa1);
fa_free(fa2);
return exn;
}
struct regexp *
regexp_minus(struct info *info, struct regexp *r1, struct regexp *r2) {
struct regexp *result = NULL;
struct fa *fa = NULL, *fa1 = NULL, *fa2 = NULL;
int r;
char *s = NULL;
size_t s_len;
fa1 = regexp_to_fa(r1);
ERR_BAIL(r1->info);
fa2 = regexp_to_fa(r2);
ERR_BAIL(r2->info);
fa = fa_minus(fa1, fa2);
if (fa == NULL)
goto error;
r = fa_as_regexp(fa, &s, &s_len);
if (r < 0)
goto error;
if (s == NULL) {
/* FA is the empty set, which we can't represent as a regexp */
goto error;
}
if (regexp_c_locale(&s, NULL) < 0)
goto error;
result = make_regexp(info, s, fa_is_nocase(fa));
s = NULL;
done:
fa_free(fa);
fa_free(fa1);
fa_free(fa2);
free(s);
return result;
error:
unref(result, regexp);
goto done;
}
static struct value *ambig_concat_check(struct info *info, const char *msg,
struct regexp *r1, struct regexp *r2) {
struct fa *fa1 = NULL;
struct fa *fa2 = NULL;
struct value *result = NULL;
result = regexp_to_fa(r1, &fa1);
if (result != NULL)
goto done;
result = regexp_to_fa(r2, &fa2);
if (result != NULL)
goto done;
result = ambig_check(info, fa1, fa2, msg);
done:
fa_free(fa1);
fa_free(fa2);
return result;
}
static struct value *ambig_iter_check(struct info *info, const char *msg,
struct regexp *r) {
struct fa *fas = NULL, *fa = NULL;
struct value *result = NULL;
result = regexp_to_fa(r, &fa);
if (result != NULL)
goto done;
fas = fa_iter(fa, 0, -1);
result = ambig_check(info, fa, fas, msg);
done:
fa_free(fa);
fa_free(fas);
return result;
}
/*
* Lens primitives
*/
struct value *lns_make_prim(enum lens_tag tag, struct info *info,
struct regexp *regexp, struct string *string) {
struct lens *lens = NULL;
struct value *exn = NULL;
struct fa *fa_slash = NULL;
struct fa *fa_key = NULL;
struct fa *fa_isect = NULL;
/* Typecheck */
if (tag == L_KEY) {
exn = str_to_fa(info, "(.|\n)*/(.|\n)*", &fa_slash);
if (exn != NULL)
goto error;
exn = regexp_to_fa(regexp, &fa_key);
if (exn != NULL)
goto error;
fa_isect = fa_intersect(fa_slash, fa_key);
if (! fa_is_basic(fa_isect, FA_EMPTY)) {
exn = make_exn_value(info,
"The key regexp /%s/ matches a '/'",
regexp->pattern->str);
goto error;
}
fa_free(fa_isect);
fa_free(fa_key);
fa_free(fa_slash);
fa_isect = fa_key = fa_slash = NULL;
} else if (tag == L_LABEL) {
if (strchr(string->str, SEP) != NULL) {
exn = make_exn_value(info,
"The label string \"%s\" contains a '/'",
string->str);
goto error;
}
} else if (tag == L_DEL) {
int cnt;
const char *dflt = string->str;
cnt = regexp_match(regexp, dflt, strlen(dflt), 0, NULL);
if (cnt != strlen(dflt)) {
char *s = escape(dflt, -1);
char *r = escape(regexp->pattern->str, -1);
exn = make_exn_value(info,
"del: the default value '%s' does not match /%s/",
s, r);
FREE(s);
FREE(r);
goto error;
}
}
/* Build the actual lens */
lens = make_lens(tag, info);
lens->regexp = regexp;
lens->string = string;
lens->key = (tag == L_KEY || tag == L_LABEL || tag == L_SEQ);
lens->value = (tag == L_STORE);
lens->consumes_value = (tag == L_STORE);
lens->atype = regexp_make_empty(info);
if (tag == L_DEL || tag == L_STORE || tag == L_KEY) {
lens->ctype = ref(regexp);
} else if (tag == L_LABEL || tag == L_SEQ || tag == L_COUNTER) {
lens->ctype = regexp_make_empty(info);
} else {
assert(0);
}
return make_lens_value(lens);
error:
fa_free(fa_isect);
fa_free(fa_key);
fa_free(fa_slash);
return exn;
}
