hammer/src/parsers/choice.c
2013-04-26 20:36:54 -07:00

113 lines
2.7 KiB
C

#include <stdarg.h>
#include "parser_internal.h"
typedef struct {
size_t len;
const HParser **p_array;
} HSequence;
static HParseResult* parse_choice(void *env, HParseState *state) {
HSequence *s = (HSequence*)env;
HInputStream backup = state->input_stream;
for (size_t i=0; i<s->len; ++i) {
if (i != 0)
state->input_stream = backup;
HParseResult *tmp = h_do_parse(s->p_array[i], state);
if (NULL != tmp)
return tmp;
}
// nothing succeeded, so fail
return NULL;
}
static bool choice_isValidRegular(void *env) {
HSequence *s = (HSequence*)env;
for (size_t i=0; i<s->len; ++i) {
if (!s->p_array[i]->vtable->isValidRegular(s->p_array[i]->env))
return false;
}
return true;
}
static bool choice_isValidCF(void *env) {
HSequence *s = (HSequence*)env;
for (size_t i=0; i<s->len; ++i) {
if (!s->p_array[i]->vtable->isValidCF(s->p_array[i]->env))
return false;
}
return true;
}
static bool choice_ctrvm(HRVMProg *prog, void* env) {
HSequence *s = (HSequence*)env;
uint16_t gotos[s->len];
uint16_t start = h_rvm_get_ip(prog);
for (size_t i=0; i<s->len; ++i) {
uint16_t insn = h_rvm_insert_insn(prog, RVM_FORK, 0);
if (!h_compile_regex(prog, s->p_array[i]->env))
return false;
gotos[i] = h_rvm_insert_insn(prog, RVM_GOTO, 0);
h_rvm_patch_arg(prog, insn, h_rvm_get_ip(prog));
}
uint16_t jump = h_rvm_insert_insn(prog, RVM_STEP, 0);
for (size_t i=start; i<s->len; ++i) {
h_rvm_patch_arg(prog, gotos[i], jump);
}
return true;
}
static const HParserVtable choice_vt = {
.parse = parse_choice,
.isValidRegular = choice_isValidRegular,
.isValidCF = choice_isValidCF,
.compile_to_rvm = choice_ctrvm,
};
HParser* h_choice(const HParser* p, ...) {
va_list ap;
va_start(ap, p);
HParser* ret = h_choice__mv(&system_allocator, p, ap);
va_end(ap);
return ret;
}
HParser* h_choice__m(HAllocator* mm__, const HParser* p, ...) {
va_list ap;
va_start(ap, p);
HParser* ret = h_choice__mv(mm__, p, ap);
va_end(ap);
return ret;
}
HParser* h_choice__v(const HParser* p, va_list ap) {
return h_choice__mv(&system_allocator, p, ap);
}
HParser* h_choice__mv(HAllocator* mm__, const HParser* p, va_list ap_) {
va_list ap;
size_t len = 0;
HSequence *s = h_new(HSequence, 1);
const HParser *arg;
va_copy(ap, ap_);
do {
len++;
arg = va_arg(ap, const HParser *);
} while (arg);
va_end(ap);
s->p_array = h_new(const HParser *, len);
va_copy(ap, ap_);
s->p_array[0] = p;
for (size_t i = 1; i < len; i++) {
s->p_array[i] = va_arg(ap, const HParser *);
} while (arg);
va_end(ap);
s->len = len;
HParser *ret = h_new(HParser, 1);
ret->vtable = &choice_vt; ret->env = (void*)s;
return ret;
}