hammer/src/parsers/token.c
2015-10-03 17:54:11 +02:00

88 lines
2.4 KiB
C

#include <assert.h>
#include "parser_internal.h"
typedef struct {
uint8_t *str;
uint8_t len;
} HToken;
static HParseResult* parse_token(void *env, HParseState *state) {
HToken *t = (HToken*)env;
for (int i=0; i<t->len; ++i) {
uint8_t chr = (uint8_t)h_read_bits(&state->input_stream, 8, false);
if (t->str[i] != chr) {
return NULL;
}
}
HParsedToken *tok = a_new(HParsedToken, 1);
tok->token_type = TT_BYTES; tok->bytes.token = t->str; tok->bytes.len = t->len;
return make_result(state->arena, tok);
}
static HParsedToken *reshape_token(const HParseResult *p, void* user_data) {
// fetch sequence of uints from p
assert(p->ast);
assert(p->ast->token_type == TT_SEQUENCE);
HCountedArray *seq = p->ast->seq;
// extract byte string
uint8_t *arr = h_arena_malloc(p->arena, seq->used);
size_t i;
for(i=0; i<seq->used; i++) {
HParsedToken *t = seq->elements[i];
assert(t->token_type == TT_UINT);
arr[i] = t->uint;
}
// create result token
HParsedToken *tok = h_arena_malloc(p->arena, sizeof(HParsedToken));
tok->token_type = TT_BYTES;
tok->bytes.len = seq->used;
tok->bytes.token = arr;
return tok;
}
static void desugar_token(HAllocator *mm__, HCFStack *stk__, void *env) {
HToken *tok = (HToken*)env;
HCFS_BEGIN_CHOICE() {
HCFS_BEGIN_SEQ() {
for (size_t i = 0; i < tok->len; i++)
HCFS_ADD_CHAR(tok->str[i]);
} HCFS_END_SEQ();
HCFS_THIS_CHOICE->reshape = reshape_token;
HCFS_THIS_CHOICE->user_data = NULL;
} HCFS_END_CHOICE();
}
static bool token_ctrvm(HRVMProg *prog, void *env) {
HToken *t = (HToken*)env;
h_rvm_insert_insn(prog, RVM_PUSH, 0);
for (int i=0; i<t->len; ++i) {
h_rvm_insert_insn(prog, RVM_MATCH, t->str[i] | t->str[i] << 8);
h_rvm_insert_insn(prog, RVM_STEP, 0);
}
h_rvm_insert_insn(prog, RVM_CAPTURE, 0);
return true;
}
const HParserVtable token_vt = {
.parse = parse_token,
.isValidRegular = h_true,
.isValidCF = h_true,
.desugar = desugar_token,
.compile_to_rvm = token_ctrvm,
.higher = false,
};
HParser* h_token(const uint8_t *str, const size_t len) {
return h_token__m(&system_allocator, str, len);
}
HParser* h_token__m(HAllocator* mm__, const uint8_t *str, const size_t len) {
HToken *t = h_new(HToken, 1);
uint8_t *str_cpy = h_new(uint8_t, len);
memcpy(str_cpy, str, len);
t->str = str_cpy, t->len = len;
return h_new_parser(mm__, &token_vt, t);
}