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add semantic actions for base64_3, base64_2, base64_1

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This commit is contained in:
Sven M. Hallberg 2013-01-10 23:44:28 +01:00
parent 2af0f9c47c
commit 54bd5a4a38
1 changed files with 80 additions and 4 deletions
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84
examples/base64_sem1.c
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@ -1,4 +1,5 @@
#include "../src/hammer.h"
#include "../src/internal.h" // for h_carray functions (XXX ?!)
#include <assert.h>
@ -77,6 +78,81 @@ const HParsedToken *act_bsfdig(const HParseResult *p)
#define act_document act_index0
// helper
void carray_append_uint(HCountedArray *array, uint8_t value)
{
HParsedToken *item = h_arena_malloc(array->arena, sizeof(HParsedToken));
item->token_type = TT_UINT;
item->uint = value;
h_carray_append(array, item);
}
const HParsedToken *act_base64_3(const HParseResult *p)
{
assert(p->ast->token_type == TT_SEQUENCE);
HParsedToken *res = h_arena_malloc(p->arena, sizeof(HParsedToken));
res->token_type = TT_SEQUENCE;
res->seq = h_carray_new_sized(p->arena, 4);
HParsedToken **digits = p->ast->seq->elements;
uint32_t x = digits[0]->uint;
x <<= 6; x |= digits[1]->uint;
x <<= 6; x |= digits[2]->uint;
x <<= 6; x |= digits[3]->uint;
carray_append_uint(res->seq, (x >> 16) & 0xFF);
carray_append_uint(res->seq, (x >> 8) & 0xFF);
carray_append_uint(res->seq, x & 0xFF);
return res;
}
const HParsedToken *act_base64_2(const HParseResult *p)
{
assert(p->ast->token_type == TT_SEQUENCE);
HParsedToken *res = h_arena_malloc(p->arena, sizeof(HParsedToken));
res->token_type = TT_SEQUENCE;
res->seq = h_carray_new_sized(p->arena, 4);
HParsedToken **digits = p->ast->seq->elements;
uint32_t x = digits[0]->uint;
x <<= 6; x |= digits[1]->uint;
x <<= 6; x |= digits[2]->uint;
carray_append_uint(res->seq, (x >> 10) & 0xFF);
carray_append_uint(res->seq, (x >> 2) & 0xFF);
return res;
}
const HParsedToken *act_base64_1(const HParseResult *p)
{
assert(p->ast->token_type == TT_SEQUENCE);
HParsedToken *res = h_arena_malloc(p->arena, sizeof(HParsedToken));
res->token_type = TT_SEQUENCE;
res->seq = h_carray_new_sized(p->arena, 4);
HParsedToken **digits = p->ast->seq->elements;
uint32_t x = digits[0]->uint;
x <<= 6; x |= digits[1]->uint;
carray_append_uint(res->seq, (x >> 4) & 0xFF);
return res;
}
#if 0
const HParsedToken *act_base64(const HParseResult *p)
{
// XXX
// concatenate base64_3 blocks
// append trailing base64_2 or _1 block
}
#endif
///
// Set up the parser with the grammar to be recognized.
@ -97,10 +173,10 @@ const HParser *init_parser(void)
H_ARULE(bsfdig, h_choice(alpha, digit, plus, slash, NULL));
H_ARULE(bsfdig_4bit, h_in((uint8_t *)"AEIMQUYcgkosw048", 16));
H_ARULE(bsfdig_2bit, h_in((uint8_t *)"AQgw", 4));
H_RULE (base64_3, h_repeat_n(bsfdig, 4));
H_RULE (base64_2, h_sequence(bsfdig, bsfdig, bsfdig_4bit, equals, NULL));
H_RULE (base64_1, h_sequence(bsfdig, bsfdig_2bit, equals, equals, NULL));
H_RULE (base64, h_sequence(h_many(base64_3),
H_ARULE(base64_3, h_repeat_n(bsfdig, 4));
H_ARULE(base64_2, h_sequence(bsfdig, bsfdig, bsfdig_4bit, equals, NULL));
H_ARULE(base64_1, h_sequence(bsfdig, bsfdig_2bit, equals, equals, NULL));
H_RULE(base64, h_sequence(h_many(base64_3),
h_optional(h_choice(base64_2,
base64_1, NULL)),
NULL));