static void desugar_sequence(HAllocator *mm__, HCFStack *stk__, void *env) {
HSequence *s = (HSequence*)env;
HCFS_BEGIN_CHOICE() {
HCFS_BEGIN_SEQ() {
for (size_t i = 0; i < s->len; i++)
HCFS_DESUGAR(s->p_array[i]);
} HCFS_END_SEQ();
HCFS_THIS_CHOICE->reshape = reshape_sequence;
} HCFS_END_CHOICE();
}
static void desugar_whitespace(HAllocator *mm__, HCFStack *stk__, void *env) {
HCharset ws_cs = new_charset(mm__);
for(size_t i=0; i<sizeof(SPACE_CHRS); i++)
charset_set(ws_cs, SPACE_CHRS[i], 1);
HCFS_BEGIN_CHOICE() {
HCFS_BEGIN_SEQ() {
HCFS_BEGIN_CHOICE() {
HCFS_BEGIN_SEQ() {
HCFS_ADD_CHARSET(ws_cs);
HCFS_APPEND(HCFS_THIS_CHOICE); // yay circular pointer!
} HCFS_END_SEQ();
HCFS_BEGIN_SEQ() {
} HCFS_END_SEQ();
} HCFS_END_CHOICE();
HCFS_DESUGAR( (HParser*)env );
} HCFS_END_SEQ();
HCFS_THIS_CHOICE->reshape = h_act_last;
} HCFS_END_CHOICE();
}
static void desugar_action(HAllocator *mm__, HCFStack *stk__, void *env) {
HParseAction *a = (HParseAction*)env;
HCFS_BEGIN_CHOICE() {
HCFS_BEGIN_SEQ() {
HCFS_DESUGAR(a->p);
} HCFS_END_SEQ();
HCFS_THIS_CHOICE->user_data = a->user_data;
HCFS_THIS_CHOICE->action = a->action;
HCFS_THIS_CHOICE->reshape = h_act_first;
} HCFS_END_CHOICE();
}
// desugar parser with a fresh start symbol
// this guarantees that the start symbol will not occur in any productions
HCFChoice *h_desugar_augmented(HAllocator *mm__, HParser *parser)
{
HCFChoice *augmented = h_new(HCFChoice, 1);
HCFStack *stk__ = h_cfstack_new(mm__);
stk__->prealloc = augmented;
HCFS_BEGIN_CHOICE() {
HCFS_BEGIN_SEQ() {
HCFS_DESUGAR(parser);
} HCFS_END_SEQ();
HCFS_THIS_CHOICE->reshape = h_act_first;
} HCFS_END_CHOICE();
h_cfstack_free(mm__, stk__);
return augmented;
}
static void desugar_optional(HAllocator *mm__, HCFStack *stk__, void *env) {
HParser *p = (HParser*) env;
/* optional(A) =>
S -> A
-> \epsilon
*/
HCFS_BEGIN_CHOICE() {
HCFS_BEGIN_SEQ() {
HCFS_DESUGAR(p);
} HCFS_END_SEQ();
HCFS_BEGIN_SEQ() {
} HCFS_END_SEQ();
HCFS_THIS_CHOICE->reshape = reshape_optional;
HCFS_THIS_CHOICE->user_data = NULL;
} HCFS_END_CHOICE();
}
static void desugar_ignoreseq(HAllocator *mm__, HCFStack *stk__, void *env) {
HIgnoreSeq *seq = (HIgnoreSeq*)env;
HCFS_BEGIN_CHOICE() {
HCFS_BEGIN_SEQ() {
for (size_t i=0; i<seq->len; ++i)
HCFS_DESUGAR(seq->parsers[i]);
} HCFS_END_SEQ();
if(seq->which == 0)
HCFS_THIS_CHOICE->reshape = h_act_first;
else if(seq->which == 1)
HCFS_THIS_CHOICE->reshape = h_act_second; // for h_middle
else if(seq->which == seq->len-1)
HCFS_THIS_CHOICE->reshape = h_act_last;
else
assert(!"Ignoreseq must select item 0, 1, or n-1");
} HCFS_END_CHOICE();
}
