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better factor out lr table writes

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This commit is contained in:
Sven M. Hallberg 2013-06-21 20:52:27 +02:00
parent 534a29b7ba
commit d67e12a825
3 changed files with 14 additions and 9 deletions
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13
src/backends/lr0.c
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@ -161,6 +161,14 @@ HLRDFA *h_lr0_dfa(HCFGrammar *g)
/* LR(0) table generation */
static inline
void put_shift(HLRTable *table, size_t state, const HCFChoice *symbol,
size_t nextstate)
{
HLRAction *action = h_shift_action(table->arena, nextstate);
h_hashtable_put(table->rows[state], symbol, action);
}
HLRTable *h_lr0_table(HCFGrammar *g, const HLRDFA *dfa)
{
HAllocator *mm__ = g->mm__;
@ -174,15 +182,14 @@ HLRTable *h_lr0_table(HCFGrammar *g, const HLRDFA *dfa)
// add dummy shift entry for the start symbol so h_lrengine_step can always
// find a shift.
// NB: nextstate=0 is used for the "victory condition" by h_lrengine_result.
h_hashtable_put(table->rows[0], g->start, h_shift_action(arena, 0));
put_shift(table, 0, g->start, 0);
// add shift entries
for(HSlistNode *x = dfa->transitions->head; x; x = x->next) {
// for each transition x-A->y, add "shift, goto y" to table entry (x,A)
HLRTransition *t = x->elem;
HLRAction *action = h_shift_action(arena, t->to);
h_hashtable_put(table->rows[t->from], t->symbol, action);
put_shift(table, t->from, t->symbol, t->to);
}
// add reduce entries, record inadequate states