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split h_lr_lookup into two (yet identical) functions

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This commit is contained in:
Sven M. Hallberg 2013-06-21 20:21:40 +02:00
parent c32cf709b2
commit 534a29b7ba
1 changed files with 32 additions and 14 deletions
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46
src/backends/lr.c
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@ -190,18 +190,6 @@ HLRAction *h_lr_conflict(HArena *arena, HLRAction *action, HLRAction *new)
/* LR driver */
const HLRAction *
h_lr_lookup(const HLRTable *table, size_t state, const HCFChoice *symbol)
{
assert(state < table->nrows);
if(table->forall[state]) {
assert(h_hashtable_empty(table->rows[state])); // that would be a conflict
return table->forall[state];
} else {
return h_hashtable_get(table->rows[state], symbol);
}
}
HLREngine *h_lrengine_new(HArena *arena, HArena *tarena, const HLRTable *table,
const HInputStream *stream)
{
@ -218,6 +206,36 @@ HLREngine *h_lrengine_new(HArena *arena, HArena *tarena, const HLRTable *table,
return engine;
}
static const HLRAction *
terminal_lookup(const HLREngine *engine, const HCFChoice *symbol)
{
const HLRTable *table = engine->table;
size_t state = engine->state;
assert(state < table->nrows);
if(table->forall[state]) {
assert(h_hashtable_empty(table->rows[state])); // that would be a conflict
return table->forall[state];
} else {
return h_hashtable_get(table->rows[state], symbol);
}
}
static const HLRAction *
nonterminal_lookup(const HLREngine *engine, const HCFChoice *symbol)
{
const HLRTable *table = engine->table;
size_t state = engine->state;
assert(state < table->nrows);
if(table->forall[state]) {
assert(h_hashtable_empty(table->rows[state])); // that would be a conflict
return table->forall[state];
} else {
return h_hashtable_get(table->rows[state], symbol);
}
}
const HLRAction *h_lrengine_action(const HLREngine *engine)
{
HArena *tarena = engine->tarena;
@ -235,7 +253,7 @@ const HLRAction *h_lrengine_action(const HLREngine *engine)
x->chr = c;
}
return h_lr_lookup(engine->table, engine->state, x);
return terminal_lookup(engine, x);
}
static HParsedToken *consume_input(HLREngine *engine)
@ -308,7 +326,7 @@ static bool h_lrengine_step_(HLREngine *engine, const HLRAction *action)
// this is LR, building a right-most derivation bottom-up, so no reduce can
// follow a reduce. we can also assume no conflict follows for GLR if we
// use LALR tables, because only terminal symbols (lookahead) get reduces.
const HLRAction *shift = h_lr_lookup(engine->table, engine->state, symbol);
const HLRAction *shift = nonterminal_lookup(engine, symbol);
if(shift == NULL)
return false; // parse error
assert(shift->type == HLR_SHIFT);