--- /dev/null
+#include <grammar.h>
+#include <stdlib.h>
+
+enum { PARSER_SHIFT, PARSER_REDUCE, PARSER_ACCEPT };
+
+struct _transition_t
+{
+ gint action;
+ gint state;
+ symbol_t* left;
+ rule_t* right;
+};
+
+struct _lr1_t
+{
+ nextcb cb;
+ gpointer data;
+ GHashTable* table;
+ GList* stack;
+};
+
+typedef struct
+{
+ gint state;
+ gpointer attrib;
+} state_t;
+
+transition_t* transition_shift_new (gint state)
+{
+ transition_t* transition;
+ transition = g_malloc (sizeof (transition_t));
+ transition->action = PARSER_SHIFT;
+ transition->state = state;
+ transition->left = NULL;
+ transition->right = NULL;
+ return transition;
+}
+
+transition_t* transition_reduce_new (symbol_t* left, rule_t* right)
+{
+ transition_t* transition;
+ transition = g_malloc (sizeof (transition_t));
+ transition->action = PARSER_REDUCE;
+ transition->state = 0;
+ transition->left = left;
+ transition->right = right;
+ return transition;
+}
+
+transition_t* transition_accept_new ()
+{
+ transition_t* transition;
+ transition = g_malloc (sizeof (transition_t));
+ transition->action = PARSER_ACCEPT;
+ transition->state = 0;
+ transition->left = NULL;
+ transition->right = NULL;
+ return transition;
+}
+
+void transition_delete (transition_t* transition)
+{
+ if (transition->left != NULL)
+ g_free (transition->left);
+ if (transition->right != NULL)
+ rule_delete (transition->right);
+ g_free (transition);
+}
+
+static void lr1_push (lr1_t* parser, gint st, gpointer attrib)
+{
+ state_t* state;
+ state = g_malloc (sizeof (state_t));
+ state->state = st;
+ state->attrib = attrib;
+ parser->stack = g_list_prepend (parser->stack, state);
+}
+
+static gboolean lr1_pop (lr1_t* parser, gpointer* attrib)
+{
+
+ GList* l;
+ state_t* state;
+ if ((l = g_list_first (parser->stack)) == NULL)
+ return FALSE;
+ parser->stack = g_list_remove_link (l, l);
+ state = (state_t*) l->data;
+ if (attrib)
+ *attrib = state->attrib;
+ g_free (state);
+ g_list_free (l);
+ return TRUE;
+
+}
+
+lr1_t* lr1_new (nextcb cb, gpointer data)
+{
+
+ lr1_t* parser;
+
+ parser = g_malloc (sizeof (lr1_t));
+ parser->cb = cb;
+ parser->data = data;
+
+ parser->stack = NULL;
+ lr1_push (parser, 0, NULL);
+ parser->table = g_hash_table_new_full (g_direct_hash, g_direct_equal,
+ NULL, g_hash_table_destroy);
+
+ return parser;
+
+}
+
+void lr1_delete (lr1_t* parser)
+{
+
+ GList* l;
+
+ for (l = g_list_first (parser->stack); l != NULL; l = g_list_next (l))
+ {
+ g_free (l->data);
+ }
+
+ g_list_free (parser->stack);
+
+ g_hash_table_destroy (parser->table);
+
+ g_free (parser);
+
+}
+
+gboolean lr1_add (lr1_t* parser, gint state, symbol_t* symbol,
+ transition_t* transition)
+{
+
+ GHashTable* table;
+
+ if (!g_hash_table_lookup_extended (parser->table, GINT_TO_POINTER(state),
+ NULL, (gpointer*) &table))
+ {
+ table = g_hash_table_new_full (symbol_hash, symbol_equal,
+ g_free, transition_delete);
+ g_hash_table_insert (parser->table, GINT_TO_POINTER(state), table);
+ }
+
+ if (g_hash_table_lookup_extended (table, symbol, NULL, NULL))
+ {
+ return FALSE;
+ }
+
+ g_hash_table_insert (table, symbol, transition);
+ return TRUE;
+
+}
+
+gboolean lr1_lookup (lr1_t* parser, gint state, symbol_t* symbol,
+ transition_t** transition)
+{
+
+ GHashTable* table;
+ transition_t* trans;
+
+ if (!g_hash_table_lookup_extended (parser->table, GINT_TO_POINTER(state),
+ NULL, (gpointer*) &table))
+ {
+ return FALSE;
+ }
+
+ if (!g_hash_table_lookup_extended (table, symbol,
+ NULL, (gpointer*) &trans))
+ {
+ return FALSE;
+ }
+
+ if (transition)
+ *transition = trans;
+
+ return TRUE;
+
+}
+
+static gpointer leaf_new (gpointer data)
+{
+ return g_node_new (data);
+}
+
+static gpointer tree_new (rule_t* rule)
+{
+ return g_node_new (rule);
+}
+
+static gpointer tree_add (gpointer tree, gpointer data)
+{
+ return g_node_prepend (tree, data);
+}
+
+gpointer lr1_build (lr1_t* parser)
+{
+
+ state_t* state;
+ symbol_t* symbol;
+ transition_t* transition;
+ gpointer attrib;
+ GList* l;
+
+ symbol = g_malloc (sizeof (symbol_t));
+
+ symbol->value = parser->cb (parser->data, &attrib);
+ symbol->terminal = TRUE;
+
+ while (1)
+ {
+
+ l = g_list_first (parser->stack);
+ state = (state_t*) l->data;
+ if (!lr1_lookup (parser, state->state, symbol, &transition))
+ return NULL;
+
+ if (transition->action == PARSER_SHIFT)
+ {
+ gint st;
+ lr1_push (parser, transition->state, leaf_new (attrib));
+ symbol->value = parser->cb (parser->data, &attrib);
+ symbol->terminal = TRUE;
+ }
+
+ else if (transition->action == PARSER_REDUCE)
+ {
+
+ state_t* state;
+ transition_t* trans;
+ GList* l;
+ gpointer attrib;
+
+ attrib = tree_new (symbol_copy (transition->left));
+
+ for (l = grammar_get_rule (transition->right);
+ l != NULL;
+ l = g_list_previous (l))
+ {
+ gpointer attr;
+ if (!lr1_pop (parser, &attr))
+ return NULL;
+ tree_add (attrib, attr);
+ }
+
+ l = g_list_first (parser->stack);
+ state = (state_t*) l->data;
+ lr1_lookup (parser, state->state, transition->left, &trans);
+ lr1_push (parser, trans->state, attrib);
+
+ }
+
+ else if (transition->action == PARSER_ACCEPT)
+ {
+ l = g_list_first (parser->stack);
+ state = (state_t*) l->data;
+ return state->attrib;
+ }
+
+ }
+
+ return NULL;
+
+}