1 files changed, 176 insertions, 0 deletions
diff --git a/src/cnp.c b/src/cnp.c
index 8c7c519..91a8df7 100644
--- a/src/cnp.c
+++ b/src/cnp.c
@@ -522,3 +522,179 @@ destroy_env(Environment *env)
   free(env->gi);
   free(env);
 }
+
+H_ATTR
+Environment *
+cnp_parse(Grammar *g, str *string)
+{
+  Environment *env = new_env(g, (str *) string);
+
+  if (crf_add_node(env_crfp(env), (pair2) { 0 })) goto cleanup;
+
+  nt_add(env, 0, 0);
+
+  CHECK_ENV_ERROR(env, goto cleanup;);
+
+  NUM current_grade = 0;
+
+  prodecor *current_prodecor = NULL;
+
+  Rule_group *rg = NULL;
+  List *right = NULL, *tnts = NULL;
+
+  NUM *num_string = NULL, num_string_len = 0;
+  BOOL errorp = 0;
+
+  env_str(env, &num_string, &num_string_len);
+
+  while ((current_prodecor =
+          pop_procr(env_r(env), env_u(env), &current_grade))) {
+    /* fleprintf("{ %ld, %ld, %ld, %ld, %ld }\n",
+     *           current_prodecor->x, current_prodecor->y,
+     *           current_prodecor->z, current_prodecor->w,
+     *           current_grade);
+     * print_procr(env_r(env)); */
+
+    /* different cases */
+
+    rg = grammar_rule(env_grammar(env), current_prodecor->x);
+    right = rg_nth(rg, current_prodecor->y);
+
+    /* separate the empty rules out */
+    if (list_length(right) == 0) {
+      errorp =
+        bsr_add(env_grammar(env), env_bsrp(env),
+                current_prodecor->x, current_prodecor->y, 0,
+                current_grade, current_grade, current_grade);
+
+      if (errorp) goto cleanup;
+
+      if (env_follow_p(env, current_prodecor->x,
+                       *(num_string+current_grade))) {
+        rtn(env, current_prodecor->x,
+            current_prodecor->w, current_grade);
+      }
+
+      goto continue_label;
+    }
+
+    /* fleprintf0("non empty rule\n"); */
+
+    /* if at the end of a rule, return if possible */
+    if (current_prodecor->z == list_length(right)) {
+      if (env_follow_p(env, current_prodecor->x,
+                       *(num_string+current_grade))) {
+        rtn(env, current_prodecor->x,
+            current_prodecor->w, current_grade);
+      }
+
+      goto continue_label;
+    }
+
+    /* fleprintf0("not at the end of the rule\n"); */
+
+    /* if at the start of a rule, no need for test_select */
+    if (current_prodecor->z == 0) {
+      /* fleprintf0("at the start of the rule\n"); */
+      current_prodecor->z = 1;
+
+      /* otherwise test select */
+    } else {
+      /* fleprintf0("start by test select\n"); */
+      tnts =
+        array_to_list(list_array(right)+current_prodecor->z,
+                      list_length(right)-current_prodecor->z);
+      if (test_select(env, *(num_string+current_grade),
+                      current_prodecor->x, tnts)) {
+        /* fleprintf0("successful test\n"); */
+        free(tnts);
+        tnts = NULL;
+        ++(current_prodecor->z);
+      } else {
+        /* fleprintf0("failed test\n"); */
+        free(tnts);
+        tnts = NULL;
+        goto continue_label;
+      }
+    }
+
+    CHECK_ENV_ERROR(env, goto cleanup;);
+
+    /* while there are terminals */
+    while (((TNT *) list_nth(right, current_prodecor->z-1))->type ==
+           TERMINAL) {
+      /* fleprintf0("found terminal\n"); */
+      /* add to BSR set */
+      errorp =
+        bsr_add(env_grammar(env), env_bsrp(env),
+                current_prodecor->x, current_prodecor->y,
+                current_prodecor->z, current_prodecor->w,
+                current_grade, current_grade+1);
+
+      if (errorp) goto cleanup;
+
+      current_grade++;
+
+      /* if at the end of the rule, return if possible */
+      if (current_prodecor->z == list_length(right)) {
+        if (env_follow_p(env, current_prodecor->x,
+                         *(num_string+current_grade))) {
+          /* fleprintf0("we choose to return\n"); */
+          rtn(env, current_prodecor->x,
+              current_prodecor->w, current_grade);
+          /* fleprintf0("hi\n"); */
+        }
+
+        goto continue_label;
+      }
+      /* fleprintf0("terminal not at the end\n"); */
+      /* else test select */
+      tnts =
+        array_to_list(list_array(right)+current_prodecor->z,
+                      list_length(right)-current_prodecor->z);
+      if (test_select(env, *(num_string+current_grade),
+                      current_prodecor->x, tnts)) {
+        /* fleprintf0("Successful test\n"); */
+        free(tnts);
+        tnts = NULL;
+        (current_prodecor->z)++;
+      } else {
+        /* fleprintf0("Failed test\n"); */
+        /* printf("next thing is "); */
+        /* print_tnt(list_nth(right, current_prodecor->z)); */
+        /* printf("\n"); */
+        free(tnts);
+        tnts = NULL;
+        goto continue_label;
+      }
+    }
+
+    /* fleprintf0("encountered non-terminal\n"); */
+
+    /* when a nonterminal is encountered, we call it */
+    cnp_call(env, (pair3) {
+        .x = current_prodecor->x,
+        .y = current_prodecor->y,
+        .z = current_prodecor->z
+      }, current_prodecor->w, current_grade);
+
+    /* fleprintf("after call { %ld, %ld, %ld, %ld, %ld }\n",
+     *           current_prodecor->x, current_prodecor->y,
+     *           current_prodecor->z, current_prodecor->w,
+     *           current_grade); */
+
+  continue_label:
+
+    CHECK_ENV_ERROR(env, goto cleanup;);
+
+    free(current_prodecor);
+  }
+
+  return env;
+
+ cleanup:
+
+  destroy_env(env);
+
+  return NULL;
+}