Add grn_expr_get_keywords()

It gets keywords from expression. TODO: Document it.
groonga · Aug 9, 2014 · 99886d9 · 99886d9
1 parent 1789121
commit 99886d9
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diff --git a/include/groonga.h b/include/groonga.h
@@ -1748,6 +1748,8 @@ GRN_API grn_rc grn_expr_snip_add_conditions(grn_ctx *ctx,
                                             const char **closetags,
                                             unsigned int *closetag_lens);
 
+GRN_API grn_rc grn_expr_get_keywords(grn_ctx *ctx, grn_obj *expr, grn_obj *got_keywords);
+
 GRN_API grn_table_sort_key *grn_table_sort_key_from_str(grn_ctx *ctx,
                                                         const char *str, unsigned int str_size,
                                                         grn_obj *table, unsigned int *nkeys);

diff --git a/lib/expr.c b/lib/expr.c
@@ -7000,3 +7000,44 @@ grn_expr_syntax_escape_query(grn_ctx *ctx, const char *query, int query_size,
                                 target_characters, GRN_QUERY_ESCAPE,
                                 escaped_query);
 }
+
+grn_rc
+grn_expr_get_keywords(grn_ctx *ctx, grn_obj *expr, grn_obj *got_keywords)
+{
+  int i, n;
+  scan_info **sis, *si;
+  GRN_API_ENTER;
+  if ((sis = scan_info_build(ctx, expr, &n, GRN_OP_OR, 0))) {
+    int butp = 0, nparens = 0, npbut = 0;
+    grn_obj but_stack;
+    GRN_UINT32_INIT(&but_stack, GRN_OBJ_VECTOR);
+    for (i = n; i--;) {
+      si = sis[i];
+      if (si->flags & SCAN_POP) {
+        nparens++;
+        if (si->logical_op == GRN_OP_AND_NOT) {
+          GRN_UINT32_PUT(ctx, &but_stack, npbut);
+          npbut = nparens;
+          butp = 1 - butp;
+        }
+      } else {
+        if (si->op == GRN_OP_MATCH && si->query) {
+          if (butp == (si->logical_op == GRN_OP_AND_NOT)) {
+            GRN_PTR_PUT(ctx, got_keywords, si->query);
+          }
+        }
+        if (si->flags & SCAN_PUSH) {
+          if (nparens == npbut) {
+            butp = 1 - butp;
+            GRN_UINT32_POP(&but_stack, npbut);
+          }
+          nparens--;
+        }
+      }
+    }
+    GRN_OBJ_FIN(ctx, &but_stack);
+    for (i = n; i--;) { SI_FREE(sis[i]); }
+    GRN_FREE(sis);
+  }
+  GRN_API_RETURN(GRN_SUCCESS);
+}