wasm: Allow arbitrary predicates in queries

lib/binding_web/binding.js

@@ -44,6 +44,8 @@ class Parser {
   delete() {
     C._ts_parser_delete(this[0]);
     C._free(this[1]);
+    this[0] = 0;
+    this[1] = 0;
   }
 
   setLanguage(language) {
@@ -163,6 +165,7 @@ class Tree {
 
   delete() {
     C._ts_tree_delete(this[0]);
+    this[0] = 0;
   }
 
   edit(edit) {
@@ -506,6 +509,7 @@ class TreeCursor {
   delete() {
     marshalTreeCursor(this);
     C._ts_tree_cursor_delete_wasm(this.tree[0]);
+    this[0] = this[1] = this[2] = 0;
   }
 
   reset(node) {
@@ -716,6 +720,7 @@ class Language {
     const assertedProperties = new Array(patternCount);
     const refutedProperties = new Array(patternCount);
     const predicates = new Array(patternCount);
+    const textPredicates = new Array(patternCount);
     for (let i = 0; i < patternCount; i++) {
       const predicatesAddress = C._ts_query_predicates_for_pattern(
         address,
@@ -725,6 +730,7 @@ class Language {
       const stepCount = getValue(TRANSFER_BUFFER, 'i32');
 
       predicates[i] = [];
+      textPredicates[i] = [];
 
       const steps = [];
       let stepAddress = predicatesAddress;
@@ -756,7 +762,7 @@ class Language {
               if (steps[2].type === 'capture') {
                 const captureName1 = steps[1].name;
                 const captureName2 = steps[2].name;
-                predicates[i].push(function(captures) {
+                textPredicates[i].push(function(captures) {
                   let node1, node2
                   for (const c of captures) {
                     if (c.name === captureName1) node1 = c.node;
@@ -767,7 +773,7 @@ class Language {
               } else {
                 const captureName = steps[1].name;
                 const stringValue = steps[2].value;
-                predicates[i].push(function(captures) {
+                textPredicates[i].push(function(captures) {
                   for (const c of captures) {
                     if (c.name === captureName) {
                       return (c.node.text === stringValue) === isPositive;
@@ -790,7 +796,7 @@ class Language {
               );
               const captureName = steps[1].name;
               const regex = new RegExp(steps[2].value);
-              predicates[i].push(function(captures) {
+              textPredicates[i].push(function(captures) {
                 for (const c of captures) {
                   if (c.name === captureName) return regex.test(c.node.text);
                 }
@@ -823,7 +829,7 @@ class Language {
               break;
 
             default:
-              throw new Error(`Unknown query predicate \`#${steps[0].value}\``);
+              predicates[i].push({operator, operands: steps.slice(1)});
           }
 
           steps.length = 0;
@@ -840,6 +846,7 @@ class Language {
       INTERNAL,
       address,
       captureNames,
+      textPredicates,
       predicates,
       Object.freeze(setProperties),
       Object.freeze(assertedProperties),
@@ -888,12 +895,13 @@ class Language {
 
 class Query {
   constructor(
-    internal, address, captureNames, predicates,
+    internal, address, captureNames, textPredicates, predicates,
     setProperties, assertedProperties, refutedProperties
   ) {
     assertInternal(internal);
     this[0] = address;
     this.captureNames = captureNames;
+    this.textPredicates = textPredicates;
     this.predicates = predicates;
     this.setProperties = setProperties;
     this.assertedProperties = assertedProperties;
@@ -902,6 +910,7 @@ class Query {
 
   delete() {
     C._ts_query_delete(this[0]);
+    this[0] = 0;
   }
 
   matches(node, startPosition, endPosition) {
@@ -932,7 +941,7 @@ class Query {
 
       const captures = new Array(captureCount);
       address = unmarshalCaptures(this, node.tree, address, captures);
-      if (this.predicates[pattern].every(p => p(captures))) {
+      if (this.textPredicates[pattern].every(p => p(captures))) {
         result[i] = {pattern, captures};
         const setProperties = this.setProperties[pattern];
         if (setProperties) result[i].setProperties = setProperties;
@@ -979,7 +988,7 @@ class Query {
       captures.length = captureCount
       address = unmarshalCaptures(this, node.tree, address, captures);
 
-      if (this.predicates[pattern].every(p => p(captures))) {
+      if (this.textPredicates[pattern].every(p => p(captures))) {
         const capture = captures[captureIndex];
         const setProperties = this.setProperties[pattern];
         if (setProperties) capture.setProperties = setProperties;
@@ -994,6 +1003,10 @@ class Query {
     C._free(startAddress);
     return result;
   }
+
+  predicatesForPattern(patternIndex) {
+    return this.predicates[patternIndex]
+  }
 }
 
 function getText(tree, startIndex, endIndex) {

lib/binding_web/test/query-test.js

@@ -45,9 +45,6 @@ describe("Query", () => {
       assert.throws(() => {
         JavaScript.query("((identifier) @a (eq? @a @a @a))");
       }, "Wrong number of arguments to `#eq?` predicate. Expected 2, got 3");
-      assert.throws(() => {
-        JavaScript.query("((identifier) @a (#something-else? @a))");
-      }, "Unknown query predicate `#something-else?`");
     });
   });
 
@@ -207,6 +204,52 @@ describe("Query", () => {
       ]);
     });
   });
+
+  describe(".predicatesForPattern(index)", () => {
+    it("returns all of the predicates as objects", () => {
+      query = JavaScript.query(`
+        (
+          (binary_expression
+            left: (identifier) @a
+            right: (identifier) @b)
+          (#something? @a @b)
+          (#match? @a "c")
+          (#something-else? @a "A" @b "B")
+        )
+
+        ((identifier) @c
+         (#hello! @c))
+
+        "if" @d
+      `);
+
+      assert.deepEqual(query.predicatesForPattern(0), [
+        {
+          operator: "something?",
+          operands: [
+            { type: "capture", name: "a" },
+            { type: "capture", name: "b" },
+          ],
+        },
+        {
+          operator: "something-else?",
+          operands: [
+            { type: "capture", name: "a" },
+            { type: "string", value: "A" },
+            { type: "capture", name: "b" },
+            { type: "string", value: "B" },
+          ],
+        },
+      ]);
+      assert.deepEqual(query.predicatesForPattern(1), [
+        {
+          operator: "hello!",
+          operands: [{ type: "capture", name: "c" }],
+        },
+      ]);
+      assert.deepEqual(query.predicatesForPattern(2), []);
+    });
+  });
 });
 
 function formatMatches(matches) {