feat(visitor): deep first traverse

Soontao · Jul 9, 2020 · 8bd49bf · 8bd49bf
1 parent b02f276
commit 8bd49bf
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Showing 2 changed files with 44 additions and 8 deletions.
diff --git a/src/visitor.ts b/src/visitor.ts
@@ -35,10 +35,32 @@ export function traverseAst(traverser: Traverser, node: Token | Array<any> | Obj
       traverseAst(traverser, item);
     });
   }
+
 }
 
-export function createTraverser(traverser: Traverser) {
-  return function t(node: Token | Array<any> | Object): void {
-    traverseAst(traverser, node);
+export function traverseAstDeepFirst(traverser: Traverser, node: Token | Array<any> | Object): void {
+
+  if (isPlainObject(node) || isArray(node) || node instanceof Token) {
+    // @ts-ignore
+    forEach(node, (item) => {
+      traverseAstDeepFirst(traverser, item);
+    });
+  }
+
+  if (node instanceof Token) {
+    if (node.type in traverser) {
+      traverser[node.type](node);
+    }
+  }
+
+}
+
+export function createTraverser(traverser: Traverser, deepFirst = false) {
+  return (node: Token | Array<any> | Object): void => {
+    if (deepFirst) {
+      traverseAstDeepFirst(traverser, node);
+    } else {
+      traverseAst(traverser, node);
+    }
   };
 }
diff --git a/test/visitor.spec.ts b/test/visitor.spec.ts
@@ -4,7 +4,7 @@ describe('Visitor Parse Suite', () => {
 
   const createSeqTokenProcessor = (key: string, arr: Array<any>) => () => arr.push(key);
 
-  const createSeqTraverser = () => {
+  const createSeqTraverser = (deepFirst = false) => {
     const visitSequence = [];
 
     const visit = createTraverser({
@@ -19,17 +19,17 @@ describe('Visitor Parse Suite', () => {
       AndExpression: createSeqTokenProcessor('and', visitSequence),
       BoolParenExpression: createSeqTokenProcessor('paren', visitSequence),
       EqualsExpression: createSeqTokenProcessor('eq', visitSequence),
-      Literal: createSeqTokenProcessor('lit', visitSequence),
-      FirstMemberExpression: createSeqTokenProcessor('mem', visitSequence)
-    });
+      OrExpression: createSeqTokenProcessor('or', visitSequence),
+      Literal: createSeqTokenProcessor('lit', visitSequence)
+    }, deepFirst);
 
     return { visit, visitSequence };
   };
 
 
   it('should visit filter', () => {
 
-    const expectedSeq = ['and', 'paren', 'eq', 'mem', 'lit', 'paren', 'eq', 'mem', 'lit'];
+    const expectedSeq = ['and', 'paren', 'eq', 'lit', 'paren', 'eq', 'lit'];
 
     const { visit, visitSequence } = createSeqTraverser();
 
@@ -41,4 +41,18 @@ describe('Visitor Parse Suite', () => {
 
   });
 
+  it('should visit filter deep first', () => {
+
+    const expectedSeq = ['lit', 'eq', 'lit', 'eq', 'or', 'paren', 'lit', 'eq', 'paren', 'and'];
+
+    const { visit, visitSequence } = createSeqTraverser(true);
+
+    const node = defaultParser.filter('(A eq 2 or A eq 3) and (V eq 3)');
+
+    visit(node);
+
+    expect(visitSequence).toEqual(expectedSeq);
+
+  });
+
 });