antlr-ng/dist/src/tree/TreeVisitor.js

Next generation ANTLR Tool

var __defProp = Object.defineProperty;
var __name = (target, value) => __defProp(target, "name", { value, configurable: true });
class TreeVisitor {
  static {
    __name(this, "TreeVisitor");
  }
  /**
   * Visit every node in tree t and trigger an action for each node before/after having visited all of its children.
   * Execute both actions even if t has no children. If a child visit yields a new child, it can update its
   * parent's child list or just return the new child. The  child update code works even if the child visit
   * alters its parent and returns the new tree.
   *
   * @param t The tree to visit.
   * @param action The action to trigger for each node.
   *
   * @returns The result of applying post action to this node.
   */
  visit(t, action) {
    const isNil = t.isNil();
    if (action && !isNil) {
      t = action.pre(t);
    }
    for (let i = 0; i < t.children.length; i++) {
      const child = t.children[i];
      const visitResult = this.visit(child, action);
      if (visitResult !== child) {
        t.setChild(i, visitResult);
      }
    }
    if (action && !isNil) {
      t = action.post(t);
    }
    return t;
  }
}
export {
  TreeVisitor
};