init commit

node_modules/@jet/environment/json/reader/object-cursor.js

@@ -0,0 +1,119 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.ObjectCursor = void 0;
+const optional_1 = require("../../types/optional");
+const clone_1 = require("../../util/clone");
+const key_path_1 = require("./key-path");
+const traverse_1 = require("./traverse");
+class ObjectCursor {
+    /**
+     * Create a cursor for an object.
+     *
+     * @param root - An object to traverse.
+     */
+    constructor(root) {
+        this.values = [root];
+        this.keyPaths = [key_path_1.thisKeyPath];
+        this.savedDepths = [];
+    }
+    /**
+     * The current value this cursor is pointing at.
+     */
+    get currentValue() {
+        return this.values[this.values.length - 1];
+    }
+    /**
+     * The key path of the value this cursor is pointing at.
+     */
+    get currentKeyPath() {
+        return this.keyPaths[this.keyPaths.length - 1];
+    }
+    /**
+     * Advance this cursor to a given value and the key path which
+     * was used to reach it.
+     *
+     * Use this method to override the internal traversal logic of
+     * the cursor as needed. Like `moveTo`, calls to this method can
+     * be balanced with calls to `back`.
+     *
+     * @param value - The new value for the cursor to represent.
+     * @param keyPath - The key path used to reach the value.
+     */
+    interject(value, keyPath) {
+        this.values.push(value);
+        this.keyPaths.push(keyPath);
+    }
+    /**
+     * Reconfigure this cursor to traverse a given object.
+     *
+     * @param newRoot - The new root object to traverse.
+     * @param keyPath - The key path specifying where the root object came from.
+     * Typically this should be `thisKeyPath` (the default value for this parameter.)
+     */
+    reuse(newRoot, keyPath = key_path_1.thisKeyPath) {
+        this.values.length = 0;
+        this.values.push(newRoot);
+        this.keyPaths.length = 0;
+        this.keyPaths.push(keyPath);
+        this.savedDepths.length = 0;
+    }
+    /**
+     * Advance this cursor to a new position in the object it is traversing,
+     * saving its previous position so that the cursor may be moved back.
+     *
+     * @param keyPath - A key path referring to a location in the cursor's current value.
+     * @returns The new current value of the cursor.
+     */
+    moveTo(keyPath) {
+        const newValue = (0, traverse_1.traverse)(this.currentValue, keyPath);
+        this.values.push(newValue);
+        this.keyPaths.push(keyPath);
+        return newValue;
+    }
+    /**
+     * Rewind this cursor to its previous position in the object it is traversing.
+     */
+    moveBack() {
+        const currentDepth = this.values.length;
+        if (currentDepth === 1) {
+            throw new Error("Cannot move back past the root of a cursor");
+        }
+        const numberOfSaves = this.savedDepths.length;
+        if (numberOfSaves > 0 && currentDepth <= this.savedDepths[numberOfSaves - 1]) {
+            throw new Error("Cannot move back past the most recent saved state");
+        }
+        this.values.pop();
+        this.keyPaths.pop();
+    }
+    /**
+     * Save the current position of this cursor so that it may be restored later.
+     *
+     * Calls to this method must be balanced with a call to `restoreState`.
+     */
+    saveState() {
+        this.savedDepths.push(this.values.length);
+    }
+    /**
+     * Restore this cursor's position to a previously saved state.
+     *
+     * Use this method to balance a previous call to `saveState`.
+     */
+    restoreState() {
+        const savedLength = this.savedDepths.pop();
+        if ((0, optional_1.isNothing)(savedLength)) {
+            throw new Error("Calls to restoreState must balance previous calls to saveState");
+        }
+        this.values.length = savedLength;
+        this.keyPaths.length = savedLength;
+    }
+    // section Cloneable
+    clone() {
+        const copy = (0, clone_1.shallowCloneOf)(this);
+        copy.values = this.values.slice();
+        copy.keyPaths = this.keyPaths.slice();
+        copy.savedDepths = this.savedDepths.slice();
+        return copy;
+    }
+}
+exports.ObjectCursor = ObjectCursor;
+//# sourceMappingURL=object-cursor.js.map