70 lines
1.8 KiB
JavaScript
70 lines
1.8 KiB
JavaScript
// Placeholders
|
|
/*jslint browser: true, unparam: true, vars: true, maxerr: 50, indent: 4 */
|
|
(function (baselib) {
|
|
'use strict';
|
|
var exports = {};
|
|
baselib.placeholders = exports;
|
|
|
|
|
|
// Placeholders: same thing as boxes. Distinct type just to support make-reader-graph.
|
|
|
|
var Placeholder = function (x, mutable) {
|
|
this.val = x;
|
|
};
|
|
|
|
Placeholder.prototype.ref = function () {
|
|
return this.val;
|
|
};
|
|
|
|
Placeholder.prototype.set = function (newVal) {
|
|
this.val = newVal;
|
|
};
|
|
|
|
Placeholder.prototype.toString = function (cache) {
|
|
return "#<placeholder>";
|
|
};
|
|
|
|
Placeholder.prototype.toWrittenString = function (cache) {
|
|
return "#<placeholder>";
|
|
};
|
|
|
|
Placeholder.prototype.toDisplayedString = function (cache) {
|
|
return "#<placeholder>";
|
|
};
|
|
|
|
Placeholder.prototype.toDomNode = function (cache) {
|
|
var parent = document.createElement("span");
|
|
parent.appendChild(document.createTextNode('#<placeholder>'));
|
|
return parent;
|
|
};
|
|
|
|
Placeholder.prototype.equals = function (other, aUnionFind) {
|
|
return ((other instanceof Placeholder) &&
|
|
baselib.equality.equals(this.val, other.val, aUnionFind));
|
|
};
|
|
|
|
Placeholder.prototype.hashCode = function(depth) {
|
|
var k = baselib.hashes.hashCode("Placeholder");
|
|
k += baselib.hashes.hashCode(this.val, depth);
|
|
return baselib.hashes.hashMix(k);
|
|
};
|
|
|
|
|
|
var makePlaceholder = function(v) {
|
|
return new Placeholder(v);
|
|
};
|
|
|
|
var isPlaceholder = function (x) {
|
|
return x instanceof Placeholder;
|
|
};
|
|
|
|
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
exports.Placeholder = Placeholder;
|
|
exports.makePlaceholder = makePlaceholder;
|
|
exports.isPlaceholder = isPlaceholder;
|
|
|
|
|
|
|
|
}(this.plt.baselib)); |