A world-class math input for the web
pulljosh.com
1import { CaretNode, h, t, VNode } from "@caret-js/core";
2import { DecimalNode } from "./decimal";
3import { MathExpressionTag } from "../tags/mathExpression";
4import { CanBeAdjacentMultRightSideTag } from "../parselets/adjacentMultiplication";
5import { ParenthesesChildTag } from "../parselets/parentheses";
6
7export class NegativeNode extends CaretNode {
8 constructor(public child: CaretNode) {
9 super();
10 this.addTag(new MathExpressionTag()).addTag(
11 new CanBeAdjacentMultRightSideTag(false) // Negative nodes cannot be on the right side of adjacent multiplication (that would just be subtraction)
12 );
13 }
14
15 static from(child: CaretNode): NegativeNode | DecimalNode {
16 if (
17 child instanceof DecimalNode &&
18 !child.value.startsWith("-") &&
19 !child.hasTag(ParenthesesChildTag)
20 ) {
21 return new DecimalNode(`-${child.value}`);
22 }
23
24 return new NegativeNode(child);
25 }
26
27 toDebugMathML(): VNode {
28 return h("mrow", {}, h("mo", {}, t("-")), this.child.toDebugMathML());
29 }
30}