A world-class math input for the web
pulljosh.com
1import {
2 CaretNode,
3 CaretParser,
4 CaretPrefixParselet,
5 TokensTag,
6} from "@caret-js/core";
7import { CharToken } from "@caret-js/core";
8import { PositiveNode } from "../nodes/positive";
9
10// This parselet looks for a sequence of `CharToken`s that form a decimal number,
11// meaning it has digits, optionally a single decimal point, and more digits. The digits
12// are optional on either side of the decimal point, but at least one digit must be present.
13
14export class UnaryPlusParselet extends CaretPrefixParselet {
15 parse(parser: CaretParser): CaretNode {
16 const token = parser.consume();
17 this.assert(
18 token instanceof CharToken && token.char === "+",
19 "Expected '+' token"
20 );
21
22 const child = parser.parseMinBP(this);
23 return PositiveNode.from(child).addTag(new TokensTag([token]));
24 }
25}