syndicate-js/packages/core/src/syntax/tokens.ts

86 lines
2.0 KiB
TypeScript

import { Pos, startPos } from './position.js';
export enum TokenType {
SPACE,
NEWLINE,
ATOM,
STRING,
OPEN,
CLOSE,
}
export interface Token {
type: TokenType;
start: Pos;
end: Pos;
text: string;
}
export interface Group {
start: Token;
end: Token | null;
items: Items;
}
export type Item = Token | Group;
export type Items = Array<Item>;
export function makeToken(text: string, name?: string | null, type: TokenType = TokenType.ATOM): Token {
const p = startPos(name ?? null);
return {
start: p,
end: p,
type,
text
};
}
export function makeGroup(start: Token, items: Array<Items>, end?: Token) {
return { start, end: end ?? null, items };
}
export function isSpace(i: Item): i is Token {
return isTokenType(i, TokenType.SPACE) || isTokenType(i, TokenType.NEWLINE);
}
export function isGroup(i: Item): i is Group {
return i && ('items' in i);
}
export function isToken(i: Item): i is Token {
return i && ('type' in i);
}
export function isTokenType(i: Item, t: TokenType): i is Token {
return isToken(i) && i.type === t;
}
export type ItemTextOptions = {
missing?: string,
color?: boolean,
};
export function itemText(i: Items, options: ItemTextOptions = {}): string {
const walkItems = (i: Items): string => i.map(walk).join('');
const walk = (i: Item): string => {
if (isGroup(i)) {
return walk(i.start) + walkItems(i.items) + (i.end ? walk(i.end) : options.missing ?? '');
} else {
if (options.color ?? false) {
switch (i.type) {
case TokenType.SPACE:
case TokenType.NEWLINE:
return '\x1b[31m' + i.text + '\x1b[0m';
case TokenType.STRING:
return '\x1b[34m' + i.text + '\x1b[0m';
default:
return i.text;
}
} else {
return i.text;
}
}
};
return walkItems(i);
}