45 lines
1.4 KiB
TypeScript
45 lines
1.4 KiB
TypeScript
import type { Token } from "./lexer.ts";
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import { is_identifier_char } from "./utils.ts";
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/**
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* Scans an identifier, at the given position in the input string.
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* This function assumes that the character at the given position is a letter.
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*
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* @param input the input string
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* @param starting_position the position to start scanning from
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* @param is_datatype whether the identifier is a datatype
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*/
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export function scan_identifier(input: string, starting_position: number, is_datatype = false): [Token, number] {
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let value = input[starting_position];
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let pos = starting_position + 1;
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while (pos < input.length) {
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const c = input[pos];
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if (is_identifier_char(c)) {
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pos += 1;
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value += c;
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}
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else {
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break;
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}
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}
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if (is_datatype) {
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return [{ v: value, token_type: "class-name" }, pos];
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}
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else {
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return [{ v: value, token_type: check_keyword(value) }, pos];
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}
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}
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function check_keyword(value: string): string {
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const keywords = ["case", "static", "const", "enum", "loop", "use", "break", "catch", "continue", "do", "else", "finally", "for", "fun", "if", "in", "fn", "nil", "return", "throw", "try", "while", "type", "match", "with", "of", "abstract", "class", "interface", "private", "pub", "override", "open", "init", "val", "var", "mut", "clone"];
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if (keywords.includes(value)) {
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return "keyword";
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}
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return "identifier";
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}
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