50 lines
1.1 KiB
TypeScript
50 lines
1.1 KiB
TypeScript
import type { Token } from "./lexer.ts";
|
|
|
|
export function scan_string(input: string, starting_position: number): [Token, number] {
|
|
let value = "\"";
|
|
let pos = starting_position + 1;
|
|
|
|
while (pos < input.length) {
|
|
const c = input[pos];
|
|
|
|
if (c === "\"") {
|
|
value += c;
|
|
pos += 1;
|
|
break;
|
|
}
|
|
if (c === "\n") {
|
|
// todo: error handling, return an error indicator and the caller should render a red wavy underline
|
|
break;
|
|
}
|
|
if (c === "\\") {
|
|
const next_char = input[pos + 1];
|
|
value += handle_escape_char(next_char);
|
|
pos += 2;
|
|
continue;
|
|
}
|
|
|
|
value += c;
|
|
pos += 1;
|
|
}
|
|
|
|
return [{ v: value, token_type: "string" }, pos];
|
|
}
|
|
|
|
function handle_escape_char(next_char: string): string {
|
|
switch (next_char) {
|
|
case "n":
|
|
return "\\n"
|
|
case "t":
|
|
return "\\t"
|
|
case "r":
|
|
return "\\r"
|
|
case "\"":
|
|
return "\\\""
|
|
case "\\":
|
|
return "\\\\"
|
|
default:
|
|
return "\\" + next_char
|
|
}
|
|
}
|
|
|