小数点の直後にドットが続くとエラーになるように

Author: takejohn

src/parser/scanner.ts

@@ -507,6 +507,9 @@ export class Scanner implements ITokenStream {
 		}
 		const decimalPoint = this.tryReadDecimalPoint(hasLeadingDot);
 		if (decimalPoint) {
+			if (this.stream.char === '.') {
+				throw new AiScriptSyntaxError('dot cannot follow a decimal point', this.stream.getPos());
+			}
 			while (!this.stream.eof as boolean && digit.test(this.stream.char as string)) {
 				fractional += this.stream.char;
 				this.stream.next();

test/syntax.ts

@@ -1,8 +1,8 @@
 import * as assert from 'assert';
-import { describe, test } from 'vitest';
+import { describe, expect, test } from 'vitest';
 import { utils } from '../src';
 import { NUM, STR, NULL, ARR, OBJ, BOOL, TRUE, FALSE, ERROR ,FN_NATIVE } from '../src/interpreter/value';
-import { AiScriptRuntimeError, AiScriptUnexpectedEOFError } from '../src/error';
+import { AiScriptRuntimeError, AiScriptSyntaxError, AiScriptUnexpectedEOFError } from '../src/error';
 import { exe, getMeta, eq } from './testutils';
 
 /*
@@ -1485,6 +1485,18 @@ describe('Infix expression', () => {
 			NUM(3)
 		);
 	});
+
+	test.concurrent('dot cannot follow a decimal point', async () => {
+		await expect(() => exe(`
+		<: 1..to_str()
+		`)).rejects.toThrow(AiScriptSyntaxError);
+	});
+
+	test.concurrent('dot following parenthesis after decimal point', async () => {
+		eq(await exe(`
+		<: (1.).to_str()
+		`), STR('1'));
+	});
 });
 
 describe('if', () => {