merge: avoid using the `/v` modifier (#5)

Reviewed-on: https://git.joinsharkey.org/Sharkey/sfm.js/pulls/5

src/internal/core/index.ts

@@ -181,6 +181,18 @@ export function notMatch(parser: Parser<any>): Parser<null> {
 	});
 }
 
+export function difference(parserIncluded: Parser<any>, parserExcluded: Parser<any>): Parser<string> {
+	return new Parser((input, index, state) => {
+		const exclude = parserExcluded.handler(input, index, state);
+
+		if (exclude.success) {
+			return failure();
+		}
+
+		return parserIncluded.handler(input, index, state);
+	});
+}
+
 export const cr = str('\r');
 export const lf = str('\n');
 export const crlf = str('\r\n');

src/internal/parser.ts

@@ -12,7 +12,7 @@ import twemojiRegex from '@twemoji/parser/dist/lib/regex';
 type ArgPair = { k: string, v: string | true };
 type Args = Record<string, string | true>;
 
-const space = P.regexp(/[\s--[\n\r]]/v);
+const space = P.difference(P.regexp(/\s/), P.newline);
 const alphaAndNum = P.regexp(/\p{Letter}|\p{Number}/iu);
 const newLine = P.alt([P.crlf, P.cr, P.lf]);
 

test/core.ts

+import assert from 'assert';
+import * as P from '../src/internal/core';
+
+describe('core', () => {
+	describe('difference', () => {
+		test('basic', () => {
+			const parser = P.difference(P.regexp(/\p{Letter}/u), P.str('x'));
+
+			let result = parser.handler('x',0,{}) as P.Success<any>;
+			assert.deepStrictEqual(result,P.failure());
+
+			result = parser.handler('a',0,{}) as P.Success<any>;
+			assert.deepStrictEqual(result,P.success(1,'a'));
+		});
+
+		test('horizontal whitespace', () => {
+			const parser = P.difference(P.regexp(/\s/u), P.newline);
+
+			let result = parser.handler('\n',0,{}) as P.Success<any>;
+			assert.deepStrictEqual(result,P.failure());
+
+			result = parser.handler(' ',0,{}) as P.Success<any>;
+			assert.deepStrictEqual(result,P.success(1,' '));
+
+			result = parser.handler('\t',0,{}) as P.Success<any>;
+			assert.deepStrictEqual(result,P.success(1,'\t'));
+		});
+
+	});
+});