chore: update based on the PR suggestions

Author: jaworek

src/__tests__/characterClasses.test.tsx

@@ -1,4 +1,4 @@
-import { whitespace } from '../characterClasses';
+import { any, digit, whitespace, word } from '../characterClasses';
 import { buildPattern } from '../compiler';
 import { one } from '../quantifiers';
 
@@ -7,3 +7,21 @@ test('"whitespace" character class', () => {
   expect(buildPattern(one('ab'), whitespace())).toEqual(`ab\\s`);
   expect(buildPattern(one('ab'), whitespace(), one('c'))).toEqual(`ab\\sc`);
 });
+
+test('"digit" character class', () => {
+  expect(buildPattern(digit())).toEqual(`\\d`);
+  expect(buildPattern(one('ab'), digit())).toEqual(`ab\\d`);
+  expect(buildPattern(one('ab'), digit(), one('c'))).toEqual(`ab\\dc`);
+});
+
+test('"word" character class', () => {
+  expect(buildPattern(word())).toEqual(`\\w`);
+  expect(buildPattern(one('ab'), word())).toEqual(`ab\\w`);
+  expect(buildPattern(one('ab'), word(), one('c'))).toEqual(`ab\\wc`);
+});
+
+test('"any" character class', () => {
+  expect(buildPattern(any())).toEqual(`.`);
+  expect(buildPattern(one('ab'), any())).toEqual(`ab.`);
+  expect(buildPattern(one('ab'), any(), one('c'))).toEqual(`ab.c`);
+});

src/characterClasses.ts

@@ -1,5 +1,24 @@
-import type { Whitespace } from './types';
+import type { Any, Digit, Whitespace, Word } from './types';
 
 export function whitespace(): Whitespace {
-  return `\\s`;
+  return { type: 'whitespace' };
 }
+
+export function digit(): Digit {
+  return { type: 'digit' };
+}
+
+export function word(): Word {
+  return { type: 'word' };
+}
+
+export function any(): Any {
+  return { type: 'any' };
+}
+
+export const compilers = {
+  whitespace: '\\s',
+  digit: '\\d',
+  word: '\\w',
+  any: '.',
+};

src/compiler.ts

@@ -1,5 +1,6 @@
 import type { RegexElement } from './types';
 import { compilers as quantifiers } from './quantifiers';
+import { compilers as characterClasses } from './characterClasses';
 
 /**
  * Generate RegExp object for elements.
@@ -32,11 +33,15 @@ function compileSingle(elements: RegexElement): string {
     return elements;
   }
 
-  const elementCompiler = quantifiers[elements.type];
-  if (!elementCompiler) {
-    throw new Error(`Unknown elements type ${elements.type}`);
+  if ('children' in elements) {
+    const elementCompiler = quantifiers[elements.type];
+    if (!elementCompiler) {
+      throw new Error(`Unknown elements type ${elements.type}`);
+    }
+
+    const children = compileList(elements.children);
+    return elementCompiler(children);
   }
 
-  const children = compileList(elements.children);
-  return elementCompiler(children);
+  return characterClasses[elements.type];
 }

src/types.ts

@@ -1,11 +1,17 @@
 export type RegexElement = string | RegexCharacterClass | RegexQuantifier;
 
-export type RegexCharacterClass = Whitespace;
+export type RegexCharacterClass = Whitespace | Digit | Word | Any;
 
 export type RegexQuantifier = One | OneOrMore | Optionally | ZeroOrMore;
 
 // Character classes
-export type Whitespace = `\\s`;
+export type Whitespace = { type: 'whitespace' };
+
+export type Digit = { type: 'digit' };
+
+export type Word = { type: 'word' };
+
+export type Any = { type: 'any' };
 
 // Quantifiers
 export type One = {