refactor: simplify exact repeat quantifier (#46)

Author: mdjastrzebski

README.md

@@ -24,8 +24,8 @@ const hexColor = buildRegExp(
   optionally('#'),
   capture(
     choiceOf(
-      repeat(hexDigit, { count: 6 }), // #rrggbb
-      repeat(hexDigit, { count: 3 }), // #rgb
+      repeat(hexDigit, 6), // #rrggbb
+      repeat(hexDigit, 3), // #rgb
     ),
   ),
   endOfString,
@@ -79,11 +79,11 @@ const currencyAmount = buildRegExp([
   choiceOf(
     '$',
     '€',
-    repeat({ count: 3 }, charRange('A', 'Z')), // ISO currency code
+    repeat(charRange('A', 'Z'), 3), // ISO currency code
   ),
   capture(
     oneOrMore(digit), // Integer part
-    optionally(['.', repeat({ count: 2 }, digit)]), // Fractional part
+    optionally(['.', repeat(digit, 2)]), // Fractional part
   ),
 ]);
 ```
@@ -114,7 +114,7 @@ Notes:
 | `zeroOrMore(x)`                  | `x*`          | Zero or more occurence of a pattern               |
 | `oneOrMore(x)`                   | `x+`          | One or more occurence of a pattern                |
 | `optionally(x)`                  | `x?`          | Zero or one occurence of a pattern                |
-| `repeat(x, { count: n })`        | `x{n}`        | Pattern repeats exact number of times             |
+| `repeat(x, n)`                   | `x{n}`        | Pattern repeats exact number of times             |
 | `repeat(x, { min: n, })`         | `x{n,}`       | Pattern repeats at least given number of times    |
 | `repeat(x, { min: n, max: n2 })` | `x{n1,n2}`    | Pattern repeats between n1 and n2 number of times |
 

docs/API.md

@@ -73,7 +73,7 @@ function optionally(
 
 ```ts
 function repeat(
-    options: { count: number } | { min: number; max?: number },
+    options: number | { min: number; max?: number },
     sequence: RegexSequence,
 ): Repeat
 ```

docs/Examples.md

@@ -7,15 +7,15 @@
 const octet = choiceOf(
   [digit],
   [charRange('1', '9'), digit],
-  ['1', repeat({ count: 2 }, digit)],
+  ['1', repeat(digit, 2)],
   ['2', charRange('0', '4'), digit],
   ['25', charRange('0', '5')]
 );
 
 // Match
 const regex = buildRegExp([
   startOfString, //
-  repeat([octet, '.'], { count: 3 }),
+  repeat([octet, '.'], 3),
   octet,
   endOfString,
 ]);

src/__tests__/examples.test.ts

@@ -12,14 +12,14 @@ test('example: IPv4 address validator', () => {
   const octet = choiceOf(
     [digit],
     [charRange('1', '9'), digit],
-    ['1', repeat(digit, { count: 2 })],
+    ['1', repeat(digit, 2)],
     ['2', charRange('0', '4'), digit],
     ['25', charRange('0', '5')],
   );
 
   const regex = buildRegExp([
     startOfString, //
-    repeat([octet, '.'], { count: 3 }),
+    repeat([octet, '.'], 3),
     octet,
     endOfString,
   ]);

src/constructs/__tests__/choice-of.test.ts

@@ -29,7 +29,7 @@ test('`choiceOf` with sequence options', () => {
 
 test('`choiceOf` using nested regex', () => {
   expect(choiceOf(oneOrMore('a'), zeroOrMore('b'))).toHavePattern(/a+|b*/);
-  expect(choiceOf(repeat('a', { min: 1, max: 3 }), repeat('bx', { count: 5 }))).toHavePattern(
+  expect(choiceOf(repeat('a', { min: 1, max: 3 }), repeat('bx', 5))).toHavePattern(
     /a{1,3}|(?:bx){5}/,
   );
 });

src/constructs/__tests__/repeat.test.tsx

@@ -5,20 +5,20 @@ import { repeat } from '../repeat';
 test('`repeat` quantifier', () => {
   expect(['a', repeat('b', { min: 1, max: 5 })]).toHavePattern(/ab{1,5}/);
   expect(['a', repeat('b', { min: 1 })]).toHavePattern(/ab{1,}/);
-  expect(['a', repeat('b', { count: 1 })]).toHavePattern(/ab{1}/);
+  expect(['a', repeat('b', 1)]).toHavePattern(/ab{1}/);
 
-  expect(['a', repeat(['a', zeroOrMore('b')], { count: 1 })]).toHavePattern(/a(?:ab*){1}/);
-  expect(repeat(['text', ' ', oneOrMore('d')], { count: 5 })).toHavePattern(/(?:text d+){5}/);
+  expect(['a', repeat(['a', zeroOrMore('b')], 1)]).toHavePattern(/a(?:ab*){1}/);
+  expect(repeat(['text', ' ', oneOrMore('d')], 5)).toHavePattern(/(?:text d+){5}/);
 });
 
 test('`repeat` optimizes grouping for atoms', () => {
-  expect(repeat(digit, { count: 2 })).toHavePattern(/\d{2}/);
+  expect(repeat(digit, 2)).toHavePattern(/\d{2}/);
   expect(repeat(digit, { min: 2 })).toHavePattern(/\d{2,}/);
   expect(repeat(digit, { min: 1, max: 5 })).toHavePattern(/\d{1,5}/);
 });
 
 test('`repeat` throws on no children', () => {
-  expect(() => repeat([], { count: 1 })).toThrowErrorMatchingInlineSnapshot(
+  expect(() => repeat([], 1)).toThrowErrorMatchingInlineSnapshot(
     `"\`repeat\` should receive at least one element"`,
   );
 });

src/constructs/repeat.ts

@@ -9,7 +9,7 @@ export interface Repeat extends RegexConstruct {
   children: RegexElement[];
 }
 
-export type RepeatOptions = { count: number } | { min: number; max?: number };
+export type RepeatOptions = number | { min: number; max?: number };
 
 export function repeat(sequence: RegexSequence, options: RepeatOptions): Repeat {
   const children = ensureArray(sequence);
@@ -29,10 +29,10 @@ export function repeat(sequence: RegexSequence, options: RepeatOptions): Repeat
 function encodeRepeat(this: Repeat): EncodeResult {
   const atomicNodes = encodeAtom(this.children);
 
-  if ('count' in this.options) {
+  if (typeof this.options === 'number') {
     return {
       precedence: 'sequence',
-      pattern: `${atomicNodes.pattern}{${this.options.count}}`,
+      pattern: `${atomicNodes.pattern}{${this.options}}`,
     };
   }