From 5087cde4825d91112cad565c68d81296359cf4d8 Mon Sep 17 00:00:00 2001 From: Marcin Chrzanowski Date: Wed, 30 Aug 2017 17:46:07 -0400 Subject: Implement multiplication --- README.md | 3 +++ __tests__/dice.test.js | 23 +++++++++++++++++++++++ __tests__/lexer.test.js | 24 ++++++++++++++++++++++++ __tests__/parser.test.js | 42 ++++++++++++++++++++++++++++++++++++++++++ index.js | 2 ++ src/dice.js | 7 +++++++ src/lexer.js | 1 + src/parser.js | 1 + 8 files changed, 103 insertions(+) diff --git a/README.md b/README.md index d5cbbbc..aecf2fe 100644 --- a/README.md +++ b/README.md @@ -80,6 +80,7 @@ The parser recognizes the following grammar: | 'd' Die | Die ' + ' Die | Die ' - ' Die + | Die ' * ' Die | Die '+' Die | Die '-' Die | '-' Die @@ -106,6 +107,8 @@ Semantics are defined in terms of the `pool` function. `D`. * `-D` returns the opposites of values generated by `D`. * `D - E` is equivalent to `D + (-E)`. +* `D * E` generates a dicepool with a single value - the produc of `roll(D)` and + `roll(E)`. * `D+E` is the additive bonus operation. For each die in `D`'s pool, the die is rolled and `roll(E)` is added to its result. * `D-E` is equivalent to `D+(-E)`. diff --git a/__tests__/dice.test.js b/__tests__/dice.test.js index caba0a9..4e89031 100644 --- a/__tests__/dice.test.js +++ b/__tests__/dice.test.js @@ -4,6 +4,7 @@ const { d, add, subtract, + multiply, bonusAdd, bonusSubtract, negative, @@ -316,6 +317,28 @@ describe('subtract', () => { }) }) +describe('multiply', () => { + describe('1d6 * 3', () => { + const die = multiply(d(constant(1), constant(6)), constant(3)) + testDie(die, { + diceCount: 1, + average: { + average: 10.5 + }, + variance: { + variance: 26.25 + }, + bounds: { + low: 3, + high: 18, + expectLow: true, + expectHigh: true + } + }) + }) +}) + + describe('bonusAdd', () => { describe('1d20+3', () => { const die = bonusAdd(d(constant(1), constant(20)), constant(3)) diff --git a/__tests__/lexer.test.js b/__tests__/lexer.test.js index b51c0f9..db7ab50 100644 --- a/__tests__/lexer.test.js +++ b/__tests__/lexer.test.js @@ -97,6 +97,30 @@ describe('lex', () => { }) }) + describe('lexes multiplication', () => { + it('1d6 * 1d4', () => { + expect(lex('1d6 * 1d4')).toEqual([ + { type: 'constant', value: 1 }, + { type: 'd' }, + { type: 'constant', value: 6 }, + { type: 'bigTimes' }, + { type: 'constant', value: 1 }, + { type: 'd' }, + { type: 'constant', value: 4 } + ]) + }) + + it('2d17 * 4', () => { + expect(lex('2d17 * 4')).toEqual([ + { type: 'constant', value: 2 }, + { type: 'd' }, + { type: 'constant', value: 17 }, + { type: 'bigTimes' }, + { type: 'constant', value: 4 } + ]) + }) + }) + describe('lexes parentheses', () => { it('(1d6)d6', () => { expect(lex('(1d6)d6')).toEqual([ diff --git a/__tests__/parser.test.js b/__tests__/parser.test.js index 6e575b6..5d4288d 100644 --- a/__tests__/parser.test.js +++ b/__tests__/parser.test.js @@ -97,6 +97,22 @@ describe('parse', () => { }) }) + it('parses dice multiplication', () => { + expect(parse('1d6 * 2d8')).toEqual({ + type: 'multiply', + left: { + type: 'd', + left: { type: 'constant', value: 1 }, + right: { type: 'constant', value: 6 } + }, + right: { + type: 'd', + left: { type: 'constant', value: 2 }, + right: { type: 'constant', value: 8 } + } + }) + }) + it('parses additive bonuses', () => { expect(parse('3d4+1')).toEqual({ type: 'bonusAdd', @@ -282,4 +298,30 @@ describe('parse', () => { }) }) }) + + describe('order of operations', () => { + test('2 * 3 + 4', () => { + expect(parse('2 * 3 + 4')).toEqual({ + type: 'add', + left: { + type: 'multiply', + left: { type: 'constant', value: 2 }, + right: { type: 'constant', value: 3 }, + }, + right: { type: 'constant', value: 4 }, + }) + }) + + test('2 + 3 * 4', () => { + expect(parse('2 + 3 * 4')).toEqual({ + type: 'add', + left: { type: 'constant', value: 2 }, + right: { + type: 'multiply', + left: { type: 'constant', value: 3 }, + right: { type: 'constant', value: 4 }, + } + }) + }) + }) }) diff --git a/index.js b/index.js index 1851a77..9a4534b 100644 --- a/index.js +++ b/index.js @@ -27,6 +27,8 @@ const interpret = tree => { return D.add(interpret(tree.left), interpret(tree.right)) case 'subtract': return D.subtract(interpret(tree.left), interpret(tree.right)) + case 'multiply': + return D.multiply(interpret(tree.left), interpret(tree.right)) case 'negative': return D.negative(interpret(tree.value)) case 'bonusAdd': diff --git a/src/dice.js b/src/dice.js index 828a772..abe3c4b 100644 --- a/src/dice.js +++ b/src/dice.js @@ -44,6 +44,12 @@ const subtract = (die1, die2) => { } } +const multiply = (die1, die2) => { + return () => { + return [() => roll(die1) * roll(die2)] + } +} + const bonusAdd = (die1, die2) => { return () => { return die1().map(die => { @@ -187,6 +193,7 @@ exports.constant = constant exports.d = d exports.add = add exports.subtract = subtract +exports.multiply = multiply exports.bonusAdd = bonusAdd exports.bonusSubtract = bonusSubtract exports.negative = negative diff --git a/src/lexer.js b/src/lexer.js index ba3d3a5..c3eec8a 100644 --- a/src/lexer.js +++ b/src/lexer.js @@ -18,6 +18,7 @@ newValueLexeme('constant', '\\d+', Number) newLexemeType('d', 'd') newLexemeType('bigPlus', ' \\+ ' ) newLexemeType('bigMinus', ' - ') +newLexemeType('bigTimes', ' \\* ') newLexemeType('plus', '\\+') newLexemeType('minus', '-') newLexemeType('(', '\\(') diff --git a/src/parser.js b/src/parser.js index adb4b9b..1a1e5d4 100644 --- a/src/parser.js +++ b/src/parser.js @@ -71,6 +71,7 @@ newDieOperation('t') newInfix('bigPlus', 20, { type: 'add' }) newInfix('bigMinus', 20, { type: 'subtract' }) +newInfix('bigTimes', 23, { type: 'multiply' }) newInfix('plus', 25, { type: 'bonusAdd' }) newInfix('minus', 25, { type: 'bonusSubtract' }) newSymbol('minus', (parser) => { -- cgit v1.2.3