m-chrzan.xyz
aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--README.md8
-rw-r--r--__tests__/dice.test.js22
-rw-r--r--__tests__/lexer.test.js24
-rw-r--r--__tests__/parser.test.js16
-rw-r--r--index.js2
-rw-r--r--src/dice.js7
-rw-r--r--src/lexer.js1
-rw-r--r--src/parser.js1
8 files changed, 80 insertions, 1 deletions
diff --git a/README.md b/README.md
index aecf2fe..c140d91 100644
--- a/README.md
+++ b/README.md
@@ -81,6 +81,7 @@ The parser recognizes the following grammar:
| Die ' + ' Die
| Die ' - ' Die
| Die ' * ' Die
+ | Die ' / ' Die
| Die '+' Die
| Die '-' Die
| '-' Die
@@ -109,6 +110,8 @@ Semantics are defined in terms of the `pool` function.
* `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` generates a dicepool with a single value - the result of integer
+ division 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)`.
@@ -140,7 +143,10 @@ Semantics are defined in terms of the `pool` function.
Additionally:
-* The binary arithmetic operations (` + `, ` - `) are left associative.
+* The binary arithmetic operations (` + `, ` - `, ` * `, ` / `) are left
+ associative.
+* The binary arithmetic operations bind as expected (multiplication and division
+ bind stronger than addition and subtraction).
* The bonus operations (`+`, `-`) are left associative. They bind stronger than
arithmetic operations.
* The die operations (`d`, `E`, `K`, etc.) are right associative (`1d2d3` is
diff --git a/__tests__/dice.test.js b/__tests__/dice.test.js
index 4e89031..d397d4c 100644
--- a/__tests__/dice.test.js
+++ b/__tests__/dice.test.js
@@ -5,6 +5,7 @@ const {
add,
subtract,
multiply,
+ divide,
bonusAdd,
bonusSubtract,
negative,
@@ -338,6 +339,27 @@ describe('multiply', () => {
})
})
+describe('divide', () => {
+ describe('1d8 / 2', () => {
+ const die = divide(d(constant(1), constant(8)), constant(2))
+ testDie(die, {
+ diceCount: 1,
+ average: {
+ average: 2
+ },
+ variance: {
+ variance: 1.5
+ },
+ bounds: {
+ low: 0,
+ high: 4,
+ expectLow: true,
+ expectHigh: true
+ }
+ })
+ })
+})
+
describe('bonusAdd', () => {
describe('1d20+3', () => {
diff --git a/__tests__/lexer.test.js b/__tests__/lexer.test.js
index db7ab50..0c615d5 100644
--- a/__tests__/lexer.test.js
+++ b/__tests__/lexer.test.js
@@ -121,6 +121,30 @@ describe('lex', () => {
})
})
+ describe('lexes division', () => {
+ it('1d6 / 1d4', () => {
+ expect(lex('1d6 / 1d4')).toEqual([
+ { type: 'constant', value: 1 },
+ { type: 'd' },
+ { type: 'constant', value: 6 },
+ { type: 'bigDivide' },
+ { 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: 'bigDivide' },
+ { 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 5d4288d..bef11c5 100644
--- a/__tests__/parser.test.js
+++ b/__tests__/parser.test.js
@@ -113,6 +113,22 @@ describe('parse', () => {
})
})
+ it('parses dice division', () => {
+ expect(parse('1d6 / 2d8')).toEqual({
+ type: 'divide',
+ 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',
diff --git a/index.js b/index.js
index 9a4534b..37883cc 100644
--- a/index.js
+++ b/index.js
@@ -29,6 +29,8 @@ const interpret = tree => {
return D.subtract(interpret(tree.left), interpret(tree.right))
case 'multiply':
return D.multiply(interpret(tree.left), interpret(tree.right))
+ case 'divide':
+ return D.divide(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 abe3c4b..d47455e 100644
--- a/src/dice.js
+++ b/src/dice.js
@@ -50,6 +50,12 @@ const multiply = (die1, die2) => {
}
}
+const divide = (die1, die2) => {
+ return () => {
+ return [() => Math.floor(roll(die1) / roll(die2))]
+ }
+}
+
const bonusAdd = (die1, die2) => {
return () => {
return die1().map(die => {
@@ -194,6 +200,7 @@ exports.d = d
exports.add = add
exports.subtract = subtract
exports.multiply = multiply
+exports.divide = divide
exports.bonusAdd = bonusAdd
exports.bonusSubtract = bonusSubtract
exports.negative = negative
diff --git a/src/lexer.js b/src/lexer.js
index c3eec8a..59fba16 100644
--- a/src/lexer.js
+++ b/src/lexer.js
@@ -19,6 +19,7 @@ newLexemeType('d', 'd')
newLexemeType('bigPlus', ' \\+ ' )
newLexemeType('bigMinus', ' - ')
newLexemeType('bigTimes', ' \\* ')
+newLexemeType('bigDivide', ' / ')
newLexemeType('plus', '\\+')
newLexemeType('minus', '-')
newLexemeType('(', '\\(')
diff --git a/src/parser.js b/src/parser.js
index 1a1e5d4..fd0fd59 100644
--- a/src/parser.js
+++ b/src/parser.js
@@ -72,6 +72,7 @@ newDieOperation('t')
newInfix('bigPlus', 20, { type: 'add' })
newInfix('bigMinus', 20, { type: 'subtract' })
newInfix('bigTimes', 23, { type: 'multiply' })
+newInfix('bigDivide', 23, { type: 'divide' })
newInfix('plus', 25, { type: 'bonusAdd' })
newInfix('minus', 25, { type: 'bonusSubtract' })
newSymbol('minus', (parser) => {