Merge pull request #112 from tidalcycles/more-functions

`.brak()`, `.inside()` and `.outside()`

packages/core/pattern.mjs

@@ -67,7 +67,7 @@ export class Pattern {
    * @param {Function} func the function to apply
    * @returns Pattern
    */
-   withQueryTime(func) {
+  withQueryTime(func) {
     return new Pattern((state) => this.query(state.withSpan((span) => span.withTime(func))));
   }
 
@@ -75,7 +75,7 @@ export class Pattern {
    * Similar to {@link Pattern#withQuerySpan|withQuerySpan}, but the function is applied to the timespans
    * of all haps returned by pattern queries (both `part` timespans, and where
    * present, `whole` timespans).
-   * @param {Function} func 
+   * @param {Function} func
    * @returns Pattern
    */
   withHapSpan(func) {
@@ -88,31 +88,31 @@ export class Pattern {
    * @param {Function} func the function to apply
    * @returns Pattern
    */
-   withHapTime(func) {
+  withHapTime(func) {
     return this.withHapSpan((span) => span.withTime(func));
   }
 
   /**
    * Returns a new pattern with the given function applied to the list of haps returned by every query.
-   * @param {Function} func 
+   * @param {Function} func
    * @returns Pattern
    */
-   _withHaps(func) {
+  _withHaps(func) {
     return new Pattern((state) => func(this.query(state)));
   }
 
   /**
    * As with {@link Pattern#_withHaps}, but applies the function to every hap, rather than every list of haps.
-   * @param {Function} func 
+   * @param {Function} func
    * @returns Pattern
    */
-   _withHap(func) {
+  _withHap(func) {
     return this._withHaps((haps) => haps.map(func));
   }
 
   /**
    * Returns a new pattern with the context field set to every hap set to the given value.
-   * @param {*} context 
+   * @param {*} context
    * @returns Pattern
    */
   _setContext(context) {
@@ -121,7 +121,7 @@ export class Pattern {
 
   /**
    * Returns a new pattern with the given function applied to the context field of every hap.
-   * @param {Function} func 
+   * @param {Function} func
    * @returns Pattern
    */
   _withContext(func) {
@@ -129,7 +129,7 @@ export class Pattern {
   }
 
   /**
-   * Returns a new pattern with the context field of every hap set to an empty object. 
+   * Returns a new pattern with the context field of every hap set to an empty object.
    * @returns Pattern
    */
   _stripContext() {
@@ -139,8 +139,8 @@ export class Pattern {
   /**
    * Returns a new pattern with the given location information added to the
    * context of every hap.
-   * @param {Number} start 
-   * @param {Number} end 
+   * @param {Number} start
+   * @param {Number} end
    * @returns Pattern
    */
   withLocation(start, end) {
@@ -183,7 +183,7 @@ export class Pattern {
   /**
    * Returns a new pattern, with the function applied to the value of
    * each hap. It has the alias {@link Pattern#fmap|fmap}.
-   * @param {Function} func 
+   * @param {Function} func
    * @returns Pattern
    */
   withValue(func) {
@@ -193,7 +193,7 @@ export class Pattern {
   /**
    * see {@link Pattern#withValue|withValue}
    */
-   fmap(func) {
+  fmap(func) {
     return this.withValue(func);
   }
 
@@ -209,7 +209,7 @@ export class Pattern {
   /**
    * As with {@link Pattern#_filterHaps}, but the function is applied to values
    * inside haps.
-   * @param {Function} value_test 
+   * @param {Function} value_test
    * @returns Pattern
    */
   _filterValues(value_test) {
@@ -231,7 +231,7 @@ export class Pattern {
    * as its `part` timespan.
    * @returns Pattern
    */
-   onsetsOnly() {
+  onsetsOnly() {
     // Returns a new pattern that will only return haps where the start
     // of the 'whole' timespan matches the start of the 'part'
     // timespan, i.e. the haps that include their 'onset'.
@@ -278,12 +278,12 @@ export class Pattern {
   /**
    * When this method is called on a pattern of functions, it matches its haps
    * with those in the given pattern of values.  A new pattern is returned, with
-   * each matching value applied to the corresponding function. 
+   * each matching value applied to the corresponding function.
    *
    * In this `appBoth` variant, where timespans of the function and value haps
    * are not the same but do intersect, the resulting hap has a timespan of the
    * intersection. This applies to both the part and the whole timespan.
-   * @param {Pattern} pat_val 
+   * @param {Pattern} pat_val
    * @returns Pattern
    */
   appBoth(pat_val) {
@@ -303,7 +303,7 @@ export class Pattern {
    * on. In practice, this means that the pattern structure, including onsets,
    * are preserved from the pattern of functions (often referred to as the left
    * hand or inner pattern).
-   * @param {Pattern} pat_val 
+   * @param {Pattern} pat_val
    * @returns Pattern
    */
   appLeft(pat_val) {
@@ -333,7 +333,7 @@ export class Pattern {
    * As with {@link Pattern#appLeft|appLeft}, but `whole` timespans are instead taken from the
    * pattern of values, i.e. structure is preserved from the right hand/outer
    * pattern.
-   * @param {Pattern} pat_val 
+   * @param {Pattern} pat_val
    * @returns Pattern
    */
   appRight(pat_val) {
@@ -696,6 +696,14 @@ export class Pattern {
     return this._fast(Fraction(1).div(factor));
   }
 
+  _inside(factor, f) {
+    return f(this._slow(factor))._fast(factor);
+  }
+
+  _outside(factor, f) {
+    return f(this._fast(factor))._slow(factor);
+  }
+
   _ply(factor) {
     return this.fmap((x) => pure(x)._fast(factor))._squeezeJoin();
   }
@@ -822,6 +830,16 @@ export class Pattern {
     return slowcatPrime(...pats);
   }
 
+  /**
+   * Returns a new pattern where every other cycle is played once, twice as
+   * fast, and offset in time by one quarter of a cycle. Creates a kind of
+   * breakbeat feel.
+   * @returns Pattern
+   */
+  brak() {
+    return this.when(slowcat(false, true), (x) => fastcat(x, silence)._late(0.25));
+  }
+
   rev() {
     const pat = this;
     const query = function (state) {
@@ -979,7 +997,7 @@ function _composeOp(a, b, func) {
 }
 
 // Make composers
-(function() {
+(function () {
   const num = (pat) => pat._asNumber();
   const numOrString = (pat) => pat._asNumber(false, true);
 
@@ -1390,6 +1408,14 @@ Pattern.prototype.compress = function (...args) {
   args = args.map(reify);
   return patternify2(Pattern.prototype._compress)(...args, this);
 };
+Pattern.prototype.outside = function (...args) {
+  args = args.map(reify);
+  return patternify2(Pattern.prototype._outside)(...args, this);
+};
+Pattern.prototype.inside = function (...args) {
+  args = args.map(reify);
+  return patternify2(Pattern.prototype._inside)(...args, this);
+};
 
 // call this after all Patter.prototype.define calls have been executed! (right before evaluate)
 Pattern.prototype.bootstrap = function () {

packages/core/test/pattern.test.mjs

@@ -41,6 +41,7 @@ import {
   tri2,
   id,
   ply,
+  rev
 } from '../index.mjs';
 
 import { steady } from '../signal.mjs';
@@ -277,10 +278,7 @@ describe('Pattern', function () {
       );
     });
     it('can SqueezeOut() structure', () => {
-      sameFirst(
-        sequence(1, [2, 3]).keepifSqueezeOut(true, true, false),
-        sequence([1, [2, 3]], [1, [2, 3]], silence),
-      );
+      sameFirst(sequence(1, [2, 3]).keepifSqueezeOut(true, true, false), sequence([1, [2, 3]], [1, [2, 3]], silence));
     });
   });
   describe('sub()', function () {
@@ -439,6 +437,20 @@ describe('Pattern', function () {
       // mini('eb3 [c3 g3]/2 ') always plays [c3 g3]
     });
   });
+  describe('inside', () => {
+    it('can rev inside a cycle', () => {
+      sameFirst(sequence('a', 'b', 'c', 'd').inside(2, rev),
+        sequence('b', 'a', 'd', 'c')
+      );
+    });
+  });
+  describe('outside', () => {
+    it('can rev outside a cycle', () => {
+      sameFirst(sequence('a', 'b', 'c', 'd')._slow(2).outside(2, rev),
+        sequence('d', 'c')
+      );
+    });
+  });
   describe('_filterValues()', function () {
     it('Filters true', function () {
       assert.equal(
@@ -589,6 +601,11 @@ describe('Pattern', function () {
       );
     });
   });
+  describe('brak()', () => {
+    it('Can make something a bit breakbeaty', () => {
+      sameFirst(sequence('a', 'b').brak()._fast(2), sequence('a', 'b', fastcat(silence, 'a'), fastcat('b', silence)));
+    });
+  });
   describe('timeCat()', function () {
     it('Can concatenate patterns with different relative durations', function () {
       assert.deepStrictEqual(