From 5490b01004540ac2fa0b08718cb682690b9d389b Mon Sep 17 00:00:00 2001
From: Ian Clester <ijc@ijc8.me>
Date: Mon, 20 Mar 2023 14:59:43 -0400
Subject: [PATCH 1/5] Maintain random seed state in parser, not globally

---
 packages/mini/krill-parser.js          | 14 +++++++----
 packages/mini/krill.pegjs              | 14 +++++++----
 packages/mini/mini.mjs                 | 34 ++++----------------------
 test/__snapshots__/tunes.test.mjs.snap |  1 +
 4 files changed, 24 insertions(+), 39 deletions(-)

diff --git a/packages/mini/krill-parser.js b/packages/mini/krill-parser.js
index 34e3843c..d2c861f2 100644
--- a/packages/mini/krill-parser.js
+++ b/packages/mini/krill-parser.js
@@ -279,7 +279,7 @@ function peg$parse(input, options) {
   var peg$f8 = function(p, s, r) { return x => x.options_['ops'].push({ type_: "bjorklund", arguments_ :{ pulse: p, step:s, rotation:r }}) };
   var peg$f9 = function(a) { return x => x.options_['ops'].push({ type_: "stretch", arguments_ :{ amount:a, type: 'slow' }}) };
   var peg$f10 = function(a) { return x => x.options_['ops'].push({ type_: "stretch", arguments_ :{ amount:a, type: 'fast' }}) };
-  var peg$f11 = function(a) { return x => x.options_['ops'].push({ type_: "degradeBy", arguments_ :{ amount:a } }) };
+  var peg$f11 = function(a) { return x => x.options_['ops'].push({ type_: "degradeBy", arguments_ :{ amount:a, seed: seed++ } }) };
   var peg$f12 = function(s) { return x => x.options_['ops'].push({ type_: "tail", arguments_ :{ element:s } }) };
   var peg$f13 = function(s, ops) { const result = new ElementStub(s, {ops: [], weight: 1, reps: 1});
     for (const op of ops) {
@@ -289,8 +289,8 @@ function peg$parse(input, options) {
   };
   var peg$f14 = function(s) { return new PatternStub(s, 'fastcat'); };
   var peg$f15 = function(tail) { return { alignment: 'stack', list: tail }; };
-  var peg$f16 = function(tail) { return { alignment: 'rand', list: tail }; };
-  var peg$f17 = function(head, tail) { if (tail && tail.list.length > 0) { return new PatternStub([head, ...tail.list], tail.alignment); } else { return head; } };
+  var peg$f16 = function(tail) { return { alignment: 'rand', list: tail, seed: seed++ }; };
+  var peg$f17 = function(head, tail) { if (tail && tail.list.length > 0) { return new PatternStub([head, ...tail.list], tail.alignment, tail.seed); } else { return head; } };
   var peg$f18 = function(head, tail) { return new PatternStub(tail ? [head, ...tail.list] : [head], 'polymeter'); };
   var peg$f19 = function(sc) { return sc; };
   var peg$f20 = function(s) { return { name: "struct", args: { mini:s }}};
@@ -2185,10 +2185,13 @@ function peg$parse(input, options) {
     this.location_ = location();
   }
 
-  var PatternStub = function(source, alignment)
+  var PatternStub = function(source, alignment, seed)
   {
     this.type_ = "pattern";
-    this.arguments_ = { alignment : alignment};
+    this.arguments_ = { alignment: alignment };
+    if (seed !== undefined) {
+      this.arguments_.seed = seed;
+    }
     this.source_ = source;
   }
 
@@ -2214,6 +2217,7 @@ function peg$parse(input, options) {
     this.options_ = options;
   }
 
+  var seed = 0;
 
   peg$result = peg$startRuleFunction();
 
diff --git a/packages/mini/krill.pegjs b/packages/mini/krill.pegjs
index f4fd7772..9ca48624 100644
--- a/packages/mini/krill.pegjs
+++ b/packages/mini/krill.pegjs
@@ -19,10 +19,13 @@ This program is free software: you can redistribute it and/or modify it under th
     this.location_ = location();
   }
 
-  var PatternStub = function(source, alignment)
+  var PatternStub = function(source, alignment, seed)
   {
     this.type_ = "pattern";
-    this.arguments_ = { alignment : alignment};
+    this.arguments_ = { alignment: alignment };
+    if (seed !== undefined) {
+      this.arguments_.seed = seed;
+    }
     this.source_ = source;
   }
 
@@ -48,6 +51,7 @@ This program is free software: you can redistribute it and/or modify it under th
     this.options_ = options;
   }
 
+  var seed = 0;
 }
 
 start = statement
@@ -137,7 +141,7 @@ op_fast = "*"a:slice
   { return x => x.options_['ops'].push({ type_: "stretch", arguments_ :{ amount:a, type: 'fast' }}) }
 
 op_degrade = "?"a:number?
-  { return x => x.options_['ops'].push({ type_: "degradeBy", arguments_ :{ amount:a } }) }
+  { return x => x.options_['ops'].push({ type_: "degradeBy", arguments_ :{ amount:a, seed: seed++ } }) }
 
 op_tail = ":" s:slice
   { return x => x.options_['ops'].push({ type_: "tail", arguments_ :{ element:s } }) }
@@ -162,12 +166,12 @@ stack_tail = tail:(comma @sequence)+
 // a choose is a series of pipe-separated sequence, one of which is
 // chosen at random, each cycle
 choose_tail = tail:(pipe @sequence)+
-  { return { alignment: 'rand', list: tail }; }
+  { return { alignment: 'rand', list: tail, seed: seed++ }; }
 
 // if the stack contains only one element, we don't create a stack but return the
 // underlying element
 stack_or_choose = head:sequence tail:(stack_tail / choose_tail)?
-  { if (tail && tail.list.length > 0) { return new PatternStub([head, ...tail.list], tail.alignment); } else { return head; } }
+  { if (tail && tail.list.length > 0) { return new PatternStub([head, ...tail.list], tail.alignment, tail.seed); } else { return head; } }
 
 polymeter_stack = head:sequence tail:stack_tail?
   { return new PatternStub(tail ? [head, ...tail.list] : [head], 'polymeter'); }
diff --git a/packages/mini/mini.mjs b/packages/mini/mini.mjs
index af6549cf..75d124fe 100644
--- a/packages/mini/mini.mjs
+++ b/packages/mini/mini.mjs
@@ -7,13 +7,8 @@ This program is free software: you can redistribute it and/or modify it under th
 import * as krill from './krill-parser.js';
 import * as strudel from '@strudel.cycles/core';
 
-/* var _seedState = 0;
 const randOffset = 0.0002;
 
-function _nextSeed() {
-  return _seedState++;
-} */
-
 const applyOptions = (parent, code) => (pat, i) => {
   const ast = parent.source_[i];
   const options = ast.options_;
@@ -44,27 +39,10 @@ const applyOptions = (parent, code) => (pat, i) => {
           break;
         }
         case 'degradeBy': {
-          // TODO: find out what is right here
-          // example:
-          /*
-           stack(
-             s("hh*8").degrade(),
-             s("[ht*8]?")
-           )
-        */
-          // above example will only be in sync when _degradeBy is used...
-          // it also seems that the nextSeed will create undeterministic behaviour
-          // as it uses a global _seedState. This is probably the reason for
-          // https://github.com/tidalcycles/strudel/issues/245
-
-          // this is how it was:
-          /* 
-        return strudel.reify(pat)._degradeByWith(
-          strudel.rand.early(randOffset * _nextSeed()).segment(1),
-          op.arguments_.amount ?? 0.5,
-        ); 
-        */
-          pat = strudel.reify(pat).degradeBy(op.arguments_.amount === null ? 0.5 : op.arguments_.amount);
+          pat = strudel.reify(pat)._degradeByWith(
+            strudel.rand.early(randOffset * op.arguments_.seed).segment(1),
+            op.arguments_.amount ?? 0.5,
+          );
           break;
         }
         case 'tail': {
@@ -114,9 +92,7 @@ export function patternifyAST(ast, code) {
         return strudel.stack(...aligned);
       }
       if (alignment === 'rand') {
-        // https://github.com/tidalcycles/strudel/issues/245#issuecomment-1345406422
-        // return strudel.chooseInWith(strudel.rand.early(randOffset * _nextSeed()).segment(1), children);
-        return strudel.chooseCycles(...children);
+        return strudel.chooseInWith(strudel.rand.early(randOffset * ast.arguments_.seed).segment(1), children);
       }
       const weightedChildren = ast.source_.some((child) => !!child.options_?.weight);
       if (!weightedChildren && alignment === 'slowcat') {
diff --git a/test/__snapshots__/tunes.test.mjs.snap b/test/__snapshots__/tunes.test.mjs.snap
index 261255f0..0822ffbb 100644
--- a/test/__snapshots__/tunes.test.mjs.snap
+++ b/test/__snapshots__/tunes.test.mjs.snap
@@ -63,6 +63,7 @@ exports[`renders tunes > tune: arpoon 1`] = `
   "[ 0/1 → 1/2 | s:bd bank:RolandTR909 gain:0.5 ]",
   "[ 1/2 → 1/1 | s:bd bank:RolandTR909 gain:0.5 ]",
   "[ 1/2 → 2/3 | s:hh bank:RolandTR909 gain:0.5 ]",
+  "[ 5/6 → 1/1 | s:hh bank:RolandTR909 gain:0.5 ]",
 ]
 `;
 

From 4b51f1a3fcb4fc6df023d88aa665701a6ce52134 Mon Sep 17 00:00:00 2001
From: Ian Clester <ijc@ijc8.me>
Date: Mon, 20 Mar 2023 15:26:27 -0400
Subject: [PATCH 2/5] Sync up `?` with `degrade()`

---
 packages/mini/mini.mjs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/mini/mini.mjs b/packages/mini/mini.mjs
index 75d124fe..1619c7ce 100644
--- a/packages/mini/mini.mjs
+++ b/packages/mini/mini.mjs
@@ -40,7 +40,7 @@ const applyOptions = (parent, code) => (pat, i) => {
         }
         case 'degradeBy': {
           pat = strudel.reify(pat)._degradeByWith(
-            strudel.rand.early(randOffset * op.arguments_.seed).segment(1),
+            strudel.rand.early(randOffset * op.arguments_.seed),
             op.arguments_.amount ?? 0.5,
           );
           break;

From 4e25990de9d35ec1a245daa6be3f4a4035890da2 Mon Sep 17 00:00:00 2001
From: Ian Clester <ijc@ijc8.me>
Date: Mon, 20 Mar 2023 17:46:57 -0400
Subject: [PATCH 3/5] Uncomment test for random choice operator (`|`)

---
 packages/mini/test/mini.test.mjs | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/packages/mini/test/mini.test.mjs b/packages/mini/test/mini.test.mjs
index 1e18dd58..71b88855 100644
--- a/packages/mini/test/mini.test.mjs
+++ b/packages/mini/test/mini.test.mjs
@@ -143,7 +143,7 @@ describe('mini', () => {
   it('supports lists', () => {
     expect(minV('a:b c:d:[e:f] g')).toEqual([['a', 'b'], ['c', 'd', ['e', 'f']], 'g']);
   });
-  /*it('supports the random choice operator ("|") with nesting', () => {
+  it('supports the random choice operator ("|") with nesting', () => {
     const numCycles = 900;
     const haps = mini('a | [b | c] | [d | e | f]').queryArc(0, numCycles);
     // Should have about 1/3 a, 1/6 each of b | c, and 1/9 each of d | e | f.
@@ -168,6 +168,5 @@ describe('mini', () => {
     // 15.086 is the chisq for 5 degrees of freedom at 99%, so for 99% of uniformly-distributed
     //  PRNG, this test should succeed
     expect(chisq <= 15.086).toBe(true);
-    // assert(chisq <= 15.086, chisq + ' was expected to be less than 15.086 under chi-squared test');
-  });*/
+  });
 });

From c98b0e968780baa39648f0bb1b9aa811811b97ff Mon Sep 17 00:00:00 2001
From: Ian Clester <ijc@ijc8.me>
Date: Mon, 20 Mar 2023 19:19:42 -0400
Subject: [PATCH 4/5] Format code with prettier

---
 packages/mini/mini.mjs | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/packages/mini/mini.mjs b/packages/mini/mini.mjs
index 1619c7ce..8e5f2f33 100644
--- a/packages/mini/mini.mjs
+++ b/packages/mini/mini.mjs
@@ -39,10 +39,9 @@ const applyOptions = (parent, code) => (pat, i) => {
           break;
         }
         case 'degradeBy': {
-          pat = strudel.reify(pat)._degradeByWith(
-            strudel.rand.early(randOffset * op.arguments_.seed),
-            op.arguments_.amount ?? 0.5,
-          );
+          pat = strudel
+            .reify(pat)
+            ._degradeByWith(strudel.rand.early(randOffset * op.arguments_.seed), op.arguments_.amount ?? 0.5);
           break;
         }
         case 'tail': {

From 4e2a5e1663ae3e00cda629e1de35370f0c27a9bd Mon Sep 17 00:00:00 2001
From: Ian Clester <ijc@ijc8.me>
Date: Mon, 20 Mar 2023 22:27:35 -0400
Subject: [PATCH 5/5] Add pairwise independence test, tweak `randOffset`

---
 packages/mini/mini.mjs           |  2 +-
 packages/mini/test/mini.test.mjs | 19 +++++++++++++++++--
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/packages/mini/mini.mjs b/packages/mini/mini.mjs
index 8e5f2f33..648499e6 100644
--- a/packages/mini/mini.mjs
+++ b/packages/mini/mini.mjs
@@ -7,7 +7,7 @@ This program is free software: you can redistribute it and/or modify it under th
 import * as krill from './krill-parser.js';
 import * as strudel from '@strudel.cycles/core';
 
-const randOffset = 0.0002;
+const randOffset = 0.0003;
 
 const applyOptions = (parent, code) => (pat, i) => {
   const ast = parent.source_[i];
diff --git a/packages/mini/test/mini.test.mjs b/packages/mini/test/mini.test.mjs
index 71b88855..70577ab0 100644
--- a/packages/mini/test/mini.test.mjs
+++ b/packages/mini/test/mini.test.mjs
@@ -140,8 +140,20 @@ describe('mini', () => {
     expect(haps.length < 230).toBe(true);
     // 'Had too many cycles remaining after degradeBy 0.8');
   });
-  it('supports lists', () => {
-    expect(minV('a:b c:d:[e:f] g')).toEqual([['a', 'b'], ['c', 'd', ['e', 'f']], 'g']);
+  it('supports multiple independent uses of the random choice operator ("|")', () => {
+    const numCycles = 1000;
+    const values = mini('[a|b] [a|b]')
+      .queryArc(0, numCycles)
+      .map((e) => e.value);
+    const observed = { aa: 0, ab: 0, ba: 0, bb: 0 };
+    for (let i = 0; i < values.length; i += 2) {
+      const chunk = values.slice(i, i + 2);
+      observed[chunk.join('')]++;
+    }
+    for (const count of Object.values(observed)) {
+      // Should fall within 99% confidence interval for binomial with p=0.25.
+      expect(215 <= count && count <= 286).toBe(true);
+    }
   });
   it('supports the random choice operator ("|") with nesting', () => {
     const numCycles = 900;
@@ -169,4 +181,7 @@ describe('mini', () => {
     //  PRNG, this test should succeed
     expect(chisq <= 15.086).toBe(true);
   });
+  it('supports lists', () => {
+    expect(minV('a:b c:d:[e:f] g')).toEqual([['a', 'b'], ['c', 'd', ['e', 'f']], 'g']);
+  });
 });