Parse square roots in val equaves

ref #314
xenharmonic-devs · May 11, 2024 · ebbf3b9 · ebbf3b9
1 parent 07d998e
commit ebbf3b9
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diff --git a/src/parser/__tests__/source.spec.ts b/src/parser/__tests__/source.spec.ts
@@ -1620,4 +1620,14 @@ describe('SonicWeave parser', () => {
       '1\\1',
     ]);
   });
+
+  it('supports radicals in SOV', () => {
+    const scale = expand(`
+      9/8
+      3/2
+      3/^2
+      [√3]8@2.√3
+    `);
+    expect(scale).toEqual(['1\\8<3>', '3\\8<3>', '1\\2<3>']);
+  });
 });
diff --git a/src/parser/chord-parser.ts b/src/parser/chord-parser.ts
@@ -76,7 +76,7 @@ export function parseVals(
       if (node.type === 'WartsLiteral') {
         val = wartsToVal(node);
       } else if (node.type === 'SparseOffsetVal') {
-        val = sparseOffsetToVal(node);
+        [val] = sparseOffsetToVal(node);
       }
       result.push(basis.map(e => val.dot(e).valueOf()));
     }

diff --git a/src/parser/expression.ts b/src/parser/expression.ts
@@ -732,13 +732,7 @@ export class ExpressionVisitor {
   }
 
   protected visitSparseOffsetVal(node: SparseOffsetVal) {
-    const val = sparseOffsetToVal(node);
-    let equave = TWO_MONZO;
-    if (node.equave) {
-      equave = TimeMonzo.fromFraction(
-        new Fraction(node.equave.numerator, node.equave.denominator ?? 1)
-      );
-    }
+    const [val, equave] = sparseOffsetToVal(node);
     return new Val(val, equave, node);
   }
 

diff --git a/src/stdlib/public.ts b/src/stdlib/public.ts
@@ -442,27 +442,32 @@ export function temper(
   interval: Interval | Interval[]
 ): typeof interval {
   const divisions = val.divisions;
-  const equave = val.equave.toFraction();
-  let equaveNumerator: number | null = null;
-  let equaveDenominator: number | null = null;
-  if (equave.compare(TWO)) {
-    equaveNumerator = equave.n;
-    if (equave.d !== 1) {
-      equaveDenominator = equave.d;
+  let step: Interval;
+  try {
+    const equave = val.equave.toFraction();
+    let equaveNumerator: number | null = null;
+    let equaveDenominator: number | null = null;
+    if (equave.compare(TWO)) {
+      equaveNumerator = equave.n;
+      if (equave.d !== 1) {
+        equaveDenominator = equave.d;
+      }
     }
+    step = new Interval(
+      TimeMonzo.fromFraction(equave).pow(divisions.inverse()),
+      'logarithmic',
+      0,
+      {
+        type: 'NedjiLiteral',
+        numerator: divisions.d,
+        denominator: divisions.n,
+        equaveNumerator,
+        equaveDenominator,
+      }
+    );
+  } catch {
+    step = new Interval(val.equave.pow(divisions.inverse()), 'logarithmic');
   }
-  const step = new Interval(
-    TimeMonzo.fromFraction(equave).pow(divisions.inverse()),
-    'logarithmic',
-    0,
-    {
-      type: 'NedjiLiteral',
-      numerator: divisions.d,
-      denominator: divisions.n,
-      equaveNumerator,
-      equaveDenominator,
-    }
-  );
   const rel = relative.bind(this);
   if (Array.isArray(interval)) {
     return interval.map(i => {

diff --git a/src/warts.ts b/src/warts.ts
@@ -8,6 +8,7 @@ import {
 } from './expression';
 import {NEGATIVE_ONE, ONE, ZERO} from './utils';
 
+const TWO_MONZO = new TimeMonzo(ZERO, [ONE]);
 const SECOND_MONZO = new TimeMonzo(ONE, []);
 const HERTZ_MONZO = new TimeMonzo(NEGATIVE_ONE, []);
 const REAL_CENT_MONZO = new TimeReal(0, 1.0005777895065548);
@@ -271,12 +272,22 @@ export function wartsToVal(node: WartsLiteral) {
   return valToTimeMonzo(val, subgroup);
 }
 
-export function sparseOffsetToVal(node: SparseOffsetVal) {
+export function sparseOffsetToVal(
+  node: SparseOffsetVal
+): [TimeMonzo, TimeMonzo] {
   const {subgroup} = parseValSubgroup(node.basis);
+  let equave = TWO_MONZO;
   if (node.equave) {
-    const equave = TimeMonzo.fromFraction(
+    equave = TimeMonzo.fromFraction(
       new Fraction(node.equave.numerator, node.equave.denominator ?? 1)
     );
+    if (node.equave.radical) {
+      const splitEquave = equave.sqrt();
+      if (splitEquave instanceof TimeReal) {
+        throw new Error('Unable to split val equave.');
+      }
+      equave = splitEquave;
+    }
     shiftEquave(equave, subgroup);
   }
   const val = patentVal(node.divisions, subgroup);
@@ -295,5 +306,5 @@ export function sparseOffsetToVal(node: SparseOffsetVal) {
       throw new Error('Tweak outside subgroup.');
     }
   }
-  return valToTimeMonzo(val, subgroup);
+  return [valToTimeMonzo(val, subgroup), equave];
 }