add ratio function

packages/core/pattern.mjs

@@ -1582,6 +1582,24 @@ export const range2 = register('range2', function (min, max, pat) {
   return pat.fromBipolar()._range(min, max);
 });
 
+/**
+ * Allows dividing numbers via list notation using ":".
+ * Returns a new pattern with just numbers.
+ * @name ratio
+ * @memberof Pattern
+ * @returns Pattern
+ * @example
+ * ratio("1, 5:4, 3:2").mul(110).freq().s("piano").slow(2)
+ */
+export const ratio = register('ratio', (pat) =>
+  pat.fmap((v) => {
+    if (!Array.isArray(v)) {
+      return v;
+    }
+    return v.slice(1).reduce((acc, n) => acc / n, v[0]);
+  }),
+);
+
 //////////////////////////////////////////////////////////////////////
 // Structural and temporal transformations
 

test/__snapshots__/examples.test.mjs.snap

@@ -3193,6 +3193,23 @@ exports[`runs examples > example "rarely" example index 0 1`] = `
 ]
 `;
 
+exports[`runs examples > example "ratio" example index 0 1`] = `
+[
+  "[ (0/1 → 1/1) ⇝ 2/1 | freq:110 s:piano ]",
+  "[ (0/1 → 1/1) ⇝ 2/1 | freq:137.5 s:piano ]",
+  "[ (0/1 → 1/1) ⇝ 2/1 | freq:165 s:piano ]",
+  "[ 0/1 ⇜ (1/1 → 2/1) | freq:110 s:piano ]",
+  "[ 0/1 ⇜ (1/1 → 2/1) | freq:137.5 s:piano ]",
+  "[ 0/1 ⇜ (1/1 → 2/1) | freq:165 s:piano ]",
+  "[ (2/1 → 3/1) ⇝ 4/1 | freq:110 s:piano ]",
+  "[ (2/1 → 3/1) ⇝ 4/1 | freq:137.5 s:piano ]",
+  "[ (2/1 → 3/1) ⇝ 4/1 | freq:165 s:piano ]",
+  "[ 2/1 ⇜ (3/1 → 4/1) | freq:110 s:piano ]",
+  "[ 2/1 ⇜ (3/1 → 4/1) | freq:137.5 s:piano ]",
+  "[ 2/1 ⇜ (3/1 → 4/1) | freq:165 s:piano ]",
+]
+`;
+
 exports[`runs examples > example "release" example index 0 1`] = `
 [
   "[ 0/1 → 1/4 | note:c3 release:0 ]",

website/src/pages/functions/value-modifiers.mdx

@@ -139,6 +139,10 @@ This group of functions allows to modify the value of events.
 
 <JsDoc client:idle name="Pattern.range2" h={0} />
 
+## ratio
+
+<JsDoc client:idle name="Pattern.ratio" h={0} />
+
 # Custom Parameters
 
 You can also create your own parameters: