some testing with Fraction mock class

packages/core/fraction.mjs

@@ -4,9 +4,68 @@ Copyright (C) 2022 Strudel contributors - see <https://github.com/tidalcycles/st
 This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */
 
-import Fraction from 'fraction.js';
+// import Fraction from 'fraction.js';
 import { TimeSpan } from './timespan.mjs';
 
+// this is a "mock" for fraction.js, using just floats without any rational arithmetic
+// to test if the performance gets better without fraction.js
+// result: it seems to get better but not by much
+// the main jankyness remains for some cpmplicated patterns
+// i tried counting the calls of Fraction.add and noticed there can be ~250 million calls per second
+// so even if the add function is just a regular add, the sheer number of calls is a problem
+
+class Fraction {
+  value; // number
+  constructor(value) {
+    if (value instanceof Fraction) {
+      this.value = value.value;
+    } else if (typeof value === 'string') {
+      const [n, d] = value.split('/');
+      this.value = n / (d || 1);
+    } else if (typeof value !== 'number' || isNaN(value)) {
+      console.warn('Fraction got NaN', value);
+    } else {
+      this.value = Number(value);
+      if (isNaN(this.value)) {
+        console.warn('Fraction parsed NaN from', value);
+      }
+    }
+  }
+  add(other) {
+    return new Fraction(this.value + other);
+  }
+  sub(other) {
+    return new Fraction(this.value - other);
+  }
+  mul(other) {
+    return new Fraction(this.value * other);
+  }
+  div(other) {
+    return new Fraction(this.value / other);
+  }
+  toString() {
+    return this.value + '';
+  }
+  valueOf() {
+    return this.value;
+  }
+  floor() {
+    return new Fraction(Math.floor(this.value));
+  }
+  abs() {
+    return new Fraction(Math.abs(this.value));
+  }
+  inverse() {
+    return new Fraction(1 / this.value);
+  }
+  compare(other) {
+    return this.value - other;
+  }
+  equals(other) {
+    return this.value.valueOf() === other.valueOf();
+  }
+}
+
 // Returns the start of the cycle.
 Fraction.prototype.sam = function () {
   return this.floor();
@@ -63,20 +122,20 @@ Fraction.prototype.or = function (other) {
   return this.eq(0) ? other : this;
 };
 
-const fraction = (n) => {
+/* const fraction = (n) => {
   if (typeof n === 'number') {
-    /*
-    https://github.com/infusion/Fraction.js/#doubles
-    „If you pass a double as it is, Fraction.js will perform a number analysis based on Farey Sequences."
-    „If you want to keep the number as it is, convert it to a string, as the string parser will not perform any further observations“
+    // https://github.com/infusion/Fraction.js/#doubles
+    // „If you pass a double as it is, Fraction.js will perform a number analysis based on Farey Sequences."
+    // „If you want to keep the number as it is, convert it to a string, as the string parser will not perform any further observations“
     
-    -> those farey sequences turn out to make pattern querying ~20 times slower! always use strings!
-    -> still, some optimizations could be done: .mul .div .add .sub calls still use numbers
-    */
+    // -> those farey sequences turn out to make pattern querying ~20 times slower! always use strings!
+    // -> still, some optimizations could be done: .mul .div .add .sub calls still use numbers
     n = String(n);
   }
   return Fraction(n);
-};
+}; */
+
+const fraction = (n) => new Fraction(n);
 
 export const gcd = (...fractions) => {
   return fractions.reduce((gcd, fraction) => gcd.gcd(fraction), fraction(1));