From 8a7e49780a13cbfabb43a9a5089a050bc69effaf Mon Sep 17 00:00:00 2001
From: Felix Roos <roos@entrecode.de>
Date: Sun, 27 Feb 2022 21:24:23 +0100
Subject: [PATCH] added _asNumber + interprete numbers as midi

---
 repl/src/useRepl.ts |  9 +++++++--
 strudel.mjs         | 30 ++++++++++++++++++++++++++----
 util.mjs            | 11 +++++++++++
 3 files changed, 44 insertions(+), 6 deletions(-)
 create mode 100644 util.mjs

diff --git a/repl/src/useRepl.ts b/repl/src/useRepl.ts
index af477c9f..22d98515 100644
--- a/repl/src/useRepl.ts
+++ b/repl/src/useRepl.ts
@@ -1,5 +1,6 @@
 import { useCallback, useState, useMemo } from 'react';
 import { isNote } from 'tone';
+import { fromMidi } from '../../util.mjs';
 import { evaluate } from './evaluate';
 import type { Pattern } from './types';
 import useCycle from './useCycle';
@@ -63,8 +64,12 @@ function useRepl({ tune, defaultSynth, autolink = true, onEvent, onDraw }: any)
           onEvent?.(event);
           const { onTrigger } = event.context;
           if (!onTrigger) {
-            const note = event.value;
-            if (!isNote(note)) {
+            let note = event.value;
+            // if value is number => interpret as midi number...
+            // TODO: what if value is meant as frequency? => check context
+            if (typeof event.value === 'number') {
+              note = fromMidi(event.value);
+            } else if (!isNote(note)) {
               throw new Error('not a note: ' + note);
             }
             if (defaultSynth) {
diff --git a/strudel.mjs b/strudel.mjs
index 505cdcb4..45ec1c31 100644
--- a/strudel.mjs
+++ b/strudel.mjs
@@ -1,5 +1,6 @@
 import Fraction from 'fraction.js'
 import { compose } from 'ramda'; // will remove this as soon as compose is implemented here
+import { isNote, toMidi } from './util.mjs';
 
 // Removes 'None' values from given list
 const removeUndefineds = xs => xs.filter(x => x != undefined)
@@ -466,20 +467,41 @@ class Pattern {
         return this.fmap(func).appLeft(reify(other))
     }
 
+    _asNumber() {
+      return this._withEvent(event => {
+        const asNumber = Number(event.value)
+        if(!isNaN(asNumber)) {
+          return asNumber;
+        }
+        const specialValue = {
+          e: Math.E,
+          pi: Math.PI
+        }[event.value];
+        if(typeof specialValue !== 'undefined') {
+          return specialValue;
+        }
+        if(isNote(event.value)) {
+          // set context type to midi to let the player know its meant as midi number and not as frequency
+          return new Hap(event.whole, event.part, toMidi(event.value), { ...event.context, type: 'midi' });
+        }
+        throw new Error('cannot parse as number: "' + event.value + '"');
+      })
+    }
+
     add(other) {
-        return this._opleft(other, a => b => a + b)
+        return this._asNumber()._opleft(other, a => b => a + b)
     }
 
     sub(other) {
-        return this._opleft(other, a => b => a - b)
+        return this._asNumber()._opleft(other, a => b => a - b)
     }
     
     mul(other) {
-        return this._opleft(other, a => b => a * b)
+        return this._asNumber()._opleft(other, a => b => a * b)
     }
 
     div(other) {
-        return this._opleft(other, a => b => a / b)
+        return this._asNumber()._opleft(other, a => b => a / b)
     }
 
     union(other) {
diff --git a/util.mjs b/util.mjs
new file mode 100644
index 00000000..ad9f58d6
--- /dev/null
+++ b/util.mjs
@@ -0,0 +1,11 @@
+export const isNote = (name) => /^[a-gA-G][#b]?[0-9]$/.test(name);
+export const tokenizeNote = (note) => note.match(/^([a-gA-G])([#b])?([0-9])?$/).slice(1);
+export const toMidi = (note) => {
+  const [pc, acc, oct] = tokenizeNote(note);
+  const chroma = { c: 0, d: 2, e: 4, f: 5, g: 7, a: 9, b: 11 }[pc];
+  const offset = acc?.split('').reduce((o, char) => o + { '#': 1, b: -1 }[char], 0) || 0;
+  return (Number(oct) + 1) * 12 + chroma + offset;
+};
+export const fromMidi = (n) => {
+  return Math.pow(2, (n - 69) / 12) * 440;
+};