Fix show() to show sign, fix off()

strudel.mjs

@@ -73,7 +73,7 @@ Fraction.prototype.min = function(other) {
 }
 
 Fraction.prototype.show = function () {
-    return this.n + "/" + this.d
+    return (this.s * this.n) + "/" + this.d
 }
 
 Fraction.prototype.or = function(other) {
@@ -574,7 +574,7 @@ class Pattern {
     }
 
     off(time_pat, func) {
-        return stack([this, func(this._early(time_pat))])
+        return stack(this, func(this.late(time_pat)))
     }
 
     every(n, func) {

test/pattern.test.mjs

@@ -355,4 +355,26 @@ describe('Pattern', function() {
       )
     })
   })
+  describe("early", () => {
+    it("Can shift an event earlier", () => {
+      assert.deepStrictEqual(
+        pure(30)._late(0.25).query(ts(1,2)),
+        [hap(ts(1/4,5/4), ts(1,5/4), 30), hap(ts(5/4,9/4), ts(5/4,2), 30)]
+      )
+    })
+    it("Can shift an event earlier, into negative time", () => {
+      assert.deepStrictEqual(
+        pure(30)._late(0.25).query(ts(0,1)),
+        [hap(ts(-3/4,1/4), ts(0,1/4), 30), hap(ts(1/4,5/4), ts(1/4,1), 30)]
+      )
+    })    
+  })
+  describe("off", () => {
+    it("Can offset a transformed pattern from the original", () => {
+      assert.deepStrictEqual(
+        pure(30).off(0.25, add(2)).firstCycle,
+        stack(pure(30), pure(30).early(0.25).add(2)).firstCycle
+      )
+    })
+  })
 })