From 5bec779b4a464093bf7415af928fa468e7bfad79 Mon Sep 17 00:00:00 2001
From: Thomas Weber <tommyweber33@gmail.com>
Date: Mon, 6 Jul 2020 18:23:16 -0500
Subject: [PATCH] minor optimizations/fixes

---
 .../blocks/compiler_scratch3_operators.js     |  4 +--
 src/compiler/compiler.js                      | 30 +++++++++----------
 src/compiler/execute.js                       | 16 +++++-----
 3 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/src/compiler/blocks/compiler_scratch3_operators.js b/src/compiler/blocks/compiler_scratch3_operators.js
index 897c0e69..35c8ee09 100644
--- a/src/compiler/blocks/compiler_scratch3_operators.js
+++ b/src/compiler/blocks/compiler_scratch3_operators.js
@@ -103,7 +103,7 @@ const multiply = /** @param {InputUtil} util */ (util) => {
 const divide = /** @param {InputUtil} util */ (util) => {
     const NUM1 = util.input('NUM1');
     const NUM2 = util.input('NUM2');
-    return util.number(`(${NUM1.asNumber()} / ${NUM2.asNumber()})`).nanable();
+    return util.number(`(${NUM1.asNumber()} / ${NUM2.asNumber()})`).setFlag(util.FLAG_NANABLE);
 };
 
 const mathop = /** @param {InputUtil} util */ (util) => {
@@ -113,7 +113,7 @@ const mathop = /** @param {InputUtil} util */ (util) => {
         case 'abs': return util.number(`Math.abs(${NUM})`);
         case 'floor': return util.number(`Math.floor(${NUM})`);
         case 'ceiling': return util.number(`Math.ceil(${NUM})`);
-        case 'sqrt': return util.number(`Math.sqrt(${NUM})`).nanable();
+        case 'sqrt': return util.number(`Math.sqrt(${NUM})`).setFlag(util.FLAG_NANABLE);
         // TODO: consider rounding as Scratch 3 does
         case 'sin': return util.number(`Math.sin((Math.PI * ${NUM}) / 180)`);
         case 'cos': return util.number(`Math.cos((Math.PI * ${NUM}) / 180)`);
diff --git a/src/compiler/compiler.js b/src/compiler/compiler.js
index dd5825c1..391e32e5 100644
--- a/src/compiler/compiler.js
+++ b/src/compiler/compiler.js
@@ -28,8 +28,7 @@ const TYPE_NUMBER = 1;
 const TYPE_BOOLEAN = 2;
 const TYPE_STRING = 3;
 
-const FLAG_NULLABLE = 1;
-const FLAG_NANABLE = 2;
+const FLAG_NANABLE = 1;
 
 defaultExtensions.forEach((ext) => {
     const extensionInputs = ext.getInputs();
@@ -49,8 +48,8 @@ defaultExtensions.forEach((ext) => {
 
 /**
  * Prevents the use of toString() on an object by throwing an error.
- * Useful to make sure that a method is always called, never stringified.
- * @param {Object} obj 
+ * Useful to make sure that a method is always called, never accidentally stringified.
+ * @param {Object} obj
  */
 const disableToString = (obj) => {
     obj.toString = () => {
@@ -67,6 +66,13 @@ class BlockUtil {
         this.block = block;
     }
 
+    // Expose some constants that are likely to be of use to blocks.
+    get TYPE_UNKNOWN() { return TYPE_UNKNOWN; }
+    get TYPE_NUMBER() { return TYPE_NUMBER; }
+    get TYPE_BOOLEAN() { return TYPE_BOOLEAN; }
+    get TYPE_STRING() { return TYPE_STRING; }
+    get FLAG_NANABLE() { return FLAG_NANABLE; }
+
     get target() {
         return this.compiler.target;
     }
@@ -281,7 +287,6 @@ class CompiledInput {
         /**
          * The input's type.
          * @readonly
-         * @private
          */
         this.type = type;
         /**
@@ -292,18 +297,11 @@ class CompiledInput {
     }
 
     /**
-     * Enable the NULLABLE flag.
+     * Enable a flag.
+     * @param {number} flag The value of the flag to enable.
      */
-    nullable() {
-        this.flags |= FLAG_NULLABLE;
-        return this;
-    }
-
-    /**
-     * Enable the NANABLE flag.
-     */
-    nanable() {
-        this.flags |= FLAG_NANABLE;
+    setFlag(flag) {
+        this.flags |= flag;
         return this;
     }
 
diff --git a/src/compiler/execute.js b/src/compiler/execute.js
index 20265486..802968fc 100644
--- a/src/compiler/execute.js
+++ b/src/compiler/execute.js
@@ -123,8 +123,7 @@ const retire = () => {
  * @returns {number}
  */
 const toNumber = (value) => {
-    // The only falsey values that Number can return is 0 and NaN, both of which are treated as 0.
-    return Number(value) || 0;
+    return +value || 0;
 };
 
 /**
@@ -152,7 +151,7 @@ const toBoolean = (value) => {
         }
         return true;
     }
-    return Boolean(value);
+    return !!value;
 };
 
 /**
@@ -183,16 +182,16 @@ const isWhiteSpace = (val) => {
  * @returns {number} Negative if v1 < v2, 0 if equal, positive if v1 > v2
  */
 const compare = (v1, v2) => {
-    let n1 = Number(v1);
-    let n2 = Number(v2);
+    let n1 = +v1;
+    let n2 = +v2;
     if (n1 === 0 && isWhiteSpace(v1)) {
         n1 = NaN;
     } else if (n2 === 0 && isWhiteSpace(v2)) {
         n2 = NaN;
     }
     if (isNaN(n1) || isNaN(n2)) {
-        const s1 = String(v1).toLowerCase();
-        const s2 = String(v2).toLowerCase();
+        const s1 = ('' + v1).toLowerCase();
+        const s2 = ('' + v2).toLowerCase();
         if (s1 < s2) {
             return -1;
         } else if (s1 > s2) {
@@ -253,8 +252,9 @@ var listIndex = (index, length) => {
             }
             return -1;
         }
+        index = toNumber(index);
     }
-    index = Math.floor(toNumber(index));
+    index = Math.floor(index);
     if (index < 1 || index > length) {
         return -1;
     }