fix: harmonise TS and AS execution

ref #17

Author: ColinEberhardt

.prettierignore

@@ -0,0 +1,2 @@
+# prettier doesn't support decorators on functions :-(
+assembly/char.ts

assembly/char.ts

@@ -5,6 +5,7 @@ export const enum Char {
   FormFeed = 0x0c,
   CarriageReturn = 0x0d,
   LineFeed = 0x0a,
+  Space = 0x20,
   Dollar = 0x24, // "$"
   LeftParenthesis = 0x28,
   RightParenthesis = 0x29,
@@ -14,11 +15,13 @@ export const enum Char {
   Minus = 0x2d, // "-"
   Dot = 0x2e, // "."
   Zero = 0x30,
+  Nine = 0x39,
   Question = 0x3f, // "?"
   A = 0x41,
   D = 0x44,
   S = 0x53,
   W = 0x57,
+  Z = 0x5a,
   LeftSquareBracket = 0x5b, // "["
   Backslash = 0x5c, // "\"
   RightSquareBracket = 0x5d, // "]"
@@ -35,40 +38,58 @@ export const enum Char {
   v = 0x76,
   w = 0x77,
   x = 0x78,
+  z = 0x7a,
   LeftCurlyBrace = 0x7b /* { */,
   VerticalBar = 0x7c /* | */,
-  RightCurlyBrace = 0x7d /*  */,
+  RightCurlyBrace = 0x7d /* { */,
+  NonBreakingSpace = 0xa0,
+}
+
+// @ts-ignore 
+@inline
+function inRange(value: u32, from: u32, to: u32): bool {
+  if (ASC_TARGET == 1) {
+    // makes use of unsigned integer operations, making this
+    // approach a little faster when compiled to WASM
+    return value - from < (to - from + 1);
+  } else {
+    return value >= from && value <= to;
+  }
 }
 
 export function isDigit(code: u32): bool {
-  return code - Char.Zero < 10;
+  return inRange(code, Char.Zero, Char.Nine);
 }
 
 export function isHexadecimalDigit(code: u32): bool {
-  return isDigit(code) || code - Char.a < 6;
+  return isDigit(code) || inRange(code, Char.a, Char.f);
 }
 
 export function isLowercaseAlpha(code: u32): bool {
-  return code - Char.a < 26;
+  return inRange(code, Char.a, Char.z);
 }
 
 export function isUppercaseAlpha(code: u32): bool {
-  return code - Char.A < 26;
+  return inRange(code, Char.A, Char.Z);
 }
 
 export function isAlpha(code: u32): bool {
-  return (code | 32) - Char.a < 26;
+  if (ASC_TARGET == 1) {
+    return (code | 32) - Char.a < 26;
+  } else {
+    return inRange(code, Char.a, Char.z) || inRange(code, Char.A, Char.Z);
+  }
 }
 
 export function isWhitespace(code: u32): bool {
-  if (code < 0x1680) {
-    // < <LS> (1)
-    // <SP>, <TAB>, <LF>, <VT>, <FF>, <CR> and <NBSP>
-    // @ts-ignore: cast
-    return ((code | 0x80) == 0xa0) | (code - 0x09 <= 0x0d - 0x09);
-  }
-  if (code - 0x2000 <= 0x200a - 0x2000) return true;
   switch (code) {
+    case Char.Space:
+    case Char.HorizontalTab:
+    case Char.VerticalTab:
+    case Char.FormFeed:
+    case Char.LineFeed:
+    case Char.CarriageReturn:
+    case Char.NonBreakingSpace:
     case 0x1680: // <LS> (1)
     case 0x2028: // <LS> (2)
     case 0x2029: // <PS>
@@ -78,5 +99,8 @@ export function isWhitespace(code: u32): bool {
     case 0xfeff:
       return true; // <ZWNBSP>
   }
+  if (inRange(code, 0x2000, 0x200a)) {
+    return true;
+  }
   return false;
 }