perf(parse): avoid more allocations

json5 · Jun 14, 2022 · 649b6ec · 649b6ec
1 parent c4ca56b
commit 649b6ec
Showing 1 changed file with 14 additions and 7 deletions.
diff --git a/lib/parse.js b/lib/parse.js
@@ -65,6  65,13 @@ const tokenRef = {
 const FIRST_DOUBLE_LENGTH_CODE = 2 ** 16
 const getCodePointLength = c => c >= FIRST_DOUBLE_LENGTH_CODE ? 2 : 1
 
 const LITERAL_ULL     = [117 /* 'u' */, 108 /* 'l' */, 108 /* 'l' */]
 const LITERAL_RUE     = [114 /* 'r' */, 117 /* 'u' */, 101 /* 'e' */]
 const LITERAL_ALSE    = [97 /* 'a' */, 108 /* 'l' */, 115 /* 's' */, 101 /* 'e' */]
 const LITERAL_NFINITY = [110 /* 'n' */, 102 /* 'f' */, 105 /* 'i' */, 110 /* 'n' */, 105 /* 'i' */, 116 /* 't' */, 121 /* 'y' */]
 const LITERAL_AN      = [97 /* 'a' */, 78 /* 'N' */]
 
 
 let source
 let parseState
 let stack
@@ -293,17  300,17 @@ const lexStates = {
 
         case 110 /* 'n' */:
             skip()
-            literal([117 /* 'u' */, 108 /* 'l' */, 108 /* 'l' */])
             literal(LITERAL_ULL)
             return newToken(Token.null, null)
 
         case 116 /* 't' */:
             skip()
-            literal([114 /* 'r' */, 117 /* 'u' */, 101 /* 'e' */])
             literal(LITERAL_RUE)
             return newToken(Token.boolean, true)
 
         case 102 /* 'f' */:
             skip()
-            literal([97 /* 'a' */, 108 /* 'l' */, 115 /* 's' */, 101 /* 'e' */])
             literal(LITERAL_ALSE)
             return newToken(Token.boolean, false)
 
         case 45 /* '-' */:
@@ -340,12  347,12 @@ const lexStates = {
 
         case 73 /* 'I' */:
             skip()
-            literal([110 /* 'n' */, 102 /* 'f' */, 105 /* 'i' */, 110 /* 'n' */, 105 /* 'i' */, 116 /* 't' */, 121 /* 'y' */])
             literal(LITERAL_NFINITY)
             return newToken(Token.numeric, Infinity)
 
         case 78 /* 'N' */:
             skip()
-            literal([97 /* 'a' */, 78 /* 'N' */])
             literal(LITERAL_AN)
             return newToken(Token.numeric, NaN)
 
         case 34 /* '"' */:
@@ -459,12  466,12 @@ const lexStates = {
 
         case 73 /* 'I' */:
             skip()
-            literal([110 /* 'n' */, 102 /* 'f' */, 105 /* 'i' */, 110 /* 'n' */, 105 /* 'i' */, 116 /* 't' */, 121 /* 'y' */])
             literal(LITERAL_NFINITY)
             return newToken(Token.numeric, sign * Infinity)
 
         case 78 /* 'N' */:
             skip()
-            literal([97 /* 'a' */, 78 /* 'N' */])
             literal(LITERAL_AN)
             return newToken(Token.numeric, NaN)
         }