Merge pull request #343 from knockout/pc/342-parser-wrong-operator-precedence

Fix operator precedence values to match MDN specification

Author: brianmhunt

packages/utils.parser/src/operators.ts

@@ -29,22 +29,22 @@ export interface Operators {
 function looseEqual(a, b) {
   return a == b
 }
-looseEqual.precedence = 10
+looseEqual.precedence = 8
 
 function looseNotEqual(a, b) {
   return a != b
 }
-looseNotEqual.precedence = 10
+looseNotEqual.precedence = 8
 
 function strictEqual(a, b) {
   return a === b
 }
-strictEqual.precedence = 10
+strictEqual.precedence = 8
 
 function strictNotEqual(a, b) {
   return a !== b
 }
-strictNotEqual.precedence = 10
+strictNotEqual.precedence = 8
 
 const operators: Operators = {
   // unary
@@ -157,69 +157,76 @@ https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Oper
 operators['@'].precedence = 21
 operators['#'].precedence = 21
 
-// Member
-operators['.'].precedence = 19
-operators['['].precedence = 19
-operators['?.'].precedence = 19
+// Member access and call
+operators['.'].precedence = 17
+operators['['].precedence = 17
+operators['?.'].precedence = 17
 
-// Logical not
-operators['!'].precedence = 16
-operators['!!'].precedence = 16 // explicit double-negative
+// Prefix operators
+operators['!'].precedence = 14
+operators['!!'].precedence = 14 // explicit double-negative
 
 // Prefix inc/dec
-operators['++'].precedence = 16
-operators['--'].precedence = 16
-operators['&-'].precedence = 16
-
-// exponent
-operators['**'].precedence = 15
-
-// mul/div/remainder
-operators['%'].precedence = 14
-operators['*'].precedence = 14
-operators['/'].precedence = 14
-
-// add/sub
-operators['+'].precedence = 13
-operators['-'].precedence = 13
-
-// bitwise
-operators['|'].precedence = 12
-operators['^'].precedence = 11
-operators['&'].precedence = 10
-
-// comparison
-operators['<'].precedence = 11
-operators['<='].precedence = 11
-operators['>'].precedence = 11
-operators['>='].precedence = 11
-
-// operators['in'].precedence = 8;
-// operators['instanceof'].precedence = 8;
-// equality
-operators['=='].precedence = 10
-operators['!='].precedence = 10
-operators['==='].precedence = 10
-operators['!=='].precedence = 10
-
-// logic
-operators['&&'].precedence = 6
-operators['||'].precedence = 5
-operators['??'].precedence = 5
+operators['++'].precedence = 14
+operators['--'].precedence = 14
+operators['&-'].precedence = 14
+
+// Exponentiation
+operators['**'].precedence = 13
+
+// Multiplicative
+operators['%'].precedence = 12
+operators['*'].precedence = 12
+operators['/'].precedence = 12
+
+// Additive
+operators['+'].precedence = 11
+operators['-'].precedence = 11
+
+// Relational
+operators['<'].precedence = 9
+operators['<='].precedence = 9
+operators['>'].precedence = 9
+operators['>='].precedence = 9
+
+// operators['in'].precedence = 9;
+// operators['instanceof'].precedence = 9;
+
+// Equality
+operators['=='].precedence = 8
+operators['!='].precedence = 8
+operators['==='].precedence = 8
+operators['!=='].precedence = 8
+
+// Bitwise AND
+operators['&'].precedence = 7
+
+// Bitwise XOR
+operators['^'].precedence = 6
+
+// Bitwise OR
+operators['|'].precedence = 5
+
+// Logical AND
+operators['&&'].precedence = 4
+
+// Logical OR / Nullish coalescing
+operators['||'].precedence = 3
+operators['??'].precedence = 3
 
 operators['&&'].earlyOut = a => !a
 operators['||'].earlyOut = a => a
 operators['??'].earlyOut = a => a
 
-// multiple values
-operators[','].precedence = 2
+// Assignment and miscellaneous (lamda)
+operators['=>'].precedence = 2
+
+// Comma, multiple values
+operators[','].precedence = 1
 
 // Call a function
 operators['call'].precedence = 1
 
-// lambda
-operators['=>'].precedence = 1
-
 // Extend the Options type so ko.options.strictEquality is strongly typed
 declare module '@tko/utils' {
   interface Options {