Merge pull request #446 from frostburn/js-exponentiation

Add ExponentiationExpression rule to javascript.pegjs
peggyjs · Dec 3, 2023 · 8aa207c · 8aa207c
2 parents f323563 + 221aa9e
commit 8aa207c
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diff --git a/AUTHORS b/AUTHORS
@@ -34,3 +34,4 @@ fpirsch <fpirsch@free.fr> (https://github.com/fpirsch/)
 markw65 <mark@replayroutes.com> (https://github.com/markw65/)
 Andy (https://github.com/AndrewRayCode)
 Kristian Dupont <kristian@kristiandupont.com> (https://github.com/kristiandupont/)
+Lumi Pakkanen <lumi.pakkanen@gmail.com> (https://github.com/frostburn/)
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -16,6 +16,7 @@ Released: TBD
 
 ### Minor Changes
 
+- [#446](https://github.com/peggyjs/peggy/pull/446) Add a right-associative `ExponentiationExpression` rule (operator `**`) to `javascript.pegjs` example grammar.
 - [#427](https://github.com/peggyjs/peggy/pull/427) Avoid double extraction of
   substrings in various MATCH_ bytecodes
 - [#425](https://github.com/peggyjs/peggy/pull/425) Add a pass to simplify single-character choices

diff --git a/examples/javascript.pegjs b/examples/javascript.pegjs
@@ -716,9 +716,17 @@ UnaryOperator
   / "~"
   / "!"
 
-MultiplicativeExpression
+ExponentiationExpression
   = head:UnaryExpression
-    tail:(__ MultiplicativeOperator __ UnaryExpression)*
+    tail:(__ ExponentiationOperator __ ExponentiationExpression)*
+    { return buildBinaryExpression(head, tail); }
+
+ExponentiationOperator
+  = $("**" !"=")
+
+MultiplicativeExpression
+  = head:ExponentiationExpression
+    tail:(__ MultiplicativeOperator __ ExponentiationExpression)*
     { return buildBinaryExpression(head, tail); }
 
 MultiplicativeOperator
@@ -930,7 +938,8 @@ AssignmentExpressionNoIn
   / ConditionalExpressionNoIn
 
 AssignmentOperator
-  = "*="
+  = "**="
+  / "*="
   / "/="
   / "%="
   / "+="