Make ** be right associative (crystal-lang#9684)

bcardiff · Oct 5, 2020 · 719d314 · 719d314
1 parent 5be111a
commit 719d314
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Showing 2 changed files with 4 additions and 3 deletions.
diff --git a/spec/compiler/parser/parser_spec.cr b/spec/compiler/parser/parser_spec.cr
@@ -136,6 +136,7 @@ module Crystal
     it_parses "foo[] /2", Call.new(Call.new("foo".call, "[]"), "/", 2.int32)
     it_parses "foo[1] /2", Call.new(Call.new("foo".call, "[]", 1.int32), "/", 2.int32)
     it_parses "[1] /2", Call.new(([1.int32] of ASTNode).array, "/", 2.int32)
+    it_parses "2**3**4", Call.new(2.int32, "**", Call.new(3.int32, "**", 4.int32))
 
     it_parses "!1", Not.new(1.int32)
     it_parses "- 1", Call.new(1.int32, "-")

diff --git a/src/compiler/crystal/syntax/parser.cr b/src/compiler/crystal/syntax/parser.cr
@@ -504,7 +504,7 @@ module Crystal
       RangeLiteral.new(exp, right, exclusive).at(location).at_end(right)
     end
 
-    macro parse_operator(name, next_operator, node, operators)
+    macro parse_operator(name, next_operator, node, operators, right_associative = false)
       def parse_{{name.id}}
         location = @token.location
 
@@ -521,7 +521,7 @@ module Crystal
 
             slash_is_regex!
             next_token_skip_space_or_newline
-            right = parse_{{next_operator.id}}
+            right = parse_{{(right_associative ? name : next_operator).id}}
             left = ({{node.id}}).at(location).at_end(right)
             left.name_location = name_location if left.is_a?(Call)
           else
@@ -579,7 +579,7 @@ module Crystal
     end
 
     parse_operator :mul_or_div, :pow, "Call.new left, method, right", %(:"*", :"/", :"//", :"%", :"&*")
-    parse_operator :pow, :prefix, "Call.new left, method, right", %(:"**", :"&**")
+    parse_operator :pow, :prefix, "Call.new left, method, right", %(:"**", :"&**"), right_associative: true
 
     def parse_prefix
       name_location = @token.location