Elixir: match arrow clauses using the branch feature

Author: azizk

syntaxes/Elixir.sublime-syntax

@@ -120,47 +120,45 @@ contexts:
   fn_block:
     - match: fn{{no_id_key_suffix}}
       scope: punctuation.section.block.begin.elixir keyword.other.fn.elixir
-      push: [fn_block_end_pop, arrow_clauses_body_pop, fn_single_body_or_pop]
-
-  fn_single_body_or_pop:
-    - match: (?=->)
-      set:
-        - match: (?=end{{no_id_key_suffix}})
-          pop: 1
-        - include: if_closing_eex_pop
-        - include: core_syntax
-    - include: if_non_space_or_eol_pop
+      push: [fn_block_end_pop, arrow_clauses_body_pop]
 
   fn_block_end_pop:
     - include: block_end_pop
     - include: core_syntax_or_if_closing_pop
 
   arrow_clauses_body_pop:
+    - include: if_closing_token_pop
     - match: (?=\S)
-      set:
-        - match: (?=->|when{{no_id_key_suffix}})
-          push: inlined_core_syntax_pop
-        # NB: no default parameters in arrow clauses
-        - match: \\\\(?!:{{no_colon_suffix}})
-          scope: keyword.operator.default.elixir invalid.illegal.default-operator.elixir
-        - include: parameters_or_if_closing_pop
-    - match: $
-      set:
-        - include: if_closing_token_pop
-        - match: ^(\s*)(?=[^#\s])
-          push: [indented_core_syntax_pop, params_until_arrow_pop]
-        - include: core_syntax
+      branch_point: non_arrow_clause_branch
+      branch: [non_arrow_core_syntax_pop, params_until_arrow_pop]
 
-  inlined_core_syntax_pop:
-    - match: (?=;)
+  non_arrow_core_syntax_pop:
+    - match: (?=->(?!:)|when{{no_id_key_suffix}})
+      fail: non_arrow_clause_branch
+    - match: (?={{operator}}(?!:))
+      push:
+        - include: operator
+        - include: if_non_space_pop
+    - match: (?=;|$)
       pop: 1
     - include: core_syntax_or_if_closing_pop
 
   params_until_arrow_pop:
-    - match: (?=->|when{{no_id_key_suffix}})
-      pop: 1
+    - match: (?=when{{no_id_key_suffix}})
+      set:
+        - include: arrow_operator_pop
+        - include: core_syntax_or_if_closing_pop
+    - include: arrow_operator_pop
+    - match: \\\\(?!:{{no_colon_suffix}})
+      comment: no default parameters in arrow clauses
+      scope: keyword.operator.default.elixir invalid.illegal.default-operator.elixir
     - include: parameters_or_if_closing_pop
 
+  arrow_operator_pop:
+    - match: ->(?!:)
+      scope: keyword.operator.arrow.elixir
+      pop: 1
+
   indented_core_syntax_pop:
     - match: ^(?=\1[^#\s]|(?!\1)(?!\s*(#|$)))
       pop: 1

tests/syntax_test_misc.ex

@@ -118,7 +118,7 @@
 #^ invalid.illegal.stray-closing-brace
 
  (fn -> ) end)
-#       ^ invalid.illegal.stray-closing-parenthesis
+#            ^ invalid.illegal.stray-closing-parenthesis
  fn -> end
 #      ^^^ punctuation.section.block.end keyword.context.block.end
 #   ^^ keyword.operator.arrow
@@ -162,8 +162,17 @@
 #          ^ variable.other -variable.parameter
 #   ^ variable.parameter
 
+ fn x when
+#     ^^^^ keyword.operator.when
+#   ^ variable.parameter
+    x -> x end
+#          ^^^ keyword.context.block.end
+#        ^ variable.other
+#   ^ variable.other
+
 fn
-   [], acc -> acc
+   [], acc \\ [] -> acc
+#          ^^ keyword.operator.default invalid.illegal.default-operator
 #    ^ punctuation.separator.sequence
    x, acc -> [x | acc]
 #   ^ punctuation.separator.sequence
@@ -215,14 +224,14 @@ y -> y
   z -> z
   #    ^ variable.other -variable.parameter
   # ^^ keyword.operator.arrow
-  #<- variable.other -variable.parameter
+  #<- variable.parameter
 end
 #^^ punctuation.section.block.end
 fn -> x; y -> z end
 #               ^^^ punctuation.section.block.end
 #             ^ variable.other
 #          ^^ keyword.operator.arrow
-#        ^ -variable.parameter
+#        ^ variable.parameter
 #     ^ variable.other
 #  ^^ keyword.operator.arrow
 fn x -> x; y -> y end
@@ -282,7 +291,7 @@ end
      -> var -> var
     #          ^^^ variable.other
     #       ^^ keyword.operator.arrow
-    #   ^^^ variable.other
+    #   ^^^ variable.parameter
     #^^ keyword.operator.arrow
     expr
     #^^^ variable.other
@@ -1252,8 +1261,8 @@ fn a,,b -> end
 #          ^ punctuation.section.group.end
 #    ^ invalid.illegal.stray-closing-parenthesis
 ( fn -> ) end )
-#             ^ punctuation.section.group.end
-#       ^ invalid.illegal.stray-closing-parenthesis
+#             ^ invalid.illegal.stray-closing-parenthesis
+#       ^ punctuation.section.group.end
 
 [ ( ] )
 #     ^ invalid.illegal.stray-closing-parenthesis
@@ -1274,8 +1283,8 @@ fn a,,b -> end
 #          ^ punctuation.section.brackets.end
 #    ^ invalid.illegal.stray-closing-bracket
 [ fn -> ] end ]
-#             ^ punctuation.section.brackets.end
-#       ^ invalid.illegal.stray-closing-bracket
+#             ^ invalid.illegal.stray-closing-bracket
+#       ^ punctuation.section.brackets.end
 
 { ( } )
 #     ^ invalid.illegal.stray-closing-parenthesis
@@ -1296,8 +1305,8 @@ fn a,,b -> end
 #          ^ punctuation.section.sequence.end
 #    ^ invalid.illegal.stray-closing-brace
 { fn -> } end }
-#             ^ punctuation.section.sequence.end
-#       ^ invalid.illegal.stray-closing-brace
+#             ^ invalid.illegal.stray-closing-brace
+#       ^ punctuation.section.sequence.end
 
 %{ ( } )
 #      ^ invalid.illegal.stray-closing-parenthesis
@@ -1318,8 +1327,8 @@ fn a,,b -> end
 #           ^ punctuation.section.mapping.end
 #     ^ invalid.illegal.stray-closing-brace
 %{ fn -> } end }
-#              ^ punctuation.section.mapping.end
-#        ^ invalid.illegal.stray-closing-brace
+#              ^ invalid.illegal.stray-closing-brace
+#        ^ punctuation.section.mapping.end
 
 << ( >> )
 #       ^ invalid.illegal.stray-closing-parenthesis
@@ -1340,8 +1349,8 @@ fn a,,b -> end
 #            ^^ punctuation.definition.string.end
 #     ^^ invalid.illegal.stray-closing-binary
 << fn -> >> end >>
-#               ^^ punctuation.definition.string.end
-#        ^^ invalid.illegal.stray-closing-binary
+#               ^^ invalid.illegal.stray-closing-binary
+#        ^^ punctuation.definition.string.end
 
 do ( end )
 #        ^ invalid.illegal.stray-closing-parenthesis