[Lua] Split out = from other operators

Author: mbartlett21

Lua/Lua.sublime-syntax

@@ -205,13 +205,13 @@ contexts:
 
     - match: local{{identifier_break}}
       scope: storage.modifier.lua
-      push: expression-list
+      push: expression-list-stmt
 
     - match: end{{identifier_break}}
       scope: invalid.illegal.unexpected-end.lua
 
     - match: (?=\S)
-      push: expression
+      push: expression-stmt
 
   block-contents:
     - meta_scope: meta.block.lua
@@ -312,15 +312,15 @@ contexts:
           - include: else-pop
 
         - - match: (?==)
-            set: expression-list-end
+            set: expression-list-stmt-end
 
           - match: in{{identifier_break}}
             scope: keyword.control.loop.lua
             set: expression-list
 
           - include: else-pop
 
-        - expression-list
+        - expression-list-stmt
 
     - match: '::'
       scope: punctuation.definition.label.begin.lua
@@ -367,12 +367,24 @@ contexts:
         - expression-end
         - expression-begin
 
+  expression-stmt:
+    - match: ''
+      set:
+        - expression-stmt-end
+        - expression-begin
+
   expression-list:
     - match: ''
       set:
         - expression-list-end
         - expression-begin
 
+  expression-list-stmt:
+    - match: ''
+      set:
+        - expression-list-stmt-end
+        - expression-begin
+
   expression-end:
     - match: (?=;)
       pop: 1
@@ -394,6 +406,12 @@ contexts:
 
     - include: else-pop
 
+  expression-stmt-end:
+    - match: =(?!=)
+      scope: keyword.operator.assignment.lua
+      push: expression-begin
+    - include: expression-end
+
   expression-list-end:
     - match: ','
       scope: punctuation.separator.comma.lua
@@ -405,6 +423,12 @@ contexts:
         - left-angle-is-less-than
     - include: expression-end
 
+  expression-list-stmt-end:
+    - match: =(?!=)
+      scope: keyword.operator.assignment.lua
+      push: expression-begin
+    - include: expression-list-end
+
   expression-begin:
     - match: (?=;)
       pop: 1
@@ -457,13 +481,19 @@ contexts:
     - match: \.\.
       scope: keyword.operator.concatenation.lua
       push: expression-begin
-    - match: =
-      scope: keyword.operator.assignment.lua
-      push: expression-begin
     - match: (?:and|or){{identifier_break}}
       scope: keyword.operator.logical.lua
       push: expression-begin
 
+    # assume that == is being typed
+    - match: =(?=\s*(?:{{reserved_word_statement}}|$))
+      scope: keyword.operator.comparison.lua
+      push: expression-begin
+    # only complain once it is clear that it isn't ==
+    - match: =(?!=)
+      scope: invalid.illegal.invalid-operator.lua
+      push: expression-begin
+
   accessor:
     - match: '[.:]'
       scope: punctuation.accessor.lua

Lua/tests/syntax_test_lua.lua

@@ -623,6 +623,15 @@
     elseif false then
 --  ^^^^^^ keyword.control.conditional
 --               ^^^^ keyword.control.conditional
+    elseif a = 0 then
+--         ^ variable.other
+--           ^ invalid.illegal.invalid-operator
+--             ^ constant.numeric.value
+--               ^^^^ keyword.control.conditional
+    elseif a = then
+--         ^ variable.other
+--           ^ keyword.operator.comparison
+--             ^^^^ keyword.control.conditional
     else
 --  ^^^^ keyword.control.conditional
     end
@@ -634,6 +643,7 @@
 
     if a ! = b then end
 --       ^ invalid.illegal.unexpected-character.lua
+--         ^ invalid.illegal.invalid-operator.lua
 --             ^^^^ keyword.control.conditional
 --                  ^^^ keyword.control.end