<NME> NegateExpression.txt
<BEF> Elm File
  ElmValueDeclaration(VALUE_DECLARATION)
    ElmFunctionDeclarationLeft(FUNCTION_DECLARATION_LEFT)
      PsiElement(LOWER_CASE_IDENTIFIER)('foo')
    PsiWhiteSpace(' ')
    PsiElement(EQ)('=')
    PsiWhiteSpace(' ')
    ElmNegateExpr(NEGATE_EXPR)
      PsiElement(OPERATOR_IDENTIFIER)('-')
      PsiErrorElement:<expression> expected
        <empty list>

<MSG> Fix negate expression grammar (#327)

The current grammar will parse `f = a -b c` as `f = a -(b c)` rather than `f = a -(b) c`.
<DFF> @@ -7,5 +7,5 @@ Elm File
     PsiWhiteSpace(' ')
     ElmNegateExpr(NEGATE_EXPR)
       PsiElement(OPERATOR_IDENTIFIER)('-')
-      PsiErrorElement:<expression> expected
-        <empty list>
\ No newline at end of file
+      PsiErrorElement:<expr> expected
+        <empty list>

Fix negate expression grammar (#327)