throw more specific errors

Author: tyru

autoload/vimlparser.vim

@@ -1916,6 +1916,14 @@ function! s:VimLParser.parse_constlvalue()
   endif
   if node.type == s:NODE_IDENTIFIER || node.type == s:NODE_CURLYNAME
     return node
+  elseif node.type == s:NODE_SUBSCRIPT || node.type == s:NODE_SLICE || node.type == s:NODE_DOT
+    throw s:Err('E996: Cannot lock a list or dict', node.pos)
+  elseif node.type == s:NODE_OPTION
+    throw s:Err('E996: Cannot lock an option', node.pos)
+  elseif node.type == s:NODE_ENV
+    throw s:Err('E996: Cannot lock an environment variable', node.pos)
+  elseif node.type == s:NODE_REG
+    throw s:Err('E996: Cannot lock a register', node.pos)
   endif
   throw s:Err('Invalid Expression', node.pos)
 endfunction

test/test_err_const1.ok

@@ -0,0 +1 @@
+vimlparser: E996: Cannot lock a list or dict: line 2 col 8

test/test_err_const1.vim

@@ -0,0 +1,2 @@
+let a = [0]
+const a[0] = 1

test/test_err_const2.ok

@@ -0,0 +1 @@
+vimlparser: E996: Cannot lock a list or dict: line 2 col 8

test/test_err_const2.vim

@@ -0,0 +1,2 @@
+let a = {}
+const a["b"] = 1

test/test_err_const3.ok

@@ -0,0 +1 @@
+vimlparser: E996: Cannot lock a list or dict: line 2 col 8

test/test_err_const3.vim

@@ -0,0 +1,2 @@
+let a = {}
+const a.b = 1

test/test_err_const4.ok

@@ -0,0 +1 @@
+vimlparser: E996: Cannot lock an environment variable: line 1 col 7

test/test_err_const4.vim

@@ -0,0 +1 @@
+const $a = 1

test/test_err_const5.ok

@@ -0,0 +1 @@
+vimlparser: E996: Cannot lock a register: line 1 col 7