# HG changeset patch
# User Bram Moolenaar <Bram@vim.org>
# Date 1608751804 -3600
# Node ID 7951c5098e8e462376989075234ab98d6ff01465
# Parent  e0a6d49ed3ad80241a7aa30bfa2aacc7599abfe0
patch 8.2.2200: Vim9: lambda without white space around -> is confusing

Commit: https://github.com/vim/vim/commit/27bf7af9d042b396c412fcad7bac59849a4a420f
Author: Bram Moolenaar <Bram@vim.org>
Date:   Wed Dec 23 20:27:31 2020 +0100

    patch 8.2.2200: Vim9: lambda without white space around -> is confusing

    Problem:    Vim9: lambda without white space around -> is confusing.
    Solution:   Require white space in a :def funtion. (issue https://github.com/vim/vim/issues/7503)

diff --git a/src/testdir/test_vim9_disassemble.vim b/src/testdir/test_vim9_disassemble.vim
--- a/src/testdir/test_vim9_disassemble.vim
+++ b/src/testdir/test_vim9_disassemble.vim
@@ -1541,10 +1541,10 @@ def Test_disassemble_compare()
         ['{a: 1} is aDict', 'COMPAREDICT is'],
         ['{a: 1} isnot aDict', 'COMPAREDICT isnot'],
 
-        ['{->33} == {->44}', 'COMPAREFUNC =='],
-        ['{->33} != {->44}', 'COMPAREFUNC !='],
-        ['{->33} is {->44}', 'COMPAREFUNC is'],
-        ['{->33} isnot {->44}', 'COMPAREFUNC isnot'],
+        ['{-> 33} == {-> 44}', 'COMPAREFUNC =='],
+        ['{-> 33} != {-> 44}', 'COMPAREFUNC !='],
+        ['{-> 33} is {-> 44}', 'COMPAREFUNC is'],
+        ['{-> 33} isnot {-> 44}', 'COMPAREFUNC isnot'],
 
         ['77 == g:xx', 'COMPAREANY =='],
         ['77 != g:xx', 'COMPAREANY !='],
diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -1863,6 +1863,10 @@ def Test_expr7_lambda()
   END
   CheckDefAndScriptSuccess(lines)
 
+  CheckDefFailure(["var Ref = {a->a + 1}"], 'E720:')
+  CheckDefFailure(["var Ref = {a-> a + 1}"], 'E720:')
+  CheckDefFailure(["var Ref = {a ->a + 1}"], 'E720:')
+
   CheckDefFailure(["filter([1, 2], {k,v -> 1})"], 'E1069:', 1)
   # error is in first line of the lambda
   CheckDefFailure(["var L = {a -> a + b}"], 'E1001:', 0)
@@ -2538,7 +2542,7 @@ func Test_expr7_fails()
   call CheckDefFailure(["'yes'->", "Echo()"], 'E488: Trailing characters: ->', 1)
 
   call CheckDefExecFailure(["[1, 2->len()"], 'E697:', 2)
-  call CheckDefExecFailure(["{a: 1->len()"], 'E451:', 1)
+  call CheckDefExecFailure(["{a: 1->len()"], 'E723:', 2)
   call CheckDefExecFailure(["{['a']: 1->len()"], 'E723:', 2)
 endfunc
 
diff --git a/src/version.c b/src/version.c
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2200,
+/**/
     2199,
 /**/
     2198,
diff --git a/src/vim9compile.c b/src/vim9compile.c
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -3915,14 +3915,19 @@ compile_expr7(
 	 * Dictionary: {'key': val, 'key': val}
 	 */
 	case '{':   {
-			char_u *start = skipwhite(*arg + 1);
-			garray_T ga_arg;
+			char_u	    *start = skipwhite(*arg + 1);
+			char_u	    *after = start;
+			garray_T    ga_arg;
 
 			// Find out what comes after the arguments.
-			ret = get_function_args(&start, '-', NULL,
+			ret = get_function_args(&after, '-', NULL,
 					&ga_arg, TRUE, NULL, NULL,
 							     TRUE, NULL, NULL);
-			if (ret != FAIL && *start == '>')
+			if (ret != FAIL && after[0] == '>'
+				&& ((after > start + 2
+						     && VIM_ISWHITE(after[-2]))
+				|| after == start + 1)
+				&& IS_WHITE_OR_NUL(after[1]))
 			    ret = compile_lambda(arg, cctx);
 			else
 			    ret = compile_dict(arg, cctx, ppconst);