changeset 24142:34acfef7f60c v8.2.2612

patch 8.2.2612: col('.') may get outdated column value Commit: https://github.com/vim/vim/commit/18b7d86d7fa997bbb02a069dafacb32a0f73ca1e Author: Bram Moolenaar <Bram@vim.org> Date: Wed Mar 17 13:28:05 2021 +0100 patch 8.2.2612: col('.') may get outdated column value Problem: col('.') may get outdated column value. Solution: Add a note to the help how to make this work and add a test for it. (closes #7971)
author Bram Moolenaar <Bram@vim.org>
date Wed, 17 Mar 2021 13:30:03 +0100
parents 6e9204b17dca
children be243d97d9bf
files runtime/doc/map.txt src/testdir/test_mapping.vim src/version.c
diffstat 3 files changed, 40 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/runtime/doc/map.txt
+++ b/runtime/doc/map.txt
@@ -263,6 +263,20 @@ input. Example: >
 	endfunc
 	nnoremap <expr> <F3> <Sid>OpenPopup()
 
+Also, keep in mind that the expression may be evaluated when looking for
+typeahead, before the previous command has been executed.  For example: >
+	func StoreColumn()
+	  let g:column = col('.')
+	  return 'x'
+	endfunc
+	nnoremap <expr> x StoreColumn()
+	nmap ! f!x
+You will notice that g:column has the value from before executing "fx",
+because "z" is evaluated before "fx" is executed.
+This can be solved by inserting <Ignore> before the character that is
+expression-mapped: >
+	nmap ! f!<Ignore>x
+
 Be very careful about side effects!  The expression is evaluated while
 obtaining characters, you may very well make the command dysfunctional.
 For this reason the following is blocked:
--- a/src/testdir/test_mapping.vim
+++ b/src/testdir/test_mapping.vim
@@ -485,6 +485,30 @@ func Test_list_mappings()
   nmapclear
 endfunc
 
+func Test_expr_map_gets_cursor()
+  new
+  call setline(1, ['one', 'some w!rd'])
+  func StoreColumn()
+    let g:exprLine = line('.')
+    let g:exprCol = col('.')
+    return 'x'
+  endfunc
+  nnoremap <expr> x StoreColumn()
+  2
+  nmap ! f!<Ignore>x
+  call feedkeys("!", 'xt')
+  call assert_equal('some wrd', getline(2))
+  call assert_equal(2, g:exprLine)
+  call assert_equal(7, g:exprCol)
+
+  bwipe!
+  unlet g:exprLine
+  unlet g:exprCol
+  delfunc ExprMapped
+  nunmap x
+  nunmap !
+endfunc
+
 func Test_expr_map_restore_cursor()
   CheckScreendump
 
--- 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 */
 /**/
+    2612,
+/**/
     2611,
 /**/
     2610,