Numeric less than or equal op begins quoting construct

[0racle]

Description of issue

When using the Numeric less than or equal to operator, the < causes the syntax highlighter to start a <> quoting construct until it sees a >.

Screenshot of the issue:

Above screenshot taken using the 256-color jellybeans color scheme.

Sample code:

if 3 <= 4 {
    say "It now thinks we are inside a '<>' quoting construct";
}

# And will continue to do so until > appears;

if 4 >= 3 { 
    say "No such problem here";
}

Link to vimrc

vimrc

Output of vim --version

VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Oct 21 2015 12:30:04)
Included patches: 1-712
Modified by pkg-vim-maintainers@lists.alioth.debian.org
Compiled by buildd@
Huge version without GUI.  Features included (+) or not (-):
+acl             +farsi           +mouse_netterm   +syntax
+arabic          +file_in_path    +mouse_sgr       +tag_binary
+autocmd         +find_in_path    -mouse_sysmouse  +tag_old_static
-balloon_eval    +float           +mouse_urxvt     -tag_any_white
-browse          +folding         +mouse_xterm     -tcl
++builtin_terms  -footer          +multi_byte      +terminfo
+byte_offset     +fork()          +multi_lang      +termresponse
+cindent         +gettext         -mzscheme        +textobjects
-clientserver    -hangul_input    +netbeans_intg   +title
-clipboard       +iconv           +path_extra      -toolbar
+cmdline_compl   +insert_expand   -perl            +user_commands
+cmdline_hist    +jumplist        +persistent_undo +vertsplit
+cmdline_info    +keymap          +postscript      +virtualedit
+comments        +langmap         +printer         +visual
+conceal         +libcall         +profile         +visualextra
+cryptv          +linebreak       +python          +viminfo
+cscope          +lispindent      -python3         +vreplace
+cursorbind      +listcmds        +quickfix        +wildignore
+cursorshape     +localmap        +reltime         +wildmenu
+dialog_con      -lua             +rightleft       +windows
+diff            +menu            -ruby            +writebackup
+digraphs        +mksession       +scrollbind      -X11
-dnd             +modify_fname    +signs           -xfontset
-ebcdic          +mouse           +smartindent     -xim
+emacs_tags      -mouseshape      -sniff           -xsmp
+eval            +mouse_dec       +startuptime     -xterm_clipboard
+ex_extra        +mouse_gpm       +statusline      -xterm_save
+extra_search    -mouse_jsbterm   -sun_workshop    -xpm
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
  fall-back for $VIM: "/usr/share/vim"
Compilation: gcc -c -I. -Iproto -DHAVE_CONFIG_H     -g -O2 -fPIE -fstack-protector-strong -Wformat -Werror=format-security -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1      
Linking: gcc   -Wl,-Bsymbolic-functions -fPIE -pie -Wl,-z,relro -Wl,-z,now -Wl,--as-needed -o vim        -lm -ltinfo -lnsl  -lselinux  -lacl -lattr -lgpm -ldl    -L/usr/lib/python2.7/config-i386-linux-gnu -lpython2.7 -lpthread -ldl -lutil -lm -Xlinker -export-dynamic -Wl,-O1 -Wl,-Bsymbolic-functions   

[hoelzro]

@0racle Thanks for the report! Which version of the vim-perl6 files are you using? I'm not seeing this on my setup (version e858f8f).

[0racle]

I'm on the same commit. I've also tried on another box (one Ubuntu, one Centos, both Vim7.4) and it is also exhibiting the same issue.

[0racle]

I used git bisect and found that ab2351f is when this issue started for me.

Further narrowing down to the offending line... If I roll back just line 363 in syntax/perl6.vim the problem goes away.

I then attempted minor changes to the line to see what would fix it and found that I can resolve my issue by making the following change

\ start="[<+~=!]\@1<!<\%(\s\|<\|=>\|\%([=-]\{1,2}>\|[=-]\{2}\)\)\@!"       BAD
\ start="[<+~=!]\@1<!<\%(\s\|<\|=>\|\%([=-]\{1,2}>\|[=-]\{1,2}\)\)\@!"     GOOD

but that causes a regression of how the following line highlights...

if < a b c > { ... }

[hoelzro]

@0racle Does this happen with no vimrc loaded? Ex. vim -u NONE -c 'source syntax/perl6.vim' -c 'syntax on' -c 'setf perl6' example.pl

I tried this after building Vim 7.4 from patch 712 (git checkout v7.4.712 && ./configure --with-features=huge && make install), and am still unable to reproduce the problem.

[0racle]

If I do the following...
vim -u NONE -c 'source syntax/perl6.vim' -c 'syntax on' -c 'setf perl6' example.pl

I don't see an issue... _but_ it looks identical if I do this
vim -u NONE -c 'syntax on' -c 'setf perl6' example.pl

which suggests the syntax file is not being sourced correctly.

However, if I copy syntax/perl6.vim to ~.vim/syntax and then do the second command, then I do see the issue.

Interestingly, if I delete the perl.vim and perl6.vim files from vim's default runtime folder (/usr/share/vim/.../syntax) and then run the first command, I get no syntax highlighting... further providing support that sourcing the syntax file via the cmdline doesn't work (at least on my machine).

I will clone the vim repo and build the same version as you (on Ubuntu and Centos) and do some more testing.

[hoelzro]

@0racle Ok, that's leading me to believe that your Vim is using an out-of-date perl6.vim file. The first command (with source syntax/perl6.vim) makes sure that only our perl6.vim is loaded. If you try vim -u NONE -c 'syntax on' -c 'setf perl6' example.pl, run :scriptnames in the vim instance that comes up. You should see an entry for syntax/perl6.vim, which is the syntax file your vim is using. If this is not the one you intend, you either don't have &runtimepath set up correctly, or our syntax/perl6.vim isn't on your runtimepath.

[zostay]

I am seeing this problem using the latest commit here cloned into my dotfiles: ccef6a3

The attached screenshots show the problem both in vim and neovim (running reasonably recent builds of each o macOS. This was running each with vim -u NONE -c 'syntax on' -c 'setf perl6' example.pl where example.pl is a module I'm porting. I ran :source syntax/perl6.vim in each and then captured the output of :scriptnames.

Here's neovim:

And here's vim:

[zostay]

I can confirm that the reversion @0racle found via bisect does fix the problem with the mentioned regression.

[0racle]

Here's an asciinema from my system showing the issue with no vimrc.

This issue was also called out by Evan Miller in his recent Review of Perl6

Referring the line I mentioned above from commit ab2351f, making the suggested change (adding 2 characters) does not appear to cause a regression with the issue that commit sought to solve (ie. Fix highlighting of <-a -b -c>).

The regression it cause with regards to if < a b c > ... is, I think, a more acceptable corner case, as it is not likely to be a common expression. Importantly, for < a b c > ... is unaffected by this change and highlights properly.

Given that the issue has been confirmed on multiple systems, and the high visibility of the issue due to Evan's review, I have created a pull request to merge this change.

[hoelzro]

Thanks for the fix @0racle - I just merged your PR!