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Vim as a Perl 6 editor 2016-08-21

Posted by claudio in Uncategorized.
Tags: , ,
1 comment so far

EDITED on 20170211: syntastic-perl6 configuration changes

If you’re a Vim user you probably use it for almost everything. Out of the box, Perl 6 support is rather limited. That’s why many people use editors like Atom for Perl 6 code.

What if with a few plugins you could configure vim to be a great Perl 6 editor? I made the following notes while configuring Vim on my main machine running Ubuntu 16.04. The instructions should be trivially easy to port to other distributions or Operating Systems. Skip the applicable steps if you already have a working vim setup (i.e. do not overwrite you .vimrc file).

I maintain my Vim plugins using pathogen, as it allows me to directly use git clones from github. This is specially important for plugins in rapid development.
(If your .vim directory is a git repository, replace ‘git clone’ in the commands by ‘git submodule add’.)

Basic vim Setup

Install vim with scripting support and pathogen. Create the directory where the plugins will live:
$ sudo apt-get install vim-nox vim-pathogen && mkdir -p ~/.vim/bundle

$ vim-addons install pathogen

Create a minimal .vimrc in your $HOME, with at least this configuration (enabling pathogen). Lines commencing with ” are comments:

“Enable extra features (e.g. when run systemwide). Must be before pathogen
set nocompatible

“Enable pathogen
execute pathogen#infect()
“Enable syntax highlighting
syntax on
“Enable indenting
filetype plugin indent on

Additionally I use these settings (the complete .vimrc is linked atthe end):

“Set line wrapping
set wrap
set linebreak
set nolist
set formatoptions+=l

“Enable 256 colours
set t_Co=256

“Set auto indenting
set autoindent

“Smart tabbing
set expandtab
set smarttab
set sw=4 ” no of spaces for indenting
set ts=4 ” show \t as 2 spaces and treat 2 spaces as \t when deleting

“Set title of xterm
set title

” Highlight search terms
set hlsearch

“Strip trailing whitespace for certain type of files
autocmd BufWritePre *.{erb,md,pl,pl6,pm,pm6,pp,rb,t,xml,yaml,go} :%s/\s\+$//e

“Override tab espace for specific languages
autocmd Filetype ruby,puppet setlocal ts=2 sw=2

“Jump to the last position when reopening a file
au BufReadPost * if line(“‘\””) > 1 && line(“‘\””) <= line(“$”) |
\ exe “normal! g’\”” | endif

“Add a coloured right margin for recent vim releases
if v:version >= 703
set colorcolumn=80

“Ubuntu suggestions
set showcmd    ” Show (partial) command in status line.
set showmatch  ” Show matching brackets.
set ignorecase ” Do case insensitive matching
set smartcase  ” Do smart case matching
set incsearch  ” Incremental search
set autowrite  ” Automatically save before commands like :next and :make
set hidden     ” Hide buffers when they are abandoned
set mouse=v    ” Enable mouse usage (all modes)

Install plugins

vim-perl for syntax highlighting:

$ git clone https://github.com/vim-perl/vim-perl.git ~ /.vim/bundle/vim-perl


vim-airline and themes for a status bar:
$ git clone https://github.com/vim-airline/vim-airline.git ~/.vim/bundle/vim-airline
$ git clone https://github.com/vim-airline/vim-airline-themes.git ~/.vim/bundle/vim-airline-themes
In vim type :Helptags

In  Ubuntu the ‘fonts-powerline’ package (sudo apt-get install fonts-powerline) installs fonts that enable nice glyphs in the statusbar (e.g. line effect instead of ‘>’, see the screenshot at https://github.com/vim-airline/vim-airline/wiki/Screenshots.

Add this to .vimrc for airline (the complete .vimrc is attached):
“airline statusbar
set laststatus=2
set ttimeoutlen=50
let g:airline#extensions#tabline#enabled = 1
let g:airline_theme=’luna’
“In order to see the powerline fonts, adapt the font of your terminal
“In Gnome Terminal: “use custom font” in the profile. I use Monospace regular.
let g:airline_powerline_fonts = 1


Tabular for aligning text (e.g. blocks):
$ git clone https://github.com/godlygeek/tabular.git ~/.vim/bundle/tabular
In vim type :Helptags

vim-fugitive for Git integration:
$ git clone https://github.com/tpope/vim-fugitive.git ~/.vim/bundle/vim-fugitive
In vim type :Helptags

vim-markdown for markdown syntax support (e.g. the README.md of your module):
$ git clone https://github.com/plasticboy/vim-markdown.git ~/.vim/bundle/vim-markdown
In vim type :Helptags

Add this to .vimrc for markdown if you don’t want folding (the complete .vimrc is attached):
“markdown support
let g:vim_markdown_folding_disabled=1

synastic-perl6 for Perl 6 syntax checking support. I wrote this plugin to add Perl 6 syntax checking support to synastic, the leading vim syntax checking plugin. See the ‘Call for Testers/Announcement’ here. Instruction can be found in the repo, but I’ll paste it here for your convenience:

You need to install syntastic to use this plugin.
$ git clone https://github.com/scrooloose/syntastic.git ~/.vim/bundle/synastic
$ git clone https://github.com/nxadm/syntastic-perl6.git ~/.vim/bundle/synastic-perl6

Type “:Helptags” in Vim to generate Help Tags.

Syntastic and syntastic-perl6 vimrc configuration, (comments start with “):

"airline statusbar integration if installed. De-comment if installed
"set laststatus=2
"set ttimeoutlen=50
"let g:airline#extensions#tabline#enabled = 1
"let g:airline_theme='luna'
"In order to see the powerline fonts, adapt the font of your terminal
"In Gnome Terminal: "use custom font" in the profile. I use Monospace regular.
"let g:airline_powerline_fonts = 1

“syntastic syntax checking
let g:syntastic_always_populate_loc_list = 1
let g:syntastic_auto_loc_list = 1
let g:syntastic_check_on_open = 1
let g:syntastic_check_on_wq = 0
set statusline+=%#warningmsg#
set statusline+=%{SyntasticStatuslineFlag()}
set statusline+=%*

“Perl 6 support
“Optional comma separated list of quoted paths to be included to -I
“let g:syntastic_perl6lib = [ ‘/home/user/Code/some_project/lib’, ‘lib’ ]
“Optional perl6 binary (defaults to perl6 in your PATH)
“let g:syntastic_perl6_exec = ‘/opt/rakudo/bin/perl6’
“Register the checker provided by this plugin
let g:syntastic_perl6_checkers = [‘perl6’]
“Enable the perl6 checker (disabled out of the box because of security reasons:
“‘perl6 -c’ executes the BEGIN and CHECK block of code it parses. This should
“be fine for your own code. See: https://docs.perl6.org/programs/00-running
let g:syntastic_enable_perl6_checker = 1

Screenshot of syntastic-perl6

You complete me fuzzy search autocomplete:

$ git clone https://github.com/Valloric/YouCompleteMe.git ~/.vim/bundle/YouCompleteMe

Read the YouCompleteMe documentation for the dependencies for your OS and for the switches for additional non-fuzzy support for additional languages like C/C++, Go and so on. If you just want fuzzy complete support for Perl 6, the default is ok. If someone is looking for a nice project, a native Perl6 autocompleter for YouCompleteMe (instead of the fuzzy one) would be a great addition. You can install YouCompleteMe like this:
$ cd ~/.vim/bundle/YouCompleteMe && ./install.py


That’s it. I hope my notes are useful to someone. The complete .vimrc can be found here.



Please test: first release of syntastic-perl6, a vim syntax checker 2016-08-20

Posted by claudio in Uncategorized.
Tags: , ,
1 comment so far

Vimlogo.svgI think that Perl 6, as a fairly new language, needs good tooling not only to attract new programmers but also to make the job of Perl 6 programmers more enjoyable. If you’ve worked with an IDE before, you certainly agree that syntax checking is one of those things that we take for granted. Syntastic-perl6 is a plugin that adds Perl 6 syntax checking in Vim using Syntastic. Syntastic is the leading Vim plugin for syntax checking. It supports many programming languages.

If the plugin proves to be useful, I plan on a parallel track for Perl 6 support in Vim. On one hand, this plugin will track the latest Perl 6 Rakudo releases (while staying as backwards compatible as possible) and be the first to receive new functionality. On the other hand, once this plugin is well-tested and feature complete, it will hopefully be added to the main syntastic repo (it has it’s own branch upstream already) in order to provide out-of-the-box support for Perl 6.

So, what do we need to get there? We need testers and users, so they can make this plugin better by:

  • sending Pull Requests to make the code (vimscript) better where needed.
  • sending Pull Requests to add tests for error cases not yet tested (see the t directory) or -more importantely- caught.
  • posting issues for bugs or errors not-yet-caught. In that case copy-paste the error (e.g. within vim: :!perl6 -c %) and post a sample of the erroneous Perl 6 code in question.

The plugin, with installation instructions, is on its github repo at syntastic-perl6. With a vim module manage like pathogen you can directly use a clone of the repo.

Keep me posted!


How to change the default shell editor in Ubuntu 2008-06-18

Posted by claudio in Uncategorized.
Tags: , , , ,
1 comment so far

Using nano as the default shell editor is probably a great choice for a Gnu/Linux distribution (also) aimed for Unix newbies. If you know your way on the command line however, you’ll scream from frustration for every “i”, “:wq!” or “ZZ” you type and you see the characters in the text you are editing. Specially frustrating in cron. If you don’t know what “i”, “:wq!” or “ZZ” do, don’t worry, nano is working fine for you. (more…)