VIMPRINT A VIM KEYSTROKE PARSER 28th May, 2013 Drew Neil @nelstrom

VIMPRINT should... visualize keystrokes in realtime

VIMPRINT should... understand all built-in commands

VIMPRINT should... be extensible

VimSpeak Turns spoken English into keystrokes https://github.com/AshleyF/VimSpeak

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VimSplain Turns keystrokes into plain English https://github.com/pafcu/Vimsplain

Vimulator Turns live keystrokes into plain English https://github.com/thoughtbot/vimulator

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VimGolf Logs real keystrokes https://github.com/igrigorik/vimgolf

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vim -w keystrokes are BUFFERED

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Parslet 1st attempt at parsing Vim keystrokes

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class Vimprint < Parslet::Parser rule(:start) { match('[iIaAoOsS]').as(:switch) } rule(:typing) { match('[^\e]').repeat.as(:typing) } rule(:terminate) { match('\e').as(:escape) } rule(:insertion) { start >> typing >> terminate } root(:insertion) end

gv major stumbling block: switch from Normal mode to Visual mode and select the last selected text

Ragel 2nd attempt at parsing Vim keystrokes

Ragel state machines can not only recognize byte sequences as regular expression machines do, but can also execute code at arbitrary points in the recognition of a regular language.

%%{ machine vim_print; action return { fret; } action push_insert_mode { fcall insert_mode; } escape = 27; input = (any - escape); motion = [hjklbwe0]; switch = [iIaAsSoO]; insert_mode := ( input* escape @return ); normal_mode := ( motion | switch @push_insert_mode )*; }%%

2 IN 1 insert_mode normal_mode '0', 'b', 'e', 'h', 'j'..'l', 'w' 'A', 'I', 'O', 'S', 'a', 'i', 'o', 's' / push_insert_mode 3 27 / return DEF

action H { @head = p } action T { @tail = p } action EmitMotion { @events << {motion: strokes} } action EmitSwitch { @events << {switch: strokes} } action EmitInput { @events << {input: strokes} } action EmitEscape { @events << {escape: ''} } escape = 27 >H@T @EmitEscape; input = (any - escape) >H@T @EmitInput; motion = [hjklbwe0] >H@T @EmitMotion; switch = [iIaAsSoO] >H@T @EmitSwitch;

class VimParser attr_accessor :head, :tail, :data def initialize(listener) @events = listener %% write data; end def process(input) @data = input.unpack("c*") eof = @data.length stack = [] %% write init; %% write exec; end def strokes @data[@head..@tail].pack('c*') end end

VimParser.new(recorder = []).process("helihello\e") puts recorder {:motion=>"h"} {:motion=>"e"} {:motion=>"l"} {:switch=>"i"} {:input=>"h"} {:input=>"e"} {:input=>"l"} {:input=>"l"} {:input=>"o"} {:escape=>""} https://gist.github.com/nelstrom/5663083

FATAL FLAWS with parsing keystrokes

FATAL FLAWS no timestamps {...}

FATAL FLAWS no document context :s/{pattern}/{string}/c

FATAL FLAWS no filetype detection

HALP! https://github.com/nelstrom/vimprint Vimprint Realtime Vim keystroke visualizer