vis

a vi-like editor based on Plan 9's structural regular expressions

git clone https://9o.is/git/vis.git

diff.lua

(987B)

      1 -- Copyright 2006-2025 Mitchell. See LICENSE.
      2 -- Diff LPeg lexer.
      3 
      4 local lexer = lexer
      5 local to_eol, starts_line = lexer.to_eol, lexer.starts_line
      6 local P, S = lpeg.P, lpeg.S
      7 
      8 local lex = lexer.new(..., {lex_by_line = true})
      9 
     10 -- Text, file headers, and separators.
     11 lex:add_rule('index', lex:tag(lexer.COMMENT, to_eol(starts_line('Index: '))))
     12 lex:add_rule('header', lex:tag(lexer.HEADING, to_eol(starts_line(P('*** ') + '--- ' + '+++ '))))
     13 lex:add_rule('separator', lex:tag(lexer.COMMENT, to_eol(starts_line(P('---') + '****' + '='))))
     14 
     15 -- Location.
     16 lex:add_rule('location', lex:tag(lexer.NUMBER, to_eol(starts_line('@@' + lexer.dec_num + '****'))))
     17 
     18 -- Additions, deletions, and changes.
     19 lex:add_rule('addition', lex:tag('addition', to_eol(starts_line(S('>+')))))
     20 lex:add_rule('deletion', lex:tag('deletion', to_eol(starts_line(S('<-')))))
     21 lex:add_rule('change', lex:tag('change', to_eol(starts_line('!'))))
     22 
     23 lex:add_rule('any_line', lex:tag(lexer.DEFAULT, lexer.to_eol()))
     24 
     25 return lex