" Language: CoffeeScript
" Maintainer: Mick Koch <kchmck@gmail.com>
" URL: http://github.com/kchmck/vim-coffee-script
" License: WTFPL
if exists("b:did_indent")
finish
endif
let b:did_indent = 1
setlocal autoindent
setlocal indentexpr=GetCoffeeIndent(v:lnum)
" Make sure GetCoffeeIndent is run when these are typed so they can be
" indented or outdented.
setlocal indentkeys+=0],0),0.,=else,=when,=catch,=finally
" Only define the function once.
if exists("*GetCoffeeIndent")
finish
endif
" Keywords to indent after
let s:INDENT_AFTER_KEYWORD = '^\%(if\|unless\|else\|for\|while\|until\|'
\ . 'loop\|switch\|when\|try\|catch\|finally\|'
\ . 'class\)\>'
" Operators to indent after
let s:INDENT_AFTER_OPERATOR = '\%([([{:=]\|[-=]>\)$'
" Keywords and operators that continue a line
let s:CONTINUATION = '\<\%(is\|isnt\|and\|or\)\>$'
\ . '\|'
\ . '\%(-\@<!-\|+\@<!+\|<\|[-=]\@<!>\|\*\|/\@<!/\|%\||\|'
\ . '&\|,\|\.\@<!\.\)$'
" Operators that block continuation indenting
let s:CONTINUATION_BLOCK = '[([{:=]$'
" A continuation dot access
let s:DOT_ACCESS = '^\.'
" Keywords to outdent after
let s:OUTDENT_AFTER = '^\%(return\|break\|continue\|throw\)\>'
" A compound assignment like `... = if ...`
let s:COMPOUND_ASSIGNMENT = '[:=]\s*\%(if\|unless\|for\|while\|until\|'
\ . 'switch\|try\|class\)\>'
" A postfix condition like `return ... if ...`.
let s:POSTFIX_CONDITION = '\S\s\+\zs\<\%(if\|unless\)\>'
" A single-line else statement like `else ...` but not `else if ...
let s:SINGLE_LINE_ELSE = '^else\s\+\%(\<\%(if\|unless\)\>\)\@!'
" Max lines to look back for a match
let s:MAX_LOOKBACK = 50
" Syntax names for strings
let s:SYNTAX_STRING = 'coffee\%(String\|AssignString\|Embed\|Regex\|Heregex\|'
\ . 'Heredoc\)'
" Syntax names for comments
let s:SYNTAX_COMMENT = 'coffee\%(Comment\|BlockComment\|HeregexComment\)'
" Syntax names for strings and comments
let s:SYNTAX_STRING_COMMENT = s:SYNTAX_STRING . '\|' . s:SYNTAX_COMMENT
" Get the linked syntax name of a character.
function! s:SyntaxName(linenum, col)
return synIDattr(synID(a:linenum, a:col, 1), 'name')
endfunction
" Check if a character is in a comment.
function! s:IsComment(linenum, col)
return s:SyntaxName(a:linenum, a:col) =~ s:SYNTAX_COMMENT
endfunction
" Check if a character is in a string.
function! s:IsString(linenum, col)
return s:SyntaxName(a:linenum, a:col) =~ s:SYNTAX_STRING
endfunction
" Check if a character is in a comment or string.
function! s:IsCommentOrString(linenum, col)
return s:SyntaxName(a:linenum, a:col) =~ s:SYNTAX_STRING_COMMENT
endfunction
" Check if a whole line is a comment.
function! s:IsCommentLine(linenum)
" Check the first non-whitespace character.
return s:IsComment(a:linenum, indent(a:linenum) + 1)
endfunction
" Repeatedly search a line for a regex until one is found outside a string or
" comment.
function! s:SmartSearch(linenum, regex)
" Start at the first column.
let col = 0
" Search until there are no more matches, unless a good match is found.
while 1
call cursor(a:linenum, col + 1)
let [_, col] = searchpos(a:regex, 'cn', a:linenum)
" No more matches.
if !col
break
endif
if !s:IsCommentOrString(a:linenum, col)
return 1
endif
endwhile
" No good match found.
return 0
endfunction
" Skip a match if it's in a comment or string, is a single-line statement that
" isn't adjacent, or is a postfix condition.
function! s:ShouldSkip(startlinenum, linenum, col)
if s:IsCommentOrString(a:linenum, a:col)
return 1
endif
" Check for a single-line statement that isn't adjacent.
if s:SmartSearch(a:linenum, '\<then\>') && a:startlinenum - a:linenum > 1
return 1
endif
if s:SmartSearch(a:linenum, s:POSTFIX_CONDITION) &&
\ !s:SmartSearch(a:linenum, s:COMPOUND_ASSIGNMENT)
return 1
endif
return 0
endfunction
" Find the farthest line to look back to, capped to line 1 (zero and negative
" numbers cause bad things).
function! s:MaxLookback(startlinenum)
return max([1, a:startlinenum - s:MAX_LOOKBACK])
endfunction
" Get the skip expression for searchpair().
function! s:SkipExpr(startlinenum)
return "s:ShouldSkip(" . a:startlinenum . ", line('.'), col('.'))"
endfunction
" Search for pairs of text.
function! s:SearchPair(start, end)
" The cursor must be in the first column for regexes to match.
call cursor(0, 1)
let startlinenum = line('.')
" Don't need the W flag since MaxLookback caps the search to line 1.
return searchpair(a:start, '', a:end, 'bcn',
\ s:SkipExpr(startlinenum),
\ s:MaxLookback(startlinenum))
endfunction
" Try to find a previous matching line.
function! s:GetMatch(curline)
let firstchar = a:curline[0]
if firstchar == '}'
return s:SearchPair('{', '}')
elseif firstchar == ')'
return s:SearchPair('(', ')')
elseif firstchar == ']'
return s:SearchPair('\[', '\]')
elseif a:curline =~ '^else\>'
return s:SearchPair('\<\%(if\|unless\|when\)\>', '\<else\>')
elseif a:curline =~ '^catch\>'
return s:SearchPair('\<try\>', '\<catch\>')
elseif a:curline =~ '^finally\>'
return s:SearchPair('\<try\>', '\<finally\>')
endif
return 0
endfunction
" Get the nearest previous line that isn't a comment.
function! s:GetPrevNormalLine(startlinenum)
let curlinenum = a:startlinenum
while curlinenum > 0
let curlinenum = prevnonblank(curlinenum - 1)
if !s:IsCommentLine(curlinenum)
return curlinenum
endif
endwhile
return 0
endfunction
" Try to find a comment in a line.
function! s:FindComment(linenum)
let col = 0
while 1
call cursor(a:linenum, col + 1)
let [_, col] = searchpos('#', 'cn', a:linenum)
if !col
break
endif
if s:IsComment(a:linenum, col)
return col
endif
endwhile
return 0
endfunction
" Get a line without comments or surrounding whitespace.
function! s:GetTrimmedLine(linenum)
let comment = s:FindComment(a:linenum)
let line = getline(a:linenum)
if comment
" Subtract 1 to get to the column before the comment and another 1 for
" zero-based indexing.
let line = line[:comment - 2]
endif
return substitute(substitute(line, '^\s\+', '', ''),
\ '\s\+$', '', '')
endfunction
function! s:GetCoffeeIndent(curlinenum)
let prevlinenum = s:GetPrevNormalLine(a:curlinenum)
" Don't do anything if there's no previous line.
if !prevlinenum
return -1
endif
let curline = s:GetTrimmedLine(a:curlinenum)
" Try to find a previous matching statement. This handles outdenting.
let matchlinenum = s:GetMatch(curline)
if matchlinenum
return indent(matchlinenum)
endif
" Try to find a matching `when`.
if curline =~ '^when\>' && !s:SmartSearch(prevlinenum, '\<switch\>')
let linenum = a:curlinenum
while linenum > 0
let linenum = s:GetPrevNormalLine(linenum)
if getline(linenum) =~ '^\s*when\>'
return indent(linenum)
endif
endwhile
return -1
endif
let prevline = s:GetTrimmedLine(prevlinenum)
let previndent = indent(prevlinenum)
" Always indent after these operators.
if prevline =~ s:INDENT_AFTER_OPERATOR
return previndent + &shiftwidth
endif
" Indent after a continuation if it's the first.
if prevline =~ s:CONTINUATION
let prevprevlinenum = s:GetPrevNormalLine(prevlinenum)
" If the continuation is the first in the file, don't run the other checks.
if !prevprevlinenum
return previndent + &shiftwidth
endif
let prevprevline = s:GetTrimmedLine(prevprevlinenum)
if prevprevline !~ s:CONTINUATION && prevprevline !~ s:CONTINUATION_BLOCK
return previndent + &shiftwidth
endif
return -1
endif
" Indent after these keywords and compound assignments if they aren't a
" single-line statement.
if prevline =~ s:INDENT_AFTER_KEYWORD || prevline =~ s:COMPOUND_ASSIGNMENT
if !s:SmartSearch(prevlinenum, '\<then\>') && prevline !~ s:SINGLE_LINE_ELSE
return previndent + &shiftwidth
endif
return -1
endif
" Indent a dot access if it's the first.
if curline =~ s:DOT_ACCESS && prevline !~ s:DOT_ACCESS
return previndent + &shiftwidth
endif
" Outdent after these keywords if they don't have a postfix condition or are
" a single-line statement.
if prevline =~ s:OUTDENT_AFTER
if !s:SmartSearch(prevlinenum, s:POSTFIX_CONDITION) ||
\ s:SmartSearch(prevlinenum, '\<then\>')
return previndent - &shiftwidth
endif
endif
" No indenting or outdenting is needed.
return -1
endfunction
" Wrap s:GetCoffeeIndent to keep the cursor position.
function! GetCoffeeIndent(curlinenum)
let oldcursor = getpos('.')
let indent = s:GetCoffeeIndent(a:curlinenum)
call setpos('.', oldcursor)
return indent
endfunction