3 " Awk indent script. It can handle multi-line statements and expressions.
4 " It works up to the point where the distinction between correct/incorrect
5 " and personal taste gets fuzzy. Drop me an e-mail for bug reports and
6 " reasonable style suggestions.
10 " - Some syntax errors may cause erratic indentation.
11 " - Same for very unusual but syntacticly correct use of { }
12 " - In some cases it's confused by the use of ( and { in strings constants
13 " - This version likes the closing brace of a multiline pattern-action be on
14 " character position 1 before the following pattern-action combination is
19 " Erik Janssen, ejanssen@itmatters.nl
23 " 26-04-2002 Got initial version working reasonably well
24 " 29-04-2002 Fixed problems in function headers and max line width
25 " Added support for two-line if's without curly braces
26 " Fixed hang: 2011 Aug 31
28 " Only load this indent file when no other was loaded.
29 if exists("b:did_indent")
35 setlocal indentexpr=GetAwkIndent()
36 " Mmm, copied from the tcl indent program. Is this okay?
37 setlocal indentkeys-=:,0#
39 " Only define the function once.
40 if exists("*GetAwkIndent")
44 " This function contains a lot of exit points. It checks for simple cases
45 " first to get out of the function as soon as possible, thereby reducing the
46 " number of possibilities later on in the difficult parts
48 function! GetAwkIndent()
50 " Find previous line and get it's indentation
51 let prev_lineno = s:Get_prev_line( v:lnum )
55 let prev_data = getline( prev_lineno )
56 let ind = indent( prev_lineno )
58 " Increase indent if the previous line contains an opening brace. Search
59 " for this brace the hard way to prevent errors if the previous line is a
60 " 'pattern { action }' (simple check match on /{/ increases the indent then)
62 if s:Get_brace_balance( prev_data, '{', '}' ) > 0
66 let brace_balance = s:Get_brace_balance( prev_data, '(', ')' )
68 " If prev line has positive brace_balance and starts with a word (keyword
69 " or function name), align the current line on the first '(' of the prev
72 if brace_balance > 0 && s:Starts_with_word( prev_data )
73 return s:Safe_indent( ind, s:First_word_len(prev_data), getline(v:lnum))
76 " If this line starts with an open brace bail out now before the line
77 " continuation checks.
79 if getline( v:lnum ) =~ '^\s*{'
83 " If prev line seems to be part of multiline statement:
84 " 1. Prev line is first line of a multiline statement
85 " -> attempt to indent on first ' ' or '(' of prev line, just like we
86 " indented the positive brace balance case above
87 " 2. Prev line is not first line of a multiline statement
88 " -> copy indent of prev line
90 let continue_mode = s:Seems_continuing( prev_data )
92 if s:Seems_continuing( getline(s:Get_prev_line( prev_lineno )) )
98 " Need continuation due to comma, backslash, etc
99 return s:Safe_indent( ind, s:First_word_len(prev_data), getline(v:lnum))
101 " if/for/while without '{'
107 " If the previous line doesn't need continuation on the current line we are
108 " on the start of a new statement. We have to make sure we align with the
109 " previous statement instead of just the previous line. This is a bit
110 " complicated because the previous statement might be multi-line.
112 " The start of a multiline statement can be found by:
114 " 1 If the previous line contains closing braces and has negative brace
115 " balance, search backwards until cumulative brace balance becomes zero,
116 " take indent of that line
117 " 2 If the line before the previous needs continuation search backward
118 " until that's not the case anymore. Take indent of one line down.
121 if prev_data =~ ')' && brace_balance < 0
122 while brace_balance != 0 && prev_lineno > 0
123 let prev_lineno = s:Get_prev_line( prev_lineno )
124 let prev_data = getline( prev_lineno )
125 let brace_balance=brace_balance+s:Get_brace_balance(prev_data,'(',')' )
127 let ind = indent( prev_lineno )
130 if s:Seems_continuing( getline( prev_lineno - 1 ) )
131 let prev_lineno = prev_lineno - 2
132 let prev_data = getline( prev_lineno )
133 while prev_lineno > 0 && (s:Seems_continuing( prev_data ) > 0)
134 let prev_lineno = s:Get_prev_line( prev_lineno )
135 let prev_data = getline( prev_lineno )
137 let ind = indent( prev_lineno + 1 )
141 " Decrease indent if this line contains a '}'.
142 if getline(v:lnum) =~ '^\s*}'
149 " Find the open and close braces in this line and return how many more open-
150 " than close braces there are. It's also used to determine cumulative balance
151 " across multiple lines.
153 function! s:Get_brace_balance( line, b_open, b_close )
154 let line2 = substitute( a:line, a:b_open, "", "g" )
155 let openb = strlen( a:line ) - strlen( line2 )
156 let line3 = substitute( line2, a:b_close, "", "g" )
157 let closeb = strlen( line2 ) - strlen( line3 )
158 return openb - closeb
161 " Find out whether the line starts with a word (i.e. keyword or function
162 " call). Might need enhancements here.
164 function! s:Starts_with_word( line )
165 if a:line =~ '^\s*[a-zA-Z_0-9]\+\s*('
171 " Find the length of the first word in a line. This is used to be able to
172 " align a line relative to the 'print ' or 'if (' on the previous line in case
173 " such a statement spans multiple lines.
174 " Precondition: only to be used on lines where 'Starts_with_word' returns 1.
176 function! s:First_word_len( line )
177 let white_end = matchend( a:line, '^\s*' )
178 if match( a:line, '^\s*func' ) != -1
179 let word_end = matchend( a:line, '[a-z]\+\s\+[a-zA-Z_0-9]\+[ (]*' )
181 let word_end = matchend( a:line, '[a-zA-Z_0-9]\+[ (]*' )
183 return word_end - white_end
186 " Determine if 'line' completes a statement or is continued on the next line.
187 " This one is far from complete and accepts illegal code. Not important for
188 " indenting, however.
190 function! s:Seems_continuing( line )
192 if a:line =~ '\(--\|++\)\s*$'
195 if a:line =~ '[\\,\|\&\+\-\*\%\^]\s*$'
198 " if/for/while (cond) eol
199 if a:line =~ '^\s*\(if\|while\|for\)\s*(.*)\s*$' || a:line =~ '^\s*else\s*'
205 " Get previous relevant line. Search back until a line is that is no
206 " comment or blank and return the line number
208 function! s:Get_prev_line( lineno )
209 let lnum = a:lineno - 1
210 let data = getline( lnum )
211 while lnum > 0 && (data =~ '^\s*#' || data =~ '^\s*$')
213 let data = getline( lnum )
218 " This function checks whether an indented line exceeds a maximum linewidth
219 " (hardcoded 80). If so and it is possible to stay within 80 positions (or
220 " limit num of characters beyond linewidth) by decreasing the indent (keeping
221 " it > base_indent), do so.
223 function! s:Safe_indent( base, wordlen, this_line )
224 let line_base = matchend( a:this_line, '^\s*' )
225 let line_len = strlen( a:this_line ) - line_base
227 if (indent + a:wordlen + line_len) > 80
228 " Simple implementation good enough for the time being
229 let indent = indent + 3
231 return indent + a:wordlen