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Diffstat (limited to 'runtime/indent/awk.vim')
| -rw-r--r-- | runtime/indent/awk.vim | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/runtime/indent/awk.vim b/runtime/indent/awk.vim new file mode 100644 index 000000000..726a5ddbe --- /dev/null +++ b/runtime/indent/awk.vim @@ -0,0 +1,228 @@ +" vim: set sw=3 sts=3: + +" Awk indent script. It can handle multi-line statements and expressions. +" It works up to the point where the distinction between correct/incorrect +" and personal taste gets fuzzy. Drop me an e-mail for bug reports and +" reasonable style suggestions. +" +" Bugs: +" ===== +" - Some syntax errors may cause erratic indentation. +" - Same for very unusual but syntacticly correct use of { } +" - In some cases it's confused by the use of ( and { in strings constants +" - This version likes the closing brace of a multiline pattern-action be on +" character position 1 before the following pattern-action combination is +" formatted + +" Author: +" ======= +" Erik Janssen, ejanssen@itmatters.nl +" +" History: +" ======== +" 26-04-2002 Got initial version working reasonably well +" 29-04-2002 Fixed problems in function headers and max line width +" Added support for two-line if's without curly braces + +" Only load this indent file when no other was loaded. +if exists("b:did_indent") + finish +endif + +let b:did_indent = 1 + +setlocal indentexpr=GetAwkIndent() +" Mmm, copied from the tcl indent program. Is this okay? +setlocal indentkeys-=:,0# + +" Only define the function once. +if exists("*GetAwkIndent") + finish +endif + +" This function contains a lot of exit points. It checks for simple cases +" first to get out of the function as soon as possible, thereby reducing the +" number of possibilities later on in the difficult parts + +function! GetAwkIndent() + + " Find previous line and get it's indentation + let prev_lineno = s:Get_prev_line( v:lnum ) + if prev_lineno == 0 + return 0 + endif + let prev_data = getline( prev_lineno ) + let ind = indent( prev_lineno ) + + " Increase indent if the previous line contains an opening brace. Search + " for this brace the hard way to prevent errors if the previous line is a + " 'pattern { action }' (simple check match on /{/ increases the indent then) + + if s:Get_brace_balance( prev_data, '{', '}' ) > 0 + return ind + &sw + endif + + let brace_balance = s:Get_brace_balance( prev_data, '(', ')' ) + + " If prev line has positive brace_balance and starts with a word (keyword + " or function name), align the current line on the first '(' of the prev + " line + + if brace_balance > 0 && s:Starts_with_word( prev_data ) + return s:Safe_indent( ind, s:First_word_len(prev_data), getline(v:lnum)) + endif + + " If this line starts with an open brace bail out now before the line + " continuation checks. + + if getline( v:lnum ) =~ '^\s*{' + return ind + endif + + " If prev line seems to be part of multiline statement: + " 1. Prev line is first line of a multiline statement + " -> attempt to indent on first ' ' or '(' of prev line, just like we + " indented the positive brace balance case above + " 2. Prev line is not first line of a multiline statement + " -> copy indent of prev line + + let continue_mode = s:Seems_continuing( prev_data ) + if continue_mode > 0 + if s:Seems_continuing( getline(s:Get_prev_line( prev_lineno )) ) + " Case 2 + return ind + else + " Case 1 + if continue_mode == 1 + " Need continuation due to comma, backslash, etc + return s:Safe_indent( ind, s:First_word_len(prev_data), getline(v:lnum)) + else + " if/for/while without '{' + return ind + &sw + endif + endif + endif + + " If the previous line doesn't need continuation on the current line we are + " on the start of a new statement. We have to make sure we align with the + " previous statement instead of just the previous line. This is a bit + " complicated because the previous statement might be multi-line. + " + " The start of a multiline statement can be found by: + " + " 1 If the previous line contains closing braces and has negative brace + " balance, search backwards until cumulative brace balance becomes zero, + " take indent of that line + " 2 If the line before the previous needs continuation search backward + " until that's not the case anymore. Take indent of one line down. + + " Case 1 + if prev_data =~ ')' && brace_balance < 0 + while brace_balance != 0 + let prev_lineno = s:Get_prev_line( prev_lineno ) + let prev_data = getline( prev_lineno ) + let brace_balance=brace_balance+s:Get_brace_balance(prev_data,'(',')' ) + endwhile + let ind = indent( prev_lineno ) + else + " Case 2 + if s:Seems_continuing( getline( prev_lineno - 1 ) ) + let prev_lineno = prev_lineno - 2 + let prev_data = getline( prev_lineno ) + while prev_lineno > 0 && (s:Seems_continuing( prev_data ) > 0) + let prev_lineno = s:Get_prev_line( prev_lineno ) + let prev_data = getline( prev_lineno ) + endwhile + let ind = indent( prev_lineno + 1 ) + endif + endif + + " Decrease indent if this line contains a '}'. + if getline(v:lnum) =~ '^\s*}' + let ind = ind - &sw + endif + + return ind +endfunction + +" Find the open and close braces in this line and return how many more open- +" than close braces there are. It's also used to determine cumulative balance +" across multiple lines. + +function! s:Get_brace_balance( line, b_open, b_close ) + let line2 = substitute( a:line, a:b_open, "", "g" ) + let openb = strlen( a:line ) - strlen( line2 ) + let line3 = substitute( line2, a:b_close, "", "g" ) + let closeb = strlen( line2 ) - strlen( line3 ) + return openb - closeb +endfunction + +" Find out whether the line starts with a word (i.e. keyword or function +" call). Might need enhancements here. + +function! s:Starts_with_word( line ) + if a:line =~ '^\s*[a-zA-Z_0-9]\+\s*(' + return 1 + endif + return 0 +endfunction + +" Find the length of the first word in a line. This is used to be able to +" align a line relative to the 'print ' or 'if (' on the previous line in case +" such a statement spans multiple lines. +" Precondition: only to be used on lines where 'Starts_with_word' returns 1. + +function! s:First_word_len( line ) + let white_end = matchend( a:line, '^\s*' ) + if match( a:line, '^\s*func' ) != -1 + let word_end = matchend( a:line, '[a-z]\+\s\+[a-zA-Z_0-9]\+[ (]*' ) + else + let word_end = matchend( a:line, '[a-zA-Z_0-9]\+[ (]*' ) + endif + return word_end - white_end +endfunction + +" Determine if 'line' completes a statement or is continued on the next line. +" This one is far from complete and accepts illegal code. Not important for +" indenting, however. + +function! s:Seems_continuing( line ) + " Unfinished lines + if a:line =~ '[\\,\|\&\+\-\*\%\^]\s*$' + return 1 + endif + " if/for/while (cond) eol + if a:line =~ '^\s*\(if\|while\|for\)\s*(.*)\s*$' || a:line =~ '^\s*else\s*' + return 2 + endif + return 0 +endfunction + +" Get previous relevant line. Search back until a line is that is no +" comment or blank and return the line number + +function! s:Get_prev_line( lineno ) + let lnum = a:lineno - 1 + let data = getline( lnum ) + while lnum > 0 && (data =~ '^\s*#' || data =~ '^\s*$') + let lnum = lnum - 1 + let data = getline( lnum ) + endwhile + return lnum +endfunction + +" This function checks whether an indented line exceeds a maximum linewidth +" (hardcoded 80). If so and it is possible to stay within 80 positions (or +" limit num of characters beyond linewidth) by decreasing the indent (keeping +" it > base_indent), do so. + +function! s:Safe_indent( base, wordlen, this_line ) + let line_base = matchend( a:this_line, '^\s*' ) + let line_len = strlen( a:this_line ) - line_base + let indent = a:base + if (indent + a:wordlen + line_len) > 80 + " Simple implementation good enough for the time being + let indent = indent + 3 + endif + return indent + a:wordlen +endfunction |