" Function to left and right align text.
"
" Written by: Preben "Peppe" Guldberg <c928400@student.dtu.dk>
" Created: 980806 14:13 (or around that time anyway)
" Revised: 001103 00:36 (See "Revisions" below)
" function Justify( [ textwidth [, maxspaces [, indent] ] ] )
"
" Justify() will left and right align a line by filling in an
" appropriate amount of spaces. Extra spaces are added to existing
" spaces starting from the right side of the line. As an example, the
" following documentation has been justified.
"
" The function takes the following arguments:
" textwidth argument
" ------------------
" If not specified, the value of the 'textwidth' option is used. If
" 'textwidth' is zero a value of 80 is used.
"
" Additionally the arguments 'tw' and '' are accepted. The value of
" 'textwidth' will be used. These are handy, if you just want to specify
" the maxspaces argument.
" maxspaces argument
" ------------------
" If specified, alignment will only be done, if the longest space run
" after alignment is no longer than maxspaces.
"
" An argument of '' is accepted, should the user like to specify all
" arguments.
"
" To aid user defined commands, negative values are accepted aswell.
" Using a negative value specifies the default behaviour: any length of
" space runs will be used to justify the text.
" indent argument
" ---------------
" This argument specifies how a line should be indented. The default is
" to keep the current indentation.
"
" Negative values: Keep current amount of leading whitespace.
" Positive values: Indent all lines with leading whitespace using this
" amount of whitespace.
"
" Note that the value 0, needs to be quoted as a string. This value
" leads to a left flushed text.
"
" Additionally units of 'shiftwidth'/'sw' and 'tabstop'/'ts' may be
" added. In this case, if the value of indent is positive, the amount of
" whitespace to be added will be multiplied by the value of the
" 'shiftwidth' and 'tabstop' settings. If these units are used, the
" argument must be given as a string, eg. Justify('','','2sw').
"
" If the values of 'sw' or 'tw' are negative, they are treated as if
" they were 0, which means that the text is flushed left. There is no
" check if a negative number prefix is used to change the sign of a
" negative 'sw' or 'ts' value.
"
" As with the other arguments, '' may be used to get the default
" behaviour.
" Notes:
"
" If the line, adjusted for space runs and leading/trailing whitespace,
" is wider than the used textwidth, the line will be left untouched (no
" whitespace removed). This should be equivalent to the behaviour of
" :left, :right and :center.
"
" If the resulting line is shorter than the used textwidth it is left
" untouched.
"
" All space runs in the line are truncated before the alignment is
" carried out.
"
" If you have set 'noexpandtab', :retab! is used to replace space runs
" with whitespace using the value of 'tabstop'. This should be
" conformant with :left, :right and :center.
"
" If joinspaces is set, an extra space is added after '.', '?' and '!'.
" If 'cpooptions' include 'j', extra space is only added after '.'.
" (This may on occasion conflict with maxspaces.)
" Related mappings:
"
" Mappings that will align text using the current text width, using at
" most four spaces in a space run and keeping current indentation.
nmap _j :%call Justify('tw',4)<CR>
vmap _j :call Justify('tw',4)<CR>
"
" Mappings that will remove space runs and format lines (might be useful
" prior to aligning the text).
nmap ,gq :%s/\s\+/ /g<CR>gq1G
vmap ,gq :s/\s\+/ /g<CR>gvgq
" User defined command:
"
" The following is an ex command that works as a shortcut to the Justify
" function. Arguments to Justify() can be added after the command.
com! -range -nargs=* Justify <line1>,<line2>call Justify(<f-args>)
"
" The following commands are all equivalent:
"
" 1. Simplest use of Justify():
" :call Justify()
" :Justify
"
" 2. The _j mapping above via the ex command:
" :%Justify tw 4
"
" 3. Justify visualised text at 72nd column while indenting all
" previously indented text two shiftwidths
" :'<,'>call Justify(72,'','2sw')
" :'<,'>Justify 72 -1 2sw
"
" This documentation has been justified using the following command:
":se et|kz|1;/^" function Justify(/+,'z-g/^" /s/^" //|call Justify(70,3)|s/^/" /
" Revisions:
" 001103: If 'joinspaces' was set, calculations could be wrong.
" Tabs at start of line could also lead to errors.
" Use setline() instead of "exec 's/foo/bar/' - safer.
" Cleaned up the code a bit.
"
" Todo: Convert maps to the new script specific form
" Error function
function! Justify_error(message)
echohl Error
echo "Justify([tw, [maxspaces [, indent]]]): " . a:message
echohl None
endfunction
" Now for the real thing
function! Justify(...) range
if a:0 > 3
call Justify_error("Too many arguments (max 3)")
return 1
endif
" Set textwidth (accept 'tw' and '' as arguments)
if a:0 >= 1
if a:1 =~ '^\(tw\)\=$'
let tw = &tw
elseif a:1 =~ '^\d\+$'
let tw = a:1
else
call Justify_error("tw must be a number (>0), '' or 'tw'")
return 2
endif
else
let tw = &tw
endif
if tw == 0
let tw = 80
endif
" Set maximum number of spaces between WORDs
if a:0 >= 2
if a:2 == ''
let maxspaces = tw
elseif a:2 =~ '^-\d\+$'
let maxspaces = tw
elseif a:2 =~ '^\d\+$'
let maxspaces = a:2
else
call Justify_error("maxspaces must be a number or ''")
return 3
endif
else
let maxspaces = tw
endif
if maxspaces <= 1
call Justify_error("maxspaces should be larger than 1")
return 4
endif
" Set the indentation style (accept sw and ts units)
let indent_fix = ''
if a:0 >= 3
if (a:3 == '') || a:3 =~ '^-[1-9]\d*\(shiftwidth\|sw\|tabstop\|ts\)\=$'
let indent = -1
elseif a:3 =~ '^-\=0\(shiftwidth\|sw\|tabstop\|ts\)\=$'
let indent = 0
elseif a:3 =~ '^\d\+\(shiftwidth\|sw\|tabstop\|ts\)\=$'
let indent = substitute(a:3, '\D', '', 'g')
elseif a:3 =~ '^\(shiftwidth\|sw\|tabstop\|ts\)$'
let indent = 1
else
call Justify_error("indent: a number with 'sw'/'ts' unit")
return 5
endif
if indent >= 0
while indent > 0
let indent_fix = indent_fix . ' '
let indent = indent - 1
endwhile
let indent_sw = 0
if a:3 =~ '\(shiftwidth\|sw\)'
let indent_sw = &sw
elseif a:3 =~ '\(tabstop\|ts\)'
let indent_sw = &ts
endif
let indent_fix2 = ''
while indent_sw > 0
let indent_fix2 = indent_fix2 . indent_fix
let indent_sw = indent_sw - 1
endwhile
let indent_fix = indent_fix2
endif
else
let indent = -1
endif
" Avoid substitution reports
let save_report = &report
set report=1000000
" Check 'joinspaces' and 'cpo'
if &js == 1
if &cpo =~ 'j'
let join_str = '\(\. \)'
else
let join_str = '\([.!?!] \)'
endif
endif
let cur = a:firstline
while cur <= a:lastline
let str_orig = getline(cur)
let save_et = &et
set et
exec cur . "retab"
let &et = save_et
let str = getline(cur)
let indent_str = indent_fix
let indent_n = strlen(indent_str)
" Shall we remember the current indentation
if indent < 0
let indent_orig = matchstr(str_orig, '^\s*')
if strlen(indent_orig) > 0
let indent_str = indent_orig
let indent_n = strlen(matchstr(str, '^\s*'))
endif
endif
" Trim trailing, leading and running whitespace
let str = substitute(str, '\s\+$', '', '')
let str = substitute(str, '^\s\+', '', '')
let str = substitute(str, '\s\+', ' ', 'g')
let str_n = strdisplaywidth(str)
" Possible addition of space after punctuation
if exists("join_str")
let str = substitute(str, join_str, '\1 ', 'g')
endif
let join_n = strdisplaywidth(str) - str_n
" Can extraspaces be added?
" Note that str_n may be less than strlen(str) [joinspaces above]
if strdisplaywidth(str) <= tw - indent_n && str_n > 0
" How many spaces should be added
let s_add = tw - str_n - indent_n - join_n
let s_nr = strlen(substitute(str, '\S', '', 'g') ) - join_n
let s_dup = s_add / s_nr
let s_mod = s_add % s_nr
" Test if the changed line fits with tw
if 0 <= (str_n + (maxspaces - 1)*s_nr + indent_n) - tw
" Duplicate spaces
while s_dup > 0
let str = substitute(str, '\( \+\)', ' \1', 'g')
let s_dup = s_dup - 1
endwhile
" Add extra spaces from the end
while s_mod > 0
let str = substitute(str, '\(\(\s\+\S\+\)\{' . s_mod . '}\)$', ' \1', '')
let s_mod = s_mod - 1
endwhile
" Indent the line
if indent_n > 0
let str = substitute(str, '^', indent_str, '' )
endif
" Replace the line
call setline(cur, str)
" Convert to whitespace
if &et == 0
exec cur . 'retab!'
endif
endif " Change of line
endif " Possible change
let cur = cur + 1
endwhile
norm ^
let &report = save_report
endfunction
" EOF vim: tw=78 ts=8 sw=4 sts=4 noet ai