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Diffstat (limited to 'ipl/progs/format.icn')
| -rw-r--r-- | ipl/progs/format.icn | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/ipl/progs/format.icn b/ipl/progs/format.icn new file mode 100644 index 0000000..fc0528d --- /dev/null +++ b/ipl/progs/format.icn @@ -0,0 +1,162 @@ +############################################################################ +# +# File: format.icn +# +# Subject: Program to word wrap a range of text +# +# Author: Robert J. Alexander +# +# Date: March 26, 2002 +# +############################################################################ +# +# This file is in the public domain. +# +############################################################################ +# +# Filter to word wrap a range of text. +# +# A number of options are available, including full justification (see +# usage text, below). All lines that have the same indentation as the +# first line (or same comment leading character format if -c option) +# are wrapped. Other lines are left as is. +# +# This program is useful in conjunction with editors that can invoke +# filters on a range of selected text. +# +# The -c option attempts to establish the form of a comment based on the +# first line, then does its best to deal properly with the following +# lines. The types of comment lines that are handled are those in +# which each line starts with a "comment" character string (possibly +# preceded by spaces). While formatting comment lines, text lines +# following the prototype line that don't match the prototype but are +# flush with the left margin are also formatted as comments. This +# feature simplifies initially entering lengthy comments or making +# major modifications, since new text can be entered without concern +# for comment formatting, which will be done automatically later. +# +############################################################################ +# +# Links: options +# +############################################################################ + +link options + +procedure main(arg) + local usage, opts, tabs, comment, format, just1, space, nspace, wchar, Entab + local line, pre, empty, outline, spaces, word, len, width, xspace, Detab + local outpre + # + # Process the options. + # + usage := + "usage: format [-options]\n_ + \t-w N\tspecify line width (default 72)\n_ + \t-t N\tspecify tab width (default 8)\n_ + \t-j\tfully justify lines\n_ + \t-J\tfully justify last line, too\n_ + \t-c\tattempt to format program comments\n_ + \t-n\tdon't put extra spaces after sentences\n_ + \t-h\tprint help message" + opts := options(arg,"ht+w+cjJn") + if \opts["h"] then stop(usage) + width := integer(\opts["w"]) | 72 + tabs := (integer(\opts["t"]) | 8) + 1 + if tabs >= 2 then { + Detab := detab + Entab := entab + } + else Entab := Detab := 1 + comment := opts["c"] + format := if \just1 | \opts["j"] then justify else 1 + just1 := opts["J"] + xspace := if \opts["s"] then '' else '.?:!' + # + # Initialize variables. + # + space := ' \t' + nspace := ~space + wchar := nspace + # + # Read the first line to establish a prototype of comment format + # if -c option, or of leading spaces if normal formatting. + # + line := Detab(read(),tabs) | exit() + line ? + pre := (tab(many(space)) | "") || + if \comment then + tab(many(nspace)) || tab(many(space)) | + stop("### Can't establish comment pattern") + else + "" + width -:= *pre + empty := trim(pre) + outpre := Entab(pre,tabs) + outline := spaces := "" + repeat { + line ? { + # + # If this line indicates a formatting break... + # + if (=empty & pos(0)) | (=pre & any(space) | pos(0)) | + (/comment & not match(pre)) then { + write(outpre,"" ~== outline) + outline := spaces := "" + write(line) + } + # + # Otherwise continue formatting. + # + else { + =pre + tab(0) ? { + tab(many(space)) + while word := tab(many(wchar)) & (tab(many(space)) | "") do { + if *outline + *spaces + *word > width then { + write(outpre,"" ~== format(outline,width)) + outline := spaces := "" + } + outline ||:= spaces || word + spaces := if any(xspace,word[-1]) then " " else " " + } + } + } + } + line := Detab(read(),tabs) | break + } + write(outpre,"" ~== (if \just1 then justify else 1)(outline,width)) +end + + +# +# justify(s,width) -- Inserts extra spaces between words of "s" so that +# "s" will be exactly "width" characters long. "s" is trimmed of +# spaces on the right and left ends. If "s" contains fewer than two +# words, or if the trimmed version is longer than "width", the trimmed +# version of "s" is returned unchanged. Where some gaps between words +# are required to be wider than others, the extra spaces are +# distributed randomly to minimize "rivering" in justified paragraphs. +# +procedure justify(s,width) + local wlist,wset,t,r + static space,nspace + initial { + space := ' ' + nspace := &cset -- space + } + s := trim(s[many(space,s) | 1:0]) + wlist := [] + s ? while put(wlist,[tab(many(nspace)),*tab(many(space)) | 0]) + if *s >= width | *wlist < 2 then return s + wset := set(wlist[1:-1]) + t := (width - *s) / *wset + every (!wset)[2] +:= t + every 1 to (width - *s) % *wset do { + (t := ?wset)[2] +:= 1 + delete(wset,t) + } + r := "" + every t := !wlist do r ||:= t[1] || repl(" ",t[2]) + return r +end |