############################################################################
#
#	File:     iprint.icn
#
#	Subject:  Program to print Icon program
#
#	Author:   Robert J. Alexander
#
#	Date:     March 26, 2002
#
############################################################################
#
#   This file is in the public domain.
#
############################################################################
#  
#     The defaults are set up for printing of Icon programs, but
#  through command line options it can be set up to print programs
#  in other languages, too (such as C). This program has several
#  features:
#  
#     If a program is written in a consistent style, this program
#  will attempt to keep whole procedures on the same page. The
#  default is to identify the end of a print group (i.e. a pro-
#  cedure) by looking for the string "end" at the beginning of a
#  line. Through the -g option, alternative strings can be used to
#  signal end of a group. Using "end" as the group delimiter
#  (inclusive), comments and declarations prior to the procedure are
#  grouped with the procedure. Specifying a null group delimiter
#  string (-g '') suppresses grouping.
#  
#     Page creases are skipped over, and form-feeds (^L) embedded in
#  the file are handled properly. (Form-feeds are treated as spaces
#  by many C compilers, and signal page ejects in a listing). Page
#  headings (file name, date, time, page number) are normally
#  printed unless suppressed by the -h option.
#  
#     Options:
#  
#       -n   number lines.
#  
#       -pN  page length: number of lines per page (default: 60
#            lines).
#  
#       -tN   tab stop spacing (default: 8).
#  
#       -h   suppress page headings.
#  
#       -l   add three lines at top of each page for laser printer.
#  
#       -gS  end of group string (default: "end").
#  
#       -cS  start of comment string (default: "#").
#  
#       -xS  end of comment string (default: none).
#  
#       -i   ignore FF at start of line.
#  
#     Any number of file names specified will be printed, each
#  starting on a new page.
#  
#     For example, to print C source files such as the Icon source
#  code, use the following options:
#  
#     iprint -g ' }' -c '/*' -x '*/' file ...
#  
#     Control lines:
#  
#     Control lines are special character strings that occur at the
#  beginnings of lines that signal special action. Control lines
#  begin with the start of comment string (see options). The control
#  lines currently recognized are:
#  
#     <comment string>eject -- page eject (line containing "eject"
#  does not print).
#  
#     <comment string>title -- define a title line to print at top
#  of each page. Title text is separated from the <comment
#  string>title control string by one space and is terminated by
#  <end of comment string> or end of line, whichever comes first.
#  
#     <comment string>subtitle -- define a sub-title line to print
#  at top of each page. Format is parallel to the "title" control
#  line, above.
#  
#     If a page eject is forced by maximum lines per page being
#  exceeded (rather than intentional eject via control line, ff, or
#  grouping), printing of blank lines at the top of the new page is
#  suppressed. Line numbers will still be printed correctly.
#  
############################################################################

global pagelines,tabsize,lines,page,datetime,title,subtitle,pagestatus,blanks,
	group,numbers,noheaders,hstuff,gpat,comment,comment_end,laser,
	ignore_ff

procedure main(arg)
  local files,x
  &dateline ? {tab(find(",")) ; move(2) ; datetime := tab(0)}
  files := []
  pagelines := 60
  tabsize := 8
  gpat := "end"
  comment := "#"

  while x := get(arg) do {
    if match("-",x) then {	# Arg is an option
      case x[2] of {
	"n": numbers := "yes"
	"p": {
	  pagelines := ("" ~== x[3:0]) | get(arg)
	  if not (pagelines := integer(pagelines)) then
		stop("Invalid -p parameter: ",pagelines)
	}
	"t": {
	  tabsize := ("" ~== x[3:0]) | get(arg)
	  if not (tabsize := integer(tabsize)) then
		stop("Invalid -t parameter: ",tabsize)
	}
	"h": noheaders := "yes"
	"l": laser := "yes"
	"g": {
	  gpat := ("" ~== x[3:0]) | get(arg)
	}
	"c": {
	  comment := ("" ~== x[3:0]) | get(arg)
	}
	"x": {
	  comment_end := ("" ~== x[3:0]) | get(arg)
	}
	"i": ignore_ff := "yes"
	default: stop("Invalid option ",x)
      }
    }
    else put(files,x)
  }
  if *files = 0 then stop("usage: iprint -options file ...\n_
	options:\n_
	\t-n\tnumber the lines\n_
	\t-p N\tspecify lines per page (default 60)\n_
	\t-t N\tspecify tab width (default 8)\n_
	\t-h\tsuppress page headers\n_
	\t-l\tadd 3 blank lines at top of each page\n_
	\t-g S\tpattern for last line in group\n_
	\t-c S\t'start of comment' string\n_
	\t-x S\t'end of comment' string\n_
	\t-i\tignore FF")
  every x := !files do expand(x)
end

procedure expand(fn)
  local f,line,cmd,linenbr,fname
  f := open(fn) | stop("Can't open ",fn)
  fn ? {
    while tab(find("/")) & move(1)
    fname := tab(0)
  }
  hstuff := fname || "  " || datetime || "  page "
  title := subtitle := &null
  lines := pagelines
  page := 0 ; linenbr := 0
  group := []
  while line := trim(read(f)) do {
    if \ignore_ff then while match("\f",line) do line[1] := ""
    linenbr +:= 1
    if match("\f",line) then {
      dumpgroup()
      lines := pagelines
      repeat {
	line[1] := ""
	if not match("\f",line) then break
      }
    }
    line ? {
      if =comment & cmd := =("eject" | "title" | "subtitle") then {
	dumpgroup()
	case cmd of {		# Command line
	  "title": (move(1) & title := trim(tab(find(comment_end)))) |
		(title := &null)
	  "subtitle": (move(1) & subtitle := trim(tab(find(comment_end)))) |
		(subtitle := &null)
	}
	lines := pagelines
      }
      else {	# Ordinary (non-command) line
	if not (*group = 0 & *line = 0) then {
	  put(group,line)
	  if \numbers then put(group,linenbr)
	}
	if endgroup(line) then dumpgroup()
      }
    }
  }
  dumpgroup()
  close(f)
  lines := pagelines
end

procedure dumpgroup()
  local line,linenbr
  if *group > 0 then {
    if lines + *group / ((\numbers & 2) | 1) + 2 >= pagelines then
	lines := pagelines
    else {write("\n") ; lines +:= 2}
    while line := get(group) do {
      if \numbers then linenbr := get(group)
      if lines >= pagelines then {
	printhead()
      }
      if *line = 0 then {
	if pagestatus ~== "empty" then {blanks +:= 1 ; lines +:= 1}
	next
      }
      every 1 to blanks do write()
      blanks := 0
      pagestatus := "not empty"
      if \numbers then writes(right(linenbr,5)," ")
      write(detab(line))
      lines +:= 1
    }
  }
  return
end

procedure endgroup(s)
  return match("" ~== gpat,s)
end

procedure printhead()
  static ff,pg
  writes(ff) ; ff := "\f"
  lines := 0
  pg := string(page +:= 1)
  if /noheaders then {
    if \laser then write("\n\n")
    write(left(\title | "",79 - *hstuff - *pg),hstuff,pg)
    lines +:= 2
    write(\subtitle) & lines +:= 1
    write()
  }
  pagestatus := "empty"
  blanks := 0
  return
end

procedure detab(s)
  local t
  t := ""
  s ? {
    while t ||:= tab(find("\t")) do {
      t ||:= repl(" ",tabsize - *t % tabsize)
      move(1)
    }
    t ||:= tab(0)
  }
  return t
end