############################################################################
#
#	File:     ibrow.icn
#
#	Subject:  Program to browse Icon files for declarations
#
#	Author:   Robert J. Alexander
#
#	Date:     September 7, 1990
#
############################################################################
#
#   This file is in the public domain.
#
############################################################################
#
#  Usage: ibrow [<Icon source file name>...]
#
#  If no source file names are provided on the command line, all *.icn
#  files in the current directory are browsed.
#
#  The program facilitates browsing of Icon programs.  It was originally
#  written to browse the Icon Program Library, for which purpose it
#  serves quite well.  The user interface is self-explanatory -- just
#  remember to use "?" for help if you're confused.
#
############################################################################
#
#  Links:  colmize
#
############################################################################
#
#  Requires:  UNIX
#
############################################################################

link colmize

procedure main(arg)
   local p, proctab, doneNames, fn, f, foundNonEmptyLine, block, lineNbr
   local line, keywd, startLine, proclist, w, i, x, proclines, cmd, b

   if not (&features == "UNIX") then stop("Runs only under UNIX")
   if *arg = 0 then {
      p := open("ls *.icn","rp")
      while put(arg,read(p))
      close(p)
      }
   proctab := table()
   #
   #  Loop to scan all of the specified source files and save their
   #  procedures and records.
   #
   doneNames := set()	# This set is used to prevent scanning twice if
			# both a source and a suffixless icode file are
			# passed as arguments (e.g. mydir/*).
   write("Icon Browser -- scanning files:")
   every fn := !arg do {
      if not (fn[-4:0] == ".icn") then fn ||:= ".icn"
      if member(doneNames,fn) then next
      insert(doneNames,fn)
      f := if fn == "-" then &input else open(fn) | next
      write("  ",fn)
      #
      #  Loop to process lines of file (in string scanning mode).
      #
      foundNonEmptyLine := &null
      block := []
      lineNbr := 0
      while line := read(f) do line ? {
	 lineNbr +:= 1
	 if not pos(0) then {
	    foundNonEmptyLine := 1
	    if (tab(many(' \t')) | "")\1 &
		  (keywd := =("end" | "global" | "link")\1) |
		  (keywd := =("procedure" | "record")\1 &
		  tab(many(' \t')) & name := tab(upto(' \t('))\1) then {
	       if keywd == ("procedure" | "record") then startLine := lineNbr
	       if keywd == "record" then {
		  until find(")",line) do {
		     put(block,line)
		     line := read(f) | break
		     lineNbr +:= 1
		     }
		  }
	       if proctab[name || case keywd of {"end": "()"; "record": "."}] :=
		     [block,fn,startLine] then put(block,line)
	       if keywd ~== "procedure" then {
		  foundNonEmptyLine := &null
		  block := []
		  }
	       }
	    }
	 if \foundNonEmptyLine then put(block,line)
	 }
      #
      #  Close this file.
      #
      close(f)
      }
   doneNames := &null
   #
   #  Reorganize the data.
   #
   proctab := sort(proctab)
   proclist := []
   w := **proctab
   i := 0
   every x := !proctab do
	 put(proclist,right(i +:= 1,w) || ". " || x[1])
   proclines := []
   every put(proclines,colmize(proclist))
   proclist := []
   every put(proclist,(!proctab)[2])
   proctab := &null
   #
   #  Interact with the user to browse.
   #
   repeat {
      write()
      every write(!proclines)
      write()
      repeat {
	 #
	 #  Prompt for, read, and analyze the user's command.
	 #
	 writes("\nq,nn,nn[fmev],<return> (? for help): ")
	 line := read() | exit()
	 case line of {
	   "q": exit()
	   "?": help() & next
	   "":  break
	 }
	 if integer(line) then line ||:= "f"
	 if cmd := line[-1] & any('fmev',cmd) &
	       block := proclist[0 < integer(line[1:-1])] then {
	    case cmd of {
	       "f": {
		  #
		  #  Write the file name containing the procedure and the
		  #  first line of the procedure.
		  #
		  b := block[1]
		  every line := b[1 to *b] do {
		     line ? (if (tab(many(' \t')) | "")\1 &
			   =("procedure" | "record") then break)
		     }
		  write(block[2],": ",line)
		  }
	       "m": {
		  #
		  #  List the procedure using "more".
		  #
		  write()
		  p := open("more","pw") | stop("Can't popen")
		  every write(p,!block[1])
		  close(p)
	          }
	       "e" | "v": {
		  #
		  #  Invoke ex or vi positioned at the first line
		  #  of procedure or record.
		  #
		  system((if cmd == "e" then "ex" else "vi") ||
		        " +" || block[3] || " " || block[2])
		  }
	       }
	    }
	 }
     }
end

procedure help()
   write(
"\nEnter:_
\n    q                     Quit_
\n    ?                     Display help message (this message)_
\n    <return>              Redisplay the list of procedure and record names_
\n    <number from list>[f] Display the file name and first line of_
\n                          procedure or record_
\n    <number from list>m   Display the procedure or record using \"more\"_
\n    <number from list>e   Invoke \"ex\" positioned to procedure or record_
\n    <number from list>v   Invoke \"vi\" positioned to procedure or record"
   )
   return
end