Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!usc!ginosko!uunet!dino!atanasoff!atanasoff.cs.iastate.edu!lakshmin
From: lakshmin@atanasoff.cs.iastate.edu (Lakshminarayana Rudrabhatla)
Newsgroups: comp.lang.icon
Subject: criticism of icon
Message-ID: <1489@atanasoff.cs.iastate.edu>
Date: 8 Sep 89 16:43:55 GMT
Sender: lakshmin@atanasoff.cs.iastate.edu
Reply-To: lakshmin@atanasoff.cs.iastate.edu (Lakshminarayana Rudrabhatla)
Distribution: usa
Organization: Iowa State U. Computer Science Department, Ames, IA
Lines: 51


procedure main()

	words:=table()
	line_no:=0
	while line:=read() do {
		line_no +:=1
		write(left(line_no,6),left(line,40))
		line:=map(line)
		i:=1
		while j:=upto(&lcase,line,i) do {
		i:=many(&lcase,line,j)
		if *line[i:j] >= 3
		then {if   \words[line[i:j]]       #line 14
	              then insert(words[line[i:j]],line_no)    #line 15
		      else {words[line[i:j]]:=set()    #line 16
		            insert(words[line[i:j]], line_no)   #line 17 
			  }
                     }
		}
        }

  	words:=sort(words)
	i:=0
	while pair:=words[i +:=1] do  {
	   writes(left(pair[1],10),":")
	   s:=!pair[2]
	   pair[2]:=delete(pair[2],!pair[2])
           every s ||:= ", " ||!pair[2]
	   write(s)
	   }
	end

---------------------------------------------------------
question:
   
   in lines 14 thru 17 of the above program i had to implicitly
   declare the type of assigned value of table "words"
   as set(){ref: line#16} before i could perform
   the insert op. in line #15.
   this problem arose because &null would'nt coerce automatically
   to set(). this inspite of the claim that icon is dynamically typed.
   As a user, my "natural" impression was to assume that &null could
   represent an set() or "" or [] , as the case may be, since
   this facilitates easier and logical manipulation of the
   assigned value part of the structure "table" in general.
   
   does anyone see any problems with modifying the language to allow
   coercion of &null to set() or "" or [], as the case maybe depending
   upon the type of operation being performed on the assigned part of
   the structure "table".