definition module PrintUtil

// a collection of print routines to write html to Std Output
// (c) MJP 2005

import StdGeneric
import StdFile
import Gerda

:: *HtmlStream	:== [# String !]

:: FoF			:== (*HtmlStream -> *HtmlStream)

:: *NWorld							// io interface
	= 	{ worldC:: !*World			// world for any io
		, inout	:: !*HtmlStream		// to read from stdin and write to stdout
		, gerda	:: *Gerda			// to read and write to the database
		}				
instance FileSystem NWorld
appWorldNWorld	:: !.(*World -> *World)       !*NWorld -> *NWorld
accWorldNWorld	:: !.(*World -> *(.a,*World)) !*NWorld -> (.a,!*NWorld)


// generic function for printing tags
// Constructors are converted to html tag strings
// prefix Name_ of Name_Attrname is removed, and Name is converted to lowercase string

generic gHpr a	:: !*HtmlStream !a -> *HtmlStream		

derive gHpr UNIT, PAIR, EITHER, CONS, OBJECT
derive gHpr Int, Real, Bool, String, Char, []

// the main print routine

print_to_stdout :: !a !*NWorld			-> *NWorld | gHpr{|*|} a

// handy utility print routines	

print 			:: !String 				-> FoF
(<+)  infixl 	:: !*HtmlStream !a 		-> *HtmlStream	| gHpr{|*|} a
(<+>) infixl 	:: !*HtmlStream !FoF 	-> *HtmlStream

htmlAttrCmnd 	:: !hdr !tag !body  	-> FoF | gHpr{|*|} hdr & gHpr{|*|} tag & gHpr{|*|} body
openCmnd 		:: !a !b 				-> FoF | gHpr{|*|} a & gHpr{|*|} b
styleCmnd 		:: !a !b 				-> FoF | gHpr{|*|} a & gHpr{|*|} b
styleAttrCmnd 	:: !a !b 				-> FoF | gHpr{|*|} a & gHpr{|*|} b