This page has some type implementations in the framework mentioned in OO libraries
Summary
dir - is a sub-type of type stream. Provides a stream abstraction of dir.
stream - an abstract type
The sub-types of this type needs to provide the implementations for read,seek,tell,open close. It presently provides for-each implementation.
Usage :
dir create a /tmp # object creation
> read a # reads the current item in the stream
> foreach a item { puts $item } # foreach is the iterator for the stream items.Modified proc ">"
proc > { args } {
set obj [lindex $args 1 ]
upvar $obj myobj
set handler $myobj(handler)
set myobj(level) [ expr [info level] - 1 ]
lvarpop args 1
lvarpush args myobj 1
$handler $args
}Type implementations:
Dir - type
package require Tclx
proc dir { args } {
if {! [ string equal [lindex $args 0] create ] } {
set args [lindex $args 0]
}
set ref [lindex $args 1 ]
set action [lindex $args 0]
upvar $ref myref
switch $action \
create {
array set myref [list handler dir]
array set myref [list dir [lindex $args 2 ]]
array set myref [list items [ glob $myref(dir)/* ] ]
array set myref [list position -1 ]
} \
open {
array set myref [list position -1 ]
} \
read {
set pres_elem {}
set max_position [ expr [llength $myref(items)] - 1 ]
if { $myref(position) < $max_position } {
set myref(position) [ expr $myref(position) + 1 ]
set pres_elem [ lindex $myref(items) $myref(position) ]
}
return $pres_elem
} \
seek {
set index [lindex $args 2 ]
if [ expr $index < [ llength $myref(items)] ] {
array set myref [list position [lindex $args 2] ]
}
} \
tell {
return $myref(position)
} \
close {
array set myref [list position -1 ]
} \
default {
lvarpop args 1
lvarpush args myref 1
set myargs $args
stream $myargs
}
}Stream - type