blob: ccb826753c229acc443e273b9632d4daadc331a5 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
# -*- tcl -*-
# # ## ### ##### ######## #############
# (C) 2009 Andreas Kupries
# @@ Meta Begin
# Package tcl::chan::random 1
# Meta as::author {Andreas Kupries}
# Meta as::copyright 2009
# Meta as::license BSD
# Meta description Implementation of a channel similar to
# Meta description Memchan's random channel. Based on Tcl
# Meta description 8.5's channel reflection support. Exports
# Meta description a single command for the creation of new
# Meta description channels. One argument, a list of
# Meta description numbers to initialize the feedback
# Meta description register of the internal random number
# Meta description generator. Result is the handle of the
# Meta description new channel.
# Meta platform tcl
# Meta require TclOO
# Meta require tcl::chan::events
# Meta require {Tcl 8.5}
# @@ Meta End
# # ## ### ##### ######## #############
package require tcl::chan::events
package require Tcl 8.5
package require TclOO
# # ## ### ##### ######## #############
namespace eval ::tcl::chan {}
proc ::tcl::chan::random {seed} {
return [::chan create {read} [random::implementation new $seed]]
}
oo::class create ::tcl::chan::random::implementation {
superclass tcl::chan::events ; # -> initialize, finalize, watch
constructor {theseed} {
my variable seed next
set seed $theseed
set next [expr "([join $seed +]) & 0xff"]
next
}
method initialize {args} {
my allow read
next {*}$args
}
# Generate and return a block of N randomly selected bytes, as
# requested. Random device.
method read {c n} {
set buffer {}
while {$n} {
append buffer [binary format c [my Next]]
incr n -1
}
return $buffer
}
variable seed
variable next
method Next {} {
my variable seed next
set result $next
set next [expr {(2*$next - [lindex $seed 0]) & 0xff}]
set seed [linsert [lrange $seed 1 end] end $result]
return $result
}
}
# # ## ### ##### ######## #############
package provide tcl::chan::random 1
return
|
