blob: aae896848739fdf90eb2a2c11cb55f541c48c990 (
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
|
############################################################################
#
# File: labeler.icn
#
# Subject: Procedure to produce successive labels
#
# Author: Gregg M. Townsend
#
# Date: April 9, 1993
#
############################################################################
#
# This file is in the public domain.
#
############################################################################
#
# This procedure produces a new label in sequence each time it's called.
# The labels consist of all possible combinations of the characters given
# in the argument the first time it is called. See star(s) in gener.icn
# for a generator that does the same thing (and much more concisely).
#
############################################################################
#
# Increment a counter and convert to a label.
procedure label(chars)
static s, abet
local i
initial {
abet := string(chars) # initialize alphabet
s := abet[1] # initialize string
return s
}
i := *s # start with last `digit'
while s[i] == abet[*abet] do { # while need to `carry'
s[i] := abet[1] # reset digit
i -:= 1 # move left one digit
if i = 0 then # if no more digits
return s := abet[1] || s # lengthen string
}
s[i] := abet[find(s[i],abet)+1] # normal case: incr one digit
return s
end
|
