nexttok.pro
3.67 KB
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
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
;
;+
; NAME:
; NEXTTOK
; PURPOSE:
; Find the next occurance of any of a set of characters in a
; string and return the character which occurs next.
; CATEGORY:
; text/strings
; CALLING SEQUENCE:
; tok = nexttok( strn, tokens )
; INPUTS:
; strn -- string to be searched for sub/superscripts in
; tokens -- string containing characters to be found. in
; KEYWORD PARAMETERS:
; POSITION -- Set to a named variable to get position out
; of next token, or -1 if none found.
; /HELP -- Print useful message and exit.
; OUTPUTS:
; tok -- Contains the character among tokens which out
; occurs next in strn, or null '' if none found.
; COMMON BLOCKS:
; SIDE EFFECTS:
; NOTES:
; EXAMPLE:
; nexttok( 'x^2 + N_j^3', '^_', position=pos ) returns '^' and sets
; pos to 1.
; MODIFICATION HISTORY:
; $Id: nexttok.pro,v 1.3 1996/06/14 20:00:27 mcraig Exp $
; $Log: nexttok.pro,v $
; Revision 1.3 1996/06/14 20:00:27 mcraig
; Updated Copyright info.
;
; Revision 1.2 1996/05/09 00:22:17 mcraig
; Generalized so that the next occurence of any of a set of characters will
; be returned.
;
; Revision 1.1 1996/01/31 18:41:06 mcraig
; Initial revision
;
; RELEASE:
; $Name: Rel_2_1 $
;
; COPYRIGHT:
; Copyright (C) 1996 The Regents of the University of California, All
; Rights Reserved. Written by Matthew W. Craig.
; See the file COPYRIGHT for restrictions on distrubting this code.
; This code comes with absolutely NO warranty; see DISCLAIMER for details.
;-
FUNCTION nexttok, strn, tokens, $
POSITION=position, $
HELP=Help
; Return to caller on error.
On_error, 2
; Help those in need of it.
IF (n_params() NE 2) OR keyword_set(Help) THEN BEGIN
offset = ' '
print, offset+'Find the next occurance of any of a set of characters in a'
print, offset+'string and return the character which occurs next.'
; CALLING SEQUENCE:
print, offset+'tok = nexttok( strn, tokens )'
; INPUTS:
print, offset+'Inputs:'
print, offset+offset+'strn -- string to be searched for sub/superscripts in'
print, offset+offset+'tokens -- string containing characters to be found. in'
; KEYWORD PARAMETERS:
print, offset+'Keywords:'
print, offset+offset+'POSITION -- Set to a named variable to get position out'
print, offset+offset+' of next token, or -1 if none found.'
print, offset+offset+'/HELP -- Print useful message and exit.'
; OUTPUTS:
print, offset+'Outputs:'
print, offset+offset+'tok -- Contains the character among tokens which out'
print, offset+offset+" occurs next in strn, or null '' if none found."
; EXAMPLE:
print, offset+'Example:'
print, offset+offset+"nexttok( 'x^2 + N_j^3', '^_', position=pos ) returns '^' and sets"
print, offset+offset+'pos to 1.'
return, ''
ENDIF
TmpStr = byte(strn)
TmpTok = byte(tokens)
NumToks = n_elements(TmpTok)
MatchIdx = 0L
Matches = 0L
FOR j=0, NumToks-1 DO BEGIN
TmpMatch = where(TmpStr EQ TmpTok(j), TmpCnt)
IF (TmpCnt GT 0) THEN BEGIN
MatchIdx = [MatchIdx, Replicate(j, TmpCnt)]
Matches = [Matches, TmpMatch]
ENDIF
ENDFOR
IF n_elements(MatchIdx) EQ 1 THEN BEGIN
Position = -1
return, ''
ENDIF
MatchIdx = MatchIdx(1:*)
Matches = Matches(1:*)
SortInd = sort(Matches)
Position = Matches(SortInd(0))
Tok = string(TmpTok(MatchIdx(SortInd(0))))
return, Tok
END