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Expand index,rindex functions to accept char array inputs * index.m, rindex.m: Allow char array inputs. Update documentation and tests.
author Rik <octave@nomad.inbox5.com>
date Fri, 07 Oct 2011 14:18:18 -0700
parents cefd568ea073
children 72c96de7a403
comparison
equal deleted inserted replaced
13288:497bb1cf7b15 13289:1a6537dbce7b
18 18
19 ## -*- texinfo -*- 19 ## -*- texinfo -*-
20 ## @deftypefn {Function File} {} index (@var{s}, @var{t}) 20 ## @deftypefn {Function File} {} index (@var{s}, @var{t})
21 ## @deftypefnx {Function File} {} index (@var{s}, @var{t}, @var{direction}) 21 ## @deftypefnx {Function File} {} index (@var{s}, @var{t}, @var{direction})
22 ## Return the position of the first occurrence of the string @var{t} in the 22 ## Return the position of the first occurrence of the string @var{t} in the
23 ## string @var{s}, or 0 if no occurrence is found. For example: 23 ## string @var{s}, or 0 if no occurrence is found. @var{s} may also be a
24 ## string array or cell array of strings.
25 ##
26 ## For example:
24 ## 27 ##
25 ## @example 28 ## @example
26 ## @group 29 ## @group
27 ## index ("Teststring", "t") 30 ## index ("Teststring", "t")
28 ## @result{} 4 31 ## @result{} 4
29 ## @end group 32 ## @end group
30 ## @end example 33 ## @end example
31 ## 34 ##
32 ## If @var{direction} is @samp{"first"}, return the first element found. 35 ## If @var{direction} is @samp{"first"}, return the first element found.
33 ## If @var{direction} is @samp{"last"}, return the last element found. 36 ## If @var{direction} is @samp{"last"}, return the last element found.
34 ## The @code{rindex} function is equivalent to @code{index} with
35 ## @var{direction} set to @samp{"last"}.
36 ## 37 ##
37 ## @strong{Caution:} This function does not work for arrays of
38 ## character strings.
39 ## @seealso{find, rindex} 38 ## @seealso{find, rindex}
40 ## @end deftypefn 39 ## @end deftypefn
41 40
42 ## Author: Kurt Hornik <Kurt.Hornik@wu-wien.ac.at> 41 ## Author: Kurt Hornik <Kurt.Hornik@wu-wien.ac.at>
43 ## Adapted-By: jwe 42 ## Adapted-By: jwe
43 ## This is patterned after the AWK function of the same name.
44 44
45 function n = index (s, t, direction) 45 function n = index (s, t, direction = "first")
46
47 ## This is patterned after the AWK function of the same name.
48 46
49 if (nargin < 2 || nargin > 3) 47 if (nargin < 2 || nargin > 3)
50 print_usage (); 48 print_usage ();
51 elseif (nargin < 3)
52 direction = "first";
53 endif 49 endif
54 direction = lower (direction); 50
51 if (ischar (s))
52 if (! isrow (s))
53 s = cellstr (s); # Handle string arrays by conversion to cellstr
54 endif
55 elseif (! iscellstr (s))
56 error ("index: S must be a string, string array, or cellstr");
57 endif
55 58
56 f = strfind (s, t); 59 f = strfind (s, t);
57 if (iscell (f)) 60 if (isempty (f))
61 f = 0;
62 elseif (iscell (f))
58 f(cellfun ("isempty", f)) = {0}; 63 f(cellfun ("isempty", f)) = {0};
59 elseif (isempty (f))
60 f = 0;
61 endif 64 endif
62 65
63 if (strcmp (direction, "last")) 66 direction = tolower (direction);
67
68 if (strcmp (direction, "first"))
64 if (iscell (f)) 69 if (iscell (f))
65 n = cellfun ("min", f); 70 n = cellfun ("min", f);
66 else 71 else
67 n = f(end); 72 n = f(1);
68 endif 73 endif
69 elseif (strcmp (direction, "first")) 74 elseif (strcmp (direction, "last"))
70 if (iscell (f)) 75 if (iscell (f))
71 n = cellfun ("max", f); 76 n = cellfun ("max", f);
72 else 77 else
73 n = f(1); 78 n = f(end);
74 endif 79 endif
75 else 80 else
76 error ("index: DIRECTION must be either \"first\" or \"last\""); 81 error ('index: DIRECTION must be either "first" or "last"');
77 endif 82 endif
83
78 endfunction 84 endfunction
79 85
80 ## Test the function out 86
81 %!assert(index("astringbstringcstring", "s"), 2) 87 %!assert (index ("foobarbaz", "b") == 4 && index ("foobarbaz", "z") == 9);
82 %!assert(index("astringbstringcstring", "st"), 2) 88
83 %!assert(index("astringbstringcstring", "str"), 2) 89 %!assert (index("astringbstringcstring", "s"), 2)
84 %!assert(index("astringbstringcstring", "string"), 2) 90 %!assert (index("astringbstringcstring", "st"), 2)
85 %!assert(index("abc---", "abc+++"), 0) 91 %!assert (index("astringbstringcstring", "str"), 2)
92 %!assert (index("astringbstringcstring", "string"), 2)
93 %!assert (index("abc---", "abc+++"), 0)
86 94
87 ## test everything out in reverse 95 ## test everything out in reverse
88 %!assert(index("astringbstringcstring", "s", "last"), 16) 96 %!assert (index("astringbstringcstring", "s", "last"), 16)
89 %!assert(index("astringbstringcstring", "st", "last"), 16) 97 %!assert (index("astringbstringcstring", "st", "last"), 16)
90 %!assert(index("astringbstringcstring", "str", "last"), 16) 98 %!assert (index("astringbstringcstring", "str", "last"), 16)
91 %!assert(index("astringbstringcstring", "string", "last"), 16) 99 %!assert (index("astringbstringcstring", "string", "last"), 16)
92 %!assert(index("abc---", "abc+++", "last"), 0) 100 %!assert (index("abc---", "abc+++", "last"), 0)
93 101
102 %!test
103 %! str = char ("Hello", "World", "Goodbye", "World");
104 %! assert (index (str, "o"), [5; 2; 2; 2]);
105 %! assert (index (str, "o", "last"), [5; 2; 3; 2]);
106 %! str = cellstr (str);
107 %! assert (index (str, "o"), [5; 2; 2; 2]);
108 %! assert (index (str, "o", "last"), [5; 2; 3; 2]);
94 109
95 %!assert(index ("foobarbaz", "b") == 4 && index ("foobarbaz", "z") == 9); 110 %% Test input validation
111 %!error index ()
112 %!error index ("a")
113 %!error index ("a", "b", "first", "d")
114 %!error index (1, "bar")
115 %!error index ("foo", "bar", 3)
96 116
97 %!error index ();
98
99 %!error index ("foo", "bar", 3);
100