Apply a function to each element of an array
Array_Type array_map (type, func, arg0, ...)
DataType_Type type;
Ref_Type func;
The array_map function may be used to apply a function to each
element of an array and returns the result as an array of a
specified type. The type parameter indicates what kind of
array should be returned and generally corresponds to the return
type of the function. The arg0 parameter should be an array
and is used to determine the dimensions of the resulting array. If
any subsequent arguments correspond to an array of the same size,
then those array elements will be passed in parallel with the first
arrays arguments.
The first example illustrates how to apply the strlen function
to an array of strings:
S = ["", "Train", "Subway", "Car"];
L = array_map (Integer_Type, &strlen, S);
This is equivalent to:
S = ["", "Train", "Subway", "Car"];
L = Integer_Type [length (S)];
for (i = 0; i < length (S); i++) L[i] = strlen (S[i]);
Now consider an example involving the strcat function:
files = ["slang", "slstring", "slarray"];
exts = ".c";
cfiles = array_map (String_Type, &strcat, files, exts);
% ==> cfiles = ["slang.c slstring.c slarray.c"];
exts = [".a",".b",".c"];
xfiles = array_map (String_Type, &strcat, files, exts);
% ==> xfiles = ["slang.a", "slstring.b", "slarray.c"];
Many mathemetical functions already work transparantly on arrays.
For example, the following two statements produce identical results:
B = sin (A);
B = array_map (Double_Type, &sin, A);
- slangrtl
-
_isnull,
_reshape,
_typeof,
array_info,
bstrlen,
create_delimited_string,
get_struct_field,
getenv,
init_char_array,
length,
reshape,
set_struct_field,
sin,
strcat,
strjoin,
strlen,
strncmp,
strsub,
substr,
transpose,
typeof,
where
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