This function tries to determine whether its argument s represents
an integer or a floating point number. If it appears to be neither,
then a string is assumed. It returns one of three values depending on
the format of the string s:
Integer_Type : If it appears to be an integer
Double_Type : If it appears to be a double
String_Type : Anything else.
For example, _slang_guess_type("1e2") returns
Double_Type but _slang_guess_type("e12") returns
String_Type.
This function is similar to the typeof function except in the
case of arrays. If the object x is an array, then the data
type of the array will be returned. otherwise _typeof returns
the data type of x.
Example
if (Integer_Type == _typeof (x))
message ("x is an integer or an integer array");
This function converts a string s to a double precision value
and returns the result. It performs no error checking on the format
of the string. The function _slang_guess_type may be used to
check the syntax of the string.
Example
define error_checked_atof (s)
{
switch (_slang_guess_type (s))
{
case Double_Type:
return atof (s);
}
{
case Integer_Type:
return double (integer (s));
}
verror ("%s is is not a double", s);
}
The char function converts an integer ascii value c to a string
of unit length such that the first character of the string is c.
For example, char('a') returns the string "a".
This function defines an upper and lowercase relationship between two
characters specified by the arguments. This relationship is used by
routines which perform uppercase and lowercase conversions.
The first integer ch_up is the ascii value of the uppercase character
and the second parameter ch_low is the ascii value of its
lowercase counterpart.
The double function typecasts an object x to double
precision. For example, if x is an array of integers, an
array of double types will be returned. If an object cannot be
converted to Double_Type, a type-mismatch error will result.
Notes
The double function is equivalent to the typecast operation
typecast (x, Double_Type)
To convert a string to a double precision number, use atoi
function.
This function performs a typecast of s from its data type to
an object of Integer_Type. If s is a string, it returns
returns the ascii value value of the first character of the string
s. If s is Double_Type, int truncates the
number to an integer and returns it.
Example
int can be used to convert single character strings to
integers. As an example, the intrinsic function isdigit may
be defined as
define isdigit (s)
{
if ((int (s) >= '0') and (int (s) <= '9')) return 1;
return 0;
}
Notes
This function is equalent to typecast (s, Integer_Type);
The integer function converts a string representation of an
integer back to an integer. If the string does not form a valid
integer, a type-mismatch error will be generated.
Example
integer ("1234") returns the integer value 1234.
Notes
This function operates only on strings and is not the same as the
more general typecast operator.
The typecast function performs a generic typecast operation on
x to convert it to new_type. If x represents an
array, the function will attempt to convert all elements of x
to new_type. Not all objects can be converted and a
type-mismatch error will result upon failure.