Type detection

From Rosetta Code
Type detection is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

This draft task needs a purpose, a description and some way to tell whether examples satisfy or do not satisfy it.


Task

Show a function/procedure that processes a block of text by printing it.

The function takes one parameter (ideally) that describes the text.

Demonstrate by calling the function twice, each time passing in a different type.


This can be done with pattern matching, multi-methods, dynamic type detection, structure(s) with a tag, etc.

The objective is write a [e.g. library] function that processes text from multiple sources (such as a string/char *, socket, file, etc).

If not practical, show how the caller would coerce a type that can be passed to the library function.

C[edit]

The closest C comes to meeting this task, short of building it into the compiler or accessing memory segments via pointers, which is not guaranteed to be portable, is the ctype.h header file. It is part of the C Standard Library and provides 11 methods for detecting the type of a character, out of which the following 7 called in the wrapper function below can be called to be unique. The function accepts a string, but it actually checks the first character. An if ladder is used instead of if-else so that all function calls which return a non-zero value for the character are satisfied and the information is printed.

 
/*Abhishek Ghosh, 10th November 2017*/
 
#include<stdio.h>
#include<ctype.h>
 
void typeDetector(char* str){
if(isalnum(str[0])!=0)
printf("\n%c is alphanumeric",str[0]);
if(isalpha(str[0])!=0)
printf("\n%c is alphabetic",str[0]);
if(iscntrl(str[0])!=0)
printf("\n%c is a control character",str[0]);
if(isdigit(str[0])!=0)
printf("\n%c is a digit",str[0]);
if(isprint(str[0])!=0)
printf("\n%c is printable",str[0]);
if(ispunct(str[0])!=0)
printf("\n%c is a punctuation character",str[0]);
if(isxdigit(str[0])!=0)
printf("\n%c is a hexadecimal digit",str[0]);
}
 
int main(int argC, char* argV[])
{
int i;
 
if(argC==1)
printf("Usage : %s <followed by ASCII characters>");
else{
for(i=1;i<argC;i++)
typeDetector(argV[i]);
}
return 0;
}
 

Output, shown for multiple inputs, as well as single ones:

C:\rosettaCode>typeDetector.exe s 3 $ f ! as 3

s is alphanumeric
s is alphabetic
s is printable
3 is alphanumeric
3 is a digit
3 is printable
3 is a hexadecimal digit
$ is printable
$ is a punctuation character
f is alphanumeric
f is alphabetic
f is printable
f is a hexadecimal digit
! is printable
! is a punctuation character
a is alphanumeric
a is alphabetic
a is printable
a is a hexadecimal digit
3 is alphanumeric
3 is a digit
3 is printable
3 is a hexadecimal digit

C:\rosettaCode>typeDetector.exe a

a is alphanumeric
a is alphabetic
a is printable
a is a hexadecimal digit
C:\rosettaCode>typeDetector.exe $

$ is printable
$ is a punctuation character
C:\rosettaCode>typeDetector.exe 3

3 is alphanumeric
3 is a digit
3 is printable
3 is a hexadecimal digit

J[edit]

Presumably this satisfies the task requirements...

   echo 'one'
one
echo 1
1

JavaScript[edit]

[1]

console.log(typeof('foo')); // Returns string
console.log(typeof(12345)); // Returns number

Kotlin[edit]

// version 1.0.6
fun showType(a: Any) = when (a) {
is Int -> println("'$a' is an integer")
is Double -> println("'$a' is a double")
is Char -> println("'$a' is a character")
else -> println("'$a' is some other type")
}
 
fun main(args: Array<String>) {
showType(5)
showType(7.5)
showType('d')
showType(true)
}
Output:
'5' is an integer
'7.5' is a double
'd' is a character
'true' is some other type

Julia[edit]

In Julia, the function that returns the type of an object is the typeof function, and the function isa tests whether an object is of that type.

 
 
julia> a = 1
1
 
julia> typeof(a)
Int32
 
julia> b = 1.0
1.0
 
julia> typeof(b)
Float64
 
julia> 1.0 isa Number
true
 
julia> 1.0 isa Int
false
 
julia> 1 isa Int
true
 
julia> typeof("hello")
String
 
julia> typeof(typeof("hello"))
DataType
 
julia> typeof(Set([1,3,4]))
Set{Int64}
 
julia> 1 isa String
false
 
julia> "1" isa Number
false
 
julia> "1" isa String
true
 
julia> isa(1.0,Float32)
false
 
julia> isa(1.0,Float64)
true
 
 

OASYS Assembler[edit]

 
; The following method checks if a global variable or property is an
; object type. Does not work with locals and arguments.
 
[&OBJ#,^]
,^<,^<<  ; Remember old value
,^<*>  ; Create new object
,^<<DES  ; Destroy the object
,^<<EX  ; Check if variable has been cleared
/>1RF  ; It is clear
 :>0RF  ; It is not clear
 


Perl 6[edit]

Perl 6 is a dynamic language that has gradual, duck typing. It provides introspection methods through its comprehensive MOP (Meta Object Protocol) making it easy to do type detection, subroutine signatures and multi-dispatch. Perl 6 types have two general flavors: content types and container types. Different container types have varying restrictions on what sort of content they can contain and in return provide specialized methods to operate on those contents. Content types give the compiler hints on how to best handle the information, what storage requirements it may have, what operators will work with it, etc.

This is really a very broad and kind of hand-wavey overview of Perl 6 types. For much more indepth coverage see Perl 6 Synopsis S02: Bits and Pieces: Built-In Data Types

sub type ($t) { say $t.perl, "\tis type: ", $t.WHAT }
 
# some content types
.&type for 1, 2.0, 3e0, 4i, π, Inf, NaN, 'String';
 
# some primitive container types
.&type for $, [ ], @, { }, %, (5 .. 7), (8 ... 10), /0/, {;}, sub {}, ( );
 
# undefined things
.&type for Any, Nil;
 
# user defined types
class my-type { };
 
my my-type $object;
 
$object.&type;
Output:
1	is type: (Int)
2.0	is type: (Rat)
3e0	is type: (Num)
<0+4i>	is type: (Complex)
3.14159265358979e0	is type: (Num)
Inf	is type: (Num)
NaN	is type: (Num)
"String"	is type: (Str)
Any	is type: (Any)
$[]	is type: (Array)
$[]	is type: (Array)
{}	is type: (Hash)
{}	is type: (Hash)
5..7	is type: (Range)
(8, 9, 10).Seq	is type: (Seq)
/0/	is type: (Regex)
-> ;; $_? is raw { #`(Block|61385680) ... }	is type: (Block)
sub () { #`(Sub|62948936) ... }	is type: (Sub)
$()	is type: (List)
Any	is type: (Any)
Nil	is type: Nil
my-type	is type: (my-type)

Phix[edit]

Phix builtin type tests are: integer(), atom(), string(), sequence(), and object() - the latter returns true unless arg is unassigned.

procedure showtype(object o)
string t = iff(atom(o)?iff(integer(o)?"integer":"atom")
 :iff(string(o)?"string":"sequence"))
 ?{t,o}
end procedure
 
showtype(5)
showtype(7.5)
showtype("string")
showtype({5,7.5,"string"})
Output:
{"integer",5}
{"atom",7.5}
{"string","string"}
{"sequence",{5,7.5,"string"}}

PHP[edit]

[2]

echo gettype('foo'); // Returns string
echo gettype(12345); // Returns integer

Specific tester functions[edit]

PowerShell[edit]

In PowerShell everything is an object and all objects have the GetType() method:

 
[string]$str = "123"
$str.GetType()
 
Output:
IsPublic IsSerial Name                                     BaseType     
-------- -------- ----                                     --------                                                                                                                  
True     True     String                                   System.Object
 
[int]$int = $str -as [int]
$int.GetType()
 
Output:
IsPublic IsSerial Name                                     BaseType        
-------- -------- ----                                     --------                                                                                                                  
True     True     Int32                                    System.ValueType

Python[edit]

Built-in function type()

>>> type('foo')
<class 'str'>
>>> type(12345)
<class 'int'>

Testing types

>>> type('foo') is str
True
>>> type(123.0) is not int
True
>>> type([]) is list
True
>>> type({}) is dict
True

Racket[edit]

Hopefully you can see how to extend the code to add all sorts of other types. If I did this, I’d swamp the task page. A good list of types supported/provided by Racket can be found in the Typed Racket reference: http://docs.racket-lang.org/ts-reference/type-ref.html

#lang racket
 
(require racket/undefined)
 
(define fooer<%> (interface ()))
(define foo% (class* object% (fooer<%>)
(super-new)))
 
(struct my-tree (l v r))
;; -----------------------------------------------------------------------------
(define (n.t f)
(list f (regexp-replace #rx"\\?" (symbol->string (object-name f)) "")))
 
;; listed in the order (as close as) shown in
;; http://docs.racket-lang.org/guide/datatypes.html (section numbers next to
;; some entries)
(define type-tests.names
`(,@(map n.t
(list boolean? immutable? ; 3.1
))
 ;; the famous scheme numerical tower
,@(map n.t ; 3.2
(list number? complex? real? rational? integer? exact-integer?
exact-nonnegative-integer? exact-positive-integer?
inexact-real? fixnum? flonum? double-flonum? single-flonum?
zero? positive? negative? odd? even? exact? inexact?))
,@(map n.t
(list char? ; 3.3 --- there are also char-alphabetic? etc -- but they're not
 ; types as such
string? ; 3.4
byte? bytes? ; 3.5
symbol? ; 3.6
keyword? ; 3.7
pair? null? list? ; 3.8
vector? ; 3.9
hash? hash-equal? hash-eqv? hash-eq? hash-weak? ; 3.10
box? ; 3.11
void? ; 3.12
))
,(list (λ (v) (eq? v undefined)) "undefined") ; 3. 12
 ;; now we move to http://docs.racket-lang.org/reference/data.html
 ;; for section numbering
,@(map n.t
(list
regexp? pregexp? byte-regexp? byte-pregexp? ; 4.7
stream? sequence? ; 4.14
dict? ; 4.15
set-equal? set-eqv? set-eq? set? set-mutable? set-weak? ; 4.16
continuation? procedure? ; 4.17
))
 ;; class/interface testing
,(list (λ (v) (is-a? v object%)) "object%")
,(list (λ (v) (is-a? v foo%)) "foo%")
,(list (λ (v) (is-a? v fooer<%>)) "fooer<%>")
 
 ;; more types from reference (sections are top-level, mostly)
,@(map n.t
(list
syntax? ; 3.
my-tree? ; 5.
exn? exn:fail? exn:fail:filesystem? ; 10.2
promise? ; 10.3
))
 
 ;; there's all sorts of other types to test!
))
 
(define (->type-names v)
(let ((rv (for/list ((t.n (in-list type-tests.names))
#:when (with-handlers
((exn? (λ (x) #f)))
((car t.n) v))) (cadr t.n))))
(if (null? rv) (list "UNKNOWN") rv)))
 
(module+ test
(require xml/xml)
 
(define test-values
(list 3.+4.i 3+4i (- pi) pi 0. 0 -0.5 0.5 -1/3 1/3
-12345678909876543210123456789 12345678909876543210123456788 -132 133
#\t #\null
"" "monkeys" "\u03BB"
-1 255 256
#"" #"nibble"
'hello '||
'#:woo
'() '(1 . 2) '(3) '(5 6)
 
#() #(1) #("foo" 2 'bar)
 
(make-hash)
(make-hasheq)
(make-hasheqv)
(hash)
(hasheq)
(hasheqv)
(make-weak-hash)
(make-weak-hasheq)
(make-weak-hasheqv)
(make-immutable-hash)
(make-immutable-hasheq)
(make-immutable-hasheqv)
 
(box "x")
(void)
undefined
#rx".*" #px"3?" #rx#"t.m" #px#".i."
(in-vector #(1 2 3)) (stream 1 2 3)
#hash((a . "apple")) #("apple" "binana") '("apple" "binana")
'((a . "apple") (b . "binana"))
(set 1 2 3) (seteq 1 2 3) (seteqv 1 2 3)
(mutable-set 1 2 3) (mutable-seteq 1 2 3) (mutable-seteqv 1 2 3)
(weak-set 1 2 3) (weak-seteq 1 2 3) (weak-seteqv 1 2 3)
 
+ (λ (x) #t) (call/cc (λ (k) k))
 
(new object%) (new foo%)
 
#'(xxy zzy)
(my-tree (my-tree #f 1 #f) 2 #f)
(with-handlers ((exn? values)) (error 'aargh!))
(with-handlers ((exn? values))
(file->string "/tmp/there-is-no-way-this-file-exists---surely?"))
(delay 3)
))
 
 ;; tempted to print a cross-reference table, but that would be too wide for RC (maybe)
(write-xexpr #:insert-newlines? #f
`(table (thead (tr (th "Value [~s]") (th "->type-name")))
"\n"
(tbody ,@(map (λ (v) `(tr "\n" (td ,(~s v))
(td ,(string-join (->type-names v) ", "))))
test-values)))))
 
Output:

The following table is generated:

<thead></thead> <tbody></tbody>
Value [~s]->type-name
3.0+4.0inumber, complex, inexact
3+4inumber, complex, exact
-3.141592653589793number, complex, real, rational, inexact-real, flonum, double-flonum, negative, inexact
3.141592653589793number, complex, real, rational, inexact-real, flonum, double-flonum, positive, inexact
0.0number, complex, real, rational, integer, inexact-real, flonum, double-flonum, zero, even, inexact
0number, complex, real, rational, integer, exact-integer, exact-nonnegative-integer, fixnum, zero, even, exact, byte, sequence
-0.5number, complex, real, rational, inexact-real, flonum, double-flonum, negative, inexact
0.5number, complex, real, rational, inexact-real, flonum, double-flonum, positive, inexact
-1/3number, complex, real, rational, negative, exact
1/3number, complex, real, rational, positive, exact
-12345678909876543210123456789number, complex, real, rational, integer, exact-integer, negative, odd, exact
12345678909876543210123456788number, complex, real, rational, integer, exact-integer, exact-nonnegative-integer, exact-positive-integer, positive, even, exact, sequence
-132number, complex, real, rational, integer, exact-integer, fixnum, negative, even, exact
133number, complex, real, rational, integer, exact-integer, exact-nonnegative-integer, exact-positive-integer, fixnum, positive, odd, exact, byte, sequence
#\tchar
#\nulchar
""immutable, string, sequence
"monkeys"immutable, string, sequence
"λ"immutable, string, sequence
-1number, complex, real, rational, integer, exact-integer, fixnum, negative, odd, exact
255number, complex, real, rational, integer, exact-integer, exact-nonnegative-integer, exact-positive-integer, fixnum, positive, odd, exact, byte, sequence
256number, complex, real, rational, integer, exact-integer, exact-nonnegative-integer, exact-positive-integer, fixnum, positive, even, exact, sequence
#""immutable, bytes, sequence
#"nibble"immutable, bytes, sequence
hellosymbol
||symbol
#:wookeyword
()null, list, stream, sequence, dict
(1 . 2)pair
(3)pair, list, stream, sequence
(5 6)pair, list, stream, sequence
#()immutable, vector, sequence, dict
#(1)immutable, vector, sequence, dict
#("foo" 2 (quote bar))immutable, vector, sequence, dict
#hash()hash, hash-equal, sequence, dict
#hasheq()hash, hash-eq, sequence, dict
#hasheqv()hash, hash-eqv, sequence, dict
#hash()immutable, hash, hash-equal, sequence, dict
#hasheq()immutable, hash, hash-eq, sequence, dict
#hasheqv()immutable, hash, hash-eqv, sequence, dict
#<hash>hash, hash-equal, hash-weak, sequence, dict
#<hash>hash, hash-eq, hash-weak, sequence, dict
#<hash>hash, hash-eqv, hash-weak, sequence, dict
#hash()immutable, hash, hash-equal, sequence, dict
#hasheq()immutable, hash, hash-eq, sequence, dict
#hasheqv()immutable, hash, hash-eqv, sequence, dict
#&"x"box
#<void>void
#<undefined>undefined
#rx".*"regexp
#px"3?"regexp, pregexp
#rx#"t.m"byte-regexp
#px#".i."byte-regexp, byte-pregexp
#<sequence>sequence
#<stream>stream, sequence
#hash((a . "apple"))immutable, hash, hash-equal, sequence, dict
#("apple" "binana")immutable, vector, sequence, dict
("apple" "binana")pair, list, stream, sequence
((a . "apple") (b . "binana"))pair, list, stream, sequence, dict
#<set: 1 3 2>stream, sequence, set-equal, set
#<seteq: 1 2 3>stream, sequence, set-eq, set
#<seteqv: 1 2 3>stream, sequence, set-eqv, set
#<mutable-set: 1 2 3>sequence, set-equal, set-mutable
#<mutable-seteq: 1 2 3>sequence, set-eq, set-mutable
#<mutable-seteqv: 1 2 3>sequence, set-eqv, set-mutable
#<weak-set: 1 3 2>sequence, set-equal, set-weak
#<weak-seteq: 1 2 3>sequence, set-eq, set-weak
#<weak-seteqv: 1 2 3>sequence, set-eqv, set-weak
#<procedure:+>procedure
#<procedure:...pe-detection.rkt:113:13>procedure
#<continuation>continuation, procedure
#(struct:object)object%
#(struct:object:foo% ...)object%, foo%, fooer<%>
#<syntax:D:\Users\tim\Dropbox\hacking\rosettacode\type-detection.rkt:117:13 (xxy zzy)>syntax
#<my-tree>my-tree
#(struct:exn:fail "error: aargh!" #<continuation-mark-set>)exn, exn:fail
#(struct:exn:fail:filesystem "file-size: file not found\n path: D:/tmp/there-is-no-way-this-file-exists---surely?" #<continuation-mark-set>)exn, exn:fail, exn:fail:filesystem
#<promise:...e/type-detection.rkt:122:11>promise

REXX[edit]

These are some of the tests that can be performed on REXX variables (values) to determine which   type   they are.

Although everything   (as far as variables are concerning)   in the REXX language is a character string,   character
strings can be classified by having certain characteristics,   or in other words, types.
Characteristics of these   types   can overlap.

/*REXX program  displays  what  "type"  a variable is  (based on the variable's value). */
signal on noValue /*trap for undefined REXX variables. */
y= 1938  ; call showType y /*╔═══════════════════════════════════╗*/
y= 77.1  ; call showType y /*║ All REXX variables are stored as ║*/
y=  ; call showType y /*║ character strings, even numbers. ║*/
y= ' '  ; call showType y /*║ If a variable string is numeric, ║*/
y= 'abc'  ; call showType y /*║ all comparisons (IF statements) ║*/
y= 'ABC'  ; call showType y /*║ that are made with numbers are ║*/
y= 'aBc'  ; call showType y /*║ compared numerically. If not ║*/
y= '1515'x  ; call showType y /*║ numeric, the string is compared ║*/
y= '10 11'x  ; call showType y /*║ char by char after leading and ║*/
y= '00 0001'b ; call showType y /*║ trailing blanks are removed, and ║*/
y= '1'b  ; call showType y /*║ shorter strings are padded with ║*/
y= ' + 1938 ' ; call showType y /*║ blanks to match the longer string.║*/
y= ' - 1.2e4' ; call showType y /*╚═══════════════════════════════════╝*/
y= '1'  ; call showType y /* */
call showType yyy /*note: the variable YYY is undefined.*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
noValue: say ' REXX variable ' condition("D") ' is undefined.'; exit
/*──────────────────────────────────────────────────────────────────────────────────────*/
showType: procedure; parse arg x 1 xu; upper xu /*get true value & an uppercase version*/
@= ' value is'; say @ x
say @ 'of length' length(x)
if x =='' then say @ "null."
if x\=='' & x='' then say @ "all blank."
if datatype(x, 'N') then say @ "numeric (decimal)."
else say @ "a character string (not numeric)."
if datatype(x, 'W') then say @ "an integer (a whole number)."
if datatype(x, 'N') &,
\datatype(x, 'W') then say @ "not an integer."
if datatype(x, 'N') &,
pos('E', xu)\==0 then say @ "a number in exponential format."
if datatype(x, 'A') then say @ "an alphanumeric string."
if datatype(x, 'U') then say @ "all uppercase (Latin) letters."
if datatype(x, 'L') then say @ "all lowercase (Latin) letters."
if \datatype(x, 'L') &,
\datatype(x, 'U') &,
datatype(x, 'M') then say @ "of mixed case (Latin) letters."
if datatype(x, 'B') then say @ "binary."
if datatype(x, 'X') then say @ "hexadecimal."
if datatype(x, 'S') then say @ "a REXX symbol."
say copies('▒', 50) /*a fence that is used as a separator. */
return
output   when using the internal default data:
      value is 1938
      value is of length 4
      value is numeric (decimal).
      value is an integer (a whole number).
      value is an alphanumeric string.
      value is hexadecimal.
      value is a REXX symbol.
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is 77.1
      value is of length 4
      value is numeric (decimal).
      value is not an integer.
      value is a REXX symbol.
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is
      value is of length 0
      value is null.
      value is a character string (not numeric).
      value is binary.
      value is hexadecimal.
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is
      value is of length 3
      value is all blank.
      value is a character string (not numeric).
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is abc
      value is of length 3
      value is a character string (not numeric).
      value is an alphanumeric string.
      value is all lowercase (Latin) letters.
      value is hexadecimal.
      value is a REXX symbol.
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is ABC
      value is of length 3
      value is a character string (not numeric).
      value is an alphanumeric string.
      value is all uppercase (Latin) letters.
      value is hexadecimal.
      value is a REXX symbol.
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is aBc
      value is of length 3
      value is a character string (not numeric).
      value is an alphanumeric string.
      value is of mixed case (Latin) letters.
      value is hexadecimal.
      value is a REXX symbol.
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is §§
      value is of length 2
      value is a character string (not numeric).
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is ►◄
      value is of length 2
      value is a character string (not numeric).
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is ☺
      value is of length 1
      value is a character string (not numeric).
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is ☺
      value is of length 1
      value is a character string (not numeric).
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is  + 1938
      value is of length 8
      value is numeric (decimal).
      value is an integer (a whole number).
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is  - 1.2e4
      value is of length 8
      value is numeric (decimal).
      value is an integer (a whole number).
      value is a number in exponential format.
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      value is 1
      value is of length 1
      value is numeric (decimal).
      value is an integer (a whole number).
      value is an alphanumeric string.
      value is binary.
      value is hexadecimal.
      value is a REXX symbol.
▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒
      REXX variable  YYY  is undefined.

Ring[edit]

 
# Project : Type detection
# Date  : 2017/10/05
# Author : Gal Zsolt (~ CalmoSoft ~)
# Email  : <[email protected]>
 
see "5 -> " + type(5) + nl
see "7.5 -> " + type(7.5) + nl
see "d -> " + type('d') + nl
 

Output:

5 -> NUMBER
7.5 -> NUMBER
d -> STRING

zkl[edit]

fcn processText(data_or_fileName){ // unknown
if (data_or_fileName.isType(String)) // == .isType("")
data_or_fileName=File(data_or_fileName,"rb").read(); //-->Data
text:=data_or_fileName.text; //-->String
doTheActualTextProcessing(text);
}
fcn doTheActualTextProcessing(text){ println(text) }

If an int is passed in, (123).text --> "123", other objects might throw an exception.

How to use:

processText("foo.txt");
processText(Data(Void,"This is some text"));
// fake up a class that holds a string:
cs:=class{ var text }; cs.text="this is more text";
processText(cs);
Output:
this is foo.txt

This is some text
this is more text