datatypes

Expression of information is not just about structure. It’s not just about name-value pairs. It’s also about the datatypes as values and the ability to handle and manipulate those too.

Meaning isn’t just in strings, it’s in the full expression itself. A holistic representation. The REBOL form includes set-words, words, strings, dates, and blocks - lexically cleaner, less syntax, as well.

Unfortunately, many programmers don’t think outside of the box. They’re stuck in a narrow world of strings and unnecessary punctuation.

The mind is naturally capable and comfortable with so much more. Use it.

-Carl, On JSON and REBOL

Values

none! none
logic! true false

string!

"Here is a single-line string"

{Here is a multiline string that
contains a "quoted" string.}

Special characters (escapes) within strings are indicated with the caret character (^).

char! #"a" "^(null)" #"^(tab)"
integer! 123 -432
float! 3.1415 1.23E12
path! a/2
time! 12:34 20:05:32 0:25.345 12:35PM
date! 20-Apr-1998 20/Apr/1998
point!/pair! 100x50
percent! 11.2%
money! $12.34 USD$12.34
tuple! 2.3.0.3.1 255.255.0
issue! #707-467-8000
file! %myfile.txt
url! http://www.rebol.com
email! info@rebol.com
tag! <title> </body>
binary! #{42652061205245424F4C}

Words

Format	What It Does
`word`	Evaluates the word.
`word:`	Sets the value of a word.
`:word`	Gets the word’s value, but doesn’t evaluate it.
`'word`	Treats the word as a symbol. The word itself is the value.

Blocks

[white red green blue]

Vectors

A vector! is a high-performance series! of items.
The items in a vector! must all have the same type (unlike a block!).

The allowable item types are: integer! float! char! percent!

Vectors of string! are not allowed.

v1: make vector! [7 13 42 108]
vector? v1       ;== true

v1 +2 ;== make vector! [9 15 44 110]
v1 *4 ;== make vector! [36 60 176 440]
v2: make vector! [1 2 3 4]
v1 + v2      ;== make vector! [37 62 179 444]

Hashes

When the key values are simple types, they get hashed, which results in a fast value lookup.

list: make hash! [a 123 "hello" b c 789]
list/c         ;== 789
find list 'b   ;== make hash! [b c 789]
select list 'c ;== 789

Maps

p: #(a: 3 b: 4 c: 5)
p/a           ;== 3
select p 'a   ;== 3
put p 'd 6    ;== 6
put p 'c none ; delete key c and its value 
probe p       ;== #(a: 3 b: 4 d: 6)