Re: Factor

; Comments start with a semicolon.
; Anything after the semicolon is ignored.

;;;;;;;;;;;;;;;;;;;
;;; Basic Types ;;;
;;;;;;;;;;;;;;;;;;;

nil         ; also known in other languages as null

; Booleans
true
false

; Strings are enclosed in double quotes
"hungarian breakfast"
"farmer's cheesy omelette"

; Characters are preceded by backslashes
\g \r \a \c \e

; Keywords start with a colon. They behave like enums. Kind of
; like symbols in Ruby.
:eggs
:cheese
:olives

; Symbols are used to represent identifiers. 
; You can namespace symbols by using /. Whatever precedes / is
; the namespace of the symbol.
spoon
kitchen/spoon ; not the same as spoon
kitchen/fork
github/fork   ; you can't eat with this

; Integers and floats
42
3.14159

; Lists are sequences of values
(:bun :beef-patty 9 "yum!")

; Vectors allow random access
[:gelato 1 2 -2]

; Maps are associative data structures that associate the key with its value
{:eggs        2
 :lemon-juice 3.5
 :butter      1}

; You're not restricted to using keywords as keys
{[1 2 3 4] "tell the people what she wore",
 [5 6 7 8] "the more you see the more you hate"}

; You may use commas for readability. They are treated as whitespace.

; Sets are collections that contain unique elements.
#{:a :b 88 "huat"}

;;;;;;;;;;;;;;;;;;;;;;;
;;; Tagged Elements ;;;
;;;;;;;;;;;;;;;;;;;;;;;

; EDN can be extended by tagging elements with # symbols.

#MyYelpClone/MenuItem {:name "eggs-benedict" :rating 10}

{
    null
    t
    f
    "hungarian breakfast"
    "farmer's cheesy omelette"
    103
    114
    97
    99
    101
    T{ keyword { name "eggs" } }
    T{ keyword { name "cheese" } }
    T{ keyword { name "olives" } }
    T{ symbol { name "spoon" } }
    T{ symbol { name "kitchen/spoon" } }
    T{ symbol { name "kitchen/fork" } }
    T{ symbol { name "github/fork" } }
    42
    3.14159
    {
        T{ keyword { name "bun" } }
        T{ keyword { name "beef-patty" } }
        9
        "yum!"
    }
    V{
        T{ keyword { name "gelato" } }
        1
        2
        -2
    }
    LH{
        { T{ keyword { name "eggs" } } 2 }
        { T{ keyword { name "lemon-juice" } } 3.5 }
        { T{ keyword { name "butter" } } 1 }
    }
    LH{
        { V{ 1 2 3 4 } "tell the people what she wore" }
        { V{ 5 6 7 8 } "the more you see the more you hate" }
    }
    HS{
        88
        T{ keyword { name "a" } }
        T{ keyword { name "b" } }
        "huat"
    }
    T{ tagged
        { name "MyYelpClone/MenuItem" }
        { value
            LH{
                { T{ keyword { name "name" } } "eggs-benedict" }
                { T{ keyword { name "rating" } } 10 }
            }
        }
    }
}

IN: scratchpad "edn" help
Extensible Data Notation (EDN)

The edn vocabulary supports reading and writing from the Extensible Data
Notation (EDN) format.

Reading from EDN:
 read-edns ( -- objects )
 read-edn ( -- object )
 edn> ( string -- objects )

Writing into EDN:
 write-edns ( objects -- )
 write-edn ( object -- )
 >edn ( object -- string )

IN: scratchpad TUPLE: foo a b c ;

IN: scratchpad 1 2 3 foo boa write-edn
#scratchpad/foo {:a 1, :b 2, :c 3}