Word! datatype

1. Abstract

A word! is a symbolic value that can be used like a variable, an identifier that refers to a value in a given context.

Words do not store values, they point to values in a given context, and will default to the global context when no context is provided.

Word! is a member of the following typesets: any-word!, all-word!, immediate!

1.1. Word Variations

Syntax

Type

Description

word

word!

Refers to a value in a given context.

word:

set-word!

Sets a reference to a value.

:word

get-word!

Gets a value without performing evalutaion.

'word

lit-word!

Suppresses evaluation. The literal value "word".

/word

refinement!

Evaluates the word as a refinement.

2. Creation

Word! values can be created using literal syntax, or at runtime using a to conversion from the datatypes: char!, logic!, string!, datatype!, issue!, and refinement!.

>> to word! #"X"
== X

>> to word! true   ; returns a word representation of the value
== true

>> to word! "Hello"
== Hello

>> to word! float!  ; returns a word representation of the value
== float!

>> to word! #hi
== hi

>> to word! /deep
== deep
Note
Attempting to convert none raises an error.

3. Literal syntax

One or more characters from the entire Unicode range, including punctuation characters from the ASCII subset: ! & ' * + - . < = > ? _ | ~`

Note
Words are case-insensitive. Changing any letter in the word into the corresponding upper-case or lower-case variant does not create a different word.

Illegal characters are control characters, whitespace characters, and punctuation characters from the ASCII subset: / \ ^ , [ ] ( ) { } " # $ % @ : ;

A word! value cannot begin with a number.

4. Evaluation Steps

  • Find the context that the word is bound to.

  • Get the value that is refered to in the context.

  • Check the type of the value:

    • If no value exists, the type is unset!, and an error is returned.

    • If the type of the value is in the any-function! typeset, call the function.

    • Otherwise, return the value.

5. Comparisons

All comparators can be applied on word!: =, ==, <>, >, <, >=, <=, =?.

6. Testing values

Use word? to check if a value is of the word! datatype.

>> word? first [let us code]
== true

Use type? to return the datatype of a given value.

>> type? first [let us code]
== word!

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