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Object! datatype

Table of Contents

1. Abstract

Object! values represent named or unnamed contexts that contain word: value pairs.

Object! is a member of the following typesets: any-object!, default!

2. Creation

Object values can be created at runtime by using a make constructor, or by using the functions context, object and construct.

Make object! creates a new object, evaluating the spec block.

The functions context and object invoke make object!.

Using make:

>> foo: make object! [x: "bar" y: "baz"]
== make object! [
    x: "bar"
    y: "baz"
]

>> foo: make object! [x: "bar" y: ()]   ; spec block is evaluated
*** Script Error: y: needs a value
*** Where: y
*** Stack:

Using context:

>> foo: context [x: "bar" y: "baz"]
== make object! [
    x: "bar"
    y: "baz"
]

>> foo: context [x: "bar" y: ()]   ; spec block is evaluated
*** Script Error: y: needs a value
*** Where: y
*** Stack: context

Using object:

>> foo: object [x: "bar" y: "baz"]
== make object! [
    x: "bar"
    y: "baz"
]

>> foo: object [x: "bar" y: ()]   ; spec block is evaluated
*** Script Error: y: needs a value
*** Where: y
*** Stack: object

If the argument to make is an object! value, a new object will be created using the argument as a prototype:

>> foo: make object! [x: "bar" y: "baz"]
== make object! [
    x: "bar"
    y: "baz"
]

>> bar: make foo [z: 42]
== make object! [
    x: "bar"
    y: "baz"
    z: 42
]

The construct function creates an object without evaluating the spec block:

>> foo: construct [x: "bar" y: ()]
== make object! [
    x: "bar"
    y: ()
]

If the /with refinement is used with construct, a new object will be created that is an extension of the supplied object! value:

>> bar: construct/with [a: 42] foo
== make object! [
    x: "bar"
    y: ()
    a: 42
]

3. Literal syntax

<object> ::= make object! <object-spec> | object <object-spec> | context <object-spec> |
             make <object> <object-spec>

<object-spec> ::= <block>

4. Comparisons

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

5. Testing values

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

>> object? foo
== true

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

>> type? foo
== object!

6. Predefined words

6.1. Actions

copy, find, put, select

6.2. Functions

any-object?, class-of, construct, context, distance?, dump-face, face?, fetch-help, foreach-face, get-scroller, help, help-string, layout, metrics?, object, object?, offset-to-caret, offset-to-char, overlap?, parse-func-spec, react, react?, request-font, rtd-layout, save, set-flag, set-focus, show, size-text, stop-reactor, unview, view

6.3. Natives

bind, context?, extend, in, set