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Routine! datatype

Table of Contents

1. Abstract

A routine! value represents a function with a given Red spec and Red/System body.

The routine specification takes Red datatypes as arguments and return value, and automatically converts them to appropriate Red/System types when called.

Red/System documentation can be found here: https://static.red-lang.org/red-system-specs.html

Routine! is a member of the following typesets: default!, any-function!

2. Creation

Routine values can be created using the built-in function routine.

3. Literal syntax

<routine> ::= routine <routine-spec> <routine-body>
<routine-spec> ::= [<docstring>° <routine-argument>* <locals>° <routine-return>°]
<routine-argument> ::= <word> <argument doc>° | <word> [<type-literal>] <argument-doc>°
<locals> ::= /local <routine-argument>*
<routine-return> ::= return: [<type-literal>]
<type-literal> ::= any-type! | <type-name>
<routine-body> ::= <block>

3.1. Runtime creation

Routine values are not allowed in the interpreter. They must be preceded by a set-word and then compiled.

Red []

increment: routine [
    n       [integer!]
    return: [integer!]
][
    n + 1
]

Argument types for routines are restricted to the single words any-type!, integer!, float!, logic!, or to a type that has a Red/System struct! alias defined here: https://github.com/red/red/blob/master/runtime/datatypes/structures.reds

Integer!, float!, and logic! are not translated to a Red/System equivalent.

Example

block! is translated to the Red/System equivalent:

red-block!: alias struct! [
	header 	[integer!]								;-- cell header
	head	[integer!]								;-- block's head index (zero-based)
	node	[node!]									;-- series node pointer
	extra	[integer!]								;-- (reserved for block-derivative types)
]

4. Testing values

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

routine? :increment

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

type? :increment

5. Predefined words

5.1. Functions

routine, routine?