JSOS API Overview

JSOS is divided into two main parts: the core and the standard library.

The core is the foundation of what makes JSOS JSOS. It contains the type system, all the basic predicate functions, multimethods, traits, and structs.

The standard library consists of optional parts of JSOS that are built on top of JSOS's foundation.

Core

These are all exports from the core module of JSOS found in @fed1/jsos.

Multimethods

import { /* <Identifier> */ } from "@fed1/jsos";

Magic Proxies:

Type	Identifier	Description
Proxy(Object)	Generic	Assigns new multimethods

Functions & Methods:

Type	Identifier	Description
JSFunction	def	Defines a method
JSFunction	methods	Lists a multimethod's methods
JSFunction	prefer	Prefers a signature over another
JSFunction	undef	Removes a method
JSFunction	unprefer	Removes a signature preference
JSFunction	which	Calculates applicable method for signature

Predicate Functions:

Type	Identifier	Description
JSFunction	isGeneric	Checks if something is a multimethod
JSFunction	isMethod	Checks if something is a method

Constants & Symbols:

Type	Identifier	Description
TEnum	METHOD_TYPE	Method types for methods()
TEnumItem	... MT_AFTER	METHOD_TYPE for after methods
TEnumItem	... MT_AROUND	METHOD_TYPE for around methods
TEnumItem	... MT_BEFORE	METHOD_TYPE for before methods
TEnumItem	... MT_PRIMARY	METHOD_TYPE for primary methods
JSSymbol	rest	Catch-all rest parameter
TEnum	RULES	Scoring rules for Generic
TEnumItem	... EQUAL	RULES constant for equality dispatch
TEnumItem	... IDENTITY	RULES constant for identity dispatch
TEnumItem	... ISA	RULES constant for is-aispatch
TEnumItem	... PREDICATE	RULES constant for predicate dispatch
TEnumItem	... TRAIT	RULES constant for trait dispatch

Qualified Methods

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
JSFunction	after	Adds an after method
JSFunction	around	Adds an around method
JSFunction	before	Adds a before method
JSFunction	isAfter	Checks if something is an 'after' method
JSFunction	isAround	Checks if something is an 'around' method
JSFunction	isBefore	Checks if something is a 'before' method
JSFunction	isPrimary	Checks if something is a primary method

Method Combinators

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
JSFunction	genlist	Runs all matches, returns all results as array
JSFunction	genpipe	Runs all matches, pipes results to next, returns last result
JSFunction	genplus	Runs all matches, sums each result
JSFunction	genprogn	Runs all matches, returns last result
JSFunction	genstd	Runs only most specific method (default)

Types

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
Proxy(Object)	Type	Creates new abstract types
JSFunction	setObjectType	Set the type of an object
JSFunction	observe	Adds listener to mutable object
JSFunction	isObservable	Checks if something is observable

Type Graph

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
JSFunction	ancestors	Returns a type's ancestors
JSFunction	children	Returns direct children of a type
JSFunction	descendants	Returns all descendants of a type
JSFunction	isAncestorOf	Is A an ancestor of B?
JSFunction	isChildOf	Is A a child of B?
JSFunction	isDescendantOf	Is A a descendant of B?
JSFunction	isParentOf	Is A a parent of B?
JSFunction	parents	Returns a type's parents
JSFunction	specificity	Calculates how far a type is from TAny

Meta Types

import { /* <Identifier> */ } from "@fed1/jsos";

Meta types are the types of types.

Type	Identifier	Description
TType	TAbstractType
TAbstractType	TDataType
TAbstractType	TDependentType
TAbstractType	TIntersectionType
TAbstractType	TJSType
TAbstractType	TType
TAbstractType	TUnionType
TAbstractType	TIntersectionType

Abstract Types

import { /* <Identifier> */ } from "@fed1/jsos";

Abstract types are types that cannot be instantiated, but they can be parameterized and be the parents of concrete types.

Type	Identifier	Description
TAbstractType	TAny
TAbstractType	TBoolean
TAbstractType	TFloat
TAbstractType	TInt
TAbstractType	TNothing
TAbstractType	TNumber
TAbstractType	TReal
TAbstractType	TString

JavaScript Types

import { /* <Identifier> */ } from "@fed1/jsos";

These types integrate JavaScript's types seamlessly into JSOS's type system.

Type	Identifier	Description
TJSType	JSArray	JavaScript's Array
TJSType	JSBigInt	JavaScript's bigint
TJSType	JSBoolean	JavaScript's boolean
TJSType	JSFunction	JavaScript's function
TJSType	JSMap	JavaScript's Map
TJSType	JSNull	JavaScript's null
TJSType	JSNumber	JavaScript's number
TJSType	JSObject	JavaScript's object
TJSType	JSSet	JavaScript's Set
TJSType	JSString	JavaScript's string
TJSType	JSSymbol	JavaScript's symbol
TJSType	JSWeakMap	JavaScript's WeakMap
TJSType	JSWeakRef	JavaScript's WeakRef
TJSType	JSWeakSet	JavaScript's WeakSet

Data Types

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
TAbstractType	TGeneric	The type of multimethods
TDataType	TTrait	The type of traits

Union Types

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
TAbstractType	TUnionType	The type of type unions
JSFunction	isUnion	Checks if something is a TUnionType
JSFunction	Union	Creates a union of types

Intersection Types

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
TAbstractType	TIntersectionType	The type of type intersections
JSFunction	isIntersection	Checks if something is a TIntersectionType
JSFunction	Intersection	Creates an intersection of types

Composite Types

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
Proxy(Function)	Struct	Creates a complex type
Proxy(Function)	MStruct	Creates a mutable complex type
JSFunction	isStructType	Checks if something is a struct type
JSFunction	isMStructType	Checks if something is a mutable struct type

Traits

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
TDataType	TTrait	The type of traits
Proxy(Object)	Trait	Creates new traits
JSFunction	hasTrait	Checks whether a type implements a trait

Enums

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier	Description
TAbstractType	TEnum	Type of enums
TAbstractType	TEnumItem	Type of enum items
Proxy(Function)	Enum	Assigns values of type TEnum
JSFunction	keyOf	Returns an enum item's key
JSFunction	valueOf	Returns an enum item's value

Predicate Functions

import { /* <Identifier> */ } from "@fed1/jsos";

Type	Identifier		Description
JSFunction	isA	a, b	Checks if a is a b
JSFunction	isAfter	a	Checks if a is an 'after' method
JSFunction	isAncestorOf	a, b	Checks if a is an ancestor to b
JSFunction	isAround	a	Checks if a is an 'around' method
JSFunction	isArray	a	Checks if a is a JS array
JSFunction	isBefore	a	Checks if a is a 'before' method
JSFunction	isBigInt	a	Checks if a is a JS bigint value
JSFunction	isBoolean	a	Checks if a is a JS boolean value
JSFunction	isChildOf	a, b	Checks if a is a child of b
JSFunction	isDependentType	a	Checks if a is a TDependentType
JSFunction	isDescendantOf	a, b	Checks if a is a descendant of b
JSFunction	isEqual	a, b	Checks if a is deep equal to b
JSFunction	isFunction	a	Checks if a is a JS function
JSFunction	isGeneric	a	Checks if a is a multimethod
JSFunction	isIdentical	a, b	Checks if a is identical to b
JSFunction	isIntersection	a	Checks if a is a TIntersectionType
JSFunction	isMap	a	Checks if a is a JS Map object
JSFunction	isMethod	a	Checks if a is a JSOS method
JSFunction	isMStructType	a	Checks if a is a mutable struct type
JSFunction	isNull	a	Checks if a is null
JSFunction	isNumber	a	Checks if a is a JS number
JSFunction	isObject	a	Checks if a is a JS object
JSFunction	isObservable	a	Checks if a can be observed
JSFunction	isParentOf	a, b	Checks if a is a parent of b
JSFunction	isPrimary	a	Checks if a is a primary method
JSFunction	isPrimitive	a	Checks if a is a primitive value
JSFunction	isRegExp	a	Checks if a is a JS regular expression
JSFunction	isSet	a	Checks if a is a JS Set object
JSFunction	isString	a	Checks if a is a JS string
JSFunction	isStructType	a	Checks if a is a struct type
JSFunction	isSymbol	a	Checks if a is a JS symbol
JSFunction	isType	a	Checks if a is a JSOS type object
JSFunction	isUndefined	a	Checks if a is undefined
JSFunction	isUnion	a	Checks if a is a TUnionType
JSFunction	isWeak	a	Checks if a is a weak JS data type
JSFunction	isWeakMap	a	Checks if a is a JS WeakMap object
JSFunction	isWeakRef	a	Checks if a is a JS WeakRef object
JSFunction	isWeakSet	a	Checks if a is a JS WeakSet object

Standard Library

Aggregate Types

Aggregate types are concrete types that can contain multiple values. Of these, JSOS's core only contains Struct and MStruct. But the following additional aggregate types are available in the standard library.

Dicts

import { /* <Identifier> */ } from "@fed1/jsos/dicts";

Type	Identifier	Description
TAbstractType	TDict	Type of dictionaries
TAbstractType	TMDict	Type of mutable dictionaries
TAbstractType	TDictDescriptor	Type of the descriptor object created by Dict/MDict
JSfunction	Dict	Creates dictionaries
JSfunction	MDict	Creates mutable dictionaries

Tuples

import { /* <Identifier> */ } from "@fed1/jsos/tuples";

Type	Identifier	Description
TAbstractType	TTuple	The type of all tuples
JSFunction	Tuple	Creates a tuple

Vectors

import { /* <Identifier> */ } from "@fed1/jsos/vectors";

Type	Identifier	Description
TAbstractType	TDict	Type of vectors
TAbstractType	TMDict	Type of mutable vectors
TAbstractType	TDictDescriptor	Type of descriptor objects created by Vector/MVector
JSfunction	Dict	Creates vectors
JSfunction	MDict	Creates mutable vectors

Interfaces

Interfaces in JSOS are comprised of traits and multimethods.

Multimethods can form an ad-hoc interface, while traits are types that formalize these interfaces by grouping related multimethods together under a common name.

Any concrete type can implement a trait using its .implement() method. When a type implements a trait, the trait can be used in multimethod signatures and then matches all the types that implement the trait.

Collections

import { /* <Identifier> */ } from "@fed1/jsos/collections";

Type	Identifier	Description
TGeneric	at
TGeneric	entries
TGeneric	has
TGeneric	keys
TGeneric	length
TGeneric	size
TGeneric	values

Introspection

import { /* <Identifier> */ } from "@fed1/jsos/introspection";

Type	Identifier	Description
TGeneric	explain	Creates a string explaining its argument

Iteration

import { /* <Identifier> */ } from "@fed1/jsos/iteration";

Type	Identifier	Description
TTrait	Iterable	Trait for iterable types
TGeneric	iterate	Iterates a sequence step by step
TGeneric	each	Applies a function to each item in a sequence
TGeneric	map	Creates a new sequence by applying a function to each item of a sequence

Stringification

import { /* <Identifier> */ } from "@fed1/jsos/stringification";

Type	Identifier	Description
TTrait	Stringifyable	Trait for types that can be converted to string
TGeneric	stringify	Multimethod for converting stuff to string