Types¶

The type system defines every type the Viper runtime understands. Type is the base class: it exposes the primitive types as static accessors (Type.INT64, Type.STRING, …) and serves as the common supertype of the parameterized container, algebraic, and user-defined types.

When to use: reach for types to describe schemas, to validate data, and to build parameterized containers such as vectors and maps before instantiating values against them.

Quick Start¶

const { Type, TypeVector, TypeMap, TypeOptional } = require('@digitalsubstrate/dsviper');

// Primitive types are static accessors on Type
const tInt = Type.INT64;
const tStr = Type.STRING;
tStr.representation();                        // "string"

// Parameterized container types — construct with `new`
const tVec = new TypeVector(Type.STRING);    // vector<string>
const tMap = new TypeMap(Type.STRING, Type.INT64);
tMap.representation();                        // "map<string, int64>"

// Nested types compose freely
const tNested = new TypeMap(Type.STRING, new TypeVector(Type.FLOAT));

// Nullable type
const tOpt = new TypeOptional(Type.STRING);
tOpt.representation();                        // "optional<string>"

A type is the schema half of the runtime; pair it with Value.create(type, native) to mint an instance (see Values):

const { Value, Type } = require('@digitalsubstrate/dsviper');

const v = Value.create(Type.STRING, 'hi');   // a ValueString
v.encoded();                                  // "hi"

Choosing the Right Type¶

Use Case	Type Class	Example
Primitive value	`Type.STRING`, `Type.INT64`	static accessors
Homogeneous list	`TypeVector`	`new TypeVector(Type.INT64)`
Key-value mapping	`TypeMap`	`new TypeMap(Type.STRING, Type.INT64)`
Nullable value	`TypeOptional`	`new TypeOptional(Type.STRING)`
Concurrent list	`TypeXArray`	`new TypeXArray(Type.STRING)`
Fixed-size tuple	`TypeTuple`	`new TypeTuple([Type.INT64, Type.STRING])`

The mirror of this page for the Python binding is Type System; for a narrative walkthrough of types and values together, see Types and Values.

Generated from the @digitalsubstrate/dsviper TypeScript declarations (index.d.ts) by TypeDoc.

Summary¶

Class	Description
`Type`	A utility class to handle type representation
`TypeAny`	A class used to represent the any type
`TypeAnyConcept`	A class used to represent the any_concept type
`TypeBlob`	A class used to represent the blob type
`TypeBlobId`	A class used to represent the blob_id type
`TypeBool`	A class used to represent the bool type
`TypeClub`	A class used to represent a club type
`TypeCommitId`	A class used to represent the commit_id type
`TypeConcept`	A class used to represent a concept type
`TypeDouble`	A class used to represent the double type
`TypeEnumeration`	A class used to represent an enum type
`TypeEnumerationCase`	A class used to represent a case for an enum type
`TypeEnumerationDescriptor`	A class used to describe the cases of an enum
`TypeFloat`	A class used to represent the float type
`TypeInt16`	A class used to represent the int16 type
`TypeInt32`	A class used to represent the int32 type
`TypeInt64`	A class used to represent the int64 type
`TypeInt8`	A class used to represent the int8 type
`TypeKey`	A class used to represent a key<element_type> type where element_type is a concept, club or any_concept
`TypeMap`	A class used to represent a map<element_type> type
`TypeMat`	A class used to represent a mat<numeric_type, columns, rows> type
`TypeName`	A class used to describe the name of a type
`TypeOptional`	A class used to represent an optional<element_type> type
`TypeSet`	A class used to represent a set<element_type> type
`TypeString`	A class used to represent the string type
`TypeStructure`	A class used to represent a struct type
`TypeStructureDescriptor`	A class used to describe the fields of a struct
`TypeStructureField`	A class used to represent a field for a struct
`TypeTuple`	A class used to represent a tuple<T0, …> type
`TypeUInt16`	A class used to represent the uint16 type
`TypeUInt32`	A class used to represent the uint32 type
`TypeUInt64`	A class used to represent the uint64 type
`TypeUInt8`	A class used to represent the uint8 type
`TypeUUId`	A class used to represent the uuid type
`TypeVariant`	A class used to represent a variant<T0, …> type
`TypeVec`	A class used to represent a vec<element_type, size> type
`TypeVector`	A class used to represent a vector<element_type> type
`TypeVoid`	A class used to represent the void type
`TypeXArray`	A class used to represent a xarray<element_type> type

Reference¶

class Type()¶

A utility class to handle type representation.

Note: Not directly instantiable.

exported from index.d

Type.ANY¶: type: readonly TypeAny

Type.ANY_CONCEPT¶: type: readonly TypeAnyConcept

Type.BLOB¶: type: readonly TypeBlob

Type.BLOB_ID¶: type: readonly TypeBlobId

Type.BOOL¶: type: readonly TypeBool

Type.COMMIT_ID¶: type: readonly TypeCommitId

Type.DOUBLE¶: type: readonly TypeDouble

Type.FLOAT¶: type: readonly TypeFloat

Type.INT16¶: type: readonly TypeInt16

Type.INT32¶: type: readonly TypeInt32

Type.INT64¶: type: readonly TypeInt64

Type.INT8¶: type: readonly TypeInt8

Type.STRING¶: type: readonly TypeString

Type.UINT16¶: type: readonly TypeUInt16

Type.UINT32¶: type: readonly TypeUInt32

Type.UINT64¶: type: readonly TypeUInt64

Type.UINT8¶: type: readonly TypeUInt8

Type.UUID¶: type: readonly TypeUUId

Type.VOID¶: type: readonly TypeVoid

Type.compare(other)¶

Arguments:

other (Type)

Returns:

number

Type.description(namespace)¶

Arguments:

namespace (NameSpace)

Returns:

string

Type.equals(other)¶

Arguments:

other (unknown)

Returns:

boolean

Type.representation(namespace)¶

Arguments:

namespace (NameSpace)

Returns:

string

Type.runtimeId()¶

Returns:: ValueUUId

Type.toString()¶

Returns:: string

Type.typeCode()¶

Returns:: string

static Type.decode(blob, definitions, streamCodecInstancing)¶

Return a type by decoding the blob with a StreamBinaryCodec if not: specified.

Arguments:

blob (ValueBlob)
definitions (DefinitionsConst)
streamCodecInstancing (StreamCodecInstancing)

Returns:

Type

static Type.encode(type, streamCodecInstancing)¶

Return a blob that encodes the type with a StreamBinaryCodec if not: specified.

Arguments:

type (Type)
streamCodecInstancing (StreamCodecInstancing)

Returns:

ValueBlob

static Type.hexdigest(type, hashing)¶

Return the hexa digest of the type computed with the hashing interface: if specified else use SHA1.

Arguments:

type (Type)
hashing (Hashing)

Returns:

string

static Type.isSized(type)¶

Return true if the type has a fixed size.

Arguments:

type (Type)

Returns:

boolean

static Type.read(streamReading, definitions)¶

Read and return a type.

Arguments:

streamReading (StreamReading)
definitions (DefinitionsConst)

Returns:

Type

static Type.sizeOf(type, streamSizing)¶

Return the fixed size of the type or throw.

Arguments:

type (Type)
streamSizing (StreamSizing)

Returns:

number

static Type.useBlobId(type)¶

Return true if the type uses the type blob_id.

Arguments:

type (Type)

Returns:

boolean

static Type.write(type, streamWriting)¶

Write a type.

Arguments:

type (Type)
streamWriting (StreamWriting)

class TypeAny()¶

A class used to represent the any type.

Use the static property Type.ANY.

exported from index.d

Extends:

Type

TypeAny.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeAnyConcept()¶

A class used to represent the any_concept type.

Use the static property Type.ANY_CONCEPT.

exported from index.d

Extends:

Type

TypeAnyConcept.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeBlob()¶

A class used to represent the blob type.

Use the static property Type.BLOB.

exported from index.d

Extends:

Type

TypeBlob.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeBlobId()¶

A class used to represent the blob_id type.

Use the static property Type.BLOB_ID.

exported from index.d

Extends:

Type

TypeBlobId.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeBool()¶

A class used to represent the bool type.

Use the static property Type.BOOL.

exported from index.d

Extends:

Type

TypeBool.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeClub()¶

A class used to represent a club type.

Note: Not directly instantiable.

exported from index.d

Extends:

Type

TypeClub.documentation()¶

Return the documentation.

Returns:: string

TypeClub.isMember(typeConcept)¶

Return true type_concept is a member.

Arguments:

typeConcept (TypeConcept)

Returns:

boolean

TypeClub.members()¶

Return the list of concepts.

Returns:: TypeConcept[]

TypeClub.typeName()¶

Return a TypeName.

Returns:: TypeName

static TypeClub.cast(type)¶

Return a type club or throw.

Arguments:

type (Type)

Returns:

TypeClub

class TypeCommitId()¶

A class used to represent the commit_id type.

Use the static property Type.COMMIT_ID.

exported from index.d

Extends:

Type

TypeCommitId.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeConcept()¶

A class used to represent a concept type.

Note: Not directly instantiable.

exported from index.d

Extends:

Type

TypeConcept.documentation()¶

Return the documentation.

Returns:: string

TypeConcept.isMember(typeConcept)¶

Return true if type_concept is related.

Arguments:

typeConcept (TypeConcept)

Returns:

boolean

TypeConcept.parent()¶

Return the parent concept or null.

Returns:: TypeConcept | undefined

TypeConcept.typeName()¶

Return a TypeName.

Returns:: TypeName

static TypeConcept.cast(type)¶

Return a concept or throw.

Arguments:

type (Type)

Returns:

TypeConcept

class TypeDouble()¶

A class used to represent the double type.

Use the static property Type.DOUBLE.

exported from index.d

Extends:

Type

TypeDouble.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeEnumeration()¶

A class used to represent an enum type.

Note: Not directly instantiable.

exported from index.d

Extends:

Type

TypeEnumeration.cases()¶

Return the list of cases.

Returns:: TypeEnumerationCase[]

TypeEnumeration.check(name)¶

Return the case or throw.

Arguments:

name (string)

Returns:

TypeEnumerationCase

TypeEnumeration.documentation()¶

Return the documentation.

Returns:: string

TypeEnumeration.query(name)¶

Return the case or null.

Arguments:

name (string)

Returns:

TypeEnumerationCase | undefined

TypeEnumeration.typeName()¶

Return a TypeName.

Returns:: TypeName

static TypeEnumeration.cast(type)¶

Return a type enum or throw.

Arguments:

type (Type)

Returns:

TypeEnumeration

class TypeEnumerationCase()¶

A class used to represent a case for an enum type.

Note: Not directly instantiable.

exported from index.d

TypeEnumerationCase.documentation()¶

Return the documentation.

Returns:: string

TypeEnumerationCase.name()¶

Return the name.

Returns:: string

class TypeEnumerationDescriptor(name, documentation)¶

A class used to describe the cases of an enum.

exported from index.d

Arguments:

name (string)
documentation (string)

TypeEnumerationDescriptor.addCase(name, documentation)¶

Add a case to the enum.

Arguments:

name (string)
documentation (string)

TypeEnumerationDescriptor.cases()¶

Return the list of cases.

Returns:: TypeEnumerationCase[]

TypeEnumerationDescriptor.description()¶

Return the description.

Returns:: string

TypeEnumerationDescriptor.documentation()¶

Return the documentation.

Returns:: string

TypeEnumerationDescriptor.name()¶

Return the name.

Returns:: string

class TypeFloat()¶

A class used to represent the float type.

Use the static property Type.FLOAT.

exported from index.d

Extends:

Type

TypeFloat.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeInt16()¶

A class used to represent the int16 type.

Use the static property Type.INT16.

exported from index.d

Extends:

Type

TypeInt16.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeInt32()¶

A class used to represent the int32 type.

Use the static property Type.INT32.

exported from index.d

Extends:

Type

TypeInt32.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeInt64()¶

A class used to represent the int64 type.

Use the static property Type.INT64.

exported from index.d

Extends:

Type

TypeInt64.typeName()¶

Return A TypeName.

Returns:: TypeName

class TypeInt8()¶

A class used to represent the int8 type.

Use the static property Type.INT8.

exported from index.d

Extends:

Type

TypeInt8.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeKey(elementType)¶

A class used to represent a key<element_type> type where element_type: is a concept, club or any_concept.

exported from index.d

Extends:

Type

Arguments:

elementType (Type)

TypeKey.elementType()¶

Return the element type.

Returns:: Type

TypeKey.isAnyConcept()¶

Return true if element_type is any_concept.

Returns:: boolean

TypeKey.isClub()¶

Return true if element_type is a club.

Returns:: boolean

TypeKey.isConcept()¶

Return true if element_type is a concept.

Returns:: boolean

static TypeKey.cast(type)¶

Return the type key<element_type> or throw.

Arguments:

type (Type)

Returns:

TypeKey

class TypeMap(keyType, elementType)¶

A class used to represent a map<element_type> type.

exported from index.d

Extends:

Type

Arguments:

keyType (Type)
elementType (Type)

TypeMap.elementType()¶

Return the element type.

Returns:: Type

TypeMap.itemType()¶

Return the type for item.

Returns:: TypeTuple

TypeMap.itemsType()¶

Return the type for items.

Returns:: TypeVector

TypeMap.keyType()¶

Return the KeyType.

Returns:: Type

TypeMap.keysType()¶

Return the type for keys.

Returns:: TypeSet

TypeMap.valuesType()¶

Return the type for values.

Returns:: TypeVector

static TypeMap.cast(type)¶

Return the type map<key_type, element_type> or throw.

Arguments:

type (Type)

Returns:

TypeMap

class TypeMat(elementType, columns, rows)¶

A class used to represent a mat<numeric_type, columns, rows> type.

exported from index.d

Extends:

Type

Arguments:

elementType (NumericType)
columns (number)
rows (number)

TypeMat.columns()¶

Return the number of columns.

Returns:: number

TypeMat.elementType()¶

Return the element type.

Returns:: NumericType

TypeMat.elementsType()¶

Return the type for elements.

Returns:: TypeVector

TypeMat.rows()¶

Return the number of rows.

Returns:: number

static TypeMat.cast(type)¶

Return the type mat<N, columns, rows> or throw.

Arguments:

type (Type)

Returns:

TypeMat

class TypeName()¶

A class used to describe the name of a type.

Note: Not directly instantiable.

exported from index.d

TypeName.name()¶

Return the name.

Returns:: string

TypeName.nameSpace()¶

Return the namespace.

Returns:: NameSpace

class TypeOptional(elementType)¶

A class used to represent an optional<element_type> type.

exported from index.d

Extends:

Type

Arguments:

elementType (Type)

TypeOptional.elementType()¶

Return the element type.

Returns:: Type

static TypeOptional.cast(type)¶

Return the type optional<element_type> or throw.

Arguments:

type (Type)

Returns:

TypeOptional

class TypeSet(elementType)¶

A class used to represent a set<element_type> type.

exported from index.d

Extends:

Type

Arguments:

elementType (Type)

TypeSet.elementType()¶

Return the element type.

Returns:: Type

TypeSet.elementsType()¶

Return the type for elements.

Returns:: TypeVector

static TypeSet.cast(type)¶

Return the type set<element_type> or throw.

Arguments:

type (Type)

Returns:

TypeSet

class TypeString()¶

A class used to represent the string type.

Use the static property Type.STRING.

exported from index.d

Extends:

Type

TypeString.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeStructure()¶

A class used to represent a struct type.

Note: Not directly instantiable.

exported from index.d

Extends:

Type

TypeStructure.check(fieldName)¶

Return the field or throw.

Arguments:

fieldName (string)

Returns:

TypeStructureField

TypeStructure.documentation()¶

Return The documentation.

Returns:: string

TypeStructure.fields()¶

Return the list of fields.

Returns:: TypeStructureField[]

TypeStructure.isCompact()¶

Return true the type is compact.

Returns:: boolean

TypeStructure.query(fieldName)¶

Return the field or null.

Arguments:

fieldName (string)

Returns:

TypeStructureField | undefined

TypeStructure.typeName()¶

Return a TypeName.

Returns:: TypeName

static TypeStructure.cast(type)¶

Return a type struct or throw.

Arguments:

type (Type)

Returns:

TypeStructure

class TypeStructureDescriptor(name, documentation)¶

A class used to describe the fields of a struct.

exported from index.d

Arguments:

name (string)
documentation (string)

TypeStructureDescriptor.addField(fieldName, type, documentation)¶

Add a field where the type is specified or deducted from the value.

Arguments:

fieldName (string)
type (Type)
documentation (string)

TypeStructureDescriptor.description()¶

Return the description.

Returns:: string

TypeStructureDescriptor.documentation()¶

Return the documentation.

Returns:: string

TypeStructureDescriptor.fields()¶

Return the list of fields.

Returns:: TypeStructureField[]

TypeStructureDescriptor.name()¶

Return the name.

Returns:: string

class TypeStructureField()¶

A class used to represent a field for a struct.

Note: Not directly instantiable.

exported from index.d

TypeStructureField.defaultValue()¶

Return the default value or null.

Returns:: Value | undefined

TypeStructureField.documentation()¶

Return the documentation.

Returns:: string

TypeStructureField.name()¶

Return the name.

Returns:: string

TypeStructureField.type()¶

Return the type.

Returns:: Type

class TypeTuple(types)¶

A class used to represent a tuple<T0, …> type.

exported from index.d

Extends:

Type

Arguments:

types (Type[])

TypeTuple.types()¶

Return the list of types.

Returns:: Type[]

static TypeTuple.cast(type)¶

Return a type tuple<T0, …> or throw.

Arguments:

type (Type)

Returns:

TypeTuple

class TypeUInt16()¶

A class used to represent the uint16 type.

Use the static property Type.UINT16.

exported from index.d

Extends:

Type

TypeUInt16.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeUInt32()¶

A class used to represent the uint32 type.

Use the static property Type.UINT32.

exported from index.d

Extends:

Type

TypeUInt32.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeUInt64()¶

A class used to represent the uint64 type.

Use the static property Type.UINT64.

exported from index.d

Extends:

Type

TypeUInt64.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeUInt8()¶

A class used to represent the uint8 type.

Use the static property Type.UINT8.

exported from index.d

Extends:

Type

TypeUInt8.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeUUId()¶

A class used to represent the uuid type.

Use the static property Type.UUID.

exported from index.d

Extends:

Type

TypeUUId.typeName()¶

Return A TypeName.

Returns:: TypeName

class TypeVariant(types)¶

A class used to represent a variant<T0, …> type.

exported from index.d

Extends:

Type

Arguments:

types (Type[])

TypeVariant.types()¶

Return the list of types.

Returns:: Type[]

static TypeVariant.cast(type)¶

Return a type variant<T0, …> or throw.

Arguments:

type (Type)

Returns:

TypeVariant

class TypeVec(elementType, size)¶

A class used to represent a vec<element_type, size> type.

exported from index.d

Extends:

Type

Arguments:

elementType (NumericType)
size (number)

TypeVec.elementType()¶

Return the element type.

Returns:: NumericType

TypeVec.elementsType()¶

Return the type for elements.

Returns:: TypeVector

TypeVec.size()¶

Return the number of elements.

Returns:: number

static TypeVec.cast(type)¶

Return a vec<N, size> or throw.

Arguments:

type (Type)

Returns:

TypeVec

class TypeVector(elementType)¶

A class used to represent a vector<element_type> type.

exported from index.d

Extends:

Type

Arguments:

elementType (Type)

TypeVector.elementType()¶

Return the element type.

Returns:: Type

static TypeVector.cast(type)¶

Return a type vector<element_type> or throw.

Arguments:

type (Type)

Returns:

TypeOptional

class TypeVoid()¶

A class used to represent the void type.

Use the static property Type.VOID.

exported from index.d

Extends:

Type

TypeVoid.typeName()¶

Return a TypeName.

Returns:: TypeName

class TypeXArray(elementType)¶

A class used to represent a xarray<element_type> type.

exported from index.d

Extends:

Type

Arguments:

elementType (Type)

TypeXArray.elementType()¶

Return the type.

Returns:: Type

TypeXArray.elementsType()¶

Return the type for elements.

Returns:: TypeVector

static TypeXArray.cast(type)¶

Return a type xarray<element_type> or throw.

Arguments:

type (Type)

Returns:

TypeXArray