schema

package
v0.16.0 Latest Latest
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 Go to latest Published: Mar 9, 2022 License: MIT Imports: 3 Imported by: 125

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Index

Constants

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const (
	Maybe_Absent = Maybe(0)
	Maybe_Null   = Maybe(1)
	Maybe_Value  = Maybe(2)
)

Variables

This section is empty.

Functions

This section is empty.

Types

type EnumRepresentation added in v0.12.3 

type EnumRepresentation interface {
	// contains filtered or unexported methods
}

type EnumRepresentation_Int added in v0.12.3 

type EnumRepresentation_Int map[string]int

type EnumRepresentation_String added in v0.12.3 

type EnumRepresentation_String map[string]string

type ErrInvalidKey added in v0.12.0 

type ErrInvalidKey struct {
	// TypeName will indicate the named type of a node the function was called on.
	TypeName string

	// Key is the key that was rejected.
	Key datamodel.Node

	// Reason, if set, may provide details (for example, the reason a key couldn't be converted to a type).
	// If absent, it'll be presumed "no such field".
	// ErrUnmatchable may show up as a reason for typed maps with complex keys.
	Reason error
}

ErrInvalidKey indicates a key is invalid for some reason.

This is only possible for typed nodes; specifically, it may show up when handling struct types, or maps with interesting key types. (Other kinds of key invalidity that happen for untyped maps fall under ErrRepeatedMapKey or ErrWrongKind.) (Union types use ErrInvalidUnionDiscriminant instead of ErrInvalidKey, even when their representation strategy is maplike.)

func (ErrInvalidKey) Error added in v0.12.0 

func (e ErrInvalidKey) Error() string

type ErrMissingRequiredField added in v0.12.0 

type ErrMissingRequiredField struct {
	Missing []string
}

ErrMissingRequiredField is returned when calling 'Finish' on a NodeAssembler for a Struct that has not has all required fields set.

func (ErrMissingRequiredField) Error added in v0.12.0 

func (e ErrMissingRequiredField) Error() string

type ErrNoSuchField added in v0.0.2 

type ErrNoSuchField struct {
	Type Type

	Field datamodel.PathSegment
}

ErrNoSuchField may be returned from lookup functions on the Node interface when a field is requested which doesn't exist, or from assigning data into on a MapAssembler for a struct when the key doesn't match a field name in the structure (or, when assigning data into a ListAssembler and the list size has reached out of bounds, in case of a struct with list-like representations!).

func (ErrNoSuchField) Error added in v0.0.2 

func (e ErrNoSuchField) Error() string

type ErrNotUnionStructure added in v0.6.0 

type ErrNotUnionStructure struct {
	TypeName string

	Detail string
}

ErrNotUnionStructure means data was fed into a union assembler that can't match the union.

This could have one of several reasons, which are explained in the detail text:

  • there are too many entries in the map;
  • the keys of critical entries aren't found;
  • keys are found that aren't any of the expected critical keys;
  • etc.

TypeName is currently a string... see comments at the top of this file for remarks on the issues we need to address about these identifiers in errors in general.

func (ErrNotUnionStructure) Error added in v0.6.0 

func (e ErrNotUnionStructure) Error() string

type ErrUnmatchable added in v0.12.0 

type ErrUnmatchable struct {
	// TypeName will indicate the named type of a node the function was called on.
	TypeName string

	// Reason must always be present.  ErrUnmatchable doesn't say much otherwise.
	Reason error
}

ErrUnmatchable is the error raised when processing data with IPLD Schemas and finding data which cannot be matched into the schema. It will be returned by NodeAssemblers and NodeBuilders when they are fed unmatchable data. As a result, it will also often be seen returned from unmarshalling when unmarshalling into schema-constrained NodeAssemblers.

ErrUnmatchable provides the name of the type in the schema that data couldn't be matched to, and wraps another error as the more detailed reason.

func (ErrUnmatchable) Error added in v0.12.0 

func (e ErrUnmatchable) Error() string

func (ErrUnmatchable) Reasonf added in v0.12.0 

func (e ErrUnmatchable) Reasonf(format string, a ...interface{}) ErrUnmatchable

Reasonf returns a new ErrUnmatchable with a Reason field set to the Errorf of the arguments. It's a helper function for creating untyped error reasons without importing the fmt package.

type ImplicitValue added in v0.4.0 

type ImplicitValue interface {
	// contains filtered or unexported methods
}

ImplicitValue is an sum type holding values that are implicits. It's not an 'Any' value because it can't be recursive (or to be slightly more specific, it can be one of the recursive kinds, but if so, only its empty value is valid here).

type ImplicitValue_Bool added in v0.12.3 

type ImplicitValue_Bool bool

type ImplicitValue_EmptyList added in v0.4.0 

type ImplicitValue_EmptyList struct{}

type ImplicitValue_EmptyMap added in v0.4.0 

type ImplicitValue_EmptyMap struct{}

type ImplicitValue_Int added in v0.4.0 

type ImplicitValue_Int int

type ImplicitValue_String added in v0.4.0 

type ImplicitValue_String string

type Maybe added in v0.0.2 

type Maybe uint8

type StructField 

type StructField struct {
	// contains filtered or unexported fields
}

func SpawnStructField 

func SpawnStructField(name string, typ TypeName, optional bool, nullable bool) StructField

func (StructField) IsMaybe added in v0.4.0 

func (f StructField) IsMaybe() bool

IsMaybe returns true if the field value is allowed to be either null or absent.

This is a simple "or" of the two properties, but this method is a shorthand that turns out useful often.

func (StructField) IsNullable 

func (f StructField) IsNullable() bool

IsNullable returns true if the field value is allowed to be null.

If is Nullable is false, note that it's still possible that the field value will be absent if the field is Optional! Being nullable is unrelated to whether the field's presence is optional as a whole.

Note that a field may be both nullable and optional simultaneously, or either, or neither.

func (StructField) IsOptional 

func (f StructField) IsOptional() bool

IsOptional returns true if the field is allowed to be absent from the object. If IsOptional is false, the field may be absent from the serial representation of the object entirely.

Note being optional is different than saying the value is permitted to be null! A field may be both nullable and optional simultaneously, or either, or neither.

func (StructField) Name 

func (f StructField) Name() string

Name returns the string name of this field. The name is the string that will be used as a map key if the structure this field is a member of is serialized as a map representation.

func (StructField) Parent added in v0.4.0 

func (f StructField) Parent() *TypeStruct

Parent returns the type information that this field describes a part of.

While in many cases, you may know the parent already from context, there may still be situations where want to pass around a field and not need to continue passing down the parent type with it; this method helps your code be less redundant in such a situation. (You'll find this useful for looking up any rename directives, for example, when holding onto a field, since that requires looking up information from the representation strategy, which is a property of the type as a whole.)

func (StructField) Type 

func (f StructField) Type() Type

Type returns the Type of this field's value. Note the field may also be unset if it is either Optional or Nullable.

type StructRepresentation 

type StructRepresentation interface {
	// contains filtered or unexported methods
}

type StructRepresentation_Map 

type StructRepresentation_Map struct {
	// contains filtered or unexported fields
}

func SpawnStructRepresentationMap added in v0.4.0 

func SpawnStructRepresentationMap(renames map[string]string) StructRepresentation_Map

func SpawnStructRepresentationMap2 added in v0.12.3 

func SpawnStructRepresentationMap2(renames map[string]string, implicits map[string]ImplicitValue) StructRepresentation_Map

func (StructRepresentation_Map) FieldHasRename added in v0.6.0 

func (r StructRepresentation_Map) FieldHasRename(field StructField) bool

func (StructRepresentation_Map) FieldImplicit added in v0.12.3 

func (r StructRepresentation_Map) FieldImplicit(field StructField) ImplicitValue

FieldImplicit returns the 'implicit' value for a field, or nil, if there isn't one.

Because this returns the golang ImplicitValue type, which is an interface, golang type switching is needed to distinguish what it holds. (In other words, be warned that this function is not very friendly to use from templating engines.)

func (StructRepresentation_Map) GetFieldKey added in v0.0.2 

func (r StructRepresentation_Map) GetFieldKey(field StructField) string

type StructRepresentation_StringPairs 

type StructRepresentation_StringPairs struct {
	// contains filtered or unexported fields
}

type StructRepresentation_Stringjoin added in v0.4.0 

type StructRepresentation_Stringjoin struct {
	// contains filtered or unexported fields
}

func SpawnStructRepresentationStringjoin added in v0.4.0 

func SpawnStructRepresentationStringjoin(delim string) StructRepresentation_Stringjoin

func (StructRepresentation_Stringjoin) GetDelim added in v0.4.0 

func (r StructRepresentation_Stringjoin) GetDelim() string

type StructRepresentation_Tuple 

type StructRepresentation_Tuple struct{}

func SpawnStructRepresentationTuple added in v0.6.0 

func SpawnStructRepresentationTuple() StructRepresentation_Tuple

type Type 

type Type interface {

	// Returns a pointer to the TypeSystem this Type is a member of.
	TypeSystem() *TypeSystem

	// Returns the string name of the Type.  This name is unique within the
	// universe this type is a member of, *unless* this type is Anonymous,
	// in which case a string describing the type will still be returned, but
	// that string will not be required to be unique.
	Name() TypeName

	// Returns the TypeKind of this Type.
	//
	// The returned value is a 1:1 association with which of the concrete
	// "schema.Type*" structs this interface can be cast to.
	//
	// Note that a schema.TypeKind is a different enum than datamodel.Kind;
	// and furthermore, there's no strict relationship between them.
	// schema.TypedNode values can be described by *two* distinct Kinds:
	// one which describes how the Node itself will act,
	// and another which describes how the Node presents for serialization.
	// For some combinations of Type and representation strategy, one or both
	// of the Kinds can be determined statically; but not always:
	// it can sometimes be necessary to inspect the value quite concretely
	// (e.g., `schema.TypedNode{}.Representation().Kind()`) in order to find
	// out exactly how a node will be serialized!  This is because some types
	// can vary in representation kind based on their value (specifically,
	// kinded-representation unions have this property).
	TypeKind() TypeKind

	// RepresentationBehavior returns a description of how the representation
	// of this type will behave in terms of the IPLD Data Model.
	// This property varies based on the representation strategy of a type.
	//
	// In one case, the representation behavior cannot be known statically,
	// and varies based on the data: kinded unions have this trait.
	//
	// This property is used by kinded unions, which require that their members
	// all have distinct representation behavior.
	// (It follows that a kinded union cannot have another kinded union as a member.)
	//
	// You may also be interested in a related property that might have been called "TypeBehavior".
	// However, this method doesn't exist, because it's a deterministic property of `TypeKind()`!
	// You can use `TypeKind.ActsLike()` to get type-level behavioral information.
	RepresentationBehavior() datamodel.Kind
	// contains filtered or unexported methods
}

typesystem.Type is an union interface; each of the `Type*` concrete types in this package are one of its members.

Specifically, 

TypeBool
TypeString
TypeBytes
TypeInt
TypeFloat
TypeMap
TypeList
TypeLink
TypeUnion
TypeStruct
TypeEnum

are all of the kinds of Type.

This is a closed union; you can switch upon the above members without including a default case. The membership is closed by the unexported '_Type' method; you may use the BurntSushi/go-sumtype tool to check your switches for completeness.

Many interesting properties of each Type are only defined for that specific type, so it's typical to use a type switch to handle each type of Type. (Your humble author is truly sorry for the word-mash that results from attempting to describe the types that describe the typesystem.Type.)

For example, to inspect the kind of fields in a struct: you might cast a `Type` interface into `TypeStruct`, and then the `Fields()` on that `TypeStruct` can be inspected. (`Fields()` isn't defined for any other kind of Type.)

type TypeAny added in v0.14.4 

type TypeAny struct {
	// contains filtered or unexported fields
}

func SpawnAny added in v0.14.4 

func SpawnAny(name TypeName) *TypeAny

func (TypeAny) Name added in v0.14.4 

func (t TypeAny) Name() TypeName

func (TypeAny) RepresentationBehavior added in v0.14.4 

func (t TypeAny) RepresentationBehavior() datamodel.Kind

func (TypeAny) TypeKind added in v0.14.4 

func (TypeAny) TypeKind() TypeKind

func (TypeAny) TypeSystem added in v0.14.4 

func (t TypeAny) TypeSystem() *TypeSystem

type TypeBool 

type TypeBool struct {
	// contains filtered or unexported fields
}

func SpawnBool added in v0.6.0 

func SpawnBool(name TypeName) *TypeBool

func (TypeBool) Name 

func (t TypeBool) Name() TypeName

func (TypeBool) RepresentationBehavior added in v0.6.0 

func (TypeBool) RepresentationBehavior() datamodel.Kind

func (TypeBool) TypeKind added in v0.7.0 

func (TypeBool) TypeKind() TypeKind

func (TypeBool) TypeSystem 

func (t TypeBool) TypeSystem() *TypeSystem

type TypeBytes 

type TypeBytes struct {
	// contains filtered or unexported fields
}

func SpawnBytes added in v0.0.2 

func SpawnBytes(name TypeName) *TypeBytes

func (TypeBytes) Name 

func (t TypeBytes) Name() TypeName

func (TypeBytes) RepresentationBehavior added in v0.6.0 

func (TypeBytes) RepresentationBehavior() datamodel.Kind

func (TypeBytes) TypeKind added in v0.7.0 

func (TypeBytes) TypeKind() TypeKind

func (TypeBytes) TypeSystem 

func (t TypeBytes) TypeSystem() *TypeSystem

type TypeEnum 

type TypeEnum struct {
	// contains filtered or unexported fields
}

func SpawnEnum added in v0.12.3 

func SpawnEnum(name TypeName, members []string, repr EnumRepresentation) *TypeEnum

func (TypeEnum) Members 

func (t TypeEnum) Members() []string

Members returns a slice the strings which are valid inhabitants of this enum.

func (TypeEnum) Name 

func (t TypeEnum) Name() TypeName

func (TypeEnum) RepresentationBehavior added in v0.6.0 

func (t TypeEnum) RepresentationBehavior() datamodel.Kind

func (TypeEnum) RepresentationStrategy added in v0.12.3 

func (t TypeEnum) RepresentationStrategy() EnumRepresentation

func (TypeEnum) TypeKind added in v0.7.0 

func (TypeEnum) TypeKind() TypeKind

func (TypeEnum) TypeSystem 

func (t TypeEnum) TypeSystem() *TypeSystem

type TypeFloat 

type TypeFloat struct {
	// contains filtered or unexported fields
}

func SpawnFloat added in v0.6.0 

func SpawnFloat(name TypeName) *TypeFloat

func (TypeFloat) Name 

func (t TypeFloat) Name() TypeName

func (TypeFloat) RepresentationBehavior added in v0.6.0 

func (TypeFloat) RepresentationBehavior() datamodel.Kind

func (TypeFloat) TypeKind added in v0.7.0 

func (TypeFloat) TypeKind() TypeKind

func (TypeFloat) TypeSystem 

func (t TypeFloat) TypeSystem() *TypeSystem

type TypeInt 

type TypeInt struct {
	// contains filtered or unexported fields
}

func SpawnInt added in v0.0.2 

func SpawnInt(name TypeName) *TypeInt

func (TypeInt) Name 

func (t TypeInt) Name() TypeName

func (TypeInt) RepresentationBehavior added in v0.6.0 

func (TypeInt) RepresentationBehavior() datamodel.Kind

func (TypeInt) TypeKind added in v0.7.0 

func (TypeInt) TypeKind() TypeKind

func (TypeInt) TypeSystem 

func (t TypeInt) TypeSystem() *TypeSystem

type TypeKind added in v0.7.0 

type TypeKind uint8

TypeKind is an enum of kind in the IPLD Schema system.

Note that schema.TypeKind is distinct from datamodel.Kind! Schema kinds include concepts such as "struct" and "enum", which are concepts only introduced by the Schema layer, and not present in the Data Model layer. 

const (
	TypeKind_Invalid TypeKind = 0
	TypeKind_Map     TypeKind = '{'
	TypeKind_List    TypeKind = '['
	TypeKind_Unit    TypeKind = '1'
	TypeKind_Bool    TypeKind = 'b'
	TypeKind_Int     TypeKind = 'i'
	TypeKind_Float   TypeKind = 'f'
	TypeKind_String  TypeKind = 's'
	TypeKind_Bytes   TypeKind = 'x'
	TypeKind_Link    TypeKind = '/'
	TypeKind_Struct  TypeKind = '$'
	TypeKind_Union   TypeKind = '^'
	TypeKind_Enum    TypeKind = '%'
	TypeKind_Any     TypeKind = '?'
)

func (TypeKind) ActsLike added in v0.7.0 

func (k TypeKind) ActsLike() datamodel.Kind

ActsLike returns a constant from the datamodel.Kind enum describing what this schema.TypeKind acts like at the Data Model layer.

Things with similar names are generally conserved (e.g. "map" acts like "map"); concepts added by the schema layer have to be mapped onto something (e.g. "struct" acts like "map").

Note that this mapping describes how a typed Node will *act*, programmatically; it does not necessarily describe how it will be *serialized* (for example, a struct will always act like a map, even if it has a tuple representation strategy and thus becomes a list when serialized).

func (TypeKind) String added in v0.7.0 

func (k TypeKind) String() string
type TypeLink struct {
	// contains filtered or unexported fields
}
func SpawnLink(name TypeName) *TypeLink

func SpawnLinkReference added in v0.0.2 

func SpawnLinkReference(name TypeName, pointsTo TypeName) *TypeLink

func (TypeLink) HasReferencedType added in v0.0.2 

func (t TypeLink) HasReferencedType() bool

HasReferencedType returns true if the link has a hint about the type it references false if it's generic

func (TypeLink) Name 

func (t TypeLink) Name() TypeName

func (TypeLink) ReferencedType added in v0.0.2 

func (t TypeLink) ReferencedType() Type

ReferencedType returns the type hint for the node on the other side of the link

func (TypeLink) RepresentationBehavior added in v0.6.0 

func (TypeLink) RepresentationBehavior() datamodel.Kind

func (TypeLink) TypeKind added in v0.7.0 

func (TypeLink) TypeKind() TypeKind

func (TypeLink) TypeSystem 

func (t TypeLink) TypeSystem() *TypeSystem

type TypeList 

type TypeList struct {
	// contains filtered or unexported fields
}

func SpawnList added in v0.0.2 

func SpawnList(name TypeName, valueType TypeName, nullable bool) *TypeList

func (TypeList) IsAnonymous 

func (t TypeList) IsAnonymous() bool

IsAnonymous is returns true if the type was unnamed. Unnamed types will claim to have a Name property like `[Foo]`, and this is not guaranteed to be a unique string for all types in the universe.

func (TypeList) Name 

func (t TypeList) Name() TypeName

func (TypeList) RepresentationBehavior added in v0.6.0 

func (TypeList) RepresentationBehavior() datamodel.Kind

func (TypeList) TypeKind added in v0.7.0 

func (TypeList) TypeKind() TypeKind

func (TypeList) TypeSystem 

func (t TypeList) TypeSystem() *TypeSystem

func (TypeList) ValueIsNullable 

func (t TypeList) ValueIsNullable() bool

ValueIsNullable returns a bool describing if the list values are permitted to be null.

func (TypeList) ValueType 

func (t TypeList) ValueType() Type

ValueType returns to the Type of the list values.

type TypeMap 

type TypeMap struct {
	// contains filtered or unexported fields
}

func SpawnMap added in v0.4.0 

func SpawnMap(name TypeName, keyType TypeName, valueType TypeName, nullable bool) *TypeMap

func (TypeMap) IsAnonymous 

func (t TypeMap) IsAnonymous() bool

IsAnonymous is returns true if the type was unnamed. Unnamed types will claim to have a Name property like `{Foo:Bar}`, and this is not guaranteed to be a unique string for all types in the universe.

func (TypeMap) KeyType 

func (t TypeMap) KeyType() Type

KeyType returns the Type of the map keys.

Note that map keys will must always be some type which is representable as a string in the IPLD Data Model (e.g. either TypeString or TypeEnum).

func (TypeMap) Name 

func (t TypeMap) Name() TypeName

func (TypeMap) RepresentationBehavior added in v0.6.0 

func (TypeMap) RepresentationBehavior() datamodel.Kind

func (TypeMap) TypeKind added in v0.7.0 

func (TypeMap) TypeKind() TypeKind

func (TypeMap) TypeSystem 

func (t TypeMap) TypeSystem() *TypeSystem

func (TypeMap) ValueIsNullable 

func (t TypeMap) ValueIsNullable() bool

ValueIsNullable returns a bool describing if the map values are permitted to be null.

func (TypeMap) ValueType 

func (t TypeMap) ValueType() Type

ValueType returns the Type of the map values.

type TypeName 

type TypeName = string

type TypeString 

type TypeString struct {
	// contains filtered or unexported fields
}

func SpawnString 

func SpawnString(name TypeName) *TypeString

func (TypeString) Name 

func (t TypeString) Name() TypeName

func (TypeString) RepresentationBehavior added in v0.6.0 

func (TypeString) RepresentationBehavior() datamodel.Kind

func (TypeString) TypeKind added in v0.7.0 

func (TypeString) TypeKind() TypeKind

func (TypeString) TypeSystem 

func (t TypeString) TypeSystem() *TypeSystem

type TypeStruct 

type TypeStruct struct {
	// contains filtered or unexported fields
}

func SpawnStruct 

func SpawnStruct(name TypeName, fields []StructField, repr StructRepresentation) *TypeStruct

func (TypeStruct) Field added in v0.0.2 

func (t TypeStruct) Field(name string) *StructField

Field looks up a StructField by name, or returns nil if no such field.

func (TypeStruct) Fields 

func (t TypeStruct) Fields() []StructField

Fields returns a slice of descriptions of the object's fields.

func (TypeStruct) Name 

func (t TypeStruct) Name() TypeName

func (TypeStruct) RepresentationBehavior added in v0.6.0 

func (t TypeStruct) RepresentationBehavior() datamodel.Kind

func (TypeStruct) RepresentationStrategy added in v0.0.2 

func (t TypeStruct) RepresentationStrategy() StructRepresentation

func (TypeStruct) TypeKind added in v0.7.0 

func (TypeStruct) TypeKind() TypeKind

func (TypeStruct) TypeSystem 

func (t TypeStruct) TypeSystem() *TypeSystem

type TypeSystem 

type TypeSystem struct {
	// contains filtered or unexported fields
}

func MustTypeSystem added in v0.12.1 

func MustTypeSystem(types ...Type) *TypeSystem

func SpawnTypeSystem added in v0.12.1 

func SpawnTypeSystem(types ...Type) (*TypeSystem, []error)

func (*TypeSystem) Accumulate added in v0.4.0 

func (ts *TypeSystem) Accumulate(typ Type)

func (TypeSystem) GetTypes added in v0.4.0 

func (ts TypeSystem) GetTypes() map[TypeName]Type

func (*TypeSystem) Init added in v0.4.0 

func (ts *TypeSystem) Init()

func (TypeSystem) Names added in v0.12.2 

func (ts TypeSystem) Names() []TypeName

func (TypeSystem) TypeByName added in v0.4.0 

func (ts TypeSystem) TypeByName(n string) Type

func (TypeSystem) ValidateGraph added in v0.6.0 

func (ts TypeSystem) ValidateGraph() []error

ValidateGraph checks that all type names referenced are defined.

It does not do any other validations of individual type's sensibleness (that should've happened when they were created (although also note many of those validates are NYI, and are roadmapped for after we research self-hosting)).

type TypeUnion 

type TypeUnion struct {
	// contains filtered or unexported fields
}

func SpawnUnion added in v0.6.0 

func SpawnUnion(name TypeName, members []TypeName, repr UnionRepresentation) *TypeUnion

func (TypeUnion) Members added in v0.6.0 

func (t TypeUnion) Members() []Type

Members returns the list of all types that are possible inhabitants of this union.

func (TypeUnion) Name 

func (t TypeUnion) Name() TypeName

func (TypeUnion) RepresentationBehavior added in v0.6.0 

func (t TypeUnion) RepresentationBehavior() datamodel.Kind

func (TypeUnion) RepresentationStrategy added in v0.6.0 

func (t TypeUnion) RepresentationStrategy() UnionRepresentation

func (TypeUnion) TypeKind added in v0.7.0 

func (TypeUnion) TypeKind() TypeKind

func (TypeUnion) TypeSystem 

func (t TypeUnion) TypeSystem() *TypeSystem

type TypedLinkNode added in v0.0.2 

type TypedLinkNode interface {
	LinkTargetNodePrototype() datamodel.NodePrototype
}

schema.TypedLinkNode is a superset of the schema.TypedNode interface, and has one additional behavior.

A schema.TypedLinkNode contains a hint for the appropriate node builder to use for loading data on the other side of the link contained within the node, so that it can be assembled into a node representation and validated against the schema as quickly as possible

So, for example, if you wanted to support loading the other side of a link with a code-gen'd node builder while utilizing the automatic loading facilities of the traversal package, you could write a LinkNodeBuilderChooser as follows: 

func LinkNodeBuilderChooser(lnk datamodel.Link, lnkCtx linking.LinkContext) datamodel.NodePrototype {
	if tlnkNd, ok := lnkCtx.LinkNode.(schema.TypedLinkNode); ok {
		return tlnkNd.LinkTargetNodePrototype()
	}
	return basicnode.Prototype.Any
}

type TypedNode added in v0.0.2 

type TypedNode interface {
	// schema.TypedNode acts just like a regular Node for almost all purposes;
	// which datamodel.Kind it acts as is determined by the TypeKind.
	// (Note that the representation strategy of the type does *not* affect
	// the Kind of schema.TypedNode -- rather, the representation strategy
	// affects the `.Representation().Kind()`.)
	//
	// For example: if the `.Type().TypeKind()` of this node is "struct",
	// it will act like Kind() == "map"
	// (even if Type().(Struct).ReprStrategy() is "tuple").
	datamodel.Node

	// Type returns a reference to the reified schema.Type value.
	Type() Type

	// Representation returns a datamodel.Node which sees the data in this node
	// in its representation form.
	//
	// For example: if the `.Type().TypeKind()` of this node is "struct",
	// `.Representation().TypeKind()` may vary based on its representation strategy:
	// if the representation strategy is "map", then it will be Kind=="map";
	// if the streatgy is "tuple", then it will be Kind=="list".
	Representation() datamodel.Node
}

schema.TypedNode is a superset of the datamodel.Node interface, and has additional behaviors.

A schema.TypedNode can be inspected for its schema.Type and schema.TypeKind, which conveys much more and richer information than the Data Model layer datamodel.Kind.

There are many different implementations of schema.TypedNode. One implementation can wrap any other existing datamodel.Node (i.e., it's zero-copy) and promises that it has *already* been validated to match the typesystem.Type; another implementation similarly wraps any other existing datamodel.Node, but defers to the typesystem validation checking to fields that are accessed; and when using code generation tools, all of the generated native Golang types produced by the codegen will each individually implement schema.TypedNode.

Typed nodes sometimes have slightly different behaviors than plain nodes: For example, when looking up fields on a typed node that's a struct, the error returned for a lookup with a key that's not a field name will be ErrNoSuchField (instead of ErrNotExists). These behaviors apply to the schema.TypedNode only and not their representations; continuing the example, the .Representation().LookupByString() method on that same node for the same key as plain `.LookupByString()` will still return ErrNotExists, because the representation isn't a schema.TypedNode!

type TypedPrototype added in v0.11.0 

type TypedPrototype interface {
	datamodel.NodePrototype

	// Type returns a reference to the reified schema.Type value.
	Type() Type

	// Representation returns a datamodel.NodePrototype for the representation
	// form of the prototype.
	Representation() datamodel.NodePrototype
}

TypedPrototype is a superset of the datamodel.Nodeprototype interface, and has additional behaviors, much like TypedNode for datamodel.Node.

type UnionRepresentation added in v0.6.0 

type UnionRepresentation interface {
	// contains filtered or unexported methods
}

type UnionRepresentation_Envelope added in v0.6.0 

type UnionRepresentation_Envelope struct {
	// contains filtered or unexported fields
}

type UnionRepresentation_Inline added in v0.6.0 

type UnionRepresentation_Inline struct {
	// contains filtered or unexported fields
}

type UnionRepresentation_Keyed added in v0.6.0 

type UnionRepresentation_Keyed struct {
	// contains filtered or unexported fields
}

func SpawnUnionRepresentationKeyed added in v0.6.0 

func SpawnUnionRepresentationKeyed(table map[string]TypeName) UnionRepresentation_Keyed

func (UnionRepresentation_Keyed) GetDiscriminant added in v0.6.0 

func (r UnionRepresentation_Keyed) GetDiscriminant(t Type) string

type UnionRepresentation_Kinded added in v0.6.0 

type UnionRepresentation_Kinded struct {
	// contains filtered or unexported fields
}

func SpawnUnionRepresentationKinded added in v0.6.0 

func SpawnUnionRepresentationKinded(table map[datamodel.Kind]TypeName) UnionRepresentation_Kinded

func (UnionRepresentation_Kinded) GetMember added in v0.6.0 

func (r UnionRepresentation_Kinded) GetMember(k datamodel.Kind) TypeName

GetMember returns type info for the member matching the kind argument, or may return nil if that kind is not mapped to a member of this union.

type UnionRepresentation_Stringprefix added in v0.9.0 

type UnionRepresentation_Stringprefix struct {
	// contains filtered or unexported fields
}

func SpawnUnionRepresentationStringprefix added in v0.9.0 

func SpawnUnionRepresentationStringprefix(delim string, table map[string]TypeName) UnionRepresentation_Stringprefix

func (UnionRepresentation_Stringprefix) GetDelim added in v0.9.0 

func (r UnionRepresentation_Stringprefix) GetDelim() string

func (UnionRepresentation_Stringprefix) GetDiscriminant added in v0.9.0 

func (r UnionRepresentation_Stringprefix) GetDiscriminant(t Type) string

Source Files

View all Source files

Directories

Path Synopsis
gen
go
go/mixins

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