Reflections for Algebraic Data Type

The Moshi.Data module provides a set of reflection functions to work with algebraic data types. This page lists all the reflection functions available in Moshi.jl.

Reflections

variants

variants(x::Type) -> Tuple

Return a tuple of variants of the given data type.

variants(x)

Return a tuple of variants of the given data type.

variant_fieldtypes

variant_fieldtypes(type::Type) -> Tuple

Return the field types of the variant.

variant_kind

variant_kind(x) -> VariantKind

Return the kind of the variant, can be Singleton, Anonymous, or Named.

data_type_name

data_type_name(x) -> Symbol

Return the data type name of the given variant.

isa_variant

isa_variant(x, variant::Type) -> Bool

Check if the given variant is an instance of the given variant type.

variant_fieldnames

variant_fieldnames(value)

Return the field names of the variant.

variant_storage_type

variant_storage_type(tag::Type) -> Type

Return the storage type of the variant.

variant_getfield

variant_getfield(value, tag::Type, field::Union{Int, Symbol})

Known the variant type tag, return the field of the variant by field name or index.

!!! note This method is used by the pattern matching system to extract the field of the variant. It is not intended to be used directly. Most of cases, you can use the x.field syntax to extract the field of the variant. However, Julia compiler is not able to infer the type of the variant usually, so if you care about performance, you may want to use this method in combine with variant_storage.

variant_storage

variant_storage(value)

Return the storage object of the variant.

variant_type

variant_type(x)

Return the variant type of the given variant.

variant_nfields

variant_nfields(value)

Return the number of fields of the variant.

is_data_type

is_data_type(x) -> Bool

Check if the given object is a variant of a algebraic data type.

variant_name

variant_name(x) -> Symbol

Return the name of the variant.

show_variant

show_variant(io::IO, mime::Base.Multimedia.MIME{Symbol("text/plain")}, x)

Print the variant to the given IO stream in multiple lines.

show_variant(io::IO, x)

Print the variant to the given IO stream in a single line.

data_type

data_type(variant::Type) -> Type

Return the data type of the given variant type.

is_variant_type

is_variant_type(x) -> Bool

Check if the given object is a variant type.

storage_types

storage_types(value::Type) -> Base.ImmutableDict{DataType, DataType}

Return the storage types of the data type.

!!! note This method is used by the pattern matching system to extract the field of the variant.