Master programming syntax, solve interactive challenges & run live code in Syntaxis Explore Arena →
menu_book Course Curriculum (Elm Complete Course) expand_more
Elm Complete Course / Custom Types

Custom union types

Learn Custom union types in Elm with a construct-specific explanation, a unique example, a practical boundary, and a mastery check.

10 min read • Beginner

Custom union types is an atomic Elm topic inside Custom Types. The example below uses the actual construct named by the lesson rather than a generic placeholder.

Focus on what Custom union types changes: the input, binding, control path, object state, collection, runtime effect, or language contract. Then alter one value and verify that the behavior changes for a reason specific to this feature.

Topic-specific example

elm-03-02-custom-union-types.elm
elm Try It Live
type Status = New | Paid | Sent
Edge case / engineering note

Pay attention to the contract exposed by the type, which members belong to instances versus the type itself, and what dispatch occurs at runtime.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content