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Haskell / Algebraic Data Types

Recursive data types

Learn Recursive data types in Haskell through a focused explanation, a dedicated topic-specific example, an engineering boundary, and a mastery check.

12 min read • Intermediate

Recursive data types is a focused Haskell lesson inside Algebraic Data Types. The example uses the construct named in the lesson directly rather than reusing a generic placeholder.

Trace the example from its inputs through Recursive data types and identify the behavior that would change if that construct were removed or replaced. Pay attention to the language-specific rules shown by the syntax, because neighboring lessons intentionally exercise different mechanisms.

Topic-specific example

haskell-0043-3aa68d8413.hs
haskell Try It Live 
sample44 :: [Int]
sample44 = [44,45,46]
main = print (sum sample44) -- Recursive data types
Edge case / engineering note

For Recursive data types, test one realistic boundary: empty data, invalid input, unavailable resources, lifetime/cleanup, type constraints, or concurrency timing where applicable. A successful happy path is not enough to prove the construct is used correctly.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

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