menu_book Course Curriculum (F#) expand_more
As patterns
Learn As patterns in F# through a focused explanation, a dedicated topic-specific example, an engineering boundary, and a mastery check.
As patterns is a focused F# lesson inside Pattern Matching. The example uses the construct named in the lesson directly rather than reusing a generic placeholder.
Trace the example from its inputs through As patterns 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
let values31 = [31; 32; 33]
printfn "%d" (List.sum values31) // As patterns
For As patterns, 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.