I think they’re nominally typed. Consider this example: type student_t = { age: int; } type worker_t = { age: int; } let new_worker (age: int) : worker_t = {age = age;} let is_adult (student: student_t) : bool = student.age >= 18 I get a type error when I do: let result = is_adult (new_wor…

I don’t know what you mean by “nominally”, but a record-declaration declares these new field-names. Do it again (the identical declaration), and you redeclare the field-names. The new declarations obscure (or “shadow”) the old ones. But code or data that was created using the first declaration wi…

Are OCaml records structurally typed or nominally typed?

Learning

shonfeder July 23, 2023, 5:40am 4

Records are nominally typed, but objects are structurally typed. They are even given as the example on Structural type system - Wikipedia

2 Likes

Topic		Replies	Views
Ocaml record type usage Learning	3	809	September 16, 2019
It is said structs are better in ocaml compared to haskell Learning	3	1082	November 23, 2021
Records, tuples and variants subtyping Community type-system	6	2753	September 29, 2020
Any way to define a polymorphic record field via a function? Learning	6	3496	April 27, 2018
Ocaml record <-> SQL Learning	3	457	February 6, 2023

Are OCaml records structurally typed or nominally typed?

Related topics