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Ques from a beginner: how to access a type defined in one .ml file in another .ml file
- Tarun Sethi
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Date: | 2010-05-12 (10:30) |
From: | Tarun Sethi <tarunsethi01@g...> |
Subject: | Ques from a beginner: how to access a type defined in one .ml file in another .ml file |
Hi, I m very new to ocaml and I am not sure if this the right forum to ask a beginner level question. I have tried reading tutorials and the manual but no help. Please help me on the problem below, In a.ml a record type t is defined and is also defined transparently in a.mli, i.e. in d interface so that the type definition is available to all other files. a.ml also has a function, func, which returns a list of t. Now in another file, b.ml i m calling func, now obviously ocaml compiler wud nt be able to infer d type of objects stored in d list, for compiler its just a list. so in b.ml, i hav something like dis, let tlist = A.func in let vart = List.hd tlist in printf "%s\n" vart.name (*name is a field in record t*) Now here i get a compiler error sayin "Unbound record field label name" which makes sense as compiler can't infer d type of vart. my first question: how do I explicitly provide d type of vart as t here? i tried doing "let vart:A.t = " but got the same error. I also tried creating another function to fetch the first element of d list and mentioning return type as A.t, but then i got the "Unbound value A.t". I did this: let firstt = function [] -> 0 | x :: _ -> A.t x ;; The problem is compiler is unable to recognize A.t (a type) in b.ml but is able to recognize function A.func. If I remove A.t from the b.ml, i don'get any compiler errors. Please help, its urgent work. Thanks in advance! ~Tarun