Idris interface syntax

Question

I am trying to compile simple example of interface in Idris.

interface Foo a where
     foo : a -> String

But I keep getting this type-checking error:

error: expected: "with",
argument expression,
function right hand side,
implicit function argument,
with pattern
interface Foo a where 
                ^

I believe it should be logically the same as the Show interface in the tutorial: http://docs.idris-lang.org/en/latest/tutorial/interfaces.html Has the syntax changed? Or where could be the problem?

I am using Idris version 0.9.12.

It works with Idris 0.12.3. – Anton Trunov Nov 17 '16 at 11:40 — Anton Trunov, Nov 17 '16 at 11:40
Upgrading fixed it, thanks. – user1747134 Nov 17 '16 at 11:44 — user1747134, Nov 17 '16 at 11:44

score 2 · Accepted Answer · answered Nov 18 '16 at 01:36

2

In Idris 0.9.12, the syntax for what is now called interfaces is class:

class Foo a where
     foo : a -> String

answered Nov 18 '16 at 01:36

Cactus

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Idris interface syntax

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