From 3f1468142badd2717596a4cd78f6f347b78010d7 Mon Sep 17 00:00:00 2001 From: Alex Beregszaszi Date: Sun, 12 Feb 2017 15:21:32 +0000 Subject: Document interfaces --- docs/contracts.rst | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/docs/contracts.rst b/docs/contracts.rst index 2ee04675..33627b92 100644 --- a/docs/contracts.rst +++ b/docs/contracts.rst @@ -922,6 +922,33 @@ Such contracts cannot be compiled (even if they contain implemented functions al If a contract inherits from an abstract contract and does not implement all non-implemented functions by overriding, it will itself be abstract. +.. index:: ! contract;interface, ! interface contract + +********** +Interfaces +********** + +Interfaces are similar to abstract contracts, but they cannot have any functions implemented. There are further restrictions: + +#. Cannot inherit other contracts or interfaces. +#. Cannot define variables. +#. Cannot define structs. + +Some of these restrictions might be lifted in the future. + +Interfaces are basically limited to what the Contract ABI can represent and the conversion between the ABI and +an Interface should be possible without any information loss. + +Interfaces are denoted by their own keyword: + +:: + + interface Token { + function transfer(address recipient, uint amount); + } + +Contracts can inherit interfaces as they would inherit other contracts. + .. index:: ! library, callcode, delegatecall .. _libraries: -- cgit