Features

Example

constinterface=@import("interface.zig");constInterface=interface.Interface;constSelfType=interface.SelfType;// Let us create a Reader interface.// We wrap it in our own struct to make function calls more natural.constReader=struct {pubconstReadError=error {CouldNotRead };constIFace=Interface(struct {// Our interface requires a single non optional, non-const read function.read:fn (*SelfType,buf: []u8)ReadError!usize,    },interface.Storage.NonOwning);// This is a non owning interface, similar to Rust dyn traits.iface:IFace,// Wrap the interface's init, since the interface is non owning it requires no allocator argument.pubfninit(impl_ptr:var)Reader {return .{ .iface=tryIFace.init(.{impl_ptr}) };    }// Wrap the read function callpubfnread(self:*Reader,buf: []u8)ReadError!usize {returnself.iface.call("read", .{buf});    }// Define additional, non-dynamic functions!pubfnreadAll(self:*Self,buf: []u8)ReadError!usize {varindex:usize=0;while (index!=buf.len) {constpartial_amt=tryself.read(buffer[index..]);if (partial_amt==0)returnindex;index+=partial_amt;        }returnindex;    }};// Let's create an example readerconstExampleReader=struct {state:u8,// Note that this reader cannot return an error, the return type// of our implementation functions only needs to coerce to the// interface's function return type.pubfnread(self:ExampleReader,buf: []u8)usize {for (buf)|*c| {c.*=self.state;        }returnbuf.len;    }};test"Use our reader interface!" {varexample_reader=ExampleReader{ .state=42 };varreader=Reader.init(&example_reader);varbuf: [100]u8=undefined;_=reader.read(&buf)catchunreachable;}