diff --git a/exercises/047_methods.zig b/exercises/047_methods.zig index 96d4c8e..6b2dbef 100644 --- a/exercises/047_methods.zig +++ b/exercises/047_methods.zig @@ -2,9 +2,9 @@ // Help! Evil alien creatures have hidden eggs all over the Earth // and they're starting to hatch! // -// Before you jump into battle, you'll need to know four things: +// Before you jump into battle, you'll need to know three things: // -// 1. You can attach functions to structs: +// 1. You can attach functions to structs (and other "type definitions"): // // const Foo = struct{ // pub fn hello() void { @@ -12,31 +12,30 @@ // } // }; // -// 2. A function that is a member of a struct is a "method" and is -// called with the "dot syntax" like so: +// 2. A function that is a member of a struct is "namespaced" within +// that struct and is called by specifying the "namespace" and then +// using the "dot syntax": // // Foo.hello(); // -// 3. The NEAT feature of methods is the special parameter named -// "self" that takes an instance of that type of struct: +// 3. The NEAT feature of these functions is that if their first argument +// is an instance of the struct (or a pointer to one) then we can use +// the instance as the namespace instead of the type: // // const Bar = struct{ -// number: u32, -// -// pub fn printMe(self: Bar) void { -// std.debug.print("{}\n", .{self.number}); -// } +// pub fn a(self: Bar) void {} +// pub fn b(this: *Bar, other: u8) void {} +// pub fn c(bar: *const Bar) void {} // }; // -// (Actually, you can name the first parameter anything, but -// please follow convention and use "self".) -// -// 4. Now when you call the method on an INSTANCE of that struct -// with the "dot syntax", the instance will be automatically -// passed as the "self" parameter: +// var bar = Bar{}; +// bar.a() // is equivalent to Bar.a(bar) +// bar.b(3) // is equivalent to Bar.b(&bar, 3) +// bar.c() // is equivalent to Bar.c(&bar) // -// var my_bar = Bar{ .number = 2000 }; -// my_bar.printMe(); // prints "2000" +// Notice that the name of the parameter doesn't matter. Some use +// self, others use a lowercase version of the type name, but feel +// free to use whatever is most appropriate. // // Okay, you're armed. //