ziglings/exercises/089_async6.zig
2021-06-30 19:59:25 -04:00

54 lines
1.4 KiB
Zig

//
// The power and purpose of async/await becomes more apparent
// when we do multiple things concurrently. Foo and Bar do not
// depend on each other and can happen at the same time, but End
// requires that they both be finished.
//
// +---------+
// | Start |
// +---------+
// / \
// / \
// +---------+ +---------+
// | Foo | | Bar |
// +---------+ +---------+
// \ /
// \ /
// +---------+
// | End |
// +---------+
//
// We can express this in Zig like so:
//
// fn foo() u32 { ... }
// fn bar() u32 { ... }
//
// // Start
//
// var foo_frame = async foo();
// var bar_frame = async bar();
//
// var foo_value = await foo_frame;
// var bar_value = await bar_frame;
//
// // End
//
// Please await TWO page titles!
//
const print = @import("std").debug.print;
pub fn main() void {
var com_frame = async getPageTitle("http://example.com");
var org_frame = async getPageTitle("http://example.org");
var com_title = com_frame;
var org_title = org_frame;
print(".com: {s}, .org: {s}.\n", .{com_title, org_title});
}
fn getPageTitle(url: []const u8) []const u8 {
// Please PRETEND this is actually making a network request.
_ = url;
return "Example Title";
}