49 lines
1.4 KiB
Zig
49 lines
1.4 KiB
Zig
//
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// Sure, we can solve our async value problem with a global
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// variable. But this hardly seems like an ideal solution.
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//
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// So how do we REALLY get return values from async functions?
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//
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// The 'await' keyword waits for an async function to complete
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// and then captures its return value.
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//
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// fn foo() u32 {
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// return 5;
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// }
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//
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// var foo_frame = async foo(); // invoke and get frame
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// var value = await foo_frame; // await result using frame
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//
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// The above example is just a silly way to call foo() and get 5
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// back. But if foo() did something more interesting such as wait
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// for a network response to get that 5, our code would pause
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// until the value was ready.
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//
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// As you can see, async/await basically splits a function call
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// into two parts:
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//
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// 1. Invoke the function ('async')
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// 2. Getting the return value ('await')
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//
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// Also notice that a 'suspend' keyword does NOT need to exist in
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// a function to be called in an async context.
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//
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// Please use 'await' to get the string returned by
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// getPageTitle().
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//
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const print = @import("std").debug.print;
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pub fn main() void {
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var myframe = async getPageTitle("http://example.com");
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var value = await myframe;
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print("{s}\n", .{value});
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}
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fn getPageTitle(url: []const u8) []const u8 {
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// Please PRETEND this is actually making a network request.
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_ = url;
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return "Example Title.";
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}
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