28 lines
598 B
Rust
28 lines
598 B
Rust
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use bad_optics::lenses::*;
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#[derive(Debug, PartialEq, Clone)]
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struct MyStruct {
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hey: (u8, (u8, i32)),
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}
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fn main() {
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// make a lens for Hello
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let hey = lens(
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|hello: MyStruct| hello.hey,
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|mut hello: MyStruct, v| {
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hello.hey = v;
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hello
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},
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);
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let my_struct = MyStruct { hey: (1, (2, -3)) };
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// the thing we want to access
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let thing = (my_struct, "hello");
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// a lens that targets the -3 inside my_struct
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let lens_that_targets_the_i32 = _0 + hey + _1 + _1;
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assert_eq!(lens_that_targets_the_i32(thing), -3);
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}
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