29 lines
1.1 KiB
Markdown
29 lines
1.1 KiB
Markdown
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Call Method as Function
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======================
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{{#include ../links.md}}
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Properties and methods in a Rust custom type registered with the [`Engine`] can be called just like a regular function in Rust.
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Unlike functions defined in script (for which all arguments are passed by _value_),
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native Rust functions may mutate the object (or the first argument if called in normal function call style).
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Custom types, properties and methods can be disabled via the [`no_object`] feature.
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```rust
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let a = new_ts(); // constructor function
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a.field = 500; // property setter
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a.update(); // method call, 'a' can be modified
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update(a); // <- this de-sugars to 'a.update()' thus if 'a' is a simple variable
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// unlike scripted functions, 'a' can be modified and is not a copy
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let array = [ a ];
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update(array[0]); // <- 'array[0]' is an expression returning a calculated value,
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// a transient (i.e. a copy) so this statement has no effect
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// except waste a lot of time cloning
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array[0].update(); // <- call this method-call style will update 'a'
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```
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