Exploring the use of pipe and Option in fp-ts for my initial encounter.
I encountered this code snippet that performs type narrowing, but I believe it can be achieved without using the if statement:
if (O.isNone(this.state)) {
return undefined;
}
return this.lens.get(this.state.value);
Typically, the concept behind using wrapping data types is to avoid premature unwrapping. In this particular scenario, given that this.state is of type Option, I suggest the following approach:
import { option } from 'fp-ts';
pipe(
this.state,
option.map(state => this.lens.get(state)),
option.toUndefined,
);
To optimize your code, consider utilizing the pipe function along with Option.fromNullable and Option.map:
import { pipe } from "fp-ts/function";
import * as O from "fp-ts/Option";
let data = {
state: {
value: "example"
}
};
function process(input: { value: string }) {
return input.value;
}
console.log(
pipe(
data.state,
O.fromNullable,
O.map((value) => process(value))
)
);
In the case of your scenario, it can be implemented as follows:
return pipe(
this.state,
O.fromNullable,
O.map(state => this.lens.get(state.value))
);
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