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24 строки
983 B
Plaintext
24 строки
983 B
Plaintext
https://nixos.wiki/wiki/Overview_of_the_Nix_Language
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With expression
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This kind of expression is something you rarely see in other languages.
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You can think of it like a more granular version of using from C++, or from module import * from Python.
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You decide per-expression when to include symbols into the scope.
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nix-repl> longName = { a = 3; b = 4; }
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nix-repl> longName.a + longName.b
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7
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nix-repl> with longName; a + b
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7
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That's it, it takes an attribute set and includes symbols from it in the scope of the inner expression.
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Of course, only valid identifiers from the keys of the set will be included.
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If a symbol exists in the outer scope and would also be introduced by the with, it will not be shadowed.
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You can however still refer to the attribute set:
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nix-repl> let a = 10; in with longName; a + b
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14
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nix-repl> let a = 10; in with longName; longName.a + b
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7
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