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Showing content from https://docs.racket-lang.org/guide/module-require.html below:

6.4 Imports: require

6.4 Imports: require🔗ℹ

The require form imports from another module. A require form can appear within a module, in which case it introduces bindings from the specified module into the importing module. A require form can also appear at the top level, in which case it both imports bindings and instantiates the specified module; that is, it evaluates the body definitions and expressions of the specified module, if they have not been evaluated already.

A single require can specify multiple imports at once:

Specifying multiple require-specs in a single require is essentially the same as using multiple requires, each with a single require-spec. The difference is minor, and confined to the top-level: a single require can import a given identifier at most once, whereas a separate require can replace the bindings of a previous require (both only at the top level, outside of a module).

The allowed shape of a require-spec is defined recursively:

In its simplest form, a require-spec is a module-path (as defined in the previous section, Module Paths). In this case, the bindings introduced by require are determined by provide declarations within each module referenced by each module-path.

Examples:

(only-in require-spec id-maybe-renamed ...)   id-maybe-renamed   =   id     |   [orig-id bind-id]

An only-in form limits the set of bindings that would be introduced by a base require-spec. Also, only-in optionally renames each binding that is preserved: in a [orig-id bind-id] form, the orig-id refers to a binding implied by require-spec, and bind-id is the name that will be bound in the importing context instead of orig-id.

Examples:

> (require (only-in 'm tastes-great?)) > tastes-great?

#t

> less-filling?

less-filling?: undefined;

 cannot reference an identifier before its definition

  in module: top-level

> (require (only-in 'm [less-filling? lite?])) > lite?

#t

This form is the complement of only-in: it excludes specific bindings from the set specified by require-spec.

(rename-in require-spec [orig-id bind-id] ...)

This form supports renaming like only-in, but leaving alone identifiers from require-spec that are not mentioned as an orig-id.

This is a shorthand for renaming, where prefix-id is added to the front of each identifier specified by require-spec.

The only-in, except-in, rename-in, and prefix-in forms can be nested to implement more complex manipulations of imported bindings. For example,

(require (prefix-in m: (except-in 'm ghost)))

imports all bindings that m exports, except for the ghost binding, and with local names that are prefixed with m:.

Equivalently, the prefix-in could be applied before except-in, as long as the omission with except-in is specified using the m: prefix:

(require (except-in (prefix-in m: 'm) m:ghost))


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