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datum->expression
8.16.0.4
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18 Converting a Datum to an Expression🔗ℹ

 (require scramble/datum-to-expr) package: scramble-lib

Added in version 0.5 of package scramble-lib.

procedure

(datum->expression v [#:convert convert]) → syntax?

  v : any/c
  convert : (-> any/c (U #f syntax?)) = (lambda (v) #f)
Converts the datum v into an expression that evaluates to a value equivalent to v. This function is useful for a macro that has a (compile-time) value and wants it to be recreated at run time, or at compile time after the macro ends, but the value contains syntax objects, so it cannot simply be wrapped in a quote expression. The expression is suitable for evaluation at either run time or compile time.

The types of values directly supported are the quotable atomic values (null, booleans, numbers, charactes, strings, byte strings, symbols, keywords, and regexps), pairs, vectors, boxes, immutable prefab structs, hashes, and syntax objects. Other types of data can be supported via the optional convert argument. The convert function is called with a value that is not one of the types listed above, and it must either produce either #f or a syntax object representing an expression to recreate the value.

The value that the expression produces is equivalent to v with the following exceptions: mutable data (strings, byte strings, vectors, boxes, and hashes) are converted into immutable variants; syntax objects may gain scopes and may lose syntax properties due to serialization. Sharing is generally not preserved.

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