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Newsgroups: comp.lang.ada
Date: Tue, 6 Mar 2018 12:45:01 -0800 (PST)
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Subject: Re: Recursive algebraic data types
From: gautier_niouzes@hotmail.com
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Xref: reader02.eternal-september.org comp.lang.ada:50859
Date: 2018-03-06T12:45:01-08:00
List-Id: <comp.lang.ada>

> for definition: please have a look at https://en.wikipedia.org/wiki/Recur=
sive_data_type

"In computer programming languages, a recursive data type (also known as a =
recursively-defined, inductively-defined or inductive data type) is a data =
type for values that may contain other values of the same type."

The definition given above is nonsensical: either the data type is empty or=
 infinitely large...

In the examples given (List), the type names can mean either a pointer to t=
he real data, or the data itself (a list's node in that case). Clearly they=
 are playing with words there: a node doesn't really contain the next node,=
 but a pointer (or a reference) to the next node. So it's not really recurs=
ive, only in appearance. They play with a shortcut notation.