Can Wolfram Language enforce pure functions?

Asked Feb 17 '20 at 14:47

Active Feb 19 '20 at 06:14

Viewed 200 times

Is there a feature in Wolfram Language that supports or enforces pure functions? WL has something that it calls "pure functions" in its documentation, but these are most emphatically not pure functions. For example, something like

z=0;
Map[{#, Print[z=z+#];z}&, Range[5]]

has side effects and modifies its environment.

Does Wolfram Language have a way of ensuring that a function is in fact pure?

edited Feb 17 '20 at 21:01

asked Feb 17 '20 at 14:47

orome

12,819
3
52
100

1

And as an aside: why does the documentation use "pure function" in the way that it does? – orome Feb 17 '20 at 14:48
The answer to the question in the title is "no". Maybe you meant to ask "Can Wolfram Language enforce pure functions?" – Henrik Schumacher Feb 17 '20 at 16:33
Towards your question in the comment: "Pure function" is used for Functions just to distinct them from "functions" defined by 'f[x_]:= ...`. However, the latter does not define a function, but a replacement rule. – Henrik Schumacher Feb 17 '20 at 16:36
5

related: Why does the documentation call functions "pure"? – WReach Feb 17 '20 at 16:57
4

@WReach That's a good reference (which I missed). I'm definitely coming from the Haskell world, which explains why the Mathematica use grates. But I didn't realize that the history was the other way round! (It remains a legitimate question though why Wolfram continues this usage, and doesn't switch to the clearer "anonymous function".) – orome Feb 17 '20 at 18:51
@HenrikSchumacher Fixed. – orome Feb 17 '20 at 21:01
Does this answer your question? Why does the documentation call functions "pure"? – MarcoB Feb 18 '20 at 02:16
@MarcoB See previous comments: it answers my side question. – orome Feb 18 '20 at 02:34
@MarcoB And it is precisely because of this that the answer to my question is not "easily found in the documentation", and stands. – orome Feb 18 '20 at 14:49

Can Wolfram Language enforce pure functions?

0 Answers0