Question

Are the following two function definitions equivalent? head1 [] = error "No head for empty lists!" head1 (x:_) = x head2 xs = case xs of [] -> error "No head for empty lists!" (x:_) -> x never always sometimes only for empty lists

Name: are the following two function definitions equivalent head1 error no head for empty lists head1 x x head2 xs case xs of error no head for empty lists x x never always sometimes only for em 98273
Uploaded: 2024-06-09T23:28:57-08:00
Duration: 2 min 32 s
Channel: Vincenzo Zaccaro
Description: are the following two function definitions equivalent head1 error no head for empty lists head1 x x head2 xs case xs of error no head for empty lists x x never always sometimes only for em 98273

          Are the following two function definitions equivalent?
head1 [] = error "No head for empty lists!"
head1 (x:_) = x
head2 xs = case xs of [] -> error "No head for empty lists!"
(x:_) -> x
never
always
sometimes
only for empty lists

are the following two function definitions equivalent head1 error no head for empty lists head1 x x head2 xs case xs of error no head for empty lists x x never always sometimes only for em 98273

Added by Julie A.

Computer Science and Information Technology

Trishna Knowledge Systems 2018 Edition

Instant Answer

Solved by Expert Vincenzo Zaccaro

06/09/2024

Step 1

Both functions aim to return the head (first element) of a list. If the list is empty, they both return an error message. Show more…

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Are the following two function definitions equivalent? head1 [] = error "No head for empty lists!" head1 (x:_) = x head2 xs = case xs of [] -> error "No head for empty lists!" (x:_) -> x never always sometimes only for empty lists