Mixing
Passing a reference to a function in SML
i would like to pass a reference to a function foo in sml and change its value. consider the following scenario:
val x = ref 5;
foo 3 x;
(* now x will be 3 *)
is it possible in sml? i know that sml does not have variables so i am not sure its possible. i would like to do that way in order to create tests such as:
val test1 = (foo (seq 2) = 2);
val test2 = (foo it = 2);
it won't work because it will contain the output of test1 (its boolean value). i would like to pass a reference x and change it every single time.
val x = ref 0;
val test1 = (foo (seq 2) x = 2);
val test2 = (foo (getnext(!x)) x = 3);
val test3 = (foo (getnext(!x)) x = 4);
val test4 = (foo (getnext(!x)) x = 5);
getnext will get the next value and foo will insert it into x, beside from returning the value so it can check the equality.
sml
asked Jan 2 at 0:35
TTaJTa4TTaJTa4
366111
add a comment |
i would like to pass a reference to a function foo in sml and change its value. consider the following scenario:
val x = ref 5;
foo 3 x;
(* now x will be 3 *)
is it possible in sml? i know that sml does not have variables so i am not sure its possible. i would like to do that way in order to create tests such as:
val test1 = (foo (seq 2) = 2);
val test2 = (foo it = 2);
it won't work because it will contain the output of test1 (its boolean value). i would like to pass a reference x and change it every single time.
val x = ref 0;
val test1 = (foo (seq 2) x = 2);
val test2 = (foo (getnext(!x)) x = 3);
val test3 = (foo (getnext(!x)) x = 4);
val test4 = (foo (getnext(!x)) x = 5);
getnext will get the next value and foo will insert it into x, beside from returning the value so it can check the equality.
sml
asked Jan 2 at 0:35
TTaJTa4TTaJTa4
366111
Leaving aside the other questions, threading a mutable state through individual unit tests is always a Bad Idea(TM). Make your unit tests set up their data independently, your future self will thank you. Try an existing unit testing module to make things slightly easier, e.g. github.com/kvalle/sml-testing
– Yawar
Jan 2 at 4:24
add a comment |
i would like to pass a reference to a function foo in sml and change its value. consider the following scenario:
val x = ref 5;
foo 3 x;
(* now x will be 3 *)
is it possible in sml? i know that sml does not have variables so i am not sure its possible. i would like to do that way in order to create tests such as:
val test1 = (foo (seq 2) = 2);
val test2 = (foo it = 2);
it won't work because it will contain the output of test1 (its boolean value). i would like to pass a reference x and change it every single time.
val x = ref 0;
val test1 = (foo (seq 2) x = 2);
val test2 = (foo (getnext(!x)) x = 3);
val test3 = (foo (getnext(!x)) x = 4);
val test4 = (foo (getnext(!x)) x = 5);
getnext will get the next value and foo will insert it into x, beside from returning the value so it can check the equality.
sml
asked Jan 2 at 0:35
TTaJTa4TTaJTa4
366111
i would like to pass a reference to a function foo in sml and change its value. consider the following scenario:
val x = ref 5;
foo 3 x;
(* now x will be 3 *)
is it possible in sml? i know that sml does not have variables so i am not sure its possible. i would like to do that way in order to create tests such as:
val test1 = (foo (seq 2) = 2);
val test2 = (foo it = 2);
it won't work because it will contain the output of test1 (its boolean value). i would like to pass a reference x and change it every single time.
val x = ref 0;
val test1 = (foo (seq 2) x = 2);
val test2 = (foo (getnext(!x)) x = 3);
val test3 = (foo (getnext(!x)) x = 4);
val test4 = (foo (getnext(!x)) x = 5);
getnext will get the next value and foo will insert it into x, beside from returning the value so it can check the equality.
sml
sml
asked Jan 2 at 0:35
TTaJTa4TTaJTa4
366111
asked Jan 2 at 0:35
TTaJTa4TTaJTa4
366111
asked Jan 2 at 0:35
TTaJTa4TTaJTa4
366111
asked Jan 2 at 0:35
TTaJTa4TTaJTa4
366111
asked Jan 2 at 0:35
TTaJTa4TTaJTa4
366111
366111
Leaving aside the other questions, threading a mutable state through individual unit tests is always a Bad Idea(TM). Make your unit tests set up their data independently, your future self will thank you. Try an existing unit testing module to make things slightly easier, e.g. github.com/kvalle/sml-testing
– Yawar
Jan 2 at 4:24
add a comment |
Leaving aside the other questions, threading a mutable state through individual unit tests is always a Bad Idea(TM). Make your unit tests set up their data independently, your future self will thank you. Try an existing unit testing module to make things slightly easier, e.g. github.com/kvalle/sml-testing
– Yawar
Jan 2 at 4:24
Leaving aside the other questions, threading a mutable state through individual unit tests is always a Bad Idea(TM). Make your unit tests set up their data independently, your future self will thank you. Try an existing unit testing module to make things slightly easier, e.g. github.com/kvalle/sml-testing
– Yawar
Jan 2 at 4:24
Leaving aside the other questions, threading a mutable state through individual unit tests is always a Bad Idea(TM). Make your unit tests set up their data independently, your future self will thank you. Try an existing unit testing module to make things slightly easier, e.g. github.com/kvalle/sml-testing
– Yawar
Jan 2 at 4:24
add a comment |
1 Answer
1
active
oldest
votes
What's wrong with
fun foo v r = (r := v; v)
?
answered Jan 2 at 9:37
Andreas RossbergAndreas Rossberg
27k24865
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
What's wrong with
fun foo v r = (r := v; v)
?
answered Jan 2 at 9:37
Andreas RossbergAndreas Rossberg
27k24865
add a comment |
What's wrong with
fun foo v r = (r := v; v)
?
answered Jan 2 at 9:37
Andreas RossbergAndreas Rossberg
27k24865
add a comment |
What's wrong with
fun foo v r = (r := v; v)
?
answered Jan 2 at 9:37
Andreas RossbergAndreas Rossberg
27k24865
What's wrong with
fun foo v r = (r := v; v)
?
answered Jan 2 at 9:37
Andreas RossbergAndreas Rossberg
27k24865
answered Jan 2 at 9:37
Andreas RossbergAndreas Rossberg
27k24865
answered Jan 2 at 9:37
Andreas RossbergAndreas Rossberg
27k24865
answered Jan 2 at 9:37
Andreas RossbergAndreas Rossberg
27k24865
27k24865
add a comment |
add a comment |
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Leaving aside the other questions, threading a mutable state through individual unit tests is always a Bad Idea(TM). Make your unit tests set up their data independently, your future self will thank you. Try an existing unit testing module to make things slightly easier, e.g. github.com/kvalle/sml-testing
– Yawar
Jan 2 at 4:24