Scan Higher Order Function Assignment
Revision as of 03:02, 11 October 2022 by Dennis.cosgrove (talk | contribs) (→val scan = fn : ('a * 'a -> 'a) -> 'a list -> 'a list)
Contents
Background
Previously, we have built sum_scan. This is a specific version of scan where the operation is +. We will build a higher-order function scan which takes an operation to apply, as well as a list.
Code To Implement
| file: | src/main/sml/scan/scan.sml |  |
| functions: | scan |
val scan = fn : ('a * 'a -> 'a) -> 'a list -> 'a list
Note: this function is not provided with an initial identity value.
Note: this higher-order function is curried.
fun scan operation xs
Example Clients
int
scan op+
For example:
scan op+ [131,231,425]
would produce:
[131, 362, 787]
xs 131 231 425 scan op+ xs 131 362 787
scan op*
For example:
scan op* [131,231,425]
would produce:
[131, 30261, 12860925]
xs 131 231 425 scan op* xs 131 30261 12860925
set
scan intersection
For example:
scan intersection [fromList([1,2,3,4,5]), fromList([2,3,4]), fromList([0,1,2]), fromList([231,425])]
would produce:
[fromList([1,2,3,4,5]), fromList([2,3,4]), fromList([2]), empty]
xs {1,2,3,4,5} {2,3,4} {0,1,2} {231,425} scan intersection xs {1,2,3,4,5} {2,3,4} {2} {}
scan union
For example:
scan intersection [fromList([1,2,3,4,5]), fromList([2,3,4]), fromList([0,1,2]), fromList([231,425])]
would produce:
[fromList([1,2,3,4,5]), fromList([1,2,3,4,5]), fromList([0,1,2,3,4,5]), fromList([0,1,2,3,4,5,231,425])]
xs {1,2,3,4,5} {2,3,4} {0,1,2} {231,425} scan union xs {1,2,3,4,5} {1,2,3,4,5} {0,1,2,3,4,5} {0,1,2,3,4,5,231,425}
Test
| source folder: | src/test/sml/scan |
| how to run with CM.make verbosity off: | sml -Ccm.verbose=false run_scan_testing.sml |
| how to run with CM.make verbosity on: | sml run_scan_testing.sml |
note: ensure that you have removed all printing to receive credit for any assignment.
