Difference between revisions of "Scan Higher Order Function Assignment"
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| {1,2,3,4,5} || {2,3,4} || {0,1,2} || {231,425} | | {1,2,3,4,5} || {2,3,4} || {0,1,2} || {231,425} | ||
|- | |- | ||
− | ! style="text-align:right;" | scan | + | ! style="text-align:right;" | scan intersection xs |
| {1,2,3,4,5} || {2,3,4} || {2} || {} | | {1,2,3,4,5} || {2,3,4} || {2} || {} | ||
|} | |} | ||
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| {1,2,3,4,5} || {2,3,4} || {0,1,2} || {231,425} | | {1,2,3,4,5} || {2,3,4} || {0,1,2} || {231,425} | ||
|- | |- | ||
− | ! style="text-align:right;" | scan | + | ! style="text-align:right;" | 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} | | {1,2,3,4,5} || {1,2,3,4,5} || {0,1,2,3,4,5} || {0,1,2,3,4,5,231,425} | ||
|} | |} |
Revision as of 09:19, 16 February 2022
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/warmup_scan/scan.sml | ![]() |
functions: | scan |
val scan = fn : ('a * 'a -> 'a) -> 'a list -> 'a list
Note: this higher-order function is curried.
fun scan operation xs
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([2,3,4]), fromList([2]), empty]
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
file: | unit_test_scan.sml | |
source folder: | src/test/sml/warmup_scan |