Difference between revisions of "Sum Scan With Tail Recursion Assignment"
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(Created page with "=Motivation= Gain experience with converting from head recursion to tail recursion with a twist. Taking the standard simple approach would leave with you with a result opposi...") |
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=A Sting In the Tail= | =A Sting In the Tail= | ||
Everything does not always goes perfectly smoothly on the jouney to the land of [https://xkcd.com/1270/ tail recursion]. Some operations are transitive (for example: + and *) and they can be performed in either order. This is not the case for [https://smlfamily.github.io/Basis/list.html#SIG:LIST.:::TY list construction with ::]. | Everything does not always goes perfectly smoothly on the jouney to the land of [https://xkcd.com/1270/ tail recursion]. Some operations are transitive (for example: + and *) and they can be performed in either order. This is not the case for [https://smlfamily.github.io/Basis/list.html#SIG:LIST.:::TY list construction with ::]. | ||
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+ | You will likely be left to decide between taking: | ||
+ | * the dreaded road that leads to n^2 of [https://smlfamily.github.io/Basis/list.html#SIG:LIST.@:VAL concatenation via @], or | ||
+ | * going the way of the [https://www.pnas.org/content/110/43/17404 Jeholornis]. | ||
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=Code to Implement= | =Code to Implement= | ||
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{{SMLToImplement|sum_scan_tail|sum_scan_tail|warmup_sum_scan_tail}} | {{SMLToImplement|sum_scan_tail|sum_scan_tail|warmup_sum_scan_tail}} | ||
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=Test= | =Test= | ||
{{SMLUnitTest|sum_scan_tail|warmup_sum_scan_tail}} | {{SMLUnitTest|sum_scan_tail|warmup_sum_scan_tail}} |
Revision as of 21:25, 7 February 2022
Motivation
Gain experience with converting from head recursion to tail recursion with a twist. Taking the standard simple approach would leave with you with a result opposite of the desired order.
A Sting In the Tail
Everything does not always goes perfectly smoothly on the jouney to the land of tail recursion. Some operations are transitive (for example: + and *) and they can be performed in either order. This is not the case for list construction with ::.
You will likely be left to decide between taking:
- the dreaded road that leads to n^2 of concatenation via @, or
- going the way of the Jeholornis.
Code to Implement
Reimplement Sum Scan with tail recursion.
file: | src/main/sml/warmup_sum_scan_tail/sum_scan_tail.sml | |
functions: | sum_scan_tail |
Test
file: | unit_test_sum_scan_tail.sml | |
source folder: | src/test/sml/warmup_sum_scan_tail |