# Functions

sum'Source

- Sums a list of numbers of arbitrary type.
- Sparks the summation of
`(list-length / chunk-size)`

chunks from the list, each of the specified size (thought the last chunk may be smaller),
then recursively sums the list of results from each spark.
- CAVEAT: unless the numbers are large,
`Rational`

(requiring *cross-multiplication*), or the list long,
`sum`

is too light-weight for sparking to be productive,
therefore it is more likely to be the parallelised deep *evaluation* of list-elements which saves time.

sumRSource

- Sums a list of
*rational* numbers.
- Sparks the summation of
`(list-length / chunk-length)`

chunks from the list, each of the specified size (thought the last chunk may be smaller),
then recursively sums the list of results from each spark.
- CAVEAT: memory-use is proportional to chunk-size.