Histograms

In histogram.diesel:

A histogram supports accumulating counts for particular values and then printing out the results in a reasonable fashion. Abstractly, a histogram is a mapping from some domain of values to integers. The increment operation bumps the count associated with a particular value. To support the histogram's hash-table-based implementation, the values being counted by the histogram must be hashable. If the keys also are ordered, then nicer output is possible. The methods new_unsorted_histogram vs. new_histogram construct the two kinds of histograms.

extend module Stdlib;

module Histogram;
class histogram[T <= hashable[T]] isa hash_CR_table[T,integer];
  fun new_unsorted_histogram[T <= hashable[T]]():histogram[T];
  fun new_unsorted_histogram[T <= hashable[T]](t:string):histogram[T];
  fun increment(t:histogram[`T], x:T):void;
  fun increment_by_count(t:histogram[`T], x:T, cnt:integer):void;
  fun increment(t:histogram[`T], x:T, elem:any):void;
  fun print_statistics(t:histogram[`T]):string;
  fun print_statistics(t:histogram[`T], some_key:T|string):string;
  fun ordered_keys(t:histogram[`T]):collection[T];
  fun frequency_sorted_print_string(t:histogram[`T]):string;
  fun percent_print_string(t:histogram[`T]):string;
  fun truncated_percent_print_string(t:histogram[`T <= ordered[T]],
                                            over:T):string;
  fun unsorted_distribution[`T <= hashable[T]](
        nm:string, cl:&(increment:&(value:T):void,
                        add_value:&(value:T, elem:any):void):void
        ):histogram[T];
class sorted_histogram[T <= ordered_hashable[T]] isa histogram[T];
  fun new_histogram[T <= ordered_hashable[T]]():histogram[T];
  fun new_histogram[T <= ordered_hashable[T]](t:string):histogram[T];
  fun distribution[`T <= ordered_hashable[T]](
        nm:string,
        cl:&(increment:&(value:T):void,
             add_value:&(value:T, elem:any):void):void
        ):histogram[T];
  fun distribution(nm:string,
                          cl:&(increment:&(value:int):void,
                               add_value:&(value:int, elem:any):void):void
                          ):histogram[int];

end module Histogram;