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Fuzion • Idioms • Idiom # 189: Filter and transform list

Idiom # 189: Filter and transform list

See programming-idioms.org:

Code

y := (x.filter P).map T

What are effects?

Running Example

ex189 is

  x := 0..                                 # all non-negative integers

  P i32 -> bool   := i -> i %% 3   # divisible by 3
  T i32 -> String := i -> "{i}² = {i*i}"

  y := (x.filter P).mapSequence T  # NYI: should be 'map', not 'mapSequence, see Fuzion #252'
  y.take 20 | e -> say e

  # alternatively, we can use 'infix &' instead of 'filter'
  y := (x & P).mapSequence T
  y.take 20 | e -> say e

  # NYI: This should be possible using pipe instead of 'map'
  #
  # y := x & P | T

What are effects?

next: NYI: Idiom # 190: Call an external C function