Fuzion • Idioms • Idiom # 36: First-class function : generic composition

Idiom # 36: First-class function : generic composition

Code

Using manual function composition:

compose(A,B,C type,
        f A -> B,
        g B -> C) A -> C => a -> g (f a)

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compose(A,B,C type,
        f A -> B,
        g B -> C) A -> C => a -> g (f a)
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
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What are effects?

Using Function.compose:

compose(A,B,C type,
        f A -> B,
        g B -> C) A -> C => a -> g (f a)

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compose(A,B,C type,
        f A -> B,
        g B -> C) A -> C => a -> g (f a)
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
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What are effects?

Running Example

Using manual function composition:

ex36 is

  compose(A,B,C type,
          f0 A -> B,
          g0 B -> C) A -> C => a -> g0 (f0 a)

  f i32  -> bool   := a -> a > 3
  g bool -> String := b -> if b then "T" else "F"

  fog := compose f g

  say (fog 10)
  say (fog 2)
  say (fog 0)

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ex36 is
  compose(A,B,C type,
          f0 A -> B,
          g0 B -> C) A -> C => a -> g0 (f0 a)
  f i32  -> bool   := a -> a > 3
  g bool -> String := b -> if b then "T" else "F"
  fog := compose f g
  say (fog 10)
  say (fog 2)
  say (fog 0)
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
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What are effects?

Using Function.compose:

ex36a is

  compose(A,B,C type,
          f0 A -> B,
          g0 B -> C) => g0 ∘ f0

  f i32  -> bool   := a -> a > 3
  g bool -> String := b -> if b then "T" else "F"

  fog := compose f g

  say (fog 10)
  say (fog 2)
  say (fog 0)

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ex36a is
  compose(A,B,C type,
          f0 A -> B,
          g0 B -> C) => g0 ∘ f0
  f i32  -> bool   := a -> a > 3
  g bool -> String := b -> if b then "T" else "F"
  fog := compose f g
  say (fog 10)
  say (fog 2)
  say (fog 0)
 
 
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
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What are effects?

last changed: 2024-07-01

next: Idiom # 37: Currying