The pipe operator in Elixir

A honey harvest flows through map, filter, sum, and round without a nested call in sight.

# |> feeds the left result in as the first argument on the right.
harvest = [12.5, 8.0, 15.25, 6.75, 11.0]

total =
  harvest
  |> Enum.map(fn lbs -> lbs * 0.9 end)
  |> Enum.filter(fn lbs -> lbs > 7 end)
  |> Enum.sum()
  |> Float.round(1)

IO.puts("market-ready honey: #{total} lbs")
IO.puts("raw off the frames: #{Float.round(Enum.sum(harvest), 1)} lbs")

How it works

1. |> feeds each result in as the next call's first argument.
2. The chain scales each frame, drops the light ones, and folds the rest into one total.
3. The last line does one step without pipes, for the before-and-after.

Keywords and builtins used here

• Enum
• Float
• IO
• end
• fn

The run, in numbers

Lines

12

Characters to type

347

Tokens

92

Three-star pace

70 tpm

At the three-star pace of 70 tokens a minute, this run takes about 79 seconds.

Type this snippet

Step 3 of 3 in Enum & pipes, step 15 of 27 in Language basics.

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