Lean has numerous features, including:
Example:
-- Defines a function that takes a name and produces a greeting.
def getGreeting (name : String) := s!"Hello, {name}! Isn't Lean great?"
-- The `main` function is the entry point of your program.
-- Its type is `IO Unit` because it can perform `IO` operations (side effects).
def main : IO Unit :=
-- Define a list of names
let names := ["Sebastian", "Leo", "Daniel"]
-- Map each name to a greeting
let greetings := names.map getGreeting
-- Print the list of greetings
for greeting in greetings do
IO.println greeting
Last modified 06 April 2022