Lambda Expressions

Lambda expressions are an alternative way of writing anonymous functions.

Lua Way
pluto
local s1 = "123"
local s2 = s1:gsub(".", function(c) return tonumber(c) + 1 end)
print(s2) --> 234

Pluto Way
pluto
local s1 = "123"
local s2 = s1:gsub(".", |c| -> tonumber(c) + 1)
print(s2) --> 234

As you can see, they take an expression after the arrow, the result of which is implicitly returned.

However, lambda expressions can also have full bodies using do...end:

pluto
local add = |a, b| -> do
    print($"Adding {a} and {b} together")
    return a + b
end

They also support all other syntax you would expect of functions, such as type hints and default arguments.