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The problem here is that its inconvinient to define a function at the Elixir REPL because it demands that it be put inside a module. Clojure REPLS allow switch

The problem here is that its inconvinient to define a function at the Elixir REPL because it demands that it be put inside a module. Clojure REPLS allow switching the namespace, and anything you define goes intoo the current namespace. So it is more ergonomic.

tomjakubowski 5y ago
IEx will let you define a module at the REPL. Combine that with a macro (exercise for reader) in your .iex.exs which expands a function into a module definition and imports it and you're in business. iex(1)> defmodule Foo, do: def bar(x), do: x + 1 {:module, Foo, <<70, 79, 82, 49, 0, 0, 4, 192, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 135, 0, 0, 0, 15, 10, 69, 108, 105, 120, 105, 114, 46, 70, 111, 111, 8, 95, 95, 105, 110, 102, 111, 95, 95, 10, 97, 116, ...>>, {:bar, 1}} iex(2)> Foo.bar(1) 2 iex(3)> import Foo Foo iex(4)> bar(1) 2
- divs1210 5y ago
  Yup, like I said, not as ergonomic as Clojure. In clojure, it is: user> (defn bar [x] (+ x 1)) If you want it inside a namespace named foo, then it is: user> (in-ns 'foo) foo> (defn bar [x] (+ x 1))
  - jeremyjh 5y ago
    I agree Clojure has a better REPL experience than Elixir. But in Elixir REPL for a quick and dirty function you'd probably just do >bar = fn x -> x + 1 end The most unfortunate thing though is then you have to have a different calling convention. Its the greatest flaw in Elixir by far but they didn't have a reasonable alternative given the constraints of Erlang. Still for defining a named function in the REPL its the same in Haskell and most other languages I believe that you can't define a new named function or add a function to a module in the REPL, though at least in Haskell the calling convention for a variable bound to a lambda is the same as for a named top-level function. LISPs have always had a different notion of how the REPL integrates into the development experience of a running program, and I don't think its really been replicated elsewhere.
    - AlchemistCamp 5y ago
      Or maybe go with the shorter anonymous function syntax: bar = &(&1 + 1)
      - divs1210 5y ago
        If we're playing code golf, then in Clojure it is: (def bar #(+ % 1)) or even (def bar inc) but the difference is that in Clojure, all of these are `IFn`s, and have the same calling syntax, unlike Elixir.
        AlchemistCamp 5y ago
        You may be "playing code golf", but I generally just use the capture syntax where the compactness aids readability. For example, a function that takes two arguments and returns their product could be written as fn x, y -> x * y end or &(&1 * &2) When used inside a map or reduce or when the function is a direct mathematical operation on its arguments, it can be a bit quicker to parse the capture syntax than the fn ... end syntax.

tomjakubowski 5y ago

IEx will let you define a module at the REPL. Combine that with a macro (exercise for reader) in your .iex.exs which expands a function into a module definition and imports it and you're in business. iex(1)> defmodule Foo, do: def bar(x), do: x + 1 {:module, Foo, <<70, 79, 82, 49, 0, 0, 4, 192, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 135, 0, 0, 0, 15, 10, 69, 108, 105, 120, 105, 114, 46, 70, 111, 111, 8, 95, 95, 105, 110, 102, 111, 95, 95, 10, 97, 116, ...>>, {:bar, 1}} iex(2)> Foo.bar(1) 2 iex(3)> import Foo Foo iex(4)> bar(1) 2

divs1210 5y ago
Yup, like I said, not as ergonomic as Clojure. In clojure, it is: user> (defn bar [x] (+ x 1)) If you want it inside a namespace named foo, then it is: user> (in-ns 'foo) foo> (defn bar [x] (+ x 1))
- jeremyjh 5y ago
  I agree Clojure has a better REPL experience than Elixir. But in Elixir REPL for a quick and dirty function you'd probably just do >bar = fn x -> x + 1 end The most unfortunate thing though is then you have to have a different calling convention. Its the greatest flaw in Elixir by far but they didn't have a reasonable alternative given the constraints of Erlang. Still for defining a named function in the REPL its the same in Haskell and most other languages I believe that you can't define a new named function or add a function to a module in the REPL, though at least in Haskell the calling convention for a variable bound to a lambda is the same as for a named top-level function. LISPs have always had a different notion of how the REPL integrates into the development experience of a running program, and I don't think its really been replicated elsewhere.
  - AlchemistCamp 5y ago
    Or maybe go with the shorter anonymous function syntax: bar = &(&1 + 1)
    - divs1210 5y ago
      If we're playing code golf, then in Clojure it is: (def bar #(+ % 1)) or even (def bar inc) but the difference is that in Clojure, all of these are `IFn`s, and have the same calling syntax, unlike Elixir.
      - AlchemistCamp 5y ago
        You may be "playing code golf", but I generally just use the capture syntax where the compactness aids readability. For example, a function that takes two arguments and returns their product could be written as fn x, y -> x * y end or &(&1 * &2) When used inside a map or reduce or when the function is a direct mathematical operation on its arguments, it can be a bit quicker to parse the capture syntax than the fn ... end syntax.