IEx - Expose API to evaluate code inside IEx session for REPL Integrations

Chat & Discussions Proposals: Ideas
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3

Hi,

I think most of what you want is achievable with Code:

def iterative_eval(code, bindings \\ [], env \\ env_for_eval([])) do
  quoted = Code.string_to_quoted(code)
  Code.eval_quoted_with_env(quoted, bindings, env)
end

Which can be used as:

iex(5)> {result, bindings, env} = Repl.iterative_eval("a = 1"); :ok # Using this `:ok` to avoid printing env
:ok
iex(6)> {result, bindings, env} = Repl.iterative_eval("a + 2", bindings, env); :ok
:ok
iex(7)> result
{:ok, 3}
iex(8)> bindings
[a: 1]

It carries the env, hence it carries aliases, requires, etc. To use the env from iex, you can just use __ENV__:

iex(9)> alias Map, as: M
Map
iex(10)> {result, bindings, env} = Repl.iterative_eval("map = M.new()", [], __ENV__); :ok
:ok
iex(11)> result
{:ok, %{}}
iex(12)> bindings
[map: %{}]
iex(13)>

I don’t know if there’s a way to load these bindings/env back in iex, though.

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