Like the sibling mentions, yaegi seems to do that today (though I haven't used it).

The method I wrote about doesn't seem particularly any more conducive to making a REPL than progressively building a valid Go program with each line and compiling/running that (since Go's compiler is very fast).

However, there may be some benefits to prototyping in an environment like this where you can ignore types for a bit.

Yaegi is a full go interpreter with a repl: https://blog.containo.us/announcing-yaegi-263a1e2d070a

Gomacro provides an interactive REPL https://github.com/cosmos72/gomacro.