Allow binding variables at the REPL's toplevel in the same way the Nix
REPL does, using the syntax <ident> = <expr>. This fully, strictly
evaluates the value and sets it in the repl's "env", which gets passed
in at the toplevel when evaluating expressions.
The laziness behavior differs from Nix's, but I think this is good:
❯ nix repl
Welcome to Nix version 2.3.18. Type :? for help.
nix-repl> x = builtins.trace "x" 1
nix-repl> x
trace: x
1
nix-repl> x
1
vs tvix:
tvix-repl> x = builtins.trace "x" 1
trace: "x" :: string
tvix-repl> x
=> 1 :: int
tvix-repl> x
=> 1 :: int
Bug: https://b.tvl.fyi/issues/371
Change-Id: Ieb2d626b7195fa87be638c9a4dae2eee45eb9ab1
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11954
Reviewed-by: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
Autosubmit: aspen <root@gws.fyi>
