A (depricated) prototype for an interactive REPL for the Rust programming langauge
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Note: This is depricated, there is now a REPL called 'rusti' in the main rust repository.


This is an interactive read-eval-print-loop (REPL) for the Rust programming language[1] being developed by Mozilla. It hopes to eventually be a viable solution to issue #1120[2]. It works by presenting a prompt, reading input, then integraing with the compiler to compile it to a LLVM module which is then executed by the JIT compiler. If an expression was given, it will evaluate and print its result.

Some portions of the implementation were based on another repl by dbp[3], but unlike his version, this aims to be more tightly integrated with the compiler, and keep everything in memory rather than use temporary files.

As the language and libraries are rapidly evolving, this is meant to work with the latest git master revision of rust on github.

Current Status

This should work fine on Linux. On OS X 10.8, the LLVM JIT will fail to execute due to a symbol resolution error, like the following:

LLVM ERROR: Program used external function '__ZN4repr14__extensions__9meth_512712visit_constr17_2ecc45fa2680b4dc3_05E' which could not be resolved!

Also, the sysroot is manually set to "/usr/local/", if this is not correct for your machine, change the maybe_sysroot value in the options definition in run_input().

Future Goals

  • Use readline or something similar for getting input, managing history etc.
  • Identify input type based on how it parses instead of str::starts_with
  • Implement commands for the REPL similar to how GHCi handles :commands

[1] http://www.rust-lang.org/
[2] https://github.com/mozilla/rust/issues/1120
[3] https://github.com/dbp/rustrepl