swift -frontend -replなんてのがあったのね。
$ swift -frontend -repl *** You are running Swift's integrated REPL, *** *** intended for compiler and stdlib *** *** development and testing purposes only. *** *** The full REPL is built as part of LLDB. *** *** Type ':help' for assistance. *** (swift) :help Available commands: :quit - quit the interpreter (you can also use :exit or Control+D or exit(0)) :autoindent (on|off) - turn on/off automatic indentation of bracketed lines :constraints debug (on|off) - turn on/off the debug output for the constraint-based type checker :dump_ir - dump the LLVM IR generated by the REPL :dump_ast - dump the AST representation of the REPL input :dump_decl <name> - dump the AST representation of the named declarations :dump_source - dump the user input (ignoring lines with errors) :print_decl <name> - print the AST representation of the named declarations :print_module <name> - print the decls in the given module, but not submodules API documentation etc. will be here eventually. (swift)