diff --git a/nix-repl.cc b/nix-repl.cc index 1077f5d8f..3834e572a 100644 --- a/nix-repl.cc +++ b/nix-repl.cc @@ -41,7 +41,7 @@ struct NixRepl NixRepl(const Strings & searchPath); void mainLoop(const Strings & files); void completePrefix(string prefix); - bool getLine(string & line); + bool getLine(string & input, const char * prompt); bool processLine(string line); void loadFile(const Path & path); void initEnv(); @@ -96,21 +96,35 @@ void NixRepl::mainLoop(const Strings & files) using_history(); read_history(0); + string input; + while (true) { - string line; - if (!getLine(line)) { + // When continuing input from previous lines, don't print a prompt, just align to the same + // number of chars as the prompt. + const char * prompt = input.empty() ? "nix-repl> " : " "; + if (!getLine(input, prompt)) { std::cout << std::endl; break; } try { - if (!processLine(removeWhitespace(line))) return; + if (!processLine(input)) return; + } catch (ParseError & e) { + if (e.msg().find("unexpected $end") != std::string::npos) { + // For parse errors on incomplete input, we continue waiting for the next line of + // input without clearing the input so far. + continue; + } else { + printMsg(lvlError, "error: " + e.msg()); + } } catch (Error & e) { printMsg(lvlError, "error: " + e.msg()); } catch (Interrupted & e) { printMsg(lvlError, "error: " + e.msg()); } + // We handled the current input fully, so we should clear it and read brand new input. + input.clear(); std::cout << std::endl; } } @@ -149,7 +163,7 @@ char * completerThunk(const char * s, int state) } -bool NixRepl::getLine(string & line) +bool NixRepl::getLine(string & input, const char * prompt) { struct sigaction act, old; act.sa_handler = sigintHandler; @@ -158,15 +172,17 @@ bool NixRepl::getLine(string & line) if (sigaction(SIGINT, &act, &old)) throw SysError("installing handler for SIGINT"); - if (sigsetjmp(sigintJmpBuf, 1)) - line = ""; - else { + if (sigsetjmp(sigintJmpBuf, 1)) { + input.clear(); + } else { curRepl = this; rl_completion_entry_function = completerThunk; - char * s = readline("nix-repl> "); + char * s = readline(prompt); if (!s) return false; - line = chomp(string(s)); + string line = chomp(string(s)); + input.append(removeWhitespace(line)); + input.push_back('\n'); free(s); if (line != "") { add_history(line.c_str()); @@ -270,7 +286,7 @@ bool NixRepl::processLine(string line) string command, arg; if (line[0] == ':') { - size_t p = line.find(' '); + size_t p = line.find_first_of(" \n\r\t"); command = string(line, 0, p); if (p != string::npos) arg = removeWhitespace(string(line, p)); } else {