/**
* The read-eval-print loop, which can take input from a console, command line expression or a
* file. There are two ways the repl can terminate:
*
* <ol>
* <li>A {@code quit} command is executed successfully, which case the system exits from the
* {@link Quit} {@code .Internal} .
* <li>EOF on the input.
* </ol>
*
* In case 2, we must implicitly execute a {@code quit("default, 0L, TRUE} command before exiting.
* So,in either case, we never return.
*/
static int readEvalPrint(PolyglotEngine vm) {
int lastStatus = 0;
ContextInfo contextInfo = ContextInfo.getContextInfo(vm);
ConsoleHandler consoleHandler = contextInfo.getConsoleHandler();
try {
// console.println("initialize time: " + (System.currentTimeMillis() - start));
REPL:
for (; ; ) {
boolean doEcho = doEcho(vm);
consoleHandler.setPrompt(doEcho ? "> " : null);
try {
String input = consoleHandler.readLine();
if (input == null) {
throw new EOFException();
}
String trInput = input.trim();
if (trInput.equals("") || trInput.charAt(0) == '#') {
// nothing to parse
continue;
}
String continuePrompt = getContinuePrompt();
StringBuffer sb = new StringBuffer(input);
Source source = RSource.fromTextInternal(sb.toString(), RSource.Internal.SHELL_INPUT);
while (true) {
lastStatus = 0;
try {
try {
vm.eval(source);
// checked exceptions are wrapped in RuntimeExceptions
} catch (RuntimeException e) {
if (e.getCause() instanceof com.oracle.truffle.api.vm.IncompleteSourceException) {
throw e.getCause().getCause();
}
throw e;
}
} catch (IncompleteSourceException e) {
// read another line of input
consoleHandler.setPrompt(doEcho ? continuePrompt : null);
String additionalInput = consoleHandler.readLine();
if (additionalInput == null) {
throw new EOFException();
}
sb.append(additionalInput);
source = RSource.fromTextInternal(sb.toString(), RSource.Internal.SHELL_INPUT);
// The only continuation in the while loop
continue;
} catch (ParseException e) {
e.report(consoleHandler);
lastStatus = 1;
} catch (RError e) {
// drop through to continue REPL and remember last eval was an error
lastStatus = 1;
} catch (JumpToTopLevelException e) {
// drop through to continue REPL
} catch (DebugExitException e) {
throw (RuntimeException) e.getCause();
} catch (ExitException e) {
// usually from quit
int status = e.getStatus();
if (contextInfo.getParent() == null) {
vm.dispose();
Utils.systemExit(status);
} else {
return status;
}
} catch (Throwable e) {
RInternalError.reportErrorAndConsoleLog(e, consoleHandler, 0);
// We continue the repl even though the system may be broken
lastStatus = 1;
}
continue REPL;
}
} catch (UserInterruptException e) {
// interrupted by ctrl-c
}
}
} catch (JumpToTopLevelException | EOFException ex) {
// JumpToTopLevelException can happen if user profile invokes browser (unlikely but
// possible)
try {
vm.eval(QUIT_EOF);
} catch (JumpToTopLevelException e) {
Utils.systemExit(0);
} catch (ExitException e) {
// normal quit, but with exit code based on lastStatus
if (contextInfo.getParent() == null) {
Utils.systemExit(lastStatus);
} else {
return lastStatus;
}
} catch (Throwable e) {
throw RInternalError.shouldNotReachHere(e);
}
} finally {
vm.dispose();
}
return 0;
}
