The REPL (read, eval, print, loop) can be useful both for learning about langur and for development.

Build and run the REPL from langur/repl/main.go (not langur/main.go). Within this source file, you can determine what you want the REPL to return by editing the Go constants (which appear something like what are shown below).

const ( PROMPT = ">> " printLexTokens = false printParseTokenRepresentation = true printParseNodes = true printCompiledInstructions = true printCompiledConstants = true printVmResultEscaped = true printVmResultGoEscaped = false printVmResultRaw = false )

minimal execution

Minimal execution may be used to test early stages of development of a feature.

If you do not print the VM result, the VM will not be run.

So it goes for the compiler and parser. Each is only run if necessary.

REPL commands

exit cleanly exits the REPL
list lists built-in functions with descriptions
reset resets the environment for the REPL