Interactive REPL engine for Vix.

Vix Reply powers the interactive vix and vix repl experience. It provides a fast shell for expressions, variables, JSON values, runtime helpers, and real C++ snippets powered by the Vix run pipeline.

Start the REPL:

vix

Or start it explicitly:

vix repl

Pass arguments to the REPL:

vix repl -- --port 8080 --mode dev

Inside the REPL:

Vix.args()

>>> println("Hello from Vix Reply")
Hello from Vix Reply

>>> 1 + 2 * 3
7

>>> name = "Vix"
name = "Vix"

>>> type(name)
string

Vix Reply can run real C++ snippets through vix run.

>>> :cpp
C++ mode. Type :run to execute or :cancel to exit.
cpp> #include <vix/print.hpp>
...   int main() {
...     vix::print("Hello from C++");
...   }
Hello from C++

You can also start a small Vix HTTP server from the REPL:

>>> :cpp
cpp> #include <vix.hpp>
...   using namespace vix;
...
...   int main() {
...     App app;
...
...     app.get("/", [](Request&, Response& res) {
...       res.send("Hello, world");
...     });
...
...     app.run(8080);
...   }

Then test it:

curl http://localhost:8080

• Interactive prompt
• Persistent history
• Line editing
• History navigation
• Basic math evaluation
• Variables and JSON values
• Function-style calls
• Runtime helpers through Vix
• Real C++ snippets powered by vix run

help
version
pwd
cd <dir>
clear
history
history clear
exit

:cpp       Enter C++ snippet mode
:run       Run the current C++ snippet
:cancel    Cancel C++ snippet mode

Vix Reply is not a full C++ interpreter.

C++ snippet mode writes the snippet to a temporary .cpp file and runs it through vix run. The code is validated by the real C++ compiler and uses the normal Vix build, diagnostics, and runtime behavior.

Full documentation is available here:

https://docs.vixcpp.com/cli/repl

#include <vix/reply/core/ReplFlow.hpp>

int repl_flow_run(const std::vector<std::string>& replArgs);

The Vix CLI uses this entry point to implement:

vix repl

• Interactive REPL prompt
• Persistent history
• Line editing
• History navigation
• Math evaluation
• Variables and JSON values
• Runtime helpers through Vix
• C++ snippet mode powered by vix run
• C++ snippets with normal Vix diagnostics
• Clean Ctrl+C behavior for long-running snippets
• Better autocomplete for variables and helpers
• Better multiline editing
• Snippet cache reuse
• Better C++ snippet session management
• More structured REPL diagnostics
• More runtime helpers

MIT