Lisp: Add source

src/step0_repl.cpp

@@ -0,0 +1,44 @@
+#include <cstdio>
+#include <iostream> // std::cin
+#include <string>   // std::getline
+#include <string_view>
+
+#if 0
+auto read(std::string_view data) -> std::string_view
+{
+	return data;
+}
+
+auto eval(std::string_view data) -> std::string_view
+{
+	return data;
+}
+
+auto print(std::string_view data) -> void
+{
+	printf("%s\n", data.data());
+}
+
+auto rep(std::string_view data) -> void
+{
+	print(eval(read(data)));
+}
+
+auto main() -> int
+{
+	while (true) {
+		printf("user> ");
+		std::string line;
+		std::getline(std::cin, line);
+
+		// Exit with Ctrl-D
+		if (std::cin.eof() || std::cin.fail()) {
+			break;
+		}
+
+		rep(line);
+	}
+
+	return 0;
+}
+#endif