Create basic REPL module

lib/include/repl.h

@@ -0,0 +1,35 @@
+#ifndef REPL_H
+#define REPL_H
+
+#include "memory_pool.h"
+
+#define REPL_LINE_BUFFER_SIZE 128
+#define REPL_RESULT_BUFFER_SIZE 128
+
+typedef enum {
+	REPL_OK,
+	REPL_ERROR,
+	REPL_EXIT,
+} repl_status_t;
+
+typedef int (*get_byte_fn_t)(void);
+typedef const expression_t *(*read_fn_t)(
+    memory_pool_t *pool, const char *input, int len);
+typedef int (*evaluate_fn_t)(const expression_t *expression);
+typedef void (*print_fn_t)(const char *output, int len);
+
+typedef struct {
+	get_byte_fn_t get_byte;
+	read_fn_t read;
+	evaluate_fn_t evaluate;
+	print_fn_t print;
+	memory_pool_t pool;
+	char line_buffer[REPL_LINE_BUFFER_SIZE];
+	char result_buffer[REPL_RESULT_BUFFER_SIZE];
+} repl_t;
+
+void init_repl(repl_t *repl);
+void step_repl(repl_t *repl);
+void run_repl(repl_t *repl);
+
+#endif