1 files changed, 67 insertions, 0 deletions
diff --git a/src/repl.c b/src/repl.c
new file mode 100644
index 0000000..236d9ec
--- /dev/null
+++ b/src/repl.c
@@ -0,0 +1,67 @@
+#include "repl.h"
+
+#include "ast.h"
+#include "object.h"
+#include "token.h"
+#include "vector.h"
+#include "parser.h"
+#include "eval.h"
+
+#define PROMPT ">> "
+
+static void
+print_parser_errors(FILE *out, struct vector *errors)
+{
+	size_t i;
+	char *msg;
+	vector_foreach(errors, i, msg) {
+		fprintf(out, "\t%s\n", msg);
+	}
+}
+
+void
+repl_start(FILE *in, FILE *out)
+{
+	char obuf[2048];
+	struct parser *parser = parser_new();
+	struct environment *env = environment_new();
+	struct vector *history = vector_new();
+	for (;;) {
+		fprintf(out, PROMPT);
+		char *input = malloc(1024);
+		if (!fgets(input, 1024, in)) {
+			if (ferror(in)) {
+				perror("REPL: can't read");
+				free(input);
+				goto end;
+			}
+			fprintf(out, "EOF\n");
+			free(input);
+			goto end;
+		}
+		parser_reset(parser, input);
+		struct program *prog = parser_parse_program(parser);
+		if (parser->errors->len > 0) {
+			print_parser_errors(out, parser->errors);
+			goto skip;
+		}
+		struct object *res = eval(env, prog);
+		if (res) {
+			fprintf(out, "%s\n", object_sprint(res, obuf));
+			object_unref(res);
+		}
+		vector_push(history, input);
+skip:
+		node_destroy(prog);
+	}
+
+end:;
+	size_t i;
+	char *input;
+	vector_foreach(history, i, input) {
+		free(input);
+	}
+	vector_free(history);
+	environment_destroy(env);
+	parser_destroy(parser);
+}