diff --git a/src/lisp/compiler.h b/src/lisp/compiler.h
new file mode 100644
index 0000000..9342a12
--- /dev/null
+++ b/src/lisp/compiler.h
@@ -0,0 +1,51 @@
+#pragma once
+
+#include "lisp.h"
+#include <stdbool.h>
+
+struct function
+{
+	char *name;
+	int nargs; // number of arguments
+
+	union {
+		struct value (*def0) ();
+		struct value (*def1) (struct value);
+		struct value (*def2) (struct value, struct value);
+		struct value (*def3) (struct value, struct value, struct value);
+		void *code_ptr;
+		unsigned long code_addr;
+	};
+
+	struct function *prev;
+};
+
+struct environment
+{
+	struct function *first;
+};
+
+struct variable
+{
+	char *name;
+	int number;
+	struct variable *prev;
+};
+
+// local environment
+struct local
+{
+	// temps are accessed at ebp - 8 * (num_vars + temp)
+	bool temps[ 64 ];
+	int num_vars;
+	struct variable *first;
+};
+
+// First pass populates local
+void firstpass (struct value val, struct environment *env, struct local *local);
+// Second pass generates code
+void secondpass (struct value val, struct environment *env,
+                 struct local *local);
+void toplevel (struct value val, struct environment *env);
+void compile (struct istream *is);
+struct function *find_function (struct environment *env, char *name);