Capturing the current execution context

Author: lastcraft

interpreter.c

@@ -19,6 +19,7 @@ static Object *apply_built_in(Object *, Object *, ErrorHandler, Binding *);
 static Object *apply_lambda(Object *, Object *, ErrorHandler, Binding *);
 static Object *execute(Callable, Object *, ErrorHandler, Binding *);
 static void bind_parameters(Object *, Object *, ErrorHandler, Binding *);
+static void binding_writer(void *, Printf);
 
 void create_interpreter(void) {
     declare_nil();
@@ -41,6 +42,14 @@ Binding *top_level(void) {
     return top_level_binding;
 }
 
+void declare_binding(void) {
+    binding_type = declare("Binding", (Free)free_binding, binding_writer);
+}
+
+Object *capture_binding(Binding *binding) {
+    return wrap(binding_type, binding);
+}
+
 Object *eval(Object *object, ErrorHandler error, Binding *binding) {
     Object *result;
     create_local();
@@ -148,3 +157,7 @@ static void bind_parameters(Object *parameters, Object *arguments, ErrorHandler
     add(binding, (char *)value(car(parameters)), clone(car(arguments)));
     bind_parameters(cdr(parameters), cdr(arguments), error, binding);
 }
+
+static void binding_writer(void *binding, Printf printer) {
+    printer("<Binding>");
+}

interpreter.h

@@ -5,9 +5,13 @@
 #include "exception.h"
 #include "binding.h"
 
+Type *binding_type;
+
 void create_interpreter(void);
 void free_interpreter(void);
 Binding *top_level(void);
+void declare_binding(void);
+Object *capture_binding(Binding *);
 Object *eval(Object *, ErrorHandler, Binding *);
 Object *apply(Object *, Object *, ErrorHandler, Binding *);
 

type.h

@@ -6,6 +6,7 @@
 typedef struct Object_ Object;
 typedef struct Type_ Type;
 typedef int (*Printf)(char *, ...);
+typedef void (*Free)(void *);
 
 Type *declare(char *name, void (*destructor)(void *), void (*writer)(void *, Printf));
 Object *wrap(Type *, void *);