New "nubake" feature: easier baking into classes.

nubake accepts three new options:
	--method <methodname>
	--class <classname>
	--category <categoryname>

When these are provided, nubake produces a source file that adds
the named category to the named class. The category adds a method
that evaluates the baked Nu code and returns the result. The
purpose of this is to bake in code that can be evaluated from Nu.
The code is evaluated in the main Nu parser's context so that
macros and other objects can be made available to subsequent
Nu code.

Example:
% nubake server.nu --method macros --category Baked --class MyServer --output MyServer+Baked.m

tools/nubake

@@ -85,6 +85,38 @@ int main(int argc, char *argv[]) {
 	return 0;
 }
 END))
+        result)
+
+     ;; This bakes Nu code into a class method that expands and evaluates it in the main parser context.
+     ;; The purpose is to have methods like (MyClass macros) that can be called from Nu to install
+     ;; macros and other helpers that are written in Nu and baked into Objective-C.
+     (+ (id) bakeNuCode:(id)program intoMethod:(id) methodName ofCategory:(id) categoryName ofClass:(id) className is
+        (set result <<-END
+//
+// THIS FILE WAS AUTOMATICALLY GENERATED
+//
+// Regenerate it with nubake:
+//   nubake <sourcefile> --method #{methodName} --category #{categoryName} --class #{className}
+//
+#import <Foundation/Foundation.h>
+#ifdef TARGET_OS_IPHONE
+#import "Nu.h"
+#else
+#import <Nu/Nu.h>
+#endif
+#import "#{className}.h"
+
+@implementation #{className} (#{categoryName})
+
++ (id) #{methodName} {
+	NuCell *code = END)
+        (result appendString:(self expandNuExpression:program))
+        (result appendString:<<-END
+		;		
+	return [[Nu sharedParser] eval:code];	
+}
+@end
+		END)    
         result))
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;
@@ -105,6 +137,9 @@ END))
 (set sourceFileName nil)
 (set functionName nil)
 (set outputFileName nil)
+(set methodName nil)
+(set categoryName nil)
+(set className nil)
 (set standalone nil)
 
 ;; process the remaining arguments
@@ -113,6 +148,10 @@ END))
              ("-n" (set argi (+ argi 1)) (set functionName (argv argi)))
              ("-o" (set argi (+ argi 1)) (set outputFileName (argv argi)))
              ("-s" (set standalone t))
+             ("--output" (set argi (+ argi 1)) (set outputFileName (argv argi)))
+             ("--method" (set argi (+ argi 1)) (set methodName (argv argi)))
+             ("--category" (set argi (+ argi 1)) (set categoryName (argv argi)))
+             ("--class" (set argi (+ argi 1)) (set className (argv argi)))
              (else (set sourceFileName (argv argi))))
        (set argi (+ argi 1)))
 
@@ -123,15 +162,26 @@ END))
          (unless outputFileName
                  (set outputFileName (+ (sourceFileName stringByDeletingPathExtension) ".m")))
          (try
-             ((NuBake bakeNuCode:(parse (NSString stringWithContentsOfFile:sourceFileName
-                                             encoding:NSUTF8StringEncoding error:nil))
-                      intoFunction:functionName
-                      standalone:standalone)
-              writeToFile:outputFileName atomically:NO)
+             (set code (parse (NSString stringWithContentsOfFile:sourceFileName
+                                   encoding:NSUTF8StringEncoding error:nil)))
+             (puts methodName)
+             (puts categoryName)
+             (puts className)
+             (puts outputFileName)
+             (if (and methodName categoryName className)
+                 (then ((NuBake bakeNuCode:code
+                                intoMethod:methodName
+                                ofCategory:categoryName
+                                ofClass:className)
+                        writeToFile:outputFileName atomically:NO))
+                 (else ((NuBake bakeNuCode:code
+                                intoFunction:functionName
+                                standalone:standalone)
+                        writeToFile:outputFileName atomically:NO)))
              (catch (exception)
                     (puts "error: #{(exception reason)}")
                     (set exit (NuBridgedFunction functionWithName:"exit" signature:"vi"))
                     (exit -1))))
     (else
-         (puts "usage: nubake <sourcefile> [-n <functionname>] [-o <outputfilename>] [-s]")))
+         (puts "usage: nubake <sourcefile> [-n <functionname>] [-o <outputfilename>] [-s] or [--method <methodname> --class <classname> --category <categoryname>]")))