Cons now allocates String objects when outputting string form. Added

support for begin expressions and tweaked the GC to be more aggressive.

ruamoko/scheme/Compiler.r

@@ -11,6 +11,7 @@ Symbol quoteSym;
 Symbol defineSym;
 Symbol ifSym;
 Symbol letrecSym;
+Symbol beginSym;
 
 @implementation Compiler
 + (void) initialize
@@ -25,6 +26,8 @@ Symbol letrecSym;
     [ifSym retain];
     letrecSym = symbol("letrec");
     [letrecSym retain];
+    beginSym = symbol("begin");
+    [beginSym retain];
 }
 
 + (id) newWithLambda: (SchemeObject) xp scope: (Scope) sc
@@ -236,6 +239,8 @@ Symbol letrecSym;
                     [self emitIf: [expression cdr] flags: fl];
             } else if ([expression car] == letrecSym) {
                     [self emitLetrec: [expression cdr] flags: fl];
+            } else if ([expression car] == beginSym) {
+                    [self emitSequence: [expression cdr] flags: fl];
             } else {
                     [self emitApply: expression flags: fl];
             }

ruamoko/scheme/Cons.r

@@ -2,6 +2,7 @@
 #include "Cons.h"
 #include "Nil.h"
 #include "defs.h"
+#include "SchemeString.h"
 
 Cons cons (SchemeObject car, SchemeObject cdr)
 {
@@ -75,7 +76,7 @@ BOOL isList (SchemeObject ls)
 
 - (string) printForm
 {
-    local string acc = "", res;
+    local string acc = "";
     local id cur, next = NIL;
 
     for (cur = self; cur; cur = next) {
@@ -91,9 +92,7 @@ BOOL isList (SchemeObject ls)
             }
     }
 
-    res = str_new();
-    str_copy(res, sprintf("(%s)", acc));
-    return res;
+    return [[String newFromString: sprintf("(%s)", acc)] stringValue];
 }
 
 @end

ruamoko/scheme/SchemeObject.r

@@ -14,7 +14,7 @@ typedef enum {
 gc_state_e gc_state;
 integer checkpoint;
 
-#define GC_AMOUNT 200
+#define GC_AMOUNT 100
 
 @implementation SchemeObject