convert testing to World.

start on Decl, but not working yet

R=austin
DELTA=762  (201 added, 205 deleted, 356 changed)
OCL=34335
CL=34349

8 files changed, 540 insertions, 544 deletions

diff --git a/usr/austin/eval/compiler.go b/usr/austin/eval/compiler.go
index b13cd298c..12cace9e0 100644
--- a/usr/austin/eval/compiler.go
+++ b/usr/austin/eval/compiler.go
@@ -41,8 +41,9 @@ func (a *compiler) numError() int {
 func newUniverse() *Scope {
 	sc := &Scope{nil, 0};
 	sc.block = &block{
-		offset: -1,
+		offset: 0,
 		scope: sc,
+		global: true,
 		defs: make(map[string] Def)
 	};
 	return sc;
diff --git a/usr/austin/eval/eval_test.go b/usr/austin/eval/eval_test.go
index 847a6f2fa..cd47a76e0 100644
--- a/usr/austin/eval/eval_test.go
+++ b/usr/austin/eval/eval_test.go
@@ -6,6 +6,7 @@ package eval
 
 import (
 	"bignum";
+	"flag";
 	"fmt";
 	"go/parser";
 	"go/scanner";
@@ -17,23 +18,23 @@ import (
 )
 
 // Print each statement or expression before parsing it
-const noisy = false
+var noisy = false
+func init() {
+	flag.BoolVar(&noisy, "noisy", false, "chatter during eval tests");
+}
 
 /*
  * Generic statement/expression test framework
  */
 
-type test struct {
-	code string;
-	rterr string;
-	exprs []exprTest;
-	cerr string;
-}
+type test []job
 
-type exprTest struct {
+type job struct {
 	code string;
-	val interface{};
+	cerr string;
 	rterr string;
+	val Value;
+	noval bool;
 }
 
 func runTests(t *testing.T, baseName string, tests []test) {
@@ -43,168 +44,102 @@ func runTests(t *testing.T, baseName string, tests []test) {
 	}
 }
 
-func (a *test) run(t *testing.T, name string) {
-	sc := newTestScope();
-
-	var fr *Frame;
-	var cerr os.Error;
-
-	if a.code != "" {
+func (a test) run(t *testing.T, name string) {
+	w := newTestWorld();
+	for _, j := range a {
+		src := j.code;
 		if noisy {
-			println(a.code);
+			println("code:", src);
 		}
 
-		// Compile statements
-		asts, err := parser.ParseStmtList(name, a.code);
-		if err != nil && cerr == nil {
-			cerr = err;
-		}
-		code, err := CompileStmts(sc, asts);
-		if err != nil && cerr == nil {
-			cerr = err;
-		}
-
-		// Execute statements
-		if cerr == nil {
-			fr = sc.NewFrame(nil);
-			rterr := code.Exec(fr);
-			if a.rterr == "" && rterr != nil {
-				t.Errorf("%s: expected %s to run, got runtime error %v", name, a.code, rterr);
-				return;
-			} else if !checkRTError(t, name, a.code, rterr, a.rterr) {
-				return;
+		code, err := w.Compile(src);
+		if err != nil {
+			if j.cerr == "" {
+				t.Errorf("%s: Compile %s: %v", name, src, err);
+				break;
 			}
+			if !match(t, err, j.cerr) {
+				t.Errorf("%s: Compile %s = error %s; want %v", name, src, err, j.cerr);
+				break;
+			}
+			continue;
 		}
-	}
-
-	if fr == nil {
-		fr = sc.NewFrame(nil);
-	}
-	for _, e := range a.exprs {
-		if cerr != nil {
+		if j.cerr != "" {
+			t.Errorf("%s: Compile %s succeeded; want %s", name, src, j.cerr);
 			break;
 		}
-
-		if noisy {
-			println(e.code);
-		}
-
-		// Compile expression
-		ast, err := parser.ParseExpr(name, e.code);
-		if err != nil && cerr == nil {
-			cerr = err;
-		}
-		code, err := CompileExpr(sc, ast);
-		if err != nil && cerr == nil {
-			cerr = err;
-		}
-
-		// Evaluate expression
-		if cerr == nil {
-			val, rterr := code.Eval(fr);
-			if e.rterr == "" && rterr != nil {
-				t.Errorf("%s: expected %q to have value %T(%v), got runtime error %v", name, e.code, e.val, e.val, rterr);
-			} else if !checkRTError(t, name, e.code, rterr, e.rterr) {
-				continue;
+		
+		val, err := code.Run();
+		if err != nil {
+			if j.rterr == "" {
+				t.Errorf("%s: Run %s: %v", name, src, err);
+				break;
 			}
-			if e.val != nil {
-				wantval := toValue(e.val);
-				if !reflect.DeepEqual(val, wantval) {
-					t.Errorf("%s: expected %q to have value %T(%v), got %T(%v)", name, e.code, wantval, wantval, val, val);
-				}
+			if !match(t, err, j.rterr) {
+				t.Errorf("%s: Run %s = error %s; want %v", name, src, err, j.rterr);
+				break;
 			}
+			continue;
 		}
-	}
-
-	// Check compile errors
-	switch {
-	case cerr == nil && a.cerr == "":
-		// Good
-	case cerr == nil && a.cerr != "":
-		t.Errorf("%s: expected compile error matching %q, got no errors", name, a.cerr);
-	case cerr != nil && a.cerr == "":
-		t.Errorf("%s: expected no compile error, got error %v", name, cerr);
-	case cerr != nil && a.cerr != "":
-		cerr := cerr.(scanner.ErrorList);
-		if len(cerr) > 1 {
-			t.Errorf("%s: expected 1 compile error matching %q, got %v", name, a.cerr, cerr);
+		if j.rterr != "" {
+			t.Errorf("%s: Run %s succeeded; want %s", name, src, j.rterr);
 			break;
 		}
-		m, err := testing.MatchString(a.cerr, cerr.String());
-		if err != "" {
-			t.Fatalf("%s: failed to compile regexp %q: %s", name, a.cerr, err);
-		}
-		if !m {
-			t.Errorf("%s: expected compile error matching %q, got compile error %v", name, a.cerr, cerr);
+	
+		if !j.noval && !reflect.DeepEqual(val, j.val) {
+			t.Errorf("%s: Run %s = %T(%v) want %T(%v)", name, src, val, val, j.val, j.val);
 		}
 	}
 }
 
-func checkRTError(t *testing.T, name string, code string, rterr os.Error, pat string) bool {
-	switch {
-	case rterr == nil && pat == "":
-		return true;
-		
-	case rterr == nil && pat != "":
-		t.Errorf("%s: expected %s to fail with runtime error matching %q, got no error", name, code, pat);
-		return false;
-
-	case rterr != nil && pat != "":
-		m, err := testing.MatchString(pat, rterr.String());
-		if err != "" {
-			t.Fatalf("%s: failed to compile regexp %q: %s", name, pat, err);
-		}
-		if !m {
-			t.Errorf("%s: expected runtime error matching %q, got runtime error %v", name, pat, rterr);
-			return false;
-		}
-		return true;
+func match(t *testing.T, err os.Error, pat string) bool {
+	ok, errstr := testing.MatchString(pat, err.String());
+	if errstr != "" {
+		t.Fatalf("compile regexp %s: %v", pat, errstr);
 	}
-	panic("rterr != nil && pat == \"\" should have been handled by the caller");
+	return ok;
 }
 
+
 /*
  * Test constructors
  */
 
 // Expression compile error
-func EErr(expr string, cerr string) test {
-	return test{"", "", []exprTest{exprTest{expr, nil, ""}}, cerr};
+func CErr(expr string, cerr string) test {
+	return test([]job{job{code: expr, cerr: cerr}})
 }
 
 // Expression runtime error
-func ERTErr(expr string, rterr string) test {
-	return test{"", "", []exprTest{exprTest{expr, nil, rterr}}, ""};
+func RErr(expr string, rterr string) test {
+	return test([]job{job{code: expr, rterr: rterr}})
 }
 
 // Expression value
 func Val(expr string, val interface{}) test {
-	return test{"", "", []exprTest{exprTest{expr, val, ""}}, ""};
-}
-
-// Statement compile error
-func SErr(stmts string, cerr string) test {
-	return test{stmts, "", nil, cerr};
-}
-
-// Statement runtime error
-func SRTErr(stmts string, rterr string) test {
-	return test{stmts, rterr, nil, ""};
+	return test([]job{job{code: expr, val: toValue(val)}})
 }
 
 // Statement runs without error
-func SRuns(stmts string) test {
-	return test{stmts, "", nil, ""};
+func Run(stmts string) test {
+	return test([]job{job{code: stmts, noval: true}})
 }
 
 // Statement runs and test one expression's value
 func Val1(stmts string, expr1 string, val1 interface{}) test {
-	return test{stmts, "", []exprTest{exprTest{expr1, val1, ""}}, ""};
+	return test([]job{
+		job{code: stmts, noval: true},
+		job{code: expr1, val: toValue(val1)}
+	})
 }
 
 // Statement runs and test two expressions' values
 func Val2(stmts string, expr1 string, val1 interface{}, expr2 string, val2 interface{}) test {
-	return test{stmts, "", []exprTest{exprTest{expr1, val1, ""}, exprTest{expr2, val2, ""}}, ""};
+	return test([]job{
+		job{code: stmts, noval: true},
+		job{code: expr1, val: toValue(val1)},
+		job{code: expr2, val: toValue(val2)}
+	})
 }
 
 /*
@@ -305,16 +240,14 @@ func (*voidFunc) NewFrame() *Frame {
 func (*voidFunc) Call(t *Thread) {
 }
 
-func newTestScope() *Scope {
-	sc := universe.ChildScope();
-	p := token.Position{"<testScope>", 0, 0, 0};
+func newTestWorld() *World {
+	w := NewWorld();
 
 	def := func(name string, t Type, val interface{}) {
-		v, _ := sc.DefineVar(name, p, t);
-		v.Init = toValue(val);
+		w.DefineVar(name, t, toValue(val));
 	};
 
-	sc.DefineConst("c", p, IdealIntType, toValue(bignum.Int(1)));
+	w.DefineConst("c", IdealIntType, toValue(bignum.Int(1)));
 	def("i", IntType, 1);
 	def("i2", IntType, 2);
 	def("u", UintType, uint(1));
@@ -329,5 +262,5 @@ func newTestScope() *Scope {
 	def("void", NewFuncType([]Type{}, false, []Type {}), &voidFunc{});
 	def("sli", NewSliceType(IntType), vslice{varray{1, 2, 3}, 2, 3});
 
-	return sc;
+	return w;
 }
diff --git a/usr/austin/eval/expr.go b/usr/austin/eval/expr.go
index a29373d6a..f24887bc2 100644
--- a/usr/austin/eval/expr.go
+++ b/usr/austin/eval/expr.go
@@ -336,8 +336,11 @@ func (a *assignCompiler) compile(b *block, lt Type) (func(Value, *Thread)) {
 	var effect func(*Thread);
 	if isUnpack {
 		// This leaks a slot, but is definitely safe.
-		temp := b.DefineSlot(a.rmt);
+		temp := b.DefineTemp(a.rmt);
 		tempIdx := temp.Index;
+		if tempIdx < 0 {
+			panicln("tempidx", tempIdx);
+		}
 		if a.isMapUnpack {
 			rf := a.rs[0].evalMapValue;
 			vt := a.rmt.Elems[0];
@@ -693,7 +696,7 @@ func (a *exprInfo) compileIdent(b *block, constant bool, callCtx bool, name stri
 			a.diag("variable %s used in constant expression", name);
 			return nil;
 		}
-		if bl.offset < 0 {
+		if bl.global {
 			return a.compileGlobalVariable(def);
 		}
 		return a.compileVariable(level, def);
@@ -1830,7 +1833,7 @@ func (a *expr) extractEffect(b *block, errOp string) (func(*Thread), *expr) {
 			log.Crashf("unexpected ideal type %v", tempType);
 		}
 	}
-	temp := b.DefineSlot(tempType);
+	temp := b.DefineTemp(tempType);
 	tempIdx := temp.Index;
 
 	// Create "temp := rhs"
@@ -1857,41 +1860,3 @@ func (a *expr) extractEffect(b *block, errOp string) (func(*Thread), *expr) {
 	}
 	return effect, deref;
 }
-
-/*
- * Public interface
- */
-
-type Expr struct {
-	e *expr;
-}
-
-func (expr *Expr) Type() Type {
-	return expr.e.t;
-}
-
-func (expr *Expr) Eval(f *Frame) (Value, os.Error) {
-	t := new(Thread);
-	t.f = f;
-	switch _ := expr.e.t.(type) {
-	case *idealIntType:
-		return &idealIntV{expr.e.asIdealInt()()}, nil;
-	case *idealFloatType:
-		return &idealFloatV{expr.e.asIdealFloat()()}, nil;
-	}
-	v := expr.e.t.Zero();
-	eval := genAssign(expr.e.t, expr.e);
-	err := t.Try(func(t *Thread){eval(v, t)});
-	return v, err;
-}
-
-func CompileExpr(scope *Scope, expr ast.Expr) (*Expr, os.Error) {
-	errors := scanner.NewErrorVector();
-	cc := &compiler{errors, 0, 0};
-
-	ec := cc.compileExpr(scope.block, false, expr);
-	if ec == nil {
-		return nil, errors.GetError(scanner.Sorted);
-	}
-	return &Expr{ec}, nil;
-}
diff --git a/usr/austin/eval/expr_test.go b/usr/austin/eval/expr_test.go
index 2b2dd9d4f..ea11cf69d 100644
--- a/usr/austin/eval/expr_test.go
+++ b/usr/austin/eval/expr_test.go
@@ -26,19 +26,19 @@ var hugeInteger = bignum.Int(1).Shl(64);
 
 var exprTests = []test {
 	Val("i", 1),
-	EErr("zzz", undefined),
+	CErr("zzz", undefined),
 	// TODO(austin) Test variable in constant context
-	//EErr("t", typeAsExpr),
+	//CErr("t", typeAsExpr),
 
 	Val("'a'", bignum.Int('a')),
 	Val("'\\uffff'", bignum.Int('\uffff')),
 	Val("'\\n'", bignum.Int('\n')),
-	EErr("''+x", badCharLit),
+	CErr("''+x", badCharLit),
 	// Produces two parse errors
-	//EErr("'''", ""),
-	EErr("'\n'", badCharLit),
-	EErr("'\\z'", illegalEscape),
-	EErr("'ab'", badCharLit),
+	//CErr("'''", ""),
+	CErr("'\n'", badCharLit),
+	CErr("'\\z'", illegalEscape),
+	CErr("'ab'", badCharLit),
 
 	Val("1.0", bignum.Rat(1, 1)),
 	Val("1.", bignum.Rat(1, 1)),
@@ -48,11 +48,11 @@ var exprTests = []test {
 	Val("\"abc\"", "abc"),
 	Val("\"\"", ""),
 	Val("\"\\n\\\"\"", "\n\""),
-	EErr("\"\\z\"", illegalEscape),
-	EErr("\"abc", "string not terminated"),
+	CErr("\"\\z\"", illegalEscape),
+	CErr("\"abc", "string not terminated"),
 
 	Val("\"abc\" \"def\"", "abcdef"),
-	EErr("\"abc\" \"\\z\"", illegalEscape),
+	CErr("\"abc\" \"\\z\"", illegalEscape),
 
 	Val("(i)", 1),
 
@@ -61,56 +61,56 @@ var exprTests = []test {
 	Val("ai[1]", 2),
 	Val("ai[i]", 2),
 	Val("ai[u]", 2),
-	EErr("ai[f]", opTypes),
-	EErr("ai[0][0]", opTypes),
-	EErr("ai[2]", "index 2 exceeds"),
-	EErr("ai[1+1]", "index 2 exceeds"),
-	EErr("ai[-1]", "negative index"),
-	ERTErr("ai[i+i]", "index 2 exceeds"),
-	ERTErr("ai[-i]", "negative index"),
-	EErr("i[0]", opTypes),
-	EErr("f[0]", opTypes),
+	CErr("ai[f]", opTypes),
+	CErr("ai[0][0]", opTypes),
+	CErr("ai[2]", "index 2 exceeds"),
+	CErr("ai[1+1]", "index 2 exceeds"),
+	CErr("ai[-1]", "negative index"),
+	RErr("ai[i+i]", "index 2 exceeds"),
+	RErr("ai[-i]", "negative index"),
+	CErr("i[0]", opTypes),
+	CErr("f[0]", opTypes),
 
 	Val("aai[0][0]", 1),
 	Val("aai[1][1]", 4),
-	EErr("aai[2][0]", "index 2 exceeds"),
-	EErr("aai[0][2]", "index 2 exceeds"),
+	CErr("aai[2][0]", "index 2 exceeds"),
+	CErr("aai[0][2]", "index 2 exceeds"),
 
 	Val("sli[0]", 1),
 	Val("sli[1]", 2),
-	EErr("sli[-1]", "negative index"),
-	ERTErr("sli[-i]", "negative index"),
-	ERTErr("sli[2]", "index 2 exceeds"),
+	CErr("sli[-1]", "negative index"),
+	RErr("sli[-i]", "negative index"),
+	RErr("sli[2]", "index 2 exceeds"),
 
 	Val("s[0]", uint8('a')),
 	Val("s[1]", uint8('b')),
-	EErr("s[-1]", "negative index"),
-	ERTErr("s[-i]", "negative index"),
-	ERTErr("s[3]", "index 3 exceeds"),
-
-	EErr("1(2)", "cannot call"),
-	EErr("fn(1,2)", "too many"),
-	EErr("fn()", "not enough"),
-	EErr("fn(true)", opTypes),
-	EErr("fn(true)", "function call"),
+	CErr("s[-1]", "negative index"),
+	RErr("s[-i]", "negative index"),
+	RErr("s[3]", "index 3 exceeds"),
+
+	CErr("1(2)", "cannot call"),
+	CErr("fn(1,2)", "too many"),
+	CErr("fn()", "not enough"),
+	CErr("fn(true)", opTypes),
+	CErr("fn(true)", "function call"),
 	// Single argument functions don't say which argument.
-	//EErr("fn(true)", "argument 1"),
+	//CErr("fn(true)", "argument 1"),
 	Val("fn(1)", 2),
 	Val("fn(1.0)", 2),
-	EErr("fn(1.5)", constantTruncated),
+	CErr("fn(1.5)", constantTruncated),
 	Val("fn(i)", 2),
-	EErr("fn(u)", opTypes),
+	CErr("fn(u)", opTypes),
 
-	EErr("void()+2", opTypes),
-	EErr("oneTwo()+2", opTypes),
+	CErr("void()+2", opTypes),
+	CErr("oneTwo()+2", opTypes),
 
 	Val("cap(ai)", 2),
 	Val("cap(&ai)", 2),
 	Val("cap(aai)", 2),
 	Val("cap(sli)", 3),
-	EErr("cap(0)", opTypes),
-	EErr("cap(i)", opTypes),
-	EErr("cap(s)", opTypes),
+	CErr("cap(0)", opTypes),
+	CErr("cap(i)", opTypes),
+	CErr("cap(s)", opTypes),
 
 	Val("len(s)", 3),
 	Val("len(ai)", 2),
@@ -118,36 +118,36 @@ var exprTests = []test {
 	Val("len(aai)", 2),
 	Val("len(sli)", 2),
 	// TODO(austin) Test len of map
-	EErr("len(0)", opTypes),
-	EErr("len(i)", opTypes),
+	CErr("len(0)", opTypes),
+	CErr("len(i)", opTypes),
 
-	EErr("*i", opTypes),
+	CErr("*i", opTypes),
 	Val("*&i", 1),
 	Val("*&(i)", 1),
-	EErr("&1", badAddrOf),
-	EErr("&c", badAddrOf),
+	CErr("&1", badAddrOf),
+	CErr("&c", badAddrOf),
 	Val("*(&ai[0])", 1),
 
 	Val("+1", bignum.Int(+1)),
 	Val("+1.0", bignum.Rat(1, 1)),
-	EErr("+\"x\"", opTypes),
+	CErr("+\"x\"", opTypes),
 
 	Val("-42", bignum.Int(-42)),
 	Val("-i", -1),
 	Val("-f", -1.0),
 	// 6g bug?
 	//Val("-(f-1)", -0.0),
-	EErr("-\"x\"", opTypes),
+	CErr("-\"x\"", opTypes),
 
 	// TODO(austin) Test unary !
 
 	Val("^2", bignum.Int(^2)),
 	Val("^(-2)", bignum.Int(^(-2))),
-	EErr("^2.0", opTypes),
-	EErr("^2.5", opTypes),
+	CErr("^2.0", opTypes),
+	CErr("^2.5", opTypes),
 	Val("^i", ^1),
 	Val("^u", ^uint(1)),
-	EErr("^f", opTypes),
+	CErr("^f", opTypes),
 
 	Val("1+i", 2),
 	Val("1+u", uint(2)),
@@ -157,8 +157,8 @@ var exprTests = []test {
 	Val("1+f", 2.0),
 	Val("1.0+1", bignum.Rat(2, 1)),
 	Val("\"abc\" + \"def\"", "abcdef"),
-	EErr("i+u", opTypes),
-	EErr("-1+u", constantUnderflows),
+	CErr("i+u", opTypes),
+	CErr("-1+u", constantUnderflows),
 	// TODO(austin) Test named types
 
 	Val("2-1", bignum.Int(1)),
@@ -170,14 +170,14 @@ var exprTests = []test {
 	Val("2*i", 2),
 	Val("3/2", bignum.Int(1)),
 	Val("3/i", 3),
-	EErr("1/0", divByZero),
-	EErr("1.0/0", divByZero),
-	ERTErr("i/0", divByZero),
+	CErr("1/0", divByZero),
+	CErr("1.0/0", divByZero),
+	RErr("i/0", divByZero),
 	Val("3%2", bignum.Int(1)),
 	Val("i%2", 1),
-	EErr("3%0", divByZero),
-	EErr("3.0%0", opTypes),
-	ERTErr("i%0", divByZero),
+	CErr("3%0", divByZero),
+	CErr("3.0%0", opTypes),
+	RErr("i%0", divByZero),
 
 	// Examples from "Arithmetic operators"
 	Val("5/3", bignum.Int(1)),
@@ -222,56 +222,56 @@ var exprTests = []test {
 	// fractional float, ideal non-fractional float, int, uint,
 	// and float.
 	Val("2<<2", bignum.Int(2<<2)),
-	EErr("2<<(-1)", constantUnderflows),
-	EErr("2<<0x10000000000000000", constantOverflows),
-	EErr("2<<2.5", constantTruncated),
+	CErr("2<<(-1)", constantUnderflows),
+	CErr("2<<0x10000000000000000", constantOverflows),
+	CErr("2<<2.5", constantTruncated),
 	Val("2<<2.0", bignum.Int(2<<2.0)),
-	EErr("2<<i", mustBeUnsigned),
+	CErr("2<<i", mustBeUnsigned),
 	Val("2<<u", 2<<1),
-	EErr("2<<f", opTypes),
+	CErr("2<<f", opTypes),
 
 	Val("-2<<2", bignum.Int(-2<<2)),
-	EErr("-2<<(-1)", constantUnderflows),
-	EErr("-2<<0x10000000000000000", constantOverflows),
-	EErr("-2<<2.5", constantTruncated),
+	CErr("-2<<(-1)", constantUnderflows),
+	CErr("-2<<0x10000000000000000", constantOverflows),
+	CErr("-2<<2.5", constantTruncated),
 	Val("-2<<2.0", bignum.Int(-2<<2.0)),
-	EErr("-2<<i", mustBeUnsigned),
+	CErr("-2<<i", mustBeUnsigned),
 	Val("-2<<u", -2<<1),
-	EErr("-2<<f", opTypes),
+	CErr("-2<<f", opTypes),
 
 	Val("0x10000000000000000<<2", hugeInteger.Shl(2)),
-	EErr("0x10000000000000000<<(-1)", constantUnderflows),
-	EErr("0x10000000000000000<<0x10000000000000000", constantOverflows),
-	EErr("0x10000000000000000<<2.5", constantTruncated),
+	CErr("0x10000000000000000<<(-1)", constantUnderflows),
+	CErr("0x10000000000000000<<0x10000000000000000", constantOverflows),
+	CErr("0x10000000000000000<<2.5", constantTruncated),
 	Val("0x10000000000000000<<2.0", hugeInteger.Shl(2)),
-	EErr("0x10000000000000000<<i", mustBeUnsigned),
-	EErr("0x10000000000000000<<u", constantOverflows),
-	EErr("0x10000000000000000<<f", opTypes),
+	CErr("0x10000000000000000<<i", mustBeUnsigned),
+	CErr("0x10000000000000000<<u", constantOverflows),
+	CErr("0x10000000000000000<<f", opTypes),
 
-	EErr("2.5<<2", opTypes),
-	EErr("2.0<<2", opTypes),
+	CErr("2.5<<2", opTypes),
+	CErr("2.0<<2", opTypes),
 
 	Val("i<<2", 1<<2),
-	EErr("i<<(-1)", constantUnderflows),
-	EErr("i<<0x10000000000000000", constantOverflows),
-	EErr("i<<2.5", constantTruncated),
+	CErr("i<<(-1)", constantUnderflows),
+	CErr("i<<0x10000000000000000", constantOverflows),
+	CErr("i<<2.5", constantTruncated),
 	Val("i<<2.0", 1<<2),
-	EErr("i<<i", mustBeUnsigned),
+	CErr("i<<i", mustBeUnsigned),
 	Val("i<<u", 1<<1),
-	EErr("i<<f", opTypes),
+	CErr("i<<f", opTypes),
 	Val("i<<u", 1<<1),
 
 	Val("u<<2", uint(1<<2)),
-	EErr("u<<(-1)", constantUnderflows),
-	EErr("u<<0x10000000000000000", constantOverflows),
-	EErr("u<<2.5", constantTruncated),
+	CErr("u<<(-1)", constantUnderflows),
+	CErr("u<<0x10000000000000000", constantOverflows),
+	CErr("u<<2.5", constantTruncated),
 	Val("u<<2.0", uint(1<<2)),
-	EErr("u<<i", mustBeUnsigned),
+	CErr("u<<i", mustBeUnsigned),
 	Val("u<<u", uint(1<<1)),
-	EErr("u<<f", opTypes),
+	CErr("u<<f", opTypes),
 	Val("u<<u", uint(1<<1)),
 
-	EErr("f<<2", opTypes),
+	CErr("f<<2", opTypes),
 
 	// <, <=, >, >=
 	Val("1<2", 1<2),
@@ -298,11 +298,11 @@ var exprTests = []test {
 	Val("s>\"ac\"", false),
 	Val("s>=\"abc\"", true),
 
-	EErr("i<u", opTypes),
-	EErr("i<f", opTypes),
-	EErr("i<s", opTypes),
-	EErr("&i<&i", opTypes),
-	EErr("ai<ai", opTypes),
+	CErr("i<u", opTypes),
+	CErr("i<f", opTypes),
+	CErr("i<s", opTypes),
+	CErr("&i<&i", opTypes),
+	CErr("ai<ai", opTypes),
 
 	// ==, !=
 	Val("1==1", true),
@@ -332,12 +332,12 @@ var exprTests = []test {
 	Val("fn==fn", true),
 	Val("fn==func(int)int{return 0}", false),
 
-	EErr("i==u", opTypes),
-	EErr("i==f", opTypes),
-	EErr("&i==&f", opTypes),
-	EErr("ai==ai", opTypes),
-	EErr("t==t", opTypes),
-	EErr("fn==oneTwo", opTypes),
+	CErr("i==u", opTypes),
+	CErr("i==f", opTypes),
+	CErr("&i==&f", opTypes),
+	CErr("ai==ai", opTypes),
+	CErr("t==t", opTypes),
+	CErr("fn==oneTwo", opTypes),
 }
 
 func TestExpr(t *testing.T) {
diff --git a/usr/austin/eval/scope.go b/usr/austin/eval/scope.go
index 1c0acb640..3fe94e4be 100644
--- a/usr/austin/eval/scope.go
+++ b/usr/austin/eval/scope.go
@@ -56,6 +56,10 @@ type block struct {
 	offset int;
 	// The number of Variables defined in this block.
 	numVars int;
+	// If global, do not allocate new vars and consts in
+	// the frame; assume that the refs will be compiled in
+	// using defs[name].Init.
+	global bool;
 }
 
 // A Scope is the compile-time analogue of a Frame, which captures
@@ -112,21 +116,25 @@ func (b *block) DefineVar(name string, pos token.Position, t Type) (*Variable, D
 	if prev, ok := b.defs[name]; ok {
 		return nil, prev;
 	}
-	v := b.DefineSlot(t);
+	v := b.defineSlot(t, false);
 	v.Position = pos;
 	b.defs[name] = v;
 	return v, nil;
 }
 
-func (b *block) DefineSlot(t Type) *Variable {
+func (b *block) DefineTemp(t Type) *Variable {
+	return b.defineSlot(t, true)
+}
+
+func (b *block) defineSlot(t Type, temp bool) *Variable {
 	if b.inner != nil && b.inner.scope == b.scope {
 		log.Crash("Failed to exit child block before defining variable");
 	}
 	index := -1;
-	if b.offset >= 0 {
+	if !b.global || temp {
 		index = b.offset+b.numVars;
 		b.numVars++;
-		if index+1 > b.scope.maxVars {
+		if index >= b.scope.maxVars {
 			b.scope.maxVars = index+1;
 		}
 	}
@@ -169,18 +177,7 @@ func (b *block) Lookup(name string) (bl *block, level int, def Def) {
 }
 
 func (s *Scope) NewFrame(outer *Frame) *Frame {
-	fr := outer.child(s.maxVars);
-	// TODO(rsc): Take this loop out once eval_test.go
-	// no longer fiddles with init.
-	for _, v := range s.defs {
-		switch v := v.(type) {
-		case *Variable:
-			if v.Index >= 0 {
-				fr.Vars[v.Index] = v.Init;
-			}
-		}
-	}
-	return fr;
+	return outer.child(s.maxVars);
 }
 
 /*
diff --git a/usr/austin/eval/stmt.go b/usr/austin/eval/stmt.go
index a3573c260..9788bb09c 100644
--- a/usr/austin/eval/stmt.go
+++ b/usr/austin/eval/stmt.go
@@ -341,36 +341,12 @@ func (a *stmtCompiler) compileDeclStmt(s *ast.DeclStmt) {
 		switch decl.Tok {
 		case token.IMPORT:
 			log.Crash("import at statement level");
-
 		case token.CONST:
 			log.Crashf("%v not implemented", decl.Tok);
-
 		case token.TYPE:
 			a.compileTypeDecl(a.block, decl);
-
 		case token.VAR:
-			for _, spec := range decl.Specs {
-				spec := spec.(*ast.ValueSpec);
-				if spec.Values == nil {
-					// Declaration without assignment
-					if spec.Type == nil {
-						// Parser should have caught
-						log.Crash("Type and Values nil");
-					}
-					t := a.compileType(a.block, spec.Type);
-					// Define placeholders even if type compile failed
-					for _, n := range spec.Names {
-						a.defineVar(n, t);
-					}
-				} else {
-					// Decalaration with assignment
-					lhs := make([]ast.Expr, len(spec.Names));
-					for i, n := range spec.Names {
-						lhs[i] = n;
-					}
-					a.doAssign(lhs, spec.Values, decl.Tok, spec.Type);
-				}
-			}
+			a.compileVarDecl(decl);
 		}
 
 	default:
@@ -378,6 +354,73 @@ func (a *stmtCompiler) compileDeclStmt(s *ast.DeclStmt) {
 	}
 }
 
+// decl might or might not be at top level;
+func (a *stmtCompiler) compileVarDecl(decl *ast.GenDecl) {
+	for _, spec := range decl.Specs {
+		spec := spec.(*ast.ValueSpec);
+		if spec.Values == nil {
+			// Declaration without assignment
+			if spec.Type == nil {
+				// Parser should have caught
+				log.Crash("Type and Values nil");
+			}
+			t := a.compileType(a.block, spec.Type);
+			// Define placeholders even if type compile failed
+			for _, n := range spec.Names {
+				a.defineVar(n, t);
+			}
+		} else {
+			// Decalaration with assignment
+			lhs := make([]ast.Expr, len(spec.Names));
+			for i, n := range spec.Names {
+				lhs[i] = n;
+			}
+			a.doAssign(lhs, spec.Values, decl.Tok, spec.Type);
+		}
+	}
+}
+
+// decl is top level
+func (a *stmtCompiler) compileDecl(decl ast.Decl) {
+	switch d := decl.(type) {
+	case *ast.BadDecl:
+		// Do nothing.  Already reported by parser.
+		a.silentErrors++;
+
+	case *ast.FuncDecl:
+		decl := a.compileFuncType(a.block, d.Type);
+		if decl == nil {
+			return;
+		}
+		// Declare and initialize v before compiling func
+		// so that body can refer to itself.
+		c := a.block.DefineConst(d.Name.Value, a.pos, decl.Type, decl.Type.Zero());
+		// TODO(rsc): How to mark v as constant
+		// so the type checker rejects assignments to it?
+		fn := a.compileFunc(a.block, decl, d.Body);
+		if fn == nil {
+			return;
+		}
+		var zeroThread Thread;
+		c.Value.(FuncValue).Set(fn(&zeroThread));
+
+	case *ast.GenDecl:
+		switch d.Tok {
+		case token.IMPORT:
+			log.Crashf("%v not implemented", d.Tok);
+		case token.CONST:
+			log.Crashf("%v not implemented", d.Tok);
+		case token.TYPE:
+			a.compileTypeDecl(a.block, d);
+		case token.VAR:
+			a.compileVarDecl(d);
+		}
+
+	default:
+		log.Crashf("Unexpected Decl type %T", decl);
+	}
+}
+
 func (a *stmtCompiler) compileLabeledStmt(s *ast.LabeledStmt) {
 	// Define label
 	l, ok := a.labels[s.Label.Value];
@@ -1205,14 +1248,14 @@ func (a *compiler) compileFunc(b *block, decl *FuncDecl, body *ast.BlockStmt) (f
 		if decl.InNames[i] != nil {
 			bodyScope.DefineVar(decl.InNames[i].Value, decl.InNames[i].Pos(), t);
 		} else {
-			bodyScope.DefineSlot(t);
+			bodyScope.DefineTemp(t);
 		}
 	}
 	for i, t := range decl.Type.Out {
 		if decl.OutNames[i] != nil {
 			bodyScope.DefineVar(decl.OutNames[i].Value, decl.OutNames[i].Pos(), t);
 		} else {
-			bodyScope.DefineSlot(t);
+			bodyScope.DefineTemp(t);
 		}
 	}
 
@@ -1271,46 +1314,3 @@ func (a *funcCompiler) checkLabels() {
 	// point of the goto.
 	a.flow.gotosObeyScopes(a.compiler);
 }
-
-/*
- * Public interface
- */
-
-type Stmt struct {
-	code code;
-}
-
-func (s *Stmt) Exec(f *Frame) os.Error {
-	t := new(Thread);
-	t.f = f;
-	return t.Try(func(t *Thread){s.code.exec(t)});
-}
-
-func CompileStmts(scope *Scope, stmts []ast.Stmt) (*Stmt, os.Error) {
-	errors := scanner.NewErrorVector();
-	cc := &compiler{errors, 0, 0};
-	cb := newCodeBuf();
-	fc := &funcCompiler{
-		compiler: cc,
-		fnType: nil,
-		outVarsNamed: false,
-		codeBuf: cb,
-		flow: newFlowBuf(cb),
-		labels: make(map[string] *label),
-	};
-	bc := &blockCompiler{
-		funcCompiler: fc,
-		block: scope.block,
-	};
-	out := make([]*Stmt, len(stmts));
-	nerr := cc.numError();
-	for i, stmt := range stmts {
-		bc.compileStmt(stmt);
-	}
-	fc.checkLabels();
-	if nerr != cc.numError() {
-		return nil, errors.GetError(scanner.Sorted);
-	}
-	code := fc.get();
-	return &Stmt{code}, nil;
-}
diff --git a/usr/austin/eval/stmt_test.go b/usr/austin/eval/stmt_test.go
index 9a62b2e0f..0324a40f1 100644
--- a/usr/austin/eval/stmt_test.go
+++ b/usr/austin/eval/stmt_test.go
@@ -18,45 +18,45 @@ var stmtTests = []test {
 	// Parallel assignment
 	Val2("a, b := 1, 2", "a", 1, "b", 2),
 	Val2("a, i := 1, 2", "a", 1, "i", 2),
-	SErr("a, i := 1, f", opTypes),
+	CErr("a, i := 1, f", opTypes),
 	// TODO(austin) The parser produces an error message for this
 	// one that's inconsistent with the errors I give for other
 	// things
-	//SErr("a, b := 1, 2, 3", "too many"),
-	SErr("a, b := 1, 2, 3", "arity"),
-	SErr("a := 1, 2", "too many"),
-	SErr("a, b := 1", "not enough"),
+	//CErr("a, b := 1, 2, 3", "too many"),
+	CErr("a, b := 1, 2, 3", "arity"),
+	CErr("a := 1, 2", "too many"),
+	CErr("a, b := 1", "not enough"),
 	// Mixed declarations
-	SErr("i := 1", atLeastOneDecl),
-	SErr("i, u := 1, 2", atLeastOneDecl),
+	CErr("i := 1", atLeastOneDecl),
+	CErr("i, u := 1, 2", atLeastOneDecl),
 	Val2("i, x := 2, f", "i", 2, "x", 1.0),
 	// Various errors
-	SErr("1 := 2", "left side of := must be a name"),
-	SErr("c, a := 1, 1", "cannot assign"),
+	CErr("1 := 2", "left side of := must be a name"),
+	CErr("c, a := 1, 1", "cannot assign"),
 	// Unpacking
 	Val2("x, y := oneTwo()", "x", 1, "y", 2),
-	SErr("x := oneTwo()", "too many"),
-	SErr("x, y, z := oneTwo()", "not enough"),
-	SErr("x, y := oneTwo(), 2", "multi-valued"),
-	SErr("x := oneTwo()+2", opTypes),
+	CErr("x := oneTwo()", "too many"),
+	CErr("x, y, z := oneTwo()", "not enough"),
+	CErr("x, y := oneTwo(), 2", "multi-valued"),
+	CErr("x := oneTwo()+2", opTypes),
 	// TOOD(austin) This error message is weird
-	SErr("x := void()", "not enough"),
+	CErr("x := void()", "not enough"),
 	// Placeholders
-	SErr("x := 1+\"x\"; i=x+1", opTypes),
+	CErr("x := 1+\"x\"; i=x+1", opTypes),
 
 	// Assignment
 	Val1("i = 2", "i", 2),
 	Val1("(i) = 2", "i", 2),
-	SErr("1 = 2", "cannot assign"),
-	SErr("1-1 = 2", "- expression"),
+	CErr("1 = 2", "cannot assign"),
+	CErr("1-1 = 2", "- expression"),
 	Val1("i = 2.0", "i", 2),
-	SErr("i = 2.2", constantTruncated),
-	SErr("u = -2", constantUnderflows),
-	SErr("i = f", opTypes),
-	SErr("i, u = 0, f", opTypes),
-	SErr("i, u = 0, f", "value 2"),
+	CErr("i = 2.2", constantTruncated),
+	CErr("u = -2", constantUnderflows),
+	CErr("i = f", opTypes),
+	CErr("i, u = 0, f", opTypes),
+	CErr("i, u = 0, f", "value 2"),
 	Val2("i, i2 = i2, i", "i", 2, "i2", 1),
-	SErr("c = 1", "cannot assign"),
+	CErr("c = 1", "cannot assign"),
 
 	Val1("x := &i; *x = 2", "i", 2),
 
@@ -65,65 +65,66 @@ var stmtTests = []test {
 	Val1("aai = aai2", "aai", varray{ varray{5, 6}, varray{7, 8} }),
 
 	// Assignment conversions
-	SRuns("var sl []int; sl = &ai"),
-	SErr("type ST []int; type AT *[2]int; var x AT = &ai; var y ST = x", opTypes),
-	SRuns("type ST []int; var y ST = &ai"),
-	SRuns("type AT *[2]int; var x AT = &ai; var y []int = x"),
+	Run("var sl []int; sl = &ai"),
+	CErr("type ST []int; type AT *[2]int; var x AT = &ai; var y ST = x", opTypes),
+	Run("type ST []int; var y ST = &ai"),
+	Run("type AT *[2]int; var x AT = &ai; var y []int = x"),
 
 	// Op-assignment
 	Val1("i += 2", "i", 3),
+	Val("i", 1),
 	Val1("f += 2", "f", 3.0),
-	SErr("2 += 2", "cannot assign"),
-	SErr("i, j += 2", "cannot be combined"),
-	SErr("i += 2, 3", "cannot be combined"),
+	CErr("2 += 2", "cannot assign"),
+	CErr("i, j += 2", "cannot be combined"),
+	CErr("i += 2, 3", "cannot be combined"),
 	Val2("s2 := s; s += \"def\"", "s2", "abc", "s", "abcdef"),
-	SErr("s += 1", opTypes),
+	CErr("s += 1", opTypes),
 	// Single evaluation
 	Val2("ai[func()int{i+=1;return 0}()] *= 3; i2 = ai[0]", "i", 2, "i2", 3),
 
 	// Type declarations
 	// Identifiers
-	SRuns("type T int"),
-	SErr("type T x", "undefined"),
-	SErr("type T c", "constant"),
-	SErr("type T i", "variable"),
-	SErr("type T T", "recursive"),
-	SErr("type T x; type U T; var v U; v = 1", "undefined"),
+	Run("type T int"),
+	CErr("type T x", "undefined"),
+	CErr("type T c", "constant"),
+	CErr("type T i", "variable"),
+	CErr("type T T", "recursive"),
+	CErr("type T x; type U T; var v U; v = 1", "undefined"),
 	// Pointer types
-	SRuns("type T *int"),
-	SRuns("type T *T"),
+	Run("type T *int"),
+	Run("type T *T"),
 	// Array types
-	SRuns("type T [5]int"),
-	SRuns("type T [c+42/2]int"),
-	SRuns("type T [2.0]int"),
-	SErr("type T [i]int", "constant expression"),
-	SErr("type T [2.5]int", constantTruncated),
-	SErr("type T [-1]int", "negative"),
-	SErr("type T [2]T", "recursive"),
+	Run("type T [5]int"),
+	Run("type T [c+42/2]int"),
+	Run("type T [2.0]int"),
+	CErr("type T [i]int", "constant expression"),
+	CErr("type T [2.5]int", constantTruncated),
+	CErr("type T [-1]int", "negative"),
+	CErr("type T [2]T", "recursive"),
 	// Struct types
-	SRuns("type T struct { a int; b int }"),
-	SRuns("type T struct { a int; int }"),
-	SRuns("type T struct { x *T }"),
-	SRuns("type T int; type U struct { T }"),
-	SErr("type T *int; type U struct { T }", "embedded.*pointer"),
-	SErr("type T *struct { T }", "embedded.*pointer"),
-	SErr("type T struct { a int; a int }", " a .*redeclared.*:1:17"),
-	SErr("type T struct { int; int }", "int .*redeclared.*:1:17"),
-	SErr("type T struct { int int; int }", "int .*redeclared.*:1:17"),
-	SRuns("type T struct { x *struct { T } }"),
-	SErr("type T struct { x struct { T } }", "recursive"),
-	SErr("type T struct { x }; type U struct { T }", "undefined"),
+	Run("type T struct { a int; b int }"),
+	Run("type T struct { a int; int }"),
+	Run("type T struct { x *T }"),
+	Run("type T int; type U struct { T }"),
+	CErr("type T *int; type U struct { T }", "embedded.*pointer"),
+	CErr("type T *struct { T }", "embedded.*pointer"),
+	CErr("type T struct { a int; a int }", " a .*redeclared.*:1:17"),
+	CErr("type T struct { int; int }", "int .*redeclared.*:1:17"),
+	CErr("type T struct { int int; int }", "int .*redeclared.*:1:17"),
+	Run("type T struct { x *struct { T } }"),
+	CErr("type T struct { x struct { T } }", "recursive"),
+	CErr("type T struct { x }; type U struct { T }", "undefined"),
 	// Function types
-	SRuns("type T func()"),
-	SRuns("type T func(a, b int) int"),
-	SRuns("type T func(a, b int) (x int, y int)"),
-	SRuns("type T func(a, a int) (a int, a int)"),
-	SRuns("type T func(a, b int) (x, y int)"),
-	SRuns("type T func(int, int) (int, int)"),
-	SErr("type T func(x); type U T", "undefined"),
-	SErr("type T func(a T)", "recursive"),
+	Run("type T func()"),
+	Run("type T func(a, b int) int"),
+	Run("type T func(a, b int) (x int, y int)"),
+	Run("type T func(a, a int) (a int, a int)"),
+	Run("type T func(a, b int) (x, y int)"),
+	Run("type T func(int, int) (int, int)"),
+	CErr("type T func(x); type U T", "undefined"),
+	CErr("type T func(a T)", "recursive"),
 	// Parens
-	SRuns("type T (int)"),
+	Run("type T (int)"),
 
 	// Variable declarations
 	Val2("var x int", "i", 1, "x", 0),
@@ -131,15 +132,15 @@ var stmtTests = []test {
 	Val1("var x = 1.0", "x", 1.0),
 	Val1("var x int = 1.0", "x", 1),
 	// Placeholders
-	SErr("var x foo; x = 1", "undefined"),
-	SErr("var x foo = 1; x = 1", "undefined"),
+	CErr("var x foo; x = 1", "undefined"),
+	CErr("var x foo = 1; x = 1", "undefined"),
 	// Redeclaration
-	SErr("var i, x int", " i .*redeclared"),
-	SErr("var x int; var x int", " x .*redeclared.*:1:5"),
+	CErr("var i, x int", " i .*redeclared"),
+	CErr("var x int; var x int", " x .*redeclared.*:1:5"),
 
 	// Expression statements
-	SErr("1-1", "expression statement"),
-	SErr("1-1", "- expression"),
+	CErr("x := func(){ 1-1 }", "expression statement"),
+	CErr("x := func(){ 1-1 }", "- expression"),
 	Val1("fn(2)", "i", 1),
 
 	// IncDec statements
@@ -152,10 +153,10 @@ var stmtTests = []test {
 	// Single evaluation
 	Val2("ai[func()int{i+=1;return 0}()]++; i2 = ai[0]", "i", 2, "i2", 2),
 	// Operand types
-	SErr("s++", opTypes),
-	SErr("s++", "'\\+\\+'"),
-	SErr("2++", "cannot assign"),
-	SErr("c++", "cannot assign"),
+	CErr("s++", opTypes),
+	CErr("s++", "'\\+\\+'"),
+	CErr("2++", "cannot assign"),
+	CErr("c++", "cannot assign"),
 
 	// Function scoping
 	Val1("fn1 := func() { i=2 }; fn1()", "i", 2),
@@ -163,9 +164,9 @@ var stmtTests = []test {
 	Val2("fn1 := func() int { i=2; i:=3; i=4; return i }; x := fn1()", "i", 2, "x", 4),
 
 	// Basic returns
-	SErr("fn1 := func() int {}", "return"),
-	SRuns("fn1 := func() {}"),
-	SErr("fn1 := func() (r int) {}", "return"),
+	CErr("fn1 := func() int {}", "return"),
+	Run("fn1 := func() {}"),
+	CErr("fn1 := func() (r int) {}", "return"),
 	Val1("fn1 := func() (r int) {return}; i = fn1()", "i", 0),
 	Val1("fn1 := func() (r int) {r = 2; return}; i = fn1()", "i", 2),
 	Val1("fn1 := func() (r int) {return 2}; i = fn1()", "i", 2),
@@ -173,40 +174,40 @@ var stmtTests = []test {
 
 	// Multi-valued returns
 	Val2("fn1 := func() (bool, int) {return true, 2}; x, y := fn1()", "x", true, "y", 2),
-	SErr("fn1 := func() int {return}", "not enough values"),
-	SErr("fn1 := func() int {return 1,2}", "too many values"),
-	SErr("fn1 := func() {return 1}", "too many values"),
-	SErr("fn1 := func() (int,int,int) {return 1,2}", "not enough values"),
+	CErr("fn1 := func() int {return}", "not enough values"),
+	CErr("fn1 := func() int {return 1,2}", "too many values"),
+	CErr("fn1 := func() {return 1}", "too many values"),
+	CErr("fn1 := func() (int,int,int) {return 1,2}", "not enough values"),
 	Val2("fn1 := func() (int, int) {return oneTwo()}; x, y := fn1()", "x", 1, "y", 2),
-	SErr("fn1 := func() int {return oneTwo()}", "too many values"),
-	SErr("fn1 := func() (int,int,int) {return oneTwo()}", "not enough values"),
+	CErr("fn1 := func() int {return oneTwo()}", "too many values"),
+	CErr("fn1 := func() (int,int,int) {return oneTwo()}", "not enough values"),
 	Val1("fn1 := func(x,y int) int {return x+y}; x := fn1(oneTwo())", "x", 3),
 
 	// Return control flow
 	Val2("fn1 := func(x *int) bool { *x = 2; return true; *x = 3; }; x := fn1(&i)", "i", 2, "x", true),
 
 	// Break/continue/goto/fallthrough
-	SErr("break", "outside"),
-	SErr("break foo", "break.*foo.*not defined"),
-	SErr("continue", "outside"),
-	SErr("continue foo", "continue.*foo.*not defined"),
-	SErr("fallthrough", "outside"),
-	SErr("goto foo", "foo.*not defined"),
-	SErr(" foo: foo:;", "foo.*redeclared.*:1:2"),
+	CErr("break", "outside"),
+	CErr("break foo", "break.*foo.*not defined"),
+	CErr("continue", "outside"),
+	CErr("continue foo", "continue.*foo.*not defined"),
+	CErr("fallthrough", "outside"),
+	CErr("goto foo", "foo.*not defined"),
+	CErr(" foo: foo:;", "foo.*redeclared.*:1:2"),
 	Val1("i+=2; goto L; i+=4; L: i+=8", "i", 1+2+8),
 	// Return checking
-	SErr("fn1 := func() int { goto L; return 1; L: }", "return"),
-	SRuns("fn1 := func() int { L: goto L; i = 2 }"),
-	SRuns("fn1 := func() int { return 1; L: goto L }"),
+	CErr("fn1 := func() int { goto L; return 1; L: }", "return"),
+	Run("fn1 := func() int { L: goto L; i = 2 }"),
+	Run("fn1 := func() int { return 1; L: goto L }"),
 	// Scope checking
-	SRuns("fn1 := func() { { L: x:=1 } goto L }"),
-	SErr("fn1 := func() { { x:=1; L: } goto L }", "into scope"),
-	SErr("fn1 := func() { goto L; x:=1; L: }", "into scope"),
-	SRuns("fn1 := func() { goto L; { L: x:=1 } }"),
-	SErr("fn1 := func() { goto L; { x:=1; L: } }", "into scope"),
+	Run("fn1 := func() { { L: x:=1 } goto L }"),
+	CErr("fn1 := func() { { x:=1; L: } goto L }", "into scope"),
+	CErr("fn1 := func() { goto L; x:=1; L: }", "into scope"),
+	Run("fn1 := func() { goto L; { L: x:=1 } }"),
+	CErr("fn1 := func() { goto L; { x:=1; L: } }", "into scope"),
 
 	// Blocks
-	SErr("fn1 := func() int {{}}", "return"),
+	CErr("fn1 := func() int {{}}", "return"),
 	Val1("fn1 := func() bool { { return true } }; b := fn1()", "b", true),
 
 	// If
@@ -227,44 +228,44 @@ var stmtTests = []test {
 	Val2("if true { i := 2 } else { i := 3 }; i2 = i", "i", 1, "i2", 1),
 	Val2("if false { i := 2 } else { i := 3 }; i2 = i", "i", 1, "i2", 1),
 	Val2("if false { i := 2 } else i := 3; i2 = i", "i", 1, "i2", 1),
-	SErr("if true { x := 2 }; x = 4", undefined),
+	CErr("if true { x := 2 }; x = 4", undefined),
 	Val2("if i := 2; true { i2 = i; i := 3 }", "i", 1, "i2", 2),
 	Val2("if i := 2; false {} else { i2 = i; i := 3 }", "i", 1, "i2", 2),
 	// Return checking
-	SRuns("fn1 := func() int { if true { return 1 } else { return 2 } }"),
-	SRuns("fn1 := func() int { if true { return 1 } else return 2 }"),
-	SErr("fn1 := func() int { if true { return 1 } else { } }", "return"),
-	SErr("fn1 := func() int { if true { } else { return 1 } }", "return"),
-	SErr("fn1 := func() int { if true { } else return 1 }", "return"),
-	SErr("fn1 := func() int { if true { } else { } }", "return"),
-	SErr("fn1 := func() int { if true { return 1 } }", "return"),
-	SErr("fn1 := func() int { if true { } }", "return"),
-	SRuns("fn1 := func() int { if true { }; return 1 }"),
-	SErr("fn1 := func() int { if { } }", "return"),
-	SErr("fn1 := func() int { if { } else { return 2 } }", "return"),
-	SRuns("fn1 := func() int { if { return 1 } }"),
-	SRuns("fn1 := func() int { if { return 1 } else { } }"),
-	SRuns("fn1 := func() int { if { return 1 } else { } }"),
+	Run("fn1 := func() int { if true { return 1 } else { return 2 } }"),
+	Run("fn1 := func() int { if true { return 1 } else return 2 }"),
+	CErr("fn1 := func() int { if true { return 1 } else { } }", "return"),
+	CErr("fn1 := func() int { if true { } else { return 1 } }", "return"),
+	CErr("fn1 := func() int { if true { } else return 1 }", "return"),
+	CErr("fn1 := func() int { if true { } else { } }", "return"),
+	CErr("fn1 := func() int { if true { return 1 } }", "return"),
+	CErr("fn1 := func() int { if true { } }", "return"),
+	Run("fn1 := func() int { if true { }; return 1 }"),
+	CErr("fn1 := func() int { if { } }", "return"),
+	CErr("fn1 := func() int { if { } else { return 2 } }", "return"),
+	Run("fn1 := func() int { if { return 1 } }"),
+	Run("fn1 := func() int { if { return 1 } else { } }"),
+	Run("fn1 := func() int { if { return 1 } else { } }"),
 
 	// Switch
 	Val1("switch { case false: i += 2; case true: i += 4; default: i += 8 }", "i", 1+4),
 	Val1("switch { default: i += 2; case false: i += 4; case true: i += 8 }", "i", 1+8),
-	SErr("switch { default: i += 2; default: i += 4 }", "more than one"),
+	CErr("switch { default: i += 2; default: i += 4 }", "more than one"),
 	Val1("switch false { case false: i += 2; case true: i += 4; default: i += 8 }", "i", 1+2),
-	SErr("switch s { case 1: }", opTypes),
-	SErr("switch ai { case ai: i += 2 }", opTypes),
+	CErr("switch s { case 1: }", opTypes),
+	CErr("switch ai { case ai: i += 2 }", opTypes),
 	Val1("switch 1.0 { case 1: i += 2; case 2: i += 4 }", "i", 1+2),
 	Val1("switch 1.5 { case 1: i += 2; case 2: i += 4 }", "i", 1),
-	SErr("switch oneTwo() {}", "multi-valued expression"),
+	CErr("switch oneTwo() {}", "multi-valued expression"),
 	Val1("switch 2 { case 1: i += 2; fallthrough; case 2: i += 4; fallthrough; case 3: i += 8; fallthrough }", "i", 1+4+8),
 	Val1("switch 5 { case 1: i += 2; fallthrough; default: i += 4; fallthrough; case 2: i += 8; fallthrough; case 3: i += 16; fallthrough }", "i", 1+4+8+16),
-	SErr("switch { case true: fallthrough; i += 2 }", "final statement"),
+	CErr("switch { case true: fallthrough; i += 2 }", "final statement"),
 	Val1("switch { case true: i += 2; fallthrough; ; ; case false: i += 4 }", "i", 1+2+4),
 	Val1("switch 2 { case 0, 1: i += 2; case 2, 3: i += 4 }", "i", 1+4),
 	Val2("switch func()int{i2++;return 5}() { case 1, 2: i += 2; case 4, 5: i += 4 }", "i", 1+4, "i2", 3),
-	SRuns("switch i { case i: }"),
+	Run("switch i { case i: }"),
 	// TODO(austin) Why doesn't this fail?
-	//SErr("case 1:", "XXX"),
+	//CErr("case 1:", "XXX"),
 
 	// For
 	Val2("for x := 1; x < 5; x++ { i+=x }; i2 = 4", "i", 11, "i2", 4),
@@ -278,44 +279,44 @@ var stmtTests = []test {
 	// Labeled break/continue
 	Val1("L1: for { L2: for { i+=2; break L1; i+=4 } i+=8 }", "i", 1+2),
 	Val1("L1: for { L2: for { i+=2; break L2; i+=4 } i+=8; break; i+=16 }", "i", 1+2+8),
-	SErr("L1: { for { break L1 } }", "break.*not defined"),
-	SErr("L1: for {} for { break L1 }", "break.*not defined"),
-	SErr("L1:; for { break L1 }", "break.*not defined"),
+	CErr("L1: { for { break L1 } }", "break.*not defined"),
+	CErr("L1: for {} for { break L1 }", "break.*not defined"),
+	CErr("L1:; for { break L1 }", "break.*not defined"),
 	Val2("L1: for i = 0; i < 2; i++ { L2: for { i2++; continue L1; i2++ } }", "i", 2, "i2", 4),
-	SErr("L1: { for { continue L1 } }", "continue.*not defined"),
-	SErr("L1:; for { continue L1 }", "continue.*not defined"),
+	CErr("L1: { for { continue L1 } }", "continue.*not defined"),
+	CErr("L1:; for { continue L1 }", "continue.*not defined"),
 	// Return checking
-	SRuns("fn1 := func() int{ for {} }"),
-	SErr("fn1 := func() int{ for true {} }", "return"),
-	SErr("fn1 := func() int{ for true {return 1} }", "return"),
-	SErr("fn1 := func() int{ for {break} }", "return"),
-	SRuns("fn1 := func() int{ for { for {break} } }"),
-	SErr("fn1 := func() int{ L1: for { for {break L1} } }", "return"),
-	SRuns("fn1 := func() int{ for true {} return 1 }"),
+	Run("fn1 := func() int{ for {} }"),
+	CErr("fn1 := func() int{ for true {} }", "return"),
+	CErr("fn1 := func() int{ for true {return 1} }", "return"),
+	CErr("fn1 := func() int{ for {break} }", "return"),
+	Run("fn1 := func() int{ for { for {break} } }"),
+	CErr("fn1 := func() int{ L1: for { for {break L1} } }", "return"),
+	Run("fn1 := func() int{ for true {} return 1 }"),
 
 	// Selectors
 	Val1("var x struct { a int; b int }; x.a = 42; i = x.a", "i", 42),
 	Val1("type T struct { x int }; var y struct { T }; y.x = 42; i = y.x", "i", 42),
 	Val2("type T struct { x int }; var y struct { T; x int }; y.x = 42; i = y.x; i2 = y.T.x", "i", 42, "i2", 0),
-	SRuns("type T struct { x int }; var y struct { *T }; a := func(){i=y.x}"),
-	SErr("type T struct { x int }; var x T; x.y = 42", "no field"),
-	SErr("type T struct { x int }; type U struct { x int }; var y struct { T; U }; y.x = 42", "ambiguous.*\tT\\.x\n\tU\\.x"),
-	SErr("type T struct { *T }; var x T; x.foo", "no field"),
+	Run("type T struct { x int }; var y struct { *T }; a := func(){i=y.x}"),
+	CErr("type T struct { x int }; var x T; x.y = 42", "no field"),
+	CErr("type T struct { x int }; type U struct { x int }; var y struct { T; U }; y.x = 42", "ambiguous.*\tT\\.x\n\tU\\.x"),
+	CErr("type T struct { *T }; var x T; x.foo", "no field"),
 
 	Val1("fib := func(int) int{return 0;}; fib = func(v int) int { if v < 2 { return 1 } return fib(v-1)+fib(v-2) }; i = fib(20)", "i", 10946),
 
 	// Make slice
 	Val2("x := make([]int, 2); x[0] = 42; i, i2 = x[0], x[1]", "i", 42, "i2", 0),
 	Val2("x := make([]int, 2); x[1] = 42; i, i2 = x[0], x[1]", "i", 0, "i2", 42),
-	SRTErr("x := make([]int, 2); x[-i] = 42", "negative index"),
-	SRTErr("x := make([]int, 2); x[2] = 42", "index 2 exceeds"),
+	RErr("x := make([]int, 2); x[-i] = 42", "negative index"),
+	RErr("x := make([]int, 2); x[2] = 42", "index 2 exceeds"),
 	Val2("x := make([]int, 2, 3); i, i2 = len(x), cap(x)", "i", 2, "i2", 3),
 	Val2("x := make([]int, 3, 2); i, i2 = len(x), cap(x)", "i", 3, "i2", 3),
-	SRTErr("x := make([]int, -i)", "negative length"),
-	SRTErr("x := make([]int, 2, -i)", "negative capacity"),
-	SRTErr("x := make([]int, 2, 3); x[2] = 42", "index 2 exceeds"),
-	SErr("x := make([]int, 2, 3, 4)", "too many"),
-	SErr("x := make([]int)", "not enough"),
+	RErr("x := make([]int, -i)", "negative length"),
+	RErr("x := make([]int, 2, -i)", "negative capacity"),
+	RErr("x := make([]int, 2, 3); x[2] = 42", "index 2 exceeds"),
+	CErr("x := make([]int, 2, 3, 4)", "too many"),
+	CErr("x := make([]int)", "not enough"),
 
 	// TODO(austin) Test make map
 
@@ -326,10 +327,10 @@ var stmtTests = []test {
 	// Not implemented
 	//Val1("x := make(map[int] int); x[1] = 42, true; i = x[1]", "i", 42),
 	//Val2("x := make(map[int] int); x[1] = 42; x[1] = 42, false; i, y := x[1]", "i", 0, "y", false),
-	SRuns("var x int; a := make(map[int] int); a[0], x = 1, 2"),
-	SErr("x := make(map[int] int); (func(a,b int){})(x[0])", "not enough"),
-	SErr("x := make(map[int] int); x[1] = oneTwo()", "too many"),
-	SRTErr("x := make(map[int] int); i = x[1]", "key '1' not found"),
+	Run("var x int; a := make(map[int] int); a[0], x = 1, 2"),
+	CErr("x := make(map[int] int); (func(a,b int){})(x[0])", "not enough"),
+	CErr("x := make(map[int] int); x[1] = oneTwo()", "too many"),
+	RErr("x := make(map[int] int); i = x[1]", "key '1' not found"),
 }
 
 func TestStmt(t *testing.T) {
diff --git a/usr/austin/eval/world.go b/usr/austin/eval/world.go
index 7f7e5fc8d..a2a905055 100644
--- a/usr/austin/eval/world.go
+++ b/usr/austin/eval/world.go
@@ -5,12 +5,14 @@
 package eval
 
 import (
-	"os";
 	"go/ast";
 	"go/parser";
+	"go/scanner";
+	"go/token";
+	"os";
 )
 
-// TODO: Make CompileExpr and CompileStmts 
+// TODO: Make CompileExpr and CompileStmts
 // methods on World.
 
 type World struct {
@@ -21,46 +23,143 @@ type World struct {
 func NewWorld() (*World) {
 	w := new(World);
 	w.scope = universe.ChildScope();
-	w.scope.offset = -1;	// this block's vars allocate directly
-	w.scope.numVars = 1;	// inner blocks have frames: offset+numVars >= 0
+	w.scope.global = true;	// this block's vars allocate directly
 	return w;
 }
 
+type Code interface {
+	// The type of the value Run returns, or nil if Run returns nil.
+	Type() Type;
 
-type Code struct {
+	// Run runs the code; if the code is a single expression
+	// with a value, it returns the value; otherwise it returns nil.
+	Run() (Value, os.Error);
+}
+
+type stmtCode struct {
 	w *World;
-	stmt *Stmt;
-	expr *Expr;
+	code code;
 }
 
-func (w *World) Compile(text string) (*Code, os.Error) {
-	asts, err := parser.ParseStmtList("input", text);
-	if err != nil {
-		return nil, err;
-	}
-	if len(asts) == 1 {
-		if s, ok := asts[0].(*ast.ExprStmt); ok {
-			expr, err := CompileExpr(w.scope, s.X);
-			if err != nil {
-				return nil, err;
-			}
-			return &Code{w: w, expr: expr}, nil;
+func (w *World) compileStmts(stmts []ast.Stmt) (Code, os.Error) {
+	if len(stmts) == 1 {
+		if s, ok := stmts[0].(*ast.ExprStmt); ok {
+			return w.compileExpr(s.X);
 		}
 	}
-	stmt, err := CompileStmts(w.scope, asts);
-	if err != nil {
-		return nil, err;
+	errors := scanner.NewErrorVector();
+	cc := &compiler{errors, 0, 0};
+	cb := newCodeBuf();
+	fc := &funcCompiler{
+		compiler: cc,
+		fnType: nil,
+		outVarsNamed: false,
+		codeBuf: cb,
+		flow: newFlowBuf(cb),
+		labels: make(map[string] *label),
+	};
+	bc := &blockCompiler{
+		funcCompiler: fc,
+		block: w.scope.block,
+	};
+	nerr := cc.numError();
+	for i, stmt := range stmts {
+		bc.compileStmt(stmt);
+	}
+	fc.checkLabels();
+	if nerr != cc.numError() {
+		return nil, errors.GetError(scanner.Sorted);
+	}
+	return &stmtCode{w, fc.get()}, nil;
+}
+
+func (w *World) compileDecls(decls []ast.Decl) (Code, os.Error) {
+	stmts := make([]ast.Stmt, len(decls));
+	for i, d := range decls {
+		stmts[i] = &ast.DeclStmt{d};
 	}
-	return &Code{w: w, stmt: stmt}, nil;
+	return w.compileStmts(stmts);
 }
 
-func (c *Code) Run() (Value, os.Error) {
-	w := c.w;
-	w.frame = w.scope.NewFrame(nil);
-	if c.stmt != nil {
-		return nil, c.stmt.Exec(w.frame);
+func (s *stmtCode) Type() Type {
+	return nil;
+}
+
+func (s *stmtCode) Run() (Value, os.Error) {
+	t := new(Thread);
+	t.f = s.w.scope.NewFrame(nil);
+	return nil, t.Try(func(t *Thread){s.code.exec(t)});
+}
+
+type exprCode struct {
+	w *World;
+	e *expr;
+	eval func(Value, *Thread);
+}
+
+func (w *World) compileExpr(e ast.Expr) (Code, os.Error) {
+	errors := scanner.NewErrorVector();
+	cc := &compiler{errors, 0, 0};
+
+	ec := cc.compileExpr(w.scope.block, false, e);
+	if ec == nil {
+		return nil, errors.GetError(scanner.Sorted);
 	}
-	val, err := c.expr.Eval(w.frame);
-	return val, err;
+	var eval func(Value, *Thread);
+	switch _ := ec.t.(type) {
+	case *idealIntType:
+		// nothing
+	case *idealFloatType:
+		// nothing
+	default:
+		eval = genAssign(ec.t, ec);
+	}
+	return &exprCode{w, ec, eval}, nil;
+}
+
+func (e *exprCode) Type() Type {
+	return e.e.t;
+}
+
+func (e *exprCode) Run() (Value, os.Error) {
+	t := new(Thread);
+	t.f = e.w.scope.NewFrame(nil);
+	switch _ := e.e.t.(type) {
+	case *idealIntType:
+		return &idealIntV{e.e.asIdealInt()()}, nil;
+	case *idealFloatType:
+		return &idealFloatV{e.e.asIdealFloat()()}, nil;
+	}
+	v := e.e.t.Zero();
+	eval := e.eval;
+	err := t.Try(func(t *Thread){eval(v, t)});
+	return v, err;
+}
+
+func (w *World) Compile(text string) (Code, os.Error) {
+	stmts, err := parser.ParseStmtList("input", text);
+	if err == nil {
+		return w.compileStmts(stmts);
+	}
+
+	// Otherwise try as DeclList.
+	decls, err1 := parser.ParseDeclList("input", text);
+	if err == nil {
+		return w.compileDecls(decls);
+	}
+
+	// Have to pick an error.
+	// Parsing as statement list admits more forms,
+	// its error is more likely to be useful.
+	return nil, err;
+}
+
+func (w *World) DefineConst(name string, t Type, val Value) {
+	w.scope.DefineConst(name, token.Position{}, t, val);
+}
+
+func (w *World) DefineVar(name string, t Type, val Value) {
+	v, _ := w.scope.DefineVar(name, token.Position{}, t);
+	v.Init = val;
 }