1 files changed, 97 insertions, 0 deletions
diff --git a/src/pkg/exp/eval/compiler.go b/src/pkg/exp/eval/compiler.go
new file mode 100644
index 000000000..f3c962c2b
--- /dev/null
+++ b/src/pkg/exp/eval/compiler.go
@@ -0,0 +1,97 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package eval
+
+import (
+	"fmt";
+	"go/scanner";
+	"go/token";
+)
+
+
+type positioned interface {
+	Pos() token.Position;
+}
+
+
+// A compiler captures information used throughout an entire
+// compilation.  Currently it includes only the error handler.
+//
+// TODO(austin) This might actually represent package level, in which
+// case it should be package compiler.
+type compiler struct {
+	errors scanner.ErrorHandler;
+	numErrors int;
+	silentErrors int;
+}
+
+func (a *compiler) diagAt(pos positioned, format string, args ...) {
+	a.errors.Error(pos.Pos(), fmt.Sprintf(format, args));
+	a.numErrors++;
+}
+
+func (a *compiler) numError() int {
+	return a.numErrors + a.silentErrors;
+}
+
+// The universal scope
+func newUniverse() *Scope {
+	sc := &Scope{nil, 0};
+	sc.block = &block{
+		offset: 0,
+		scope: sc,
+		global: true,
+		defs: make(map[string] Def)
+	};
+	return sc;
+}
+var universe *Scope = newUniverse();
+
+
+// TODO(austin) These can all go in stmt.go now
+type label struct {
+	name string;
+	desc string;
+	// The PC goto statements should jump to, or nil if this label
+	// cannot be goto'd (such as an anonymous for loop label).
+	gotoPC *uint;
+	// The PC break statements should jump to, or nil if a break
+	// statement is invalid.
+	breakPC *uint;
+	// The PC continue statements should jump to, or nil if a
+	// continue statement is invalid.
+	continuePC *uint;
+	// The position where this label was resolved.  If it has not
+	// been resolved yet, an invalid position.
+	resolved token.Position;
+	// The position where this label was first jumped to.
+	used token.Position;
+}
+
+// A funcCompiler captures information used throughout the compilation
+// of a single function body.
+type funcCompiler struct {
+	*compiler;
+	fnType *FuncType;
+	// Whether the out variables are named.  This affects what
+	// kinds of return statements are legal.
+	outVarsNamed bool;
+	*codeBuf;
+	flow *flowBuf;
+	labels map[string] *label;
+}
+
+// A blockCompiler captures information used throughout the compilation
+// of a single block within a function.
+type blockCompiler struct {
+	*funcCompiler;
+	block *block;
+	// The label of this block, used for finding break and
+	// continue labels.
+	label *label;
+	// The blockCompiler for the block enclosing this one, or nil
+	// for a function-level block.
+	parent *blockCompiler;
+}