From 05d8ec6a16acf88c5ae7521d86131f5ea7f9b4e4 Mon Sep 17 00:00:00 2001
From: "Andrew Gallant (Ocelot)" <Andrew.Gallant@tufts.edu>
Date: Mon, 30 Apr 2012 02:40:55 -0400
Subject: [PATCH] complete and total overhaul like i promised. things are much
 easier to reason about. still not working yet though.

---
 nexgb/xgbgen/context.go        |  25 +-
 nexgb/xgbgen/expression.go     | 276 +++++++++++++
 nexgb/xgbgen/field.go          | 170 ++++++++
 nexgb/xgbgen/go.go             | 735 +++++++++++++--------------------
 nexgb/xgbgen/main.go           |   2 +-
 nexgb/xgbgen/morph.go          |  50 +++
 nexgb/xgbgen/representation.go |  56 +++
 nexgb/xgbgen/size.go           |  22 +
 nexgb/xgbgen/translation.go    | 426 +++++++++++++++++++
 nexgb/xgbgen/type.go           | 365 ++++++++++++++++
 nexgb/xgbgen/xml.go            | 349 +++-------------
 nexgb/xgbgen/xml_expression.go |  30 +-
 nexgb/xgbgen/xml_fields.go     |  58 +--
 13 files changed, 1777 insertions(+), 787 deletions(-)
 create mode 100644 nexgb/xgbgen/expression.go
 create mode 100644 nexgb/xgbgen/field.go
 create mode 100644 nexgb/xgbgen/morph.go
 create mode 100644 nexgb/xgbgen/representation.go
 create mode 100644 nexgb/xgbgen/size.go
 create mode 100644 nexgb/xgbgen/translation.go
 create mode 100644 nexgb/xgbgen/type.go

diff --git a/nexgb/xgbgen/context.go b/nexgb/xgbgen/context.go
index 712cad4..d3cbb81 100644
--- a/nexgb/xgbgen/context.go
+++ b/nexgb/xgbgen/context.go
@@ -8,13 +8,12 @@ import (
 )
 
 type Context struct {
-	xml *XML
+	protocol *Protocol
 	out *bytes.Buffer
 }
 
 func newContext() *Context {
 	return &Context{
-		xml: &XML{},
 		out: bytes.NewBuffer([]byte{}),
 	}
 }
@@ -32,22 +31,24 @@ func (c *Context) Put(format string, v ...interface{}) {
 	}
 }
 
-
-// Translate is the big daddy of them all. It takes in an XML byte slice
+// Morph is the big daddy of them all. It takes in an XML byte slice,
+// parse it, transforms the XML types into more usable types,
 // and writes Go code to the 'out' buffer.
-func (c *Context) Translate(xmlBytes []byte) {
-	err := xml.Unmarshal(xmlBytes, c.xml)
+func (c *Context) Morph(xmlBytes []byte) {
+	parsedXml := &XML{}
+	err := xml.Unmarshal(xmlBytes, parsedXml)
 	if err != nil {
 		log.Fatal(err)
 	}
 
 	// Parse all imports
-	c.xml.Imports.Eval()
+	parsedXml.Imports.Eval()
 
-	// Make sure all top level enumerations have expressions
-	// (For when there are empty items.)
-	c.xml.Enums.Eval()
+	// Translate XML types to nice types
+	c.protocol = parsedXml.Translate()
 
-	// It's Morphin' Time!
-	c.xml.Morph(c)
+	// Now write Go source code
+	for _, typ := range c.protocol.Types {
+		typ.Define(c)
+	}
 }
diff --git a/nexgb/xgbgen/expression.go b/nexgb/xgbgen/expression.go
new file mode 100644
index 0000000..a163692
--- /dev/null
+++ b/nexgb/xgbgen/expression.go
@@ -0,0 +1,276 @@
+package main
+
+import (
+	"fmt"
+	"log"
+)
+
+type Expression interface {
+	Concrete() bool
+	Eval() uint
+	Reduce(prefix, fun string) string
+	String() string
+	Initialize(p *Protocol)
+}
+
+type BinaryOp struct {
+	Op string
+	Expr1 Expression
+	Expr2 Expression
+}
+
+func newBinaryOp(op string, expr1, expr2 Expression) Expression {
+	switch {
+	case expr1 != nil && expr2 != nil:
+		return &BinaryOp{
+			Op: op,
+			Expr1: expr1,
+			Expr2: expr2,
+		}
+	case expr1 != nil && expr2 == nil:
+		return expr1
+	case expr1 == nil && expr2 != nil:
+		return expr2
+	case expr1 == nil && expr2 == nil:
+		return nil
+	}
+	panic("unreachable")
+}
+
+func (e *BinaryOp) Concrete() bool {
+	return e.Expr1.Concrete() && e.Expr2.Concrete()
+}
+
+func (e *BinaryOp) Eval() uint {
+	switch e.Op {
+	case "+":
+		return e.Expr1.Eval() + e.Expr2.Eval()
+	case "-":
+		return e.Expr1.Eval() - e.Expr2.Eval()
+	case "*":
+		return e.Expr1.Eval() * e.Expr2.Eval()
+	case "/":
+		return e.Expr1.Eval() / e.Expr2.Eval()
+	case "&amp;":
+		return e.Expr1.Eval() & e.Expr2.Eval()
+	case "&lt;&lt;":
+		return e.Expr1.Eval() << e.Expr2.Eval()
+	}
+
+	log.Fatalf("Invalid binary operator '%s' for expression.", e.Op)
+	panic("unreachable")
+}
+
+func (e *BinaryOp) Reduce(prefix, fun string) string {
+	if e.Concrete() {
+		return fmt.Sprintf("%d", e.Eval())
+	}
+	return fmt.Sprintf("(%s %s %s)",
+		e.Expr1.Reduce(prefix, fun), e.Op, e.Expr2.Reduce(prefix, fun))
+}
+
+func (e *BinaryOp) String() string {
+	return e.Reduce("", "")
+}
+
+func (e *BinaryOp) Initialize(p *Protocol) {
+	e.Expr1.Initialize(p)
+	e.Expr2.Initialize(p)
+}
+
+type UnaryOp struct {
+	Op string
+	Expr Expression
+}
+
+func (e *UnaryOp) Concrete() bool {
+	return e.Expr.Concrete()
+}
+
+func (e *UnaryOp) Eval() uint {
+	switch e.Op {
+	case "~":
+		return ^e.Expr.Eval()
+	}
+
+	log.Fatalf("Invalid unary operator '%s' for expression.", e.Op)
+	panic("unreachable")
+}
+
+func (e *UnaryOp) Reduce(prefix, fun string) string {
+	if e.Concrete() {
+		return fmt.Sprintf("%d", e.Eval())
+	}
+	return fmt.Sprintf("(%s (%s))", e.Op, e.Expr.Reduce(prefix, fun))
+}
+
+func (e *UnaryOp) String() string {
+	return e.Reduce("", "")
+}
+
+func (e *UnaryOp) Initialize(p *Protocol) {
+	e.Expr.Initialize(p)
+}
+
+type PopCount struct {
+	Expr Expression
+}
+
+func (e *PopCount) Concrete() bool {
+	return e.Expr.Concrete()
+}
+
+func (e *PopCount) Eval() uint {
+	return popCount(e.Expr.Eval())
+}
+
+func (e *PopCount) Reduce(prefix, fun string) string {
+	if e.Concrete() {
+		return fmt.Sprintf("%d", e.Eval())
+	}
+	return fmt.Sprintf("popCount(%s)", e.Expr.Reduce(prefix, fun))
+}
+
+func (e *PopCount) String() string {
+	return e.Reduce("", "")
+}
+
+func (e *PopCount) Initialize(p *Protocol) {
+	e.Expr.Initialize(p)
+}
+
+type Value struct {
+	v uint
+}
+
+func (e *Value) Concrete() bool {
+	return true
+}
+
+func (e *Value) Eval() uint {
+	return e.v
+}
+
+func (e *Value) Reduce(prefix, fun string) string {
+	return fmt.Sprintf("%d", e.v)
+}
+
+func (e *Value) String() string {
+	return e.Reduce("", "")
+}
+
+func (e *Value) Initialize(p *Protocol) { }
+
+type Bit struct {
+	b uint
+}
+
+func (e *Bit) Concrete() bool {
+	return true
+}
+
+func (e *Bit) Eval() uint {
+	return 1 << e.b
+}
+
+func (e *Bit) Reduce(prefix, fun string) string {
+	return fmt.Sprintf("%d", e.Eval())
+}
+
+func (e *Bit) String() string {
+	return e.Reduce("", "")
+}
+
+func (e *Bit) Initialize(p *Protocol) { }
+
+type FieldRef struct {
+	Name string
+}
+
+func (e *FieldRef) Concrete() bool {
+	return false
+}
+
+func (e *FieldRef) Eval() uint {
+	log.Fatalf("Cannot evaluate a 'FieldRef'. It is not concrete.")
+	panic("unreachable")
+}
+
+func (e *FieldRef) Reduce(prefix, fun string) string {
+	val := e.Name
+	if len(prefix) > 0 {
+		val = fmt.Sprintf("%s%s", prefix, val)
+	}
+	if len(fun) > 0 {
+		val = fmt.Sprintf("%s(%s)", fun, val)
+	}
+	return val
+}
+
+func (e *FieldRef) String() string {
+	return e.Reduce("", "")
+}
+
+func (e *FieldRef) Initialize(p *Protocol) {
+	e.Name = SrcName(e.Name)
+}
+
+type EnumRef struct {
+	EnumKind Type
+	EnumItem string
+}
+
+func (e *EnumRef) Concrete() bool {
+	return false
+}
+
+func (e *EnumRef) Eval() uint {
+	log.Fatalf("Cannot evaluate an 'EnumRef'. It is not concrete.")
+	panic("unreachable")
+}
+
+func (e *EnumRef) Reduce(prefix, fun string) string {
+	val := fmt.Sprintf("%s%s", e.EnumKind, e.EnumItem)
+	if len(fun) > 0 {
+		val = fmt.Sprintf("%s(%s)", fun, val)
+	}
+	return val
+}
+
+func (e *EnumRef) String() string {
+	return e.Reduce("", "")
+}
+
+func (e *EnumRef) Initialize(p *Protocol) {
+	e.EnumKind = e.EnumKind.(*Translation).RealType(p)
+	e.EnumItem = SrcName(e.EnumItem)
+}
+
+type SumOf struct {
+	Name string
+}
+
+func (e *SumOf) Concrete() bool {
+	return false
+}
+
+func (e *SumOf) Eval() uint {
+	log.Fatalf("Cannot evaluate a 'SumOf'. It is not concrete.")
+	panic("unreachable")
+}
+
+func (e *SumOf) Reduce(prefix, fun string) string {
+	if len(prefix) > 0 {
+		return fmt.Sprintf("sum(%s%s)", prefix, e.Name)
+	}
+	return fmt.Sprintf("sum(%s)", e.Name)
+}
+
+func (e *SumOf) String() string {
+	return e.Reduce("", "")
+}
+
+func (e *SumOf) Initialize(p *Protocol) {
+	e.Name = SrcName(e.Name)
+}
+
diff --git a/nexgb/xgbgen/field.go b/nexgb/xgbgen/field.go
new file mode 100644
index 0000000..a659e6e
--- /dev/null
+++ b/nexgb/xgbgen/field.go
@@ -0,0 +1,170 @@
+package main
+
+type Field interface {
+	Initialize(p *Protocol)
+	SrcName() string
+	XmlName() string
+	Size() Size
+
+	Define(c *Context)
+	Read(c *Context)
+}
+
+func (pad *PadField) Initialize(p *Protocol) {}
+
+type PadField struct {
+	Bytes uint
+}
+
+func (p *PadField) SrcName() string {
+	panic("illegal to take source name of a pad field")
+}
+
+func (p *PadField) XmlName() string {
+	panic("illegal to take XML name of a pad field")
+}
+
+func (p *PadField) Size() Size {
+	return newFixedSize(p.Bytes)
+}
+
+type SingleField struct {
+	srcName string
+	xmlName string
+	Type Type
+}
+
+func (f *SingleField) Initialize(p *Protocol) {
+	f.srcName = SrcName(f.XmlName())
+	f.Type = f.Type.(*Translation).RealType(p)
+}
+
+func (f *SingleField) SrcName() string {
+	return f.srcName
+}
+
+func (f *SingleField) XmlName() string {
+	return f.xmlName
+}
+
+func (f *SingleField) Size() Size {
+	return f.Type.Size()
+}
+
+type ListField struct {
+	srcName string
+	xmlName string
+	Type Type
+	LengthExpr Expression
+}
+
+func (f *ListField) SrcName() string {
+	return f.srcName
+}
+
+func (f *ListField) XmlName() string {
+	return f.xmlName
+}
+
+func (f *ListField) Size() Size {
+	return newExpressionSize(f.LengthExpr).Multiply(f.Type.Size())
+}
+
+func (f *ListField) Initialize(p *Protocol) {
+	f.srcName = SrcName(f.XmlName())
+	f.Type = f.Type.(*Translation).RealType(p)
+	if f.LengthExpr != nil {
+		f.LengthExpr.Initialize(p)
+	}
+}
+
+type LocalField struct {
+	*SingleField
+}
+
+type ExprField struct {
+	srcName string
+	xmlName string
+	Type Type
+	Expr Expression
+}
+
+func (f *ExprField) SrcName() string {
+	return f.srcName
+}
+
+func (f *ExprField) XmlName() string {
+	return f.xmlName
+}
+
+func (f *ExprField) Size() Size {
+	return f.Type.Size()
+}
+
+func (f *ExprField) Initialize(p *Protocol) {
+	f.srcName = SrcName(f.XmlName())
+	f.Type = f.Type.(*Translation).RealType(p)
+	f.Expr.Initialize(p)
+}
+
+type ValueField struct {
+	MaskType Type
+	MaskName string
+	ListName string
+}
+
+func (f *ValueField) SrcName() string {
+	panic("it is illegal to call SrcName on a ValueField field")
+}
+
+func (f *ValueField) XmlName() string {
+	panic("it is illegal to call XmlName on a ValueField field")
+}
+
+func (f *ValueField) Size() Size {
+	return f.MaskType.Size()
+}
+
+func (f *ValueField) Initialize(p *Protocol) {
+	f.MaskType = f.MaskType.(*Translation).RealType(p)
+	f.MaskName = SrcName(f.MaskName)
+	f.ListName = SrcName(f.ListName)
+}
+
+type SwitchField struct {
+	Name string
+	Expr Expression
+	Bitcases []*Bitcase
+}
+
+func (f *SwitchField) SrcName() string {
+	panic("it is illegal to call SrcName on a SwitchField field")
+}
+
+func (f *SwitchField) XmlName() string {
+	panic("it is illegal to call XmlName on a SwitchField field")
+}
+
+// XXX: This is a bit tricky. The size has to be represented as a non-concrete
+// expression that finds *which* bitcase fields are included, and sums the
+// sizes of those fields.
+func (f *SwitchField) Size() Size {
+	return newFixedSize(0)
+}
+
+func (f *SwitchField) Initialize(p *Protocol) {
+	f.Name = SrcName(f.Name)
+	f.Expr.Initialize(p)
+	for _, bitcase := range f.Bitcases {
+		bitcase.Expr.Initialize(p)
+		for _, field := range bitcase.Fields {
+			field.Initialize(p)
+		}
+	}
+}
+
+type Bitcase struct {
+	Fields []Field
+	Expr Expression
+}
+
diff --git a/nexgb/xgbgen/go.go b/nexgb/xgbgen/go.go
index b939b3a..ac3ed2c 100644
--- a/nexgb/xgbgen/go.go
+++ b/nexgb/xgbgen/go.go
@@ -1,36 +1,13 @@
 package main
-/*
-	To the best of my ability, these are all of the Go specific formatting
-	functions. If I've designed xgbgen correctly, this should be only the
-	place that you change things to generate code for a new language.
-
-	This file is organized as follows:
-
-	* Imports and helper variables.
-	* Manual type and name override maps.
-	* Constants for tweaking various morphing functions.
-	* Helper morphing functions.
-	* Morphing functions for each "sub-unit."
-	* Morphing functions for each "unit".
-	* Morphing functions for collections of "units".
-	
-	Units can be thought of as the top-level elements in an XML protocol
-	description file. Namely, structs, xidtypes, imports, enums, unions, etc.
-	Collections of units are simply "all of the UNIT in the XML file."
-	Sub-units can be thought of as recurring bits like struct contents (which
-	is used in events, replies, requests, errors, etc.) and expression
-	evaluation.
-*/
 
 import (
 	"fmt"
 	"log"
-	"strings"
 )
 
-/******************************************************************************/
-// Manual type and name overrides.
-/******************************************************************************/
+// xgbResourceIdName is the name of the type used for all resource identifiers.
+// As of right now, it needs to be declared somewhere manually.
+var xgbGenResourceIdName = "Id"
 
 // BaseTypeMap is a map from X base types to Go types.
 // X base types should correspond to the smallest set of X types
@@ -50,6 +27,8 @@ var BaseTypeMap = map[string]string{
 	"float": "float64",
 	"double": "float64",
 	"char": "byte",
+	"void": "byte",
+	"Id": "Id",
 }
 
 // BaseTypeSizes should have precisely the same keys as in BaseTypeMap,
@@ -66,6 +45,7 @@ var BaseTypeSizes = map[string]uint{
 	"float": 4,
 	"double": 8,
 	"char": 1,
+	"void": 1,
 	"Id": 4,
 }
 
@@ -82,483 +62,350 @@ var TypeMap = map[string]string{
 // NameMap is the same as TypeMap, but for names.
 var NameMap = map[string]string{ }
 
-/******************************************************************************/
-// Constants for changing the semantics of morphing functions.
-// These are mainly used to tweaking the writing of fields.
-// Namely, reading/writing is not exactly the same across events,
-// requests/replies and errors.
-/******************************************************************************/
-const (
-	FieldsEvent = iota
-	FieldsRequestReply
-	FieldsError
-)
+// Reading, writing and defining...
 
-/******************************************************************************/
-// Helper functions that aide in morphing repetitive constructs.
-// i.e., type and identifier names, etc.
-/******************************************************************************/
-
-// Morph changes every TYPE (not names) into something suitable
-// for your language. It also handles adding suffixes like 'Event'
-// and 'Union'. (A 'Union' suffix is used in Go because unions aren't
-// supported at the language level.)
-func (typ Type) Morph(c *Context) string {
-	t := string(typ)
-
-	// If this is a base type, then write the raw Go type.
-	if newt, ok := BaseTypeMap[t]; ok {
-		return newt
-	}
-
-	// If it's in the type map, use that translation.
-	if newt, ok := TypeMap[t]; ok {
-		return newt
-	}
-
-	// If it's a resource type, just use 'Id'.
-	if c.xml.IsResource(typ) {
-		return "Id"
-	}
-
-	// If there's a namespace to this type, just use it and be done.
-	if colon := strings.Index(t, ":"); colon > -1 {
-		namespace := t[:colon]
-		rest := t[colon+1:]
-		return splitAndTitle(namespace) + splitAndTitle(rest)
-	}
-
-	// Since there is no namespace, we need to look for a namespace
-	// in the current context.
-	return typ.Prefix(c) + splitAndTitle(t)
-}
-
-// Prefix searches the parsed XML for a type matching 'typ'.
-// It then returns the appropriate prefix to be used in source code.
-// Note that the core X protocol *is* a namespace, but does not have a prefix.
-// Also note that you should probably check the BaseTypeMap and TypeMap
-// before calling this function.
-func (typ Type) Prefix(c *Context) string {
-	// If this is xproto, quit. No prefixes needed.
-	if c.xml.Header == "xproto" {
-		return ""
-	}
-
-	// First check for the type in the current namespace.
-	if c.xml.HasType(typ) {
-		return strings.Title(c.xml.Header)
-	}
-
-	// Now check each of the imports...
-	for _, imp := range c.xml.Imports {
-		if imp.xml.Header != "xproto" && imp.xml.HasType(typ) {
-			return strings.Title(imp.xml.Header)
-		}
-	}
-
-	return ""
-}
-
-// Morph changes every identifier (NOT type) into something suitable
-// for your language.
-func (name Name) Morph(c *Context) string {
-	n := string(name)
-
-	// If it's in the name map, use that translation.
-	if newn, ok := NameMap[n]; ok {
-		return newn
-	}
-
-	return splitAndTitle(n)
-}
-
-/******************************************************************************/
-// Sub-unit morphing.
-// Below are functions that morph sub-units. Like collections of fields,
-// expressions, etc.
-// Note that collections of fields can be used in three different contexts:
-// definitions, reading from the wire and writing to the wire. Thus, there
-// exists 'MorphDefine', 'MorphRead', 'MorphWrite' defined on Fields.
-/******************************************************************************/
-func (fields Fields) MorphDefine(c *Context) {
-	for _, field := range fields {
-		field.MorphDefine(c)
-	}
-}
-
-func (field *Field) MorphDefine(c *Context) {
-	// We omit 'pad' and 'exprfield'
-	switch field.XMLName.Local {
-	case "field":
-		c.Putln("%s %s", field.Name.Morph(c), field.Type.Morph(c))
-	case "list":
-		c.Putln("%s []%s", field.Name.Morph(c), field.Type.Morph(c))
-	case "localfield":
-		c.Putln("%s %s", field.Name.Morph(c), field.Type.Morph(c))
-	case "valueparam":
-		c.Putln("%s %s", field.ValueMaskName.Morph(c),
-			field.ValueMaskType.Morph(c))
-		c.Putln("%s []%s", field.ValueListName.Morph(c),
-			field.ValueMaskType.Morph(c))
-	case "switch":
-		field.Bitcases.MorphDefine(c)
-	}
-}
-
-func (bitcases Bitcases) MorphDefine(c *Context) {
-	for _, bitcase := range bitcases {
-		bitcase.MorphDefine(c)
-	}
-}
-
-func (bitcase *Bitcase) MorphDefine(c *Context) {
-	bitcase.Fields.MorphDefine(c)
-}
-
-func (fields Fields) MorphRead(c *Context, kind int, evNoSeq bool,
-	prefix string, byt uint) uint {
-
-	nextByte := byt
-	for _, field := range fields {
-		nextByte = field.MorphRead(c, kind, nextByte, prefix)
-		switch kind {
-		case FieldsEvent:
-			// Skip the sequence id
-			if !evNoSeq && (nextByte == 2 || nextByte == 3) {
-				nextByte = 4
-			}
-		}
-	}
-	return nextByte
-}
-
-func (field *Field) MorphRead(c *Context, kind int, byt uint,
-	prefix string) uint {
-
-	nextByte := byt
-	switch field.XMLName.Local {
-	case "pad":
-		nextByte += uint(field.Bytes)
-	case "field":
-		nextByte = field.MorphReadField(c, kind, nextByte, prefix)
-	case "list":
-		typ := field.Type.Morph(c)
-
-		// Create a temporary Field so we can use MorphReadField.
-		// temp := &Field{ 
-			// XMLName: xml.Name{Local: "field"}, 
-			// Name: field.Name, 
-			// Type: field.Type, 
-		// } 
-
-		// Special case: if the list is just raw bytes, use copy!
-		if typ == "byte" {
-			c.Putln("copy(%s%s, buf[%d:])", prefix, field.Name.Morph(c),
-				byt)
-			nextByte = byt + 20
-		} else {
-			c.Putln("//list!")
-		}
-	}
-	return nextByte
-}
-
-func (field *Field) MorphReadField(c *Context, kind int, byt uint,
-	prefix string) uint {
-
-	if union := field.Type.Union(c); union != nil {
-		c.Putln("")
-		c.Putln("%s%s = %s{}", prefix, field.Name.Morph(c), field.Type.Morph(c))
-		union.Fields.MorphRead(c, kind, false,
-			fmt.Sprintf("%s%s.", prefix, field.Name.Morph(c)), byt)
-		c.Putln("")
-		return byt
-	}
-
-	size := field.Type.Size(c)
-	typ := field.Type.Morph(c)
-	name := field.Name.Morph(c)
-	_, isBase := BaseTypeMap[string(field.Type)]
-
-	c.Put("%s%s = ", prefix, name)
-	if !isBase {
-		c.Put("%s(", typ)
-	}
-	switch size {
-	case 1:	c.Put("buf[%d]", byt)
-	case 2: c.Put("get16(buf[%d:])", byt)
-	case 4: c.Put("get32(buf[%d:])", byt)
-	case 8: c.Put("get64(buf[%d:])", byt)
-	default:
-		log.Fatalf("Unsupported field size '%d' for field '%s'.",
-			size, field)
-	}
-	if !isBase {
-		c.Put(")")
-	}
+// Base types
+func (b *Base) Define(c *Context) {
+	c.Putln("// Skipping definition for base type '%s'", SrcName(b.XmlName()))
 	c.Putln("")
-
-	return byt + size
 }
 
-func (fields Fields) MorphWrite(c *Context, kind int) {
-	var nextByte uint
-
-	switch kind {
-	case FieldsEvent:
-		nextByte = 1
-	}
-
-	for _, field := range fields {
-		nextByte = field.MorphWrite(c, kind, nextByte)
-	}
-}
-
-func (field *Field) MorphWrite(c *Context, kind int, byt uint) uint {
-	consumed := uint(0)
-	switch field.XMLName.Local {
-	case "pad":
-		consumed = uint(field.Bytes)
-	case "field":
-		size := field.Type.Size(c)
-		typ := field.Type.Morph(c)
-		name := field.Name.Morph(c)
-		switch size {
-		case 1:
-			c.Putln("v.%s = %s(buf[%d])", name, typ, byt)
-		case 2:
-			c.Putln("v.%s = %s(get16(buf[%d:]))", name, typ, byt)
-		case 4:
-			c.Putln("v.%s = %s(get32(buf[%d:]))", name, typ, byt)
-		case 8:
-			c.Putln("v.%s = %s(get64(buf[%d:]))", name, typ, byt)
-		}
-		consumed = size
-	case "list":
-		c.Putln("IDK")
-	}
-	return byt + consumed
-}
-
-/******************************************************************************/
-// Per element morphing.
-// Below are functions that morph a single unit.
-/******************************************************************************/
-
-// Import morphing.
-func (imp *Import) Morph(c *Context) {
-	c.Putln("// import \"%s\"", imp.Name)
-}
-
-// Enum morphing.
-func (enum *Enum) Morph(c *Context) {
+// Enum types
+func (enum *Enum) Define(c *Context) {
 	c.Putln("const (")
 	for _, item := range enum.Items {
-		c.Putln("%s%s = %d", enum.Name.Morph(c), item.Name.Morph(c),
-			item.Expr.Eval())
+		c.Putln("%s%s = %d", enum.SrcName(), item.srcName, item.Expr.Eval())
 	}
-	c.Putln(")\n")
-}
-
-// Xid morphing.
-func (xid *Xid) Morph(c *Context) {
-	// Don't emit anything for xid types for now.
-	// We're going to force them all to simply be 'Id'
-	// to avoid excessive type converting.
-	// c.Putln("type %s Id", xid.Name.Morph(c)) 
-}
-
-// TypeDef morphing.
-func (typedef *TypeDef) Morph(c *Context) {
-	c.Putln("type %s %s", typedef.New.Morph(c), typedef.Old.Morph(c))
-}
-
-// Struct morphing.
-func (strct *Struct) Morph(c *Context) {
-	c.Putln("type %s struct {", strct.Name.Morph(c))
-	strct.Fields.MorphDefine(c)
-	c.Putln("}")
-	c.Putln("\n")
-}
-
-// Union morphing.
-func (union *Union) Morph(c *Context) {
-	c.Putln("type %s struct {", union.Name.Morph(c))
-	union.Fields.MorphDefine(c)
-	c.Putln("}")
-	c.Putln("\n")
-}
-
-// Request morphing.
-func (request *Request) Morph(c *Context) {
-}
-
-// Event morphing.
-func (ev *Event) Morph(c *Context) {
-	name := ev.Name.Morph(c)
-
-	c.Putln("const %s = %d", name, ev.Number)
+	c.Putln(")")
 	c.Putln("")
-	c.Putln("type %sEvent struct {", name)
-	ev.Fields.MorphDefine(c)
+}
+
+// Resource types
+func (res *Resource) Define(c *Context) {
+	c.Putln("// Skipping resource definition of '%s'", SrcName(res.XmlName()))
+	c.Putln("")
+}
+
+// TypeDef types
+func (td *TypeDef) Define(c *Context) {
+	c.Putln("type %s %s", td.srcName, td.Old.SrcName())
+	c.Putln("")
+}
+
+// Struct types
+func (s *Struct) Define(c *Context) {
+	c.Putln("// '%s' struct definition", s.SrcName())
+	c.Putln("// Size: %s", s.Size())
+	c.Putln("type %s struct {", s.SrcName())
+	for _, field := range s.Fields {
+		field.Define(c)
+	}
 	c.Putln("}")
 	c.Putln("")
-	c.Putln("func New%s(buf []byte) %sEvent {", name, name)
-	c.Putln("var v %sEvent", name)
-	ev.Fields.MorphRead(c, FieldsEvent, ev.NoSequence, "v.", 1)
-	c.Putln("return v")
+
+	// Write function that reads bytes and produces this struct.
+	s.Read(c)
+
+	// Write function that reads a list of this structs.
+	s.ReadList(c)
+
+	// Write function that writes bytes given this struct.
+	s.Write(c)
+
+	// Write function that writes a list of this struct.
+	s.WriteList(c)
+}
+
+// Read for a struct creates a function 'NewStructName' that takes a byte
+// slice and produces TWO values: an instance of 'StructName' and the number
+// of bytes read from the byte slice.
+// 'NewStructName' should only be used to read raw reply data from the wire.
+func (s *Struct) Read(c *Context) {
+	c.Putln("// Struct read %s", s.SrcName())
+	c.Putln("func New%s(buf []byte) (%s, int) {", s.SrcName(), s.SrcName())
+
+	c.Putln("v := %s{}", s.SrcName())
+	c.Putln("b := 0")
+	c.Putln("consumed := 0")
+	c.Putln("consumed = 0 + consumed // no-op") // dirty hack for a no-op
+	c.Putln("")
+	for _, field := range s.Fields {
+		field.Read(c)
+	}
+	c.Putln("return v, b")
+
 	c.Putln("}")
 	c.Putln("")
-	c.Putln("func (err %sEvent) ImplementsEvent() { }", name)
+}
+
+// ReadList for a struct creates a function 'ReadStructNameList' that takes
+// a byte slice and a length and produces TWO values: an slice of StructName 
+// and the number of bytes read from the byte slice.
+func (s *Struct) ReadList(c *Context) {
+	c.Putln("// Struct list read %s", s.SrcName())
+	c.Putln("func Read%sList(buf []byte, length int) ([]%s, int) {",
+		s.SrcName(), s.SrcName())
+
+	c.Putln("v := make([]%s, length)", s.SrcName())
+	c.Putln("b := 0")
+	c.Putln("consumed := 0")
+	c.Putln("consumed = 0 + consumed // no-op") // dirty hack for a no-op
+	c.Putln("for i := 0; i < length; i++ {")
+		c.Putln("v[i], consumed = New%s(buf[b:])", s.SrcName())
+		c.Putln("b += consumed")
+	c.Putln("}")
+
+	c.Putln("return v, pad(b)")
+
+	c.Putln("}")
 	c.Putln("")
-	c.Putln("func (ev %sEvent) Bytes() []byte {", name)
-	// ev.Fields.MorphWrite(c, FieldsEvent) 
+}
+
+func (s *Struct) Write(c *Context) {
+	c.Putln("// Struct write %s", s.SrcName())
+	c.Putln("")
+}
+
+func (s *Struct) WriteList(c *Context) {
+	c.Putln("// Write struct list %s", s.SrcName())
+	c.Putln("")
+}
+
+// Union types
+func (u *Union) Define(c *Context) {
+	c.Putln("// Union definition %s", u.SrcName())
+}
+
+func (u *Union) Read(c *Context, prefix string) {
+	c.Putln("// Union read %s", u.SrcName())
+}
+
+func (u *Union) Write(c *Context, prefix string) {
+	c.Putln("// Union write %s", u.SrcName())
+}
+
+// Event types
+func (e *Event) Define(c *Context) {
+	c.Putln("// Event definition %s (%d)", e.SrcName(), e.Number)
+}
+
+func (e *Event) Read(c *Context, prefix string) {
+	c.Putln("// Event read %s", e.SrcName())
+}
+
+func (e *Event) Write(c *Context, prefix string) {
+	c.Putln("// Event write %s", e.SrcName())
+}
+
+// EventCopy types
+func (e *EventCopy) Define(c *Context) {
+	c.Putln("// EventCopy definition %s (%d)", e.SrcName(), e.Number)
+	c.Putln("")
+	c.Putln("const %s = %d", e.SrcName(), e.Number)
+	c.Putln("")
+	c.Putln("type %s %s", e.EvType(), e.Old.(*Event).EvType())
+	c.Putln("")
+	c.Putln("func New%s(buf []byte) %s {", e.SrcName(), e.EvType())
+	c.Putln("return (%s)(New%s(buf))", e.EvType(), e.Old.SrcName())
+	c.Putln("}")
+	c.Putln("")
+	c.Putln("func (ev %s) ImplementsEvent() { }", e.EvType())
+	c.Putln("")
+	c.Putln("func (ev %s) Bytes() []byte {", e.EvType())
+	c.Putln("return (%s)(ev).Bytes()", e.Old.(*Event).EvType())
 	c.Putln("}")
 	c.Putln("")
 	c.Putln("func init() {")
-	c.Putln("newEventFuncs[%d] = New%s", ev.Number, name)
+	c.Putln("newEventFuncs[%d] = New%s", e.Number, e.SrcName())
 	c.Putln("}")
 	c.Putln("")
 }
 
-// EventCopy morphing.
-func (evcopy *EventCopy) Morph(c *Context) {
-	oldName, newName := evcopy.Ref.Morph(c), evcopy.Name.Morph(c)
+// Error types
+func (e *Error) Define(c *Context) {
+	c.Putln("// Error definition %s (%d)", e.SrcName(), e.Number)
+	c.Putln("")
+}
 
-	c.Putln("const %s = %d", newName, evcopy.Number)
+func (e *Error) Read(c *Context, prefix string) {
+	c.Putln("// Error read %s", e.SrcName())
+}
+
+func (e *Error) Write(c *Context, prefix string) {
+	c.Putln("// Error write %s", e.SrcName())
+}
+
+// ErrorCopy types
+func (e *ErrorCopy) Define(c *Context) {
+	c.Putln("// ErrorCopy definition %s (%d)", e.SrcName(), e.Number)
 	c.Putln("")
-	c.Putln("type %sEvent %sEvent", newName, oldName)
+	c.Putln("const %s = %d", e.ErrConst(), e.Number)
 	c.Putln("")
-	c.Putln("func New%s(buf []byte) %sEvent {", newName, newName)
-	c.Putln("return (%sEvent)(New%s(buf))", newName, oldName)
+	c.Putln("type %s %s", e.ErrType(), e.Old.(*Error).ErrType())
+	c.Putln("")
+	c.Putln("func New%s(buf []byte) %s {", e.SrcName(), e.ErrType())
+	c.Putln("return (%s)(New%s(buf))", e.ErrType(), e.Old.SrcName())
 	c.Putln("}")
 	c.Putln("")
-	c.Putln("func (err %sEvent) ImplementsEvent() { }", newName)
+	c.Putln("func (err %s) ImplementsError() { }", e.ErrType())
 	c.Putln("")
-	c.Putln("func (ev %sEvent) Bytes() []byte {", newName)
-	c.Putln("return (%sEvent)(ev).Bytes()", oldName)
+	c.Putln("func (err %s) Bytes() []byte {", e.ErrType())
+	c.Putln("return (%s)(err).Bytes()", e.Old.(*Error).ErrType())
 	c.Putln("}")
 	c.Putln("")
 	c.Putln("func init() {")
-	c.Putln("newEventFuncs[%d] = New%s", evcopy.Number, newName)
+	c.Putln("newErrorFuncs[%d] = New%s", e.Number, e.SrcName())
 	c.Putln("}")
 	c.Putln("")
 }
 
-// Error morphing.
-func (err *Error) Morph(c *Context) {
+// Field definitions, reads and writes.
+
+// Pad fields
+func (f *PadField) Define(c *Context) {
+	c.Putln("// padding: %d bytes", f.Bytes)
 }
 
-// ErrorCopy morphing.
-func (errcopy *ErrorCopy) Morph(c *Context) {
-	oldName, newName := errcopy.Ref.Morph(c), errcopy.Name.Morph(c)
-
-	c.Putln("const Bad%s = %d", newName, errcopy.Number)
-	c.Putln("")
-	c.Putln("type %sError %sError", newName, oldName)
-	c.Putln("")
-	c.Putln("func New%sError(buf []byte) %sError {", newName, newName)
-	c.Putln("return (%sError)(New%sError(buf))", newName, oldName)
-	c.Putln("}")
-	c.Putln("")
-	c.Putln("func (err %sError) ImplementsError() { }", newName)
-	c.Putln("")
-	c.Putln("func (err %sError) Bytes() []byte {", newName)
-	c.Putln("return (%sError)(err).Bytes()", oldName)
-	c.Putln("}")
-	c.Putln("")
-	c.Putln("func init() {")
-	c.Putln("newErrorFuncs[%d] = New%sError", errcopy.Number, newName)
-	c.Putln("}")
+func (f *PadField) Read(c *Context) {
+	c.Putln("b += %s // padding", f.Size())
 	c.Putln("")
 }
 
-/******************************************************************************/
-// Collection morphing.
-// Below are functions that morph a collections of units.
-// Most of these can probably remain unchanged, but they are useful if you
-// need to group all of some "unit" in a single block or something.
-/******************************************************************************/
-func (imports Imports) Morph(c *Context) {
-	if len(imports) == 0 {
-		return
+// Single fields
+func (f *SingleField) Define(c *Context) {
+	c.Putln("%s %s", f.SrcName(), f.Type.SrcName())
+}
+
+func ReadSimpleSingleField(c *Context, name string, typ Type) {
+	switch t := typ.(type) {
+	case *Resource:
+		c.Putln("%s = get32(buf[b:])", name)
+	case *TypeDef:
+		switch t.Size().Eval() {
+		case 1:
+			c.Putln("%s = %s(buf[b])", name, t.SrcName())
+		case 2:
+			c.Putln("%s = %s(get16(buf[b:]))", name, t.SrcName())
+		case 4:
+			c.Putln("%s = %s(get32(buf[b:]))", name, t.SrcName())
+		case 8:
+			c.Putln("%s = %s(get64(buf[b:]))", name, t.SrcName())
+		}
+	case *Base:
+		var val string
+		switch t.Size().Eval() {
+		case 1:
+			val = fmt.Sprintf("buf[b]")
+		case 2:
+			val = fmt.Sprintf("get16(buf[b:])")
+		case 4:
+			val = fmt.Sprintf("get32(buf[b:])")
+		case 8:
+			val = fmt.Sprintf("get64(buf[b:])")
+		}
+
+		// We need to convert base types if they aren't uintXX or byte
+		ty := t.SrcName()
+		if ty != "byte" && ty != "uint16" && ty != "uint32" && ty != "uint64" {
+			val = fmt.Sprintf("%s(%s)", ty, val)
+		}
+		c.Putln("%s = %s", name, val)
+	default:
+		log.Fatalf("Cannot read field '%s' as a simple field with %T type.",
+			name, typ)
 	}
 
-	c.Putln("// Imports are not required for XGB since everything is in")
-	c.Putln("// a single package. Still these may be useful for ")
-	c.Putln("// reference purposes.")
-	for _, imp := range imports {
-		imp.Morph(c)
+	c.Putln("b += %s", typ.Size())
+}
+
+func (f *SingleField) Read(c *Context) {
+	switch t := f.Type.(type) {
+	case *Resource:
+		ReadSimpleSingleField(c, fmt.Sprintf("v.%s", f.SrcName()), t)
+	case *TypeDef:
+		ReadSimpleSingleField(c, fmt.Sprintf("v.%s", f.SrcName()), t)
+	case *Base:
+		ReadSimpleSingleField(c, fmt.Sprintf("v.%s", f.SrcName()), t)
+	case *Struct:
+		c.Putln("v.%s, consumed = New%s(buf[b:])", f.SrcName(), t.SrcName())
+		c.Putln("b += consumed")
+		c.Putln("")
+	default:
+		log.Fatalf("Cannot read field '%s' with %T type.", f.XmlName(), f.Type)
 	}
 }
 
-func (enums Enums) Morph(c *Context) {
-	c.Putln("// Enums\n")
-	for _, enum := range enums {
-		enum.Morph(c)
+// List fields
+func (f *ListField) Define(c *Context) {
+	c.Putln("%s []%s // length: %s",
+		f.SrcName(), f.Type.SrcName(), f.Size())
+}
+
+func (f *ListField) Read(c *Context) {
+	switch t := f.Type.(type) {
+	case *Resource:
+		length := f.LengthExpr.Reduce("v.", "")
+		c.Putln("v.%s = make([]Id, %s)", f.SrcName(), length)
+		c.Putln("for i := 0; i < %s; i++ {", length)
+			ReadSimpleSingleField(c, fmt.Sprintf("v.%s[i]", f.SrcName()), t)
+		c.Putln("}")
+		c.Putln("")
+	case *Base:
+		length := f.LengthExpr.Reduce("v.", "")
+		c.Putln("v.%s = make([]%s, %s)", f.SrcName(), t.SrcName(), length)
+		c.Putln("for i := 0; i < %s; i++ {", length)
+			ReadSimpleSingleField(c, fmt.Sprintf("v.%s[i]", f.SrcName()), t)
+		c.Putln("}")
+		c.Putln("")
+	case *Struct:
+		c.Putln("v.%s, consumed = Read%sList(buf[b:], %s)",
+			f.SrcName(), t.SrcName(), f.LengthExpr.Reduce("v.", ""))
+		c.Putln("b += consumed")
+		c.Putln("")
+	default:
+		log.Fatalf("Cannot read list field '%s' with %T type.",
+			f.XmlName(), f.Type)
 	}
 }
 
-func (xids Xids) Morph(c *Context) {
-	c.Putln("// Xids\n")
-	for _, xid := range xids {
-		xid.Morph(c)
-	}
+// Local fields
+func (f *LocalField) Define(c *Context) {
+	c.Putln("// local field: %s %s", f.SrcName(), f.Type.SrcName())
 }
 
-func (typedefs TypeDefs) Morph(c *Context) {
-	c.Putln("// TypeDefs\n")
-	for _, typedef := range typedefs {
-		typedef.Morph(c)
-	}
+func (f *LocalField) Read(c *Context) {
+	c.Putln("// reading local field: %s (%s) :: %s",
+		f.SrcName(), f.Size(), f.Type.SrcName())
 }
 
-func (strct Structs) Morph(c *Context) {
-	c.Putln("// Structs\n")
-	for _, typedef := range strct {
-		typedef.Morph(c)
-	}
+// Expr fields
+func (f *ExprField) Define(c *Context) {
+	c.Putln("// expression field: %s %s (%s)",
+		f.SrcName(), f.Type.SrcName(), f.Expr)
 }
 
-func (union Unions) Morph(c *Context) {
-	c.Putln("// Unions\n")
-	for _, typedef := range union {
-		typedef.Morph(c)
-	}
+func (f *ExprField) Read(c *Context) {
+	c.Putln("// reading expression field: %s (%s) (%s) :: %s",
+		f.SrcName(), f.Size(), f.Expr, f.Type.SrcName())
 }
 
-func (request Requests) Morph(c *Context) {
-	c.Putln("// Requests\n")
-	for _, typedef := range request {
-		typedef.Morph(c)
-	}
+// Value field
+func (f *ValueField) Define(c *Context) {
+	c.Putln("// valueparam field: type: %s, mask name: %s, list name: %s",
+		f.MaskType.SrcName(), f.MaskName, f.ListName)
 }
 
-func (event Events) Morph(c *Context) {
-	c.Putln("// Events\n")
-	for _, typedef := range event {
-		typedef.Morph(c)
-	}
+func (f *ValueField) Read(c *Context) {
+	c.Putln("// reading valueparam: type: %s, mask name: %s, list name: %s",
+		f.MaskType.SrcName(), f.MaskName, f.ListName)
 }
 
-func (evcopy EventCopies) Morph(c *Context) {
-	c.Putln("// Event Copies\n")
-	for _, typedef := range evcopy {
-		typedef.Morph(c)
-	}
+// Switch field
+func (f *SwitchField) Define(c *Context) {
+	c.Putln("// switch field: %s (%s)", f.Name, f.Expr)
 }
 
-func (err Errors) Morph(c *Context) {
-	c.Putln("// Errors\n")
-	for _, typedef := range err {
-		typedef.Morph(c)
-	}
-}
-
-func (errcopy ErrorCopies) Morph(c *Context) {
-	c.Putln("// Error copies\n")
-	for _, typedef := range errcopy {
-		typedef.Morph(c)
-	}
+func (f *SwitchField) Read(c *Context) {
+	c.Putln("// reading switch field: %s (%s)", f.Name, f.Expr)
 }
 
diff --git a/nexgb/xgbgen/main.go b/nexgb/xgbgen/main.go
index c69c8aa..33f7971 100644
--- a/nexgb/xgbgen/main.go
+++ b/nexgb/xgbgen/main.go
@@ -47,7 +47,7 @@ func main() {
 
 	// Initialize the buffer, parse it, and filter it through gofmt.
 	c := newContext()
-	c.Translate(xmlBytes)
+	c.Morph(xmlBytes)
 
 	if !*gofmt {
 		c.out.WriteTo(os.Stdout)
diff --git a/nexgb/xgbgen/morph.go b/nexgb/xgbgen/morph.go
new file mode 100644
index 0000000..c39b333
--- /dev/null
+++ b/nexgb/xgbgen/morph.go
@@ -0,0 +1,50 @@
+
+// Morph cascades down all of the XML and calls each type's corresponding
+// Morph function with itself as an argument (the context).
+func (x *XML) Morph(c *Context) {
+	// Start the header...
+	c.Putln("package xgb")
+	c.Putln("/*")
+	c.Putln("\tX protocol API for '%s.xml'.", c.xml.Header)
+	c.Putln("\tThis file is automatically generated. Edit at your own peril!")
+	c.Putln("\tGenerated on %s",
+		time.Now().Format("Jan 2, 2006 at 3:04:05pm MST"))
+	c.Putln("*/")
+	c.Putln("")
+
+	x.Imports.Morph(c)
+	c.Putln("")
+
+	x.Enums.Morph(c)
+	c.Putln("")
+
+	x.Xids.Morph(c)
+	c.Putln("")
+
+	x.XidUnions.Morph(c)
+	c.Putln("")
+
+	x.TypeDefs.Morph(c)
+	c.Putln("")
+
+	x.Structs.Morph(c)
+	c.Putln("")
+
+	x.Unions.Morph(c)
+	c.Putln("")
+
+	x.Requests.Morph(c)
+	c.Putln("")
+
+	x.Errors.Morph(c)
+	c.Putln("")
+
+	x.ErrorCopies.Morph(c)
+	c.Putln("")
+
+	x.Events.Morph(c)
+	c.Putln("")
+
+	x.EventCopies.Morph(c)
+	c.Putln("")
+}
diff --git a/nexgb/xgbgen/representation.go b/nexgb/xgbgen/representation.go
new file mode 100644
index 0000000..928e219
--- /dev/null
+++ b/nexgb/xgbgen/representation.go
@@ -0,0 +1,56 @@
+package main
+
+type Protocol struct {
+	Name string
+	ExtXName string
+	ExtName string
+	MajorVersion string
+	MinorVersion string
+
+	Imports []*Protocol
+	Types []Type
+	Requests []*Request
+}
+
+// Initialize traverses all structures, looks for 'Translation' type,
+// and looks up the real type in the namespace. It also sets the source
+// name for all relevant fields/structures.
+// This is necessary because we don't traverse the XML in order initially.
+func (p *Protocol) Initialize() {
+	for _, typ := range p.Types {
+		typ.Initialize(p)
+	}
+	for _, req := range p.Requests {
+		req.Initialize(p)
+	}
+}
+
+type Request struct {
+	srcName string
+	xmlName string
+	Opcode int
+	Combine bool
+	Fields []Field
+	Reply *Reply
+}
+
+func (r *Request) Initialize(p *Protocol) {
+	r.srcName = SrcName(r.xmlName)
+	if r.Reply != nil {
+		r.Reply.Initialize(p)
+	}
+	for _, field := range r.Fields {
+		field.Initialize(p)
+	}
+}
+
+type Reply struct {
+	Fields []Field
+}
+
+func (r *Reply) Initialize(p *Protocol) {
+	for _, field := range r.Fields {
+		field.Initialize(p)
+	}
+}
+
diff --git a/nexgb/xgbgen/size.go b/nexgb/xgbgen/size.go
new file mode 100644
index 0000000..d00e297
--- /dev/null
+++ b/nexgb/xgbgen/size.go
@@ -0,0 +1,22 @@
+package main
+
+type Size struct {
+	Expression
+}
+
+func newFixedSize(fixed uint) Size {
+	return Size{&Value{v: fixed}}
+}
+
+func newExpressionSize(variable Expression) Size {
+	return Size{variable}
+}
+
+func (s1 Size) Add(s2 Size) Size {
+	return Size{newBinaryOp("+", s1, s2)}
+}
+
+func (s1 Size) Multiply(s2 Size) Size {
+	return Size{newBinaryOp("*", s1, s2)}
+}
+
diff --git a/nexgb/xgbgen/translation.go b/nexgb/xgbgen/translation.go
new file mode 100644
index 0000000..85e756d
--- /dev/null
+++ b/nexgb/xgbgen/translation.go
@@ -0,0 +1,426 @@
+package main
+/*
+	translation.go provides a 'Translate' method on every XML type that converts
+	the XML type into our "better" representation.
+
+	i.e., the representation of Fields and Expressions is just too general.
+	We end up losing a lot of the advantages of static typing if we keep
+	the types that encoding/xml forces us into.
+
+	Please see 'representation.go' for the type definitions that we're
+	translating to.
+*/
+
+import (
+	"log"
+	"strconv"
+	"strings"
+)
+
+func (xml *XML) Translate() *Protocol {
+	protocol := &Protocol{
+		Name: xml.Header,
+		ExtXName: xml.ExtensionXName,
+		ExtName: xml.ExtensionName,
+		MajorVersion: xml.MajorVersion,
+		MinorVersion: xml.MinorVersion,
+
+		Imports: make([]*Protocol, 0),
+		Types: make([]Type, 0),
+		Requests: make([]*Request, len(xml.Requests)),
+	}
+
+	for _, imp := range xml.Imports {
+		if imp.xml != nil {
+			protocol.Imports = append(protocol.Imports, imp.xml.Translate())
+		}
+	}
+
+	for xmlName, srcName := range BaseTypeMap {
+		newBaseType := &Base{
+			srcName: srcName,
+			xmlName: xmlName,
+			size: newFixedSize(BaseTypeSizes[xmlName]),
+		}
+		protocol.Types = append(protocol.Types, newBaseType)
+	}
+	for _, enum := range xml.Enums {
+		protocol.Types = append(protocol.Types, enum.Translate())
+	}
+	for _, xid := range xml.Xids {
+		protocol.Types = append(protocol.Types, xid.Translate())
+	}
+	for _, xidunion := range xml.XidUnions {
+		protocol.Types = append(protocol.Types, xidunion.Translate())
+	}
+	for _, typedef := range xml.TypeDefs {
+		protocol.Types = append(protocol.Types, typedef.Translate())
+	}
+	for _, s := range xml.Structs {
+		protocol.Types = append(protocol.Types, s.Translate())
+	}
+	for _, union := range xml.Unions {
+		protocol.Types = append(protocol.Types, union.Translate())
+	}
+	for _, ev := range xml.Events {
+		protocol.Types = append(protocol.Types, ev.Translate())
+	}
+	for _, evcopy := range xml.EventCopies {
+		protocol.Types = append(protocol.Types, evcopy.Translate())
+	}
+	for _, err := range xml.Errors {
+		protocol.Types = append(protocol.Types, err.Translate())
+	}
+	for _, errcopy := range xml.ErrorCopies {
+		protocol.Types = append(protocol.Types, errcopy.Translate())
+	}
+
+	for i, request := range xml.Requests {
+		protocol.Requests[i] = request.Translate()
+	}
+
+	// Now load all of the type and source name information.
+	protocol.Initialize()
+
+	// Make sure all enums have concrete values.
+	for _, typ := range protocol.Types {
+		enum, ok := typ.(*Enum)
+		if !ok {
+			continue
+		}
+		nextValue := uint(0)
+		for _, item := range enum.Items {
+			if item.Expr == nil {
+				item.Expr = &Value{v: nextValue}
+				nextValue++
+			} else {
+				nextValue = item.Expr.Eval() + 1
+			}
+		}
+	}
+
+	return protocol
+}
+
+func (x *XMLEnum) Translate() *Enum {
+	enum := &Enum{
+		xmlName: x.Name,
+		Items: make([]*EnumItem, len(x.Items)),
+	}
+	for i, item := range x.Items {
+		enum.Items[i] = &EnumItem{
+			xmlName: item.Name,
+			Expr: item.Expr.Translate(),
+		}
+	}
+	return enum
+}
+
+func (x *XMLXid) Translate() *Resource {
+	return &Resource{
+		xmlName: x.Name,
+	}
+}
+
+func (x *XMLTypeDef) Translate() *TypeDef {
+	return &TypeDef{
+		xmlName: x.New,
+		Old: newTranslation(x.Old),
+	}
+}
+
+func (x *XMLEvent) Translate() *Event {
+	ev := &Event{
+		xmlName: x.Name,
+		Number: x.Number,
+		NoSequence: x.NoSequence,
+		Fields: make([]Field, len(x.Fields)),
+	}
+	for i, field := range x.Fields {
+		ev.Fields[i] = field.Translate()
+	}
+	return ev
+}
+
+func (x *XMLEventCopy) Translate() *EventCopy {
+	return &EventCopy{
+		xmlName: x.Name,
+		Number: x.Number,
+		Old: newTranslation(x.Ref),
+	}
+}
+
+func (x *XMLError) Translate() *Error {
+	err := &Error{
+		xmlName: x.Name,
+		Number: x.Number,
+		Fields: make([]Field, len(x.Fields)),
+	}
+	for i, field := range x.Fields {
+		err.Fields[i] = field.Translate()
+	}
+	return err
+}
+
+func (x *XMLErrorCopy) Translate() *ErrorCopy {
+	return &ErrorCopy{
+		xmlName: x.Name,
+		Number: x.Number,
+		Old: newTranslation(x.Ref),
+	}
+}
+
+func (x *XMLStruct) Translate() *Struct {
+	s := &Struct{
+		xmlName: x.Name,
+		Fields: make([]Field, len(x.Fields)),
+	}
+	for i, field := range x.Fields {
+		s.Fields[i] = field.Translate()
+	}
+	return s
+}
+
+func (x *XMLUnion) Translate() *Union {
+	u := &Union{
+		xmlName: x.Name,
+		Fields: make([]Field, len(x.Fields)),
+	}
+	for i, field := range x.Fields {
+		u.Fields[i] = field.Translate()
+	}
+	return u
+}
+
+func (x *XMLRequest) Translate() *Request {
+	r := &Request{
+		xmlName: x.Name,
+		Opcode: x.Opcode,
+		Combine: x.Combine,
+		Fields: make([]Field, len(x.Fields)),
+		Reply: x.Reply.Translate(),
+	}
+	for i, field := range x.Fields {
+		r.Fields[i] = field.Translate()
+	}
+
+	// Address bug (or legacy code) in QueryTextExtents.
+	// The XML protocol description references 'string_len' in the
+	// computation of the 'odd_length' field. However, 'string_len' is not
+	// defined. Therefore, let's forcefully add it as a 'local field'.
+	// (i.e., a parameter in the caller but does not get send over the wire.)
+	stringLenLocal := &LocalField{&SingleField{
+		xmlName: "string_len",
+		Type: newTranslation("CARD16"),
+	}}
+	r.Fields = append(r.Fields, stringLenLocal)
+
+	return r
+}
+
+func (x *XMLReply) Translate() *Reply {
+	if x == nil {
+		return nil
+	}
+
+	r := &Reply{
+		Fields: make([]Field, len(x.Fields)),
+	}
+	for i, field := range x.Fields {
+		r.Fields[i] = field.Translate()
+	}
+	return r
+}
+
+func (x *XMLExpression) Translate() Expression {
+	if x == nil {
+		return nil
+	}
+
+	switch x.XMLName.Local {
+	case "op":
+		if len(x.Exprs) != 2 {
+			log.Panicf("'op' found %d expressions; expected 2.", len(x.Exprs))
+		}
+		return &BinaryOp{
+			Op: x.Op,
+			Expr1: x.Exprs[0].Translate(),
+			Expr2: x.Exprs[1].Translate(),
+		}
+	case "unop":
+		if len(x.Exprs) != 1 {
+			log.Panicf("'unop' found %d expressions; expected 1.", len(x.Exprs))
+		}
+		return &UnaryOp{
+			Op: x.Op,
+			Expr: x.Exprs[0].Translate(),
+		}
+	case "popcount":
+		if len(x.Exprs) != 1 {
+			log.Panicf("'popcount' found %d expressions; expected 1.",
+				len(x.Exprs))
+		}
+		return &PopCount{
+			Expr: x.Exprs[0].Translate(),
+		}
+	case "value":
+		val, err := strconv.Atoi(x.Data)
+		if err != nil {
+			log.Panicf("Could not convert '%s' in 'value' expression to int.",
+				x.Data)
+		}
+		return &Value{
+			v: uint(val),
+		}
+	case "bit":
+		bit, err := strconv.Atoi(x.Data)
+		if err != nil {
+			log.Panicf("Could not convert '%s' in 'bit' expression to int.",
+				x.Data)
+		}
+		if bit < 0 || bit > 31 {
+			log.Panicf("A 'bit' literal must be in the range [0, 31], but " +
+				" is %d", bit)
+		}
+		return &Bit{
+			b: uint(bit),
+		}
+	case "fieldref":
+		return &FieldRef{
+			Name: x.Data,
+		}
+	case "enumref":
+		return &EnumRef{
+			EnumKind: newTranslation(x.Ref),
+			EnumItem: x.Data,
+		}
+	case "sumof":
+		return &SumOf{
+			Name: x.Ref,
+		}
+	}
+
+	log.Panicf("Unrecognized tag '%s' in expression context. Expected one of " +
+		"op, fieldref, value, bit, enumref, unop, sumof or popcount.",
+		x.XMLName.Local)
+	panic("unreachable")
+}
+
+func (x *XMLField) Translate() Field {
+	switch x.XMLName.Local {
+	case "pad":
+		return &PadField{
+			Bytes: x.Bytes,
+		}
+	case "field":
+		return &SingleField{
+			xmlName: x.Name,
+			Type: newTranslation(x.Type),
+		}
+	case "list":
+		return &ListField{
+			xmlName: x.Name,
+			Type: newTranslation(x.Type),
+			LengthExpr: x.Expr.Translate(),
+		}
+	case "localfield":
+		return &LocalField{&SingleField{
+			xmlName: x.Name,
+			Type: newTranslation(x.Type),
+		}}
+	case "exprfield":
+		return &ExprField{
+			xmlName: x.Name,
+			Type: newTranslation(x.Type),
+			Expr: x.Expr.Translate(),
+		}
+	case "valueparam":
+		return &ValueField{
+			MaskType: newTranslation(x.ValueMaskType),
+			MaskName: x.ValueMaskName,
+			ListName: x.ValueListName,
+		}
+	case "switch":
+		swtch := &SwitchField{
+			Name: x.Name,
+			Expr: x.Expr.Translate(),
+			Bitcases: make([]*Bitcase, len(x.Bitcases)),
+		}
+		for i, bitcase := range x.Bitcases {
+			swtch.Bitcases[i] = bitcase.Translate()
+		}
+		return swtch
+	}
+
+	log.Panicf("Unrecognized field element: %s", x.XMLName.Local)
+	panic("unreachable")
+}
+
+func (x *XMLBitcase) Translate() *Bitcase {
+	b := &Bitcase{
+		Expr: x.Expr().Translate(),
+		Fields: make([]Field, len(x.Fields)),
+	}
+	for i, field := range x.Fields {
+		b.Fields[i] = field.Translate()
+	}
+	return b
+}
+
+// SrcName is used to translate any identifier into a Go name.
+// Mostly used for fields, but used in a couple other places too (enum items).
+func SrcName(name string) string {
+	// If it's in the name map, use that translation.
+	if newn, ok := NameMap[name]; ok {
+		return newn
+	}
+
+	return splitAndTitle(name)
+}
+
+func TypeSrcName(p *Protocol, typ Type) string {
+	t := typ.XmlName()
+
+	// If this is a base type, then write the raw Go type.
+	if baseType, ok := typ.(*Base); ok {
+		return baseType.SrcName()
+	}
+
+	// If it's in the type map, use that translation.
+	if newt, ok := TypeMap[t]; ok {
+		return newt
+	}
+
+	// If it's a resource type, just use 'Id'.
+	if _, ok := typ.(*Resource); ok {
+		return xgbGenResourceIdName
+	}
+
+	// If there's a namespace to this type, just use it and be done.
+	if colon := strings.Index(t, ":"); colon > -1 {
+		namespace := t[:colon]
+		rest := t[colon+1:]
+		return splitAndTitle(namespace) + splitAndTitle(rest)
+	}
+
+	// Since there is no namespace, we need to look for a namespace
+	// in the current context.
+	niceType := splitAndTitle(t)
+	if p.Name != "xproto" {
+		for _, typ2 := range p.Types {
+			if t == typ2.XmlName() {
+				return strings.Title(p.Name) + niceType
+			}
+		}
+		for _, imp := range p.Imports {
+			for _, typ2 := range imp.Types {
+				if t == typ2.XmlName() {
+					return strings.Title(imp.Name) + niceType
+				}
+			}
+		}
+	}
+
+	// We couldn't find one, so return it without a prefix.
+	return niceType
+}
diff --git a/nexgb/xgbgen/type.go b/nexgb/xgbgen/type.go
new file mode 100644
index 0000000..1574922
--- /dev/null
+++ b/nexgb/xgbgen/type.go
@@ -0,0 +1,365 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+)
+
+type Type interface {
+	Initialize(p *Protocol)
+	SrcName() string
+	XmlName() string
+	Size() Size
+
+	Define(c *Context)
+}
+
+// Translation is used *only* when transitioning from XML types to
+// our better representation. They are placeholders for the real types (below)
+// that will replace them.
+type Translation struct {
+	xmlName string
+}
+
+func newTranslation(name string) *Translation {
+	return &Translation{xmlName: name}
+}
+
+// RealType takes 'XmlName' and finds its real concrete type in our Protocol.
+// It is an error if we can't find such a type.
+func (t *Translation) RealType(p *Protocol) Type {
+	// Check to see if there is a namespace. If so, strip it and use it to
+	// make sure we only look for a type in that protocol.
+	namespace, typeName := "", t.XmlName()
+	if ni := strings.Index(t.XmlName(), ":"); ni > -1 {
+		namespace, typeName = strings.ToLower(typeName[:ni]), typeName[ni+1:]
+	}
+
+	if len(namespace) == 0 || namespace == strings.ToLower(p.Name) {
+		for _, typ := range p.Types {
+			if typeName == typ.XmlName() {
+				return typ
+			}
+		}
+	}
+	for _, imp := range p.Imports {
+		if len(namespace) == 0 || namespace == strings.ToLower(imp.Name) {
+			for _, typ := range imp.Types {
+				if typeName == typ.XmlName() {
+					return typ
+				}
+			}
+		}
+	}
+	panic("Could not find real type for translation type: " + t.XmlName())
+}
+
+func (t *Translation) SrcName() string {
+	panic("it is illegal to call SrcName on a translation type")
+}
+
+func (t *Translation) XmlName() string {
+	return t.xmlName
+}
+
+func (t *Translation) Size() Size {
+	panic("it is illegal to call Size on a translation type")
+}
+
+func (t *Translation) Define(c *Context) {
+	panic("it is illegal to call Define on a translation type")
+}
+
+func (t *Translation) Initialize(p *Protocol) {
+	panic("it is illegal to call Initialize on a translation type")
+}
+
+type Base struct {
+	srcName string
+	xmlName string
+	size Size
+}
+
+func (b *Base) SrcName() string {
+	return b.srcName
+}
+
+func (b *Base) XmlName() string {
+	return b.xmlName
+}
+
+func (b *Base) Size() Size {
+	return b.size
+}
+
+func (b *Base) Initialize(p *Protocol) {
+	b.srcName = TypeSrcName(p, b)
+}
+
+type Enum struct {
+	srcName string
+	xmlName string
+	Items []*EnumItem
+}
+
+type EnumItem struct {
+	srcName string
+	xmlName string
+	Expr Expression
+}
+
+func (enum *Enum) SrcName() string {
+	return enum.srcName
+}
+
+func (enum *Enum) XmlName() string {
+	return enum.xmlName
+}
+
+func (enum *Enum) Size() Size {
+	panic("Cannot take size of enum")
+}
+
+func (enum *Enum) Initialize(p *Protocol) {
+	enum.srcName = TypeSrcName(p, enum)
+	for _, item := range enum.Items {
+		item.srcName = SrcName(item.xmlName)
+		if item.Expr != nil {
+			item.Expr.Initialize(p)
+		}
+	}
+}
+
+type Resource struct {
+	srcName string
+	xmlName string
+}
+
+func (r *Resource) SrcName() string {
+	return r.srcName
+}
+
+func (r *Resource) XmlName() string {
+	return r.xmlName
+}
+
+func (r *Resource) Size() Size {
+	return newFixedSize(BaseTypeSizes["Id"])
+}
+
+func (r *Resource) Initialize(p *Protocol) {
+	r.srcName = TypeSrcName(p, r)
+}
+
+type TypeDef struct {
+	srcName string
+	xmlName string
+	Old Type
+}
+
+func (t *TypeDef) SrcName() string {
+	return t.srcName
+}
+
+func (t *TypeDef) XmlName() string {
+	return t.xmlName
+}
+
+func (t *TypeDef) Size() Size {
+	return t.Old.Size()
+}
+
+func (t *TypeDef) Initialize(p *Protocol) {
+	t.Old = t.Old.(*Translation).RealType(p)
+	t.srcName = TypeSrcName(p, t)
+}
+
+type Event struct {
+	srcName string
+	xmlName string
+	Number int
+	NoSequence bool
+	Fields []Field
+}
+
+func (e *Event) SrcName() string {
+	return e.srcName
+}
+
+func (e *Event) XmlName() string {
+	return e.xmlName
+}
+
+func (e *Event) Size() Size {
+	panic("Cannot take size of Event type.")
+}
+
+func (e *Event) Initialize(p *Protocol) {
+	e.srcName = TypeSrcName(p, e)
+	for _, field := range e.Fields {
+		field.Initialize(p)
+	}
+}
+
+func (e *Event) EvType() string {
+	return fmt.Sprintf("%sEvent", e.srcName)
+}
+
+type EventCopy struct {
+	srcName string
+	xmlName string
+	Old Type
+	Number int
+}
+
+func (e *EventCopy) SrcName() string {
+	return e.srcName
+}
+
+func (e *EventCopy) XmlName() string {
+	return e.xmlName
+}
+
+func (e *EventCopy) Size() Size {
+	panic("Cannot take size of EventCopy type.")
+}
+
+func (e *EventCopy) Initialize(p *Protocol) {
+	e.srcName = TypeSrcName(p, e)
+	e.Old = e.Old.(*Translation).RealType(p)
+	if _, ok := e.Old.(*Event); !ok {
+		panic("an EventCopy's old type *must* be *Event")
+	}
+}
+
+func (e *EventCopy) EvType() string {
+	return fmt.Sprintf("%sEvent", e.srcName)
+}
+
+type Error struct {
+	srcName string
+	xmlName string
+	Number int
+	Fields []Field
+}
+
+func (e *Error) SrcName() string {
+	return e.srcName
+}
+
+func (e *Error) XmlName() string {
+	return e.xmlName
+}
+
+func (e *Error) Size() Size {
+	panic("Cannot take size of Error type.")
+}
+
+func (e *Error) Initialize(p *Protocol) {
+	e.srcName = TypeSrcName(p, e)
+}
+
+func (e *Error) ErrConst() string {
+	return fmt.Sprintf("Bad%s", e.srcName)
+}
+
+func (e *Error) ErrType() string {
+	return fmt.Sprintf("%sError", e.srcName)
+}
+
+type ErrorCopy struct {
+	srcName string
+	xmlName string
+	Old Type
+	Number int
+}
+
+func (e *ErrorCopy) SrcName() string {
+	return e.srcName
+}
+
+func (e *ErrorCopy) XmlName() string {
+	return e.xmlName
+}
+
+func (e *ErrorCopy) Size() Size {
+	panic("Cannot take size of ErrorCopy type.")
+}
+
+func (e *ErrorCopy) Initialize(p *Protocol) {
+	e.srcName = TypeSrcName(p, e)
+	e.Old = e.Old.(*Translation).RealType(p)
+	if _, ok := e.Old.(*Error); !ok {
+		panic("an ErrorCopy's old type *must* be *Event")
+	}
+}
+
+func (e *ErrorCopy) ErrConst() string {
+	return fmt.Sprintf("Bad%s", e.srcName)
+}
+
+func (e *ErrorCopy) ErrType() string {
+	return fmt.Sprintf("%sError", e.srcName)
+}
+
+type Struct struct {
+	srcName string
+	xmlName string
+	Fields []Field
+}
+
+func (s *Struct) SrcName() string {
+	return s.srcName
+}
+
+func (s *Struct) XmlName() string {
+	return s.xmlName
+}
+
+func (s *Struct) Size() Size {
+	size := newFixedSize(0)
+	for _, field := range s.Fields {
+		size = size.Add(field.Size())
+	}
+	return size
+}
+
+func (s *Struct) Initialize(p *Protocol) {
+	s.srcName = TypeSrcName(p, s)
+	for _, field := range s.Fields {
+		field.Initialize(p)
+	}
+}
+
+type Union struct {
+	srcName string
+	xmlName string
+	Fields []Field
+}
+
+func (u *Union) SrcName() string {
+	return u.srcName
+}
+
+func (u *Union) XmlName() string {
+	return u.xmlName
+}
+
+// Size for Union is broken. At least, it's broken for XKB.
+// It *looks* like the protocol inherently relies on some amount of
+// memory unsafety, since some members of unions in XKB are *variable* in
+// length! The only thing I can come up with, maybe, is when a union has
+// variable size, simply return the raw bytes. Then it's up to the user to
+// pass those raw bytes into the appropriate New* constructor. GROSS!
+// As of now, just pluck out the first field and return that size. This
+// should work for union elements in randr.xml and xproto.xml.
+func (u *Union) Size() Size {
+	return u.Fields[0].Size()
+}
+
+func (u *Union) Initialize(p *Protocol) {
+	u.srcName = TypeSrcName(p, u)
+	for _, field := range u.Fields {
+		field.Initialize(p)
+	}
+}
diff --git a/nexgb/xgbgen/xml.go b/nexgb/xgbgen/xml.go
index e4202d0..7e50831 100644
--- a/nexgb/xgbgen/xml.go
+++ b/nexgb/xgbgen/xml.go
@@ -4,7 +4,6 @@ import (
 	"encoding/xml"
 	"io/ioutil"
 	"log"
-	"time"
 )
 
 type XML struct {
@@ -18,231 +17,25 @@ type XML struct {
 
 	// Types for all top-level elements.
 	// First are the simple ones.
-	Imports Imports `xml:"import"`
-	Enums Enums `xml:"enum"`
-	Xids Xids `xml:"xidtype"`
-	XidUnions Xids `xml:"xidunion"`
-	TypeDefs TypeDefs `xml:"typedef"`
-	EventCopies EventCopies `xml:"eventcopy"`
-	ErrorCopies ErrorCopies `xml:"errorcopy"`
+	Imports XMLImports `xml:"import"`
+	Enums XMLEnums `xml:"enum"`
+	Xids XMLXids `xml:"xidtype"`
+	XidUnions XMLXids `xml:"xidunion"`
+	TypeDefs XMLTypeDefs `xml:"typedef"`
+	EventCopies XMLEventCopies `xml:"eventcopy"`
+	ErrorCopies XMLErrorCopies `xml:"errorcopy"`
 
 	// Here are the complex ones, i.e., anything with "structure contents"
-	Structs Structs `xml:"struct"`
-	Unions Unions `xml:"union"`
-	Requests Requests `xml:"request"`
-	Events Events `xml:"event"`
-	Errors Errors `xml:"error"`
+	Structs XMLStructs `xml:"struct"`
+	Unions XMLUnions `xml:"union"`
+	Requests XMLRequests `xml:"request"`
+	Events XMLEvents `xml:"event"`
+	Errors XMLErrors `xml:"error"`
 }
 
-// Morph cascades down all of the XML and calls each type's corresponding
-// Morph function with itself as an argument (the context).
-func (x *XML) Morph(c *Context) {
-	// Start the header...
-	c.Putln("package xgb")
-	c.Putln("/*")
-	c.Putln("\tX protocol API for '%s.xml'.", c.xml.Header)
-	c.Putln("\tThis file is automatically generated. Edit at your own peril!")
-	c.Putln("\tGenerated on %s",
-		time.Now().Format("Jan 2, 2006 at 3:04:05pm MST"))
-	c.Putln("*/")
-	c.Putln("")
+type XMLImports []*XMLImport
 
-	x.Imports.Morph(c)
-	c.Putln("")
-
-	x.Enums.Morph(c)
-	c.Putln("")
-
-	x.Xids.Morph(c)
-	c.Putln("")
-
-	x.XidUnions.Morph(c)
-	c.Putln("")
-
-	x.TypeDefs.Morph(c)
-	c.Putln("")
-
-	x.Structs.Morph(c)
-	c.Putln("")
-
-	x.Unions.Morph(c)
-	c.Putln("")
-
-	x.Requests.Morph(c)
-	c.Putln("")
-
-	x.Errors.Morph(c)
-	c.Putln("")
-
-	x.ErrorCopies.Morph(c)
-	c.Putln("")
-
-	x.Events.Morph(c)
-	c.Putln("")
-
-	x.EventCopies.Morph(c)
-	c.Putln("")
-}
-
-// IsResource returns true if the 'needle' type is a resource type.
-// i.e., an "xid"
-func (x *XML) IsResource(needle Type) bool {
-	for _, xid := range x.Xids {
-		if needle == xid.Name {
-			return true
-		}
-	}
-	for _, xidunion := range x.XidUnions {
-		if needle == xidunion.Name {
-			return true
-		}
-	}
-	for _, imp := range x.Imports {
-		if imp.xml.IsResource(needle) {
-			return true
-		}
-	}
-	return false
-}
-
-// HasType returns true if the 'needle' type can be found in the protocol
-// description represented by 'x'.
-func (x *XML) HasType(needle Type) bool {
-	for _, enum := range x.Enums {
-		if needle == enum.Name {
-			return true
-		}
-	}
-	for _, xid := range x.Xids {
-		if needle == xid.Name {
-			return true
-		}
-	}
-	for _, xidunion := range x.XidUnions {
-		if needle == xidunion.Name {
-			return true
-		}
-	}
-	for _, typedef := range x.TypeDefs {
-		if needle == typedef.New {
-			return true
-		}
-	}
-	for _, evcopy := range x.EventCopies {
-		if needle == evcopy.Name {
-			return true
-		}
-	}
-	for _, errcopy := range x.ErrorCopies {
-		if needle == errcopy.Name {
-			return true
-		}
-	}
-	for _, strct := range x.Structs {
-		if needle == strct.Name {
-			return true
-		}
-	}
-	for _, union := range x.Unions {
-		if needle == union.Name {
-			return true
-		}
-	}
-	for _, ev := range x.Events {
-		if needle == ev.Name {
-			return true
-		}
-	}
-	for _, err := range x.Errors {
-		if needle == err.Name {
-			return true
-		}
-	}
-
-	return false
-}
-
-type Name string
-
-type Type string
-
-// Union returns the 'Union' struct corresponding to this type, if
-// one exists.
-func (typ Type) Union(c *Context) *Union {
-	// If this is a typedef, use that instead.
-	if oldTyp, ok := typ.TypeDef(c); ok {
-		return oldTyp.Union(c)
-	}
-
-	// Otherwise, just look for a union type with 'typ' name.
-	for _, union := range c.xml.Unions {
-		if typ == union.Name {
-			return union
-		}
-	}
-	for _, imp := range c.xml.Imports {
-		for _, union := range imp.xml.Unions {
-			if typ == union.Name {
-				return union
-			}
-		}
-	}
-	return nil
-}
-
-// TypeDef returns the 'old' type corresponding to this type, if it's found
-// in a type def. If not found, the second return value is false.
-func (typ Type) TypeDef(c *Context) (Type, bool) {
-	for _, typedef := range c.xml.TypeDefs {
-		if typ == typedef.New {
-			return typedef.Old, true
-		}
-	}
-	for _, imp := range c.xml.Imports {
-		for _, typedef := range imp.xml.TypeDefs {
-			if typ == typedef.New {
-				return typedef.Old, true
-			}
-		}
-	}
-	return "", false
-}
-
-// Size is a nifty function that takes any type and digs until it finds
-// its underlying base type. At which point, the size can be determined.
-func (typ Type) Size(c *Context) uint {
-	// If this is a base type, we're done.
-	if size, ok := BaseTypeSizes[string(typ)]; ok {
-		return size
-	}
-
-	// If it's a resource, we're also done.
-	if c.xml.IsResource(typ) {
-		return BaseTypeSizes["Id"]
-	}
-
-	// It's not, so that implies there is *some* typedef declaring it
-	// in terms of another type. Just follow that chain until we get to
-	// a base type. We also need to check imported stuff.
-	for _, typedef := range c.xml.TypeDefs {
-		if typ == typedef.New {
-			return typedef.Old.Size(c)
-		}
-	}
-	for _, imp := range c.xml.Imports {
-		for _, typedef := range imp.xml.TypeDefs {
-			if typ == typedef.New {
-				return typedef.Old.Size(c)
-			}
-		}
-	}
-	log.Panicf("Could not find base size of type '%s'.", typ)
-	panic("unreachable")
-}
-
-type Imports []*Import
-
-func (imports Imports) Eval() {
+func (imports XMLImports) Eval() {
 	for _, imp := range imports {
 		xmlBytes, err := ioutil.ReadFile(*protoPath + "/" + imp.Name + ".xml")
 		if err != nil {
@@ -256,117 +49,101 @@ func (imports Imports) Eval() {
 			log.Fatal("Could not parse X protocol description for import " +
 				"'%s' because: %s", imp.Name, err)
 		}
+
+		// recursive imports...
+		imp.xml.Imports.Eval()
 	}
 }
 
-type Import struct {
+type XMLImport struct {
 	Name string `xml:",chardata"`
 	xml *XML `xml:"-"`
 }
 
-type Enums []Enum
+type XMLEnums []XMLEnum
 
-// Eval on the list of all enum types goes through and forces every enum
-// item to have a valid expression.
-// This is necessary because when an item is empty, it is defined to have
-// the value of "one more than that of the previous item, or 0 for the first
-// item".
-func (enums Enums) Eval() {
-	for _, enum := range enums {
-		nextValue := uint(0)
-		for _, item := range enum.Items {
-			if item.Expr == nil {
-				item.Expr = newValueExpression(nextValue)
-				nextValue++
-			} else {
-				nextValue = item.Expr.Eval() + 1
-			}
-		}
-	}
+type XMLEnum struct {
+	Name string `xml:"name,attr"`
+	Items []*XMLEnumItem `xml:"item"`
 }
 
-type Enum struct {
-	Name Type `xml:"name,attr"`
-	Items []*EnumItem `xml:"item"`
+type XMLEnumItem struct {
+	Name string `xml:"name,attr"`
+	Expr *XMLExpression `xml:",any"`
 }
 
-type EnumItem struct {
-	Name Name `xml:"name,attr"`
-	Expr *Expression `xml:",any"`
-}
+type XMLXids []*XMLXid
 
-type Xids []*Xid
-
-type Xid struct {
+type XMLXid struct {
 	XMLName xml.Name
-	Name Type `xml:"name,attr"`
+	Name string `xml:"name,attr"`
 }
 
-type TypeDefs []*TypeDef
+type XMLTypeDefs []*XMLTypeDef
 
-type TypeDef struct {
-	Old Type `xml:"oldname,attr"`
-	New Type `xml:"newname,attr"`
+type XMLTypeDef struct {
+	Old string `xml:"oldname,attr"`
+	New string `xml:"newname,attr"`
 }
 
-type EventCopies []*EventCopy
+type XMLEventCopies []*XMLEventCopy
 
-type EventCopy struct {
-	Name Type `xml:"name,attr"`
+type XMLEventCopy struct {
+	Name string `xml:"name,attr"`
 	Number int `xml:"number,attr"`
-	Ref Type `xml:"ref,attr"`
+	Ref string `xml:"ref,attr"`
 }
 
-type ErrorCopies []*ErrorCopy
+type XMLErrorCopies []*XMLErrorCopy
 
-type ErrorCopy struct {
-	Name Type `xml:"name,attr"`
+type XMLErrorCopy struct {
+	Name string `xml:"name,attr"`
 	Number int `xml:"number,attr"`
-	Ref Type `xml:"ref,attr"`
+	Ref string `xml:"ref,attr"`
 }
 
-type Structs []*Struct
+type XMLStructs []*XMLStruct
 
-type Struct struct {
-	Name Type `xml:"name,attr"`
-	Fields Fields `xml:",any"`
+type XMLStruct struct {
+	Name string `xml:"name,attr"`
+	Fields XMLFields `xml:",any"`
 }
 
-type Unions []*Union
+type XMLUnions []*XMLUnion
 
-type Union struct {
-	Name Type `xml:"name,attr"`
-	Fields Fields `xml:",any"`
+type XMLUnion struct {
+	Name string `xml:"name,attr"`
+	Fields XMLFields `xml:",any"`
 }
 
-type Requests []*Request
+type XMLRequests []*XMLRequest
 
-type Request struct {
-	Name Type `xml:"name,attr"`
+type XMLRequest struct {
+	Name string `xml:"name,attr"`
 	Opcode int `xml:"opcode,attr"`
 	Combine bool `xml:"combine-adjacent,attr"`
-	Fields Fields `xml:",any"`
-	Reply *Reply `xml:"reply"`
+	Fields XMLFields `xml:",any"`
+	Reply *XMLReply `xml:"reply"`
 }
 
-type Reply struct {
-	Fields Fields `xml:",any"`
+type XMLReply struct {
+	Fields XMLFields `xml:",any"`
 }
 
-type Events []*Event
+type XMLEvents []*XMLEvent
 
-type Event struct {
-	Name Type `xml:"name,attr"`
+type XMLEvent struct {
+	Name string `xml:"name,attr"`
 	Number int `xml:"number,attr"`
 	NoSequence bool `xml:"no-sequence-number,true"`
-	Fields Fields `xml:",any"`
+	Fields XMLFields `xml:",any"`
 }
 
-type Errors []*Error
+type XMLErrors []*XMLError
 
-type Error struct {
-	Name Type `xml:"name,attr"`
+type XMLError struct {
+	Name string `xml:"name,attr"`
 	Number int `xml:"number,attr"`
-	Fields Fields `xml:",any"`
+	Fields XMLFields `xml:",any"`
 }
 
diff --git a/nexgb/xgbgen/xml_expression.go b/nexgb/xgbgen/xml_expression.go
index dd32512..57ff62e 100644
--- a/nexgb/xgbgen/xml_expression.go
+++ b/nexgb/xgbgen/xml_expression.go
@@ -7,25 +7,25 @@ import (
 	"strconv"
 )
 
-type Expression struct {
+type XMLExpression struct {
 	XMLName xml.Name
 
-	Exprs []*Expression `xml:",any"`
+	Exprs []*XMLExpression `xml:",any"`
 
 	Data string `xml:",chardata"`
 	Op string `xml:"op,attr"`
 	Ref string `xml:"ref,attr"`
 }
 
-func newValueExpression(v uint) *Expression {
-	return &Expression{
+func newValueExpression(v uint) *XMLExpression {
+	return &XMLExpression{
 		XMLName: xml.Name{Local: "value"},
 		Data: fmt.Sprintf("%d", v),
 	}
 }
 
 // String is for debugging. For actual use, please use 'Morph'.
-func (e *Expression) String() string {
+func (e *XMLExpression) String() string {
 	switch e.XMLName.Local {
 	case "op":
 		return fmt.Sprintf("(%s %s %s)", e.Exprs[0], e.Op, e.Exprs[1])
@@ -55,7 +55,7 @@ func (e *Expression) String() string {
 // empty items in enums.
 // We can't compute a concrete value for expressions that rely on a context,
 // i.e., some field value.
-func (e *Expression) Eval() uint {
+func (e *XMLExpression) Eval() uint {
 	switch e.XMLName.Local {
 	case "op":
 		if len(e.Exprs) != 2 {
@@ -108,7 +108,7 @@ func (e *Expression) Eval() uint {
 	panic("unreachable")
 }
 
-func (e *Expression) BinaryOp(operand1, operand2 *Expression) *Expression {
+func (e *XMLExpression) BinaryOp(oprnd1, oprnd2 *XMLExpression) *XMLExpression {
 	if e.XMLName.Local != "op" {
 		log.Panicf("Cannot perform binary operation on non-op expression: %s",
 			e.XMLName.Local)
@@ -121,17 +121,17 @@ func (e *Expression) BinaryOp(operand1, operand2 *Expression) *Expression {
 	wrap := newValueExpression
 	switch e.Op {
 	case "+":
-		return wrap(operand1.Eval() + operand2.Eval())
+		return wrap(oprnd1.Eval() + oprnd2.Eval())
 	case "-":
-		return wrap(operand1.Eval() + operand2.Eval())
+		return wrap(oprnd1.Eval() + oprnd2.Eval())
 	case "*":
-		return wrap(operand1.Eval() * operand2.Eval())
+		return wrap(oprnd1.Eval() * oprnd2.Eval())
 	case "/":
-		return wrap(operand1.Eval() / operand2.Eval())
+		return wrap(oprnd1.Eval() / oprnd2.Eval())
 	case "&amp;":
-		return wrap(operand1.Eval() & operand2.Eval())
+		return wrap(oprnd1.Eval() & oprnd2.Eval())
 	case "&lt;&lt;":
-		return wrap(operand1.Eval() << operand2.Eval())
+		return wrap(oprnd1.Eval() << oprnd2.Eval())
 	}
 
 	log.Panicf("Invalid binary operator '%s' for '%s' expression.",
@@ -139,7 +139,7 @@ func (e *Expression) BinaryOp(operand1, operand2 *Expression) *Expression {
 	panic("unreachable")
 }
 
-func (e *Expression) UnaryOp(operand *Expression) *Expression {
+func (e *XMLExpression) UnaryOp(oprnd *XMLExpression) *XMLExpression {
 	if e.XMLName.Local != "unop" {
 		log.Panicf("Cannot perform unary operation on non-unop expression: %s",
 			e.XMLName.Local)
@@ -151,7 +151,7 @@ func (e *Expression) UnaryOp(operand *Expression) *Expression {
 
 	switch e.Op {
 	case "~":
-		return newValueExpression(^operand.Eval())
+		return newValueExpression(^oprnd.Eval())
 	}
 
 	log.Panicf("Invalid unary operator '%s' for '%s' expression.",
diff --git a/nexgb/xgbgen/xml_fields.go b/nexgb/xgbgen/xml_fields.go
index c1a7240..d6d99c5 100644
--- a/nexgb/xgbgen/xml_fields.go
+++ b/nexgb/xgbgen/xml_fields.go
@@ -23,40 +23,40 @@ import (
 	"strings"
 )
 
-type Fields []*Field
+type XMLFields []*XMLField
 
-type Field struct {
+type XMLField struct {
 	XMLName xml.Name
 
 	// For 'pad' element
-	Bytes int `xml:"bytes,attr"`
+	Bytes uint `xml:"bytes,attr"`
 
 	// For 'field', 'list', 'localfield', 'exprfield' and 'switch' elements.
-	Name Name `xml:"name,attr"`
+	Name string `xml:"name,attr"`
 
 	// For 'field', 'list', 'localfield', and 'exprfield' elements.
-	Type Type `xml:"type,attr"`
+	Type string `xml:"type,attr"`
 
 	// For 'list', 'exprfield' and 'switch' elements.
-	Expr *Expression `xml:",any"`
+	Expr *XMLExpression `xml:",any"`
 
 	// For 'valueparm' element.
-	ValueMaskType Type `xml:"value-mask-type,attr"`
-	ValueMaskName Name `xml:"value-mask-name,attr"`
-	ValueListName Name `xml:"value-list-name,attr"`
+	ValueMaskType string `xml:"value-mask-type,attr"`
+	ValueMaskName string `xml:"value-mask-name,attr"`
+	ValueListName string `xml:"value-list-name,attr"`
 
 	// For 'switch' element.
-	Bitcases Bitcases `xml:"bitcase"`
+	Bitcases XMLBitcases `xml:"bitcase"`
 
 	// I don't know which elements these are for. The documentation is vague.
 	// They also seem to be completely optional.
-	OptEnum Type `xml:"enum,attr"`
-	OptMask Type `xml:"mask,attr"`
-	OptAltEnum Type `xml:"altenum,attr"`
+	OptEnum string `xml:"enum,attr"`
+	OptMask string `xml:"mask,attr"`
+	OptAltEnum string `xml:"altenum,attr"`
 }
 
 // String is for debugging purposes.
-func (f *Field) String() string {
+func (f *XMLField) String() string {
 	switch f.XMLName.Local {
 	case "pad":
 		return fmt.Sprintf("pad (%d bytes)", f.Bytes)
@@ -88,7 +88,7 @@ func (f *Field) String() string {
 	panic("unreachable")
 }
 
-type Bitcases []*Bitcase
+type XMLBitcases []*XMLBitcase
 
 // Bitcase represents a single expression followed by any number of fields.
 // Namely, if the switch's expression (all bitcases are inside a switch),
@@ -98,24 +98,24 @@ type Bitcases []*Bitcase
 // siblings, we must exhaustively search for one of them. Essentially,
 // it's the closest thing to a Union I can get to in Go without interfaces.
 // Would an '<expression>' tag have been too much to ask? :-(
-type Bitcase struct {
-	Fields Fields `xml:",any"`
+type XMLBitcase struct {
+	Fields XMLFields `xml:",any"`
 
 	// All the different expressions.
 	// When it comes time to choose one, use the 'Expr' method.
-	ExprOp *Expression `xml:"op"`
-	ExprUnOp *Expression `xml:"unop"`
-	ExprField *Expression `xml:"fieldref"`
-	ExprValue *Expression `xml:"value"`
-	ExprBit *Expression `xml:"bit"`
-	ExprEnum *Expression `xml:"enumref"`
-	ExprSum *Expression `xml:"sumof"`
-	ExprPop *Expression `xml:"popcount"`
+	ExprOp *XMLExpression `xml:"op"`
+	ExprUnOp *XMLExpression `xml:"unop"`
+	ExprField *XMLExpression `xml:"fieldref"`
+	ExprValue *XMLExpression `xml:"value"`
+	ExprBit *XMLExpression `xml:"bit"`
+	ExprEnum *XMLExpression `xml:"enumref"`
+	ExprSum *XMLExpression `xml:"sumof"`
+	ExprPop *XMLExpression `xml:"popcount"`
 }
 
 // StringPrefix is for debugging purposes only.
 // StringPrefix takes a string to prefix to every extra line for formatting.
-func (b *Bitcase) StringPrefix(prefix string) string {
+func (b *XMLBitcase) StringPrefix(prefix string) string {
 	fields := make([]string, len(b.Fields))
 	for i, field := range b.Fields {
 		fields[i] = fmt.Sprintf("%s%s", prefix, field)
@@ -126,13 +126,13 @@ func (b *Bitcase) StringPrefix(prefix string) string {
 
 // Expr chooses the only non-nil Expr* field from Bitcase.
 // Panic if there is more than one non-nil expression.
-func (b *Bitcase) Expr() *Expression {
-	choices := []*Expression{
+func (b *XMLBitcase) Expr() *XMLExpression {
+	choices := []*XMLExpression{
 		b.ExprOp, b.ExprUnOp, b.ExprField, b.ExprValue,
 		b.ExprBit, b.ExprEnum, b.ExprSum, b.ExprPop,
 	}
 
-	var choice *Expression = nil
+	var choice *XMLExpression = nil
 	numNonNil := 0
 	for _, c := range choices {
 		if c != nil {