x/model: disambiguate type names

There are now more than just File to the model package.  This change
disambiguates types like Error to FileError, etc. It also helps line
things up with GoDoc.

x/model/file.go

@@ -1,3 +1,4 @@
+// Package model implements the Modelfile and Path formats.
 package model
 
 import (
@@ -7,12 +8,12 @@ import (
 	"strings"
 )
 
-type Param struct {
+type ParameterPragma struct {
 	Key   string
 	Value string
 }
 
-type Message struct {
+type MessagePragma struct {
 	Role    string
 	Content string
 }
@@ -23,24 +24,25 @@ type File struct {
 	From string
 
 	// Optional
-	Params   []Param
+	Params   []ParameterPragma
 	Template string
 	System   string
 	Adapter  string
-	Messages []Message
+	Messages []MessagePragma
 
 	License string
 }
 
-type Error struct {
+type FileError struct {
 	Pragma  string
 	Message string
 }
 
-func (e *Error) Error() string {
+func (e *FileError) Error() string {
 	return e.Pragma + ": " + e.Message
 }
 
+// Pragma represents a single pragma in a Modelfile.
 type Pragma struct {
 	// The pragma name
 	Name string
@@ -57,7 +59,7 @@ func (p Pragma) Arg(i int) string {
 	return p.Args[i]
 }
 
-func Pragmas(r io.Reader) iter.Seq2[Pragma, error] {
+func FilePragmas(r io.Reader) iter.Seq2[Pragma, error] {
 	return func(yield func(Pragma, error) bool) {
 		sc := bufio.NewScanner(r)
 		for sc.Scan() {
@@ -93,9 +95,9 @@ func Pragmas(r io.Reader) iter.Seq2[Pragma, error] {
 	}
 }
 
-func Decode(r io.Reader) (File, error) {
+func ParseFile(r io.Reader) (File, error) {
 	var f File
-	for p, err := range Pragmas(r) {
+	for p, err := range FilePragmas(r) {
 		if err != nil {
 			return File{}, err
 		}
@@ -103,7 +105,7 @@ func Decode(r io.Reader) (File, error) {
 		case "FROM":
 			f.From = p.Arg(0)
 		case "PARAMETER":
-			f.Params = append(f.Params, Param{
+			f.Params = append(f.Params, ParameterPragma{
 				Key:   strings.ToLower(p.Arg(0)),
 				Value: p.Arg(1),
 			})
@@ -114,7 +116,7 @@ func Decode(r io.Reader) (File, error) {
 		case "ADAPTER":
 			f.Adapter = p.Arg(0)
 		case "MESSAGE":
-			f.Messages = append(f.Messages, Message{
+			f.Messages = append(f.Messages, MessagePragma{
 				Role:    p.Arg(0),
 				Content: p.Arg(1),
 			})

x/model/path.go

@@ -9,11 +9,11 @@ import (
 
 const MaxPathLength = 255
 
-type PartKind int
+type PathPart int
 
 // Levels of concreteness
 const (
-	Invalid PartKind = iota
+	Invalid PathPart = iota
 	Domain
 	Namespace
 	Name
@@ -21,7 +21,7 @@ const (
 	Build
 )
 
-var kindNames = map[PartKind]string{
+var kindNames = map[PathPart]string{
 	Invalid:   "Invalid",
 	Domain:    "Domain",
 	Namespace: "Namespace",
@@ -153,7 +153,7 @@ func (r Path) Build() string     { return r.build }
 //	""
 func ParsePath(s string) Path {
 	var r Path
-	for kind, part := range Parts(s) {
+	for kind, part := range PathParts(s) {
 		switch kind {
 		case Domain:
 			r.domain = part
@@ -196,8 +196,8 @@ func Merge(a, b Path) Path {
 //
 // It normalizes the input string by removing "http://" and "https://" only.
 // No other normalization is done.
-func Parts(s string) iter.Seq2[PartKind, string] {
-	return func(yield func(PartKind, string) bool) {
+func PathParts(s string) iter.Seq2[PathPart, string] {
+	return func(yield func(PathPart, string) bool) {
 		if strings.HasPrefix(s, "http://") {
 			s = s[len("http://"):]
 		}
@@ -209,7 +209,7 @@ func Parts(s string) iter.Seq2[PartKind, string] {
 			return
 		}
 
-		yieldValid := func(kind PartKind, part string) bool {
+		yieldValid := func(kind PathPart, part string) bool {
 			if !isValidPart(part) {
 				yield(Invalid, "")
 				return false