cue: remove FileSet from API

Change-Id: Idc52c4a07cc2ddfaaa217b30050a14e14584655d
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/2123
Reviewed-by: Marcel van Lohuizen <mpvl@google.com>
diff --git a/internal/protobuf/parse.go b/internal/protobuf/parse.go
index b81bd5c..0298db3 100644
--- a/internal/protobuf/parse.go
+++ b/internal/protobuf/parse.go
@@ -596,8 +596,7 @@
 
 		case "(cue.val)":
 			// TODO: set filename and base offset.
-			fset := token.NewFileSet()
-			expr, err := parser.ParseExpr(fset, "", o.Constant.Source)
+			expr, err := parser.ParseExpr("", o.Constant.Source)
 			if err != nil {
 				failf("invalid cue.val value: %v", err)
 			}
diff --git a/internal/third_party/yaml/decode.go b/internal/third_party/yaml/decode.go
index 0626801..2b985b0 100644
--- a/internal/third_party/yaml/decode.go
+++ b/internal/third_party/yaml/decode.go
@@ -75,7 +75,7 @@
 	return ioutil.ReadFile(filename)
 }
 
-func newParser(fset *token.FileSet, filename string, src interface{}) (*parser, error) {
+func newParser(filename string, src interface{}) (*parser, error) {
 	b, err := readSource(filename, src)
 	if err != nil {
 		return nil, err
diff --git a/internal/third_party/yaml/decode_test.go b/internal/third_party/yaml/decode_test.go
index 2e2122d..71cbf3c 100644
--- a/internal/third_party/yaml/decode_test.go
+++ b/internal/third_party/yaml/decode_test.go
@@ -13,7 +13,6 @@
 
 	"cuelang.org/go/cue/ast"
 	"cuelang.org/go/cue/format"
-	"cuelang.org/go/cue/token"
 	"cuelang.org/go/internal/third_party/yaml"
 )
 
@@ -624,8 +623,6 @@
 	C int
 }
 
-var fset = token.NewFileSet()
-
 func cueStr(node ast.Node) string {
 	if s, ok := node.(*ast.StructLit); ok {
 		node = &ast.File{
@@ -638,7 +635,7 @@
 }
 
 func newDecoder(t *testing.T, data string) *yaml.Decoder {
-	dec, err := yaml.NewDecoder(fset, "test.yaml", strings.NewReader(data))
+	dec, err := yaml.NewDecoder("test.yaml", strings.NewReader(data))
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -646,7 +643,7 @@
 }
 
 func callUnmarshal(t *testing.T, data string) (ast.Expr, error) {
-	return yaml.Unmarshal(fset, "test.yaml", []byte(data))
+	return yaml.Unmarshal("test.yaml", []byte(data))
 }
 
 func TestUnmarshal(t *testing.T) {
@@ -806,7 +803,7 @@
 			if err != nil {
 				t.Fatal(err)
 			}
-			expr, err := yaml.Unmarshal(fset, "test.yaml", mergeTests)
+			expr, err := yaml.Unmarshal("test.yaml", mergeTests)
 			if err != nil {
 				t.Fatal(err)
 			}
diff --git a/internal/third_party/yaml/yaml.go b/internal/third_party/yaml/yaml.go
index 8251f39..955cd82 100644
--- a/internal/third_party/yaml/yaml.go
+++ b/internal/third_party/yaml/yaml.go
@@ -16,7 +16,6 @@
 	"sync"
 
 	"cuelang.org/go/cue/ast"
-	"cuelang.org/go/cue/token"
 )
 
 // MapSlice encodes and decodes as a YAML map.
@@ -81,8 +80,8 @@
 // See the documentation of Marshal for the format of tags and a list of
 // supported tag options.
 //
-func Unmarshal(fset *token.FileSet, filename string, in []byte) (expr ast.Expr, err error) {
-	return unmarshal(fset, filename, in)
+func Unmarshal(filename string, in []byte) (expr ast.Expr, err error) {
+	return unmarshal(filename, in)
 }
 
 // A Decorder reads and decodes YAML values from an input stream.
@@ -95,8 +94,8 @@
 //
 // The decoder introduces its own buffering and may read
 // data from r beyond the YAML values requested.
-func NewDecoder(fset *token.FileSet, filename string, r io.Reader) (*Decoder, error) {
-	d, err := newParser(fset, filename, r)
+func NewDecoder(filename string, r io.Reader) (*Decoder, error) {
+	d, err := newParser(filename, r)
 	if err != nil {
 		return nil, err
 	}
@@ -122,9 +121,9 @@
 	return expr, nil
 }
 
-func unmarshal(fset *token.FileSet, filename string, in []byte) (expr ast.Expr, err error) {
+func unmarshal(filename string, in []byte) (expr ast.Expr, err error) {
 	defer handleErr(&err)
-	p, err := newParser(fset, filename, in)
+	p, err := newParser(filename, in)
 	if err != nil {
 		return nil, err
 	}