diff --git a/encoding/jsonschema/pointer.go b/encoding/jsonschema/pointer.go
index 1dbe4f0ce..bff9b690f 100644
--- a/encoding/jsonschema/pointer.go
+++ b/encoding/jsonschema/pointer.go
@@ -1,6 +1,9 @@
 package jsonschema
 
-import "strings"
+import (
+	"iter"
+	"strings"
+)
 
 // TODO this file contains functionality that mimics the JSON Pointer functionality
 // in https://pkg.go.dev/github.com/go-json-experiment/json/jsontext#Pointer;
@@ -11,20 +14,16 @@ var (
 	jsonPtrUnesc = strings.NewReplacer("~0", "~", "~1", "/")
 )
 
-// TODO(go1.23) func jsonPointerFromTokens(tokens iter.Seq[string]) string
-func jsonPointerFromTokens(tokens func(func(string) bool)) string {
+func jsonPointerFromTokens(tokens iter.Seq[string]) string {
 	var buf strings.Builder
-	// TODO for tok := range tokens {
-	tokens(func(tok string) bool {
+	for tok := range tokens {
 		buf.WriteByte('/')
 		buf.WriteString(jsonPtrEsc.Replace(tok))
-		return true
-	})
+	}
 	return buf.String()
 }
 
-// TODO(go1.23) func jsonPointerTokens(p string) iter.Seq[string]
-func jsonPointerTokens(p string) func(func(string) bool) {
+func jsonPointerTokens(p string) iter.Seq[string] {
 	return func(yield func(string) bool) {
 		needUnesc := strings.IndexByte(p, '~') >= 0
 		for len(p) > 0 {
diff --git a/encoding/jsonschema/ref.go b/encoding/jsonschema/ref.go
index c802d6ddb..ca92b480e 100644
--- a/encoding/jsonschema/ref.go
+++ b/encoding/jsonschema/ref.go
@@ -62,9 +62,8 @@ func parseRootRef(str string) (cue.Path, error) {
 
 var errRefNotFound = errors.New("JSON Pointer reference not found")
 
-func lookupJSONPointer(v cue.Value, p string) (_ cue.Value, _err error) {
-	// TODO(go1.23) for part := range jsonPointerTokens(p)
-	jsonPointerTokens(p)(func(part string) bool {
+func lookupJSONPointer(v cue.Value, p string) (cue.Value, error) {
+	for part := range jsonPointerTokens(p) {
 		// Note: a JSON Pointer doesn't distinguish between indexing
 		// and struct lookup. We have to use the value itself to decide
 		// which operation is appropriate.
@@ -76,23 +75,19 @@ func lookupJSONPointer(v cue.Value, p string) (_ cue.Value, _err error) {
 			idx := int64(0)
 			if len(part) > 1 && part[0] == '0' {
 				// Leading zeros are not allowed
-				_err = errRefNotFound
-				return false
+				return cue.Value{}, errRefNotFound
 			}
 			idx, err := strconv.ParseInt(part, 10, 64)
 			if err != nil {
-				_err = errRefNotFound
-				return false
+				return cue.Value{}, errRefNotFound
 			}
 			v = v.LookupPath(cue.MakePath(cue.Index(idx)))
 		}
 		if !v.Exists() {
-			_err = errRefNotFound
-			return false
+			return cue.Value{}, errRefNotFound
 		}
-		return true
-	})
-	return v, _err
+	}
+	return v, nil
 }
 
 func sameSchemaRoot(u1, u2 *url.URL) bool {
diff --git a/internal/mod/modimports/modimports.go b/internal/mod/modimports/modimports.go
index 81c10a3d4..4499b6a7f 100644
--- a/internal/mod/modimports/modimports.go
+++ b/internal/mod/modimports/modimports.go
@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"io/fs"
+	"iter"
 	"maps"
 	"path"
 	"slices"
@@ -32,7 +33,7 @@ type ModuleFile struct {
 // AllImports returns a sorted list of all the package paths
 // imported by the module files produced by modFilesIter
 // in canonical form.
-func AllImports(modFilesIter func(func(ModuleFile, error) bool)) (_ []string, retErr error) {
+func AllImports(modFilesIter iter.Seq2[ModuleFile, error]) (_ []string, retErr error) {
 	pkgPaths := make(map[string]bool)
 	modFilesIter(func(mf ModuleFile, err error) bool {
 		if err != nil {
@@ -65,7 +66,7 @@ func AllImports(modFilesIter func(func(ModuleFile, error) bool)) (_ []string, re
 //
 // TODO(mvdan): this should now be called InstanceFiles, to follow the naming from
 // https://cuelang.org/docs/concept/modules-packages-instances/#instances.
-func PackageFiles(fsys fs.FS, dir string, pkgQualifier string) func(func(ModuleFile, error) bool) {
+func PackageFiles(fsys fs.FS, dir string, pkgQualifier string) iter.Seq2[ModuleFile, error] {
 	return func(yield func(ModuleFile, error) bool) {
 		// Start at the target directory, but also include package files
 		// from packages with the same name(s) in parent directories.
@@ -146,7 +147,7 @@ func PackageFiles(fsys fs.FS, dir string, pkgQualifier string) func(func(ModuleF
 // module at the given root.
 //
 // The caller may assume that files from the same package are always adjacent.
-func AllModuleFiles(fsys fs.FS, root string) func(func(ModuleFile, error) bool) {
+func AllModuleFiles(fsys fs.FS, root string) iter.Seq2[ModuleFile, error] {
 	return func(yield func(ModuleFile, error) bool) {
 		yieldAllModFiles(fsys, root, true, yield)
 	}
diff --git a/internal/mod/modload/tidy.go b/internal/mod/modload/tidy.go
index 7913e1097..ddd4b5a63 100644
--- a/internal/mod/modload/tidy.go
+++ b/internal/mod/modload/tidy.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io/fs"
+	"iter"
 	"log"
 	"maps"
 	"path"
@@ -713,15 +714,16 @@ func (ld *loader) spotCheckRoots(ctx context.Context, rs *modrequirements.Requir
 	return true
 }
 
-func withoutIgnoredFiles(iter func(func(modimports.ModuleFile, error) bool)) func(func(modimports.ModuleFile, error) bool) {
+func withoutIgnoredFiles(modFiles iter.Seq2[modimports.ModuleFile, error]) iter.Seq2[modimports.ModuleFile, error] {
 	return func(yield func(modimports.ModuleFile, error) bool) {
-		// TODO for mf, err := range iter {
-		iter(func(mf modimports.ModuleFile, err error) bool {
+		for mf, err := range modFiles {
 			if err == nil && buildattr.ShouldIgnoreFile(mf.Syntax) {
-				return true
+				continue
 			}
-			return yield(mf, err)
-		})
+			if !yield(mf, err) {
+				break
+			}
+		}
 	}
 }
 
diff --git a/mod/modregistry/client.go b/mod/modregistry/client.go
index efcf6a929..d003c7b86 100644
--- a/mod/modregistry/client.go
+++ b/mod/modregistry/client.go
@@ -27,6 +27,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"iter"
 	"net/http"
 	"strings"
 
@@ -124,13 +125,11 @@ func (src *Client) Mirror(ctx context.Context, dst *Client, mv module.Version) e
 	// on whatever is calling the function too rather than just doing
 	// all uploads in parallel.
 	var g errgroup.Group
-	// TODO for desc := range manifestRefs(m.manifest)
-	manifestRefs(m.manifest)(func(desc ociregistry.Descriptor) bool {
+	for desc := range manifestRefs(m.manifest) {
 		g.Go(func() error {
 			return mirrorBlob(ctx, m.loc, dstLoc, desc)
 		})
-		return true
-	})
+	}
 	if err := g.Wait(); err != nil {
 		return err
 	}
@@ -570,7 +569,7 @@ func (r singleResolver) ResolveToRegistry(mpath, vers string) (RegistryLocation,
 
 // manifestRefs returns an iterator that produces all the references
 // contained in m.
-func manifestRefs(m ocispec.Manifest) func(func(ociregistry.Descriptor) bool) {
+func manifestRefs(m ocispec.Manifest) iter.Seq[ociregistry.Descriptor] {
 	return func(yield func(ociregistry.Descriptor) bool) {
 		if !yield(m.Config) {
 			return