Remove more uses of fmt.

capnpc-go/fileparts.go

@@ -21,7 +21,6 @@ var (
 		{path: flowcontrolImport, name: "fc"},
 
 		// stdlib imports
-		{path: "fmt", name: "fmt"},
 		{path: "context", name: "context"},
 		{path: "math", name: "math"},
 		{path: "strconv", name: "strconv"},
@@ -106,10 +105,6 @@ func (i *imports) FlowControl() string {
 	return i.add(importSpec{path: flowcontrolImport, name: "fc"})
 }
 
-func (i *imports) Fmt() string {
-	return i.add(importSpec{path: "fmt", name: "fmt"})
-}
-
 func (i *imports) Context() string {
 	return i.add(importSpec{path: "context", name: "context"})
 }

capnpc-go/templates/interfaceClient

@@ -39,7 +39,7 @@ func (c {{$.Node.Name}}) WaitStreaming() error {
 // should not be used to compare clients.  Use IsSame to compare clients
 // for equality.
 func (c {{$.Node.Name}}) String() string {
-	return {{$.G.Imports.Fmt}}.Sprintf("%T(%v)", c, capnp.Client(c))
+	return "{{$.Node.Name}}(" + capnp.Client(c).String() + ")"
 }
 
 // AddRef creates a new Client that refers to the same capability as c.

encoding/text/marshal.go

@@ -3,14 +3,15 @@ package text
 
 import (
 	"bytes"
-	"fmt"
+	"errors"
 	"io"
 	"math"
 	"strconv"
 
 	"capnproto.org/go/capnp/v3"
 	"capnproto.org/go/capnp/v3/internal/nodemap"
 	"capnproto.org/go/capnp/v3/internal/schema"
+	"capnproto.org/go/capnp/v3/internal/str"
 	"capnproto.org/go/capnp/v3/internal/strquote"
 	"capnproto.org/go/capnp/v3/schemas"
 )
@@ -119,7 +120,7 @@ func (enc *Encoder) marshalStruct(typeID uint64, s capnp.Struct) error {
 		return err
 	}
 	if !n.IsValid() || n.Which() != schema.Node_Which_structNode {
-		return fmt.Errorf("cannot find struct type %#x", typeID)
+		return errors.New("cannot find struct type " + str.UToHex(typeID))
 	}
 	var discriminant uint16
 	if n.StructNode().DiscriminantCount() > 0 {
@@ -171,7 +172,11 @@ func (enc *Encoder) marshalFieldValue(s capnp.Struct, f schema.Field) error {
 	}
 	if dv.IsValid() && int(typ.Which()) != int(dv.Which()) {
 		name, _ := f.Name()
-		return fmt.Errorf("marshal field %s: default value is a %v, want %v", name, dv.Which(), typ.Which())
+		return errors.New(
+			"marshal field " + name +
+				": default value is a " + dv.Which().String() +
+				", want " + typ.Which().String(),
+		)
 	}
 	switch typ.Which() {
 	case schema.Type_Which_void:
@@ -277,7 +282,7 @@ func (enc *Encoder) marshalFieldValue(s capnp.Struct, f schema.Field) error {
 	case schema.Type_Which_anyPointer:
 		enc.w.WriteString(anyPointerMarker)
 	default:
-		return fmt.Errorf("unknown field type %v", typ.Which())
+		return errors.New("unknown field type " + typ.Which().String())
 	}
 	return nil
 }
@@ -394,7 +399,7 @@ func (enc *Encoder) marshalList(elem schema.Type, l capnp.List) error {
 		}
 		enc.w.WriteByte(']')
 	default:
-		return fmt.Errorf("unknown list type %v", elem.Which())
+		return errors.New("unknown list type " + elem.Which().String())
 	}
 	return nil
 }
@@ -405,7 +410,9 @@ func (enc *Encoder) marshalEnum(typ uint64, val uint16) error {
 		return err
 	}
 	if n.Which() != schema.Node_Which_enum {
-		return fmt.Errorf("marshaling enum of type @%#x: type is not an enum", typ)
+		return errors.New(
+			"marshaling enum of type @" + str.UToHex(typ) + ": type is not an enum",
+		)
 	}
 	enums, err := n.Enum().Enumerants()
 	if err != nil {

list.go

@@ -1,9 +1,7 @@
 package capnp
 
 import (
-	"bytes"
 	"errors"
-	"fmt"
 	"math"
 	"strconv"
 
@@ -1080,20 +1078,6 @@ func (s StructList[T]) Set(i int, v T) error {
 	return List(s).SetStruct(i, Struct(v))
 }
 
-// String returns the list in Cap'n Proto schema format (e.g. "[(x = 1), (x = 2)]").
-func (s StructList[T]) String() string {
-	buf := &bytes.Buffer{}
-	buf.WriteByte('[')
-	for i := 0; i < s.Len(); i++ {
-		if i > 0 {
-			buf.WriteString(", ")
-		}
-		fmt.Fprint(buf, s.At(i))
-	}
-	buf.WriteByte(']')
-	return buf.String()
-}
-
 // A list of some Cap'n Proto capability type T.
 type CapList[T ~ClientKind] PointerList
 

schemas/schemas.go

@@ -12,12 +12,12 @@ import (
 	"bytes"
 	"compress/zlib"
 	"errors"
-	"fmt"
 	"io"
 	"io/ioutil"
 	"strings"
 	"sync"
 
+	"capnproto.org/go/capnp/v3/internal/str"
 	"capnproto.org/go/capnp/v3/packed"
 )
 
@@ -164,15 +164,15 @@ type dupeError struct {
 }
 
 func (e *dupeError) Error() string {
-	return fmt.Sprintf("schemas: registered @%#x twice", e.id)
+	return "schemas: registered @" + str.UToHex(e.id) + " twice"
 }
 
 type notFoundError struct {
 	id uint64
 }
 
 func (e *notFoundError) Error() string {
-	return fmt.Sprintf("schemas: could not find @%#x", e.id)
+	return "schemas: could not find @" + str.UToHex(e.id)
 }
 
 type decompressError struct {
@@ -181,5 +181,5 @@ type decompressError struct {
 }
 
 func (e *decompressError) Error() string {
-	return fmt.Sprintf("schemas: decompressing schema for @%#x: %v", e.id, e.err)
+	return "schemas: decompressing schema for @" + str.UToHex(e.id) + ": " + e.err.Error()
 }