You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: exprstring.go
    path of file: ./repos/gccrs/libgo/go/go/types
    
    the code of the file until where you have to start completion: // Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// This file implements printing of expressions.

package types

import (
	"bytes"
	"fmt"
	"go/ast"
	"go/internal/typeparams"
)

// ExprString returns the (possibly shortened) string representation for x.
// Shortened representations are suitable for user interfaces but may not
// necessarily follow Go syntax.
func Exp
    
func writeFieldList(buf *bytes.Buffer, list []*ast.Field, sep string, iface bool) {
	for i, f := range list {
		if i > 0 {
			buf.WriteString(sep)
		}

		// field list names
		writeIdentList(buf, f.Names)

		// types of interface methods consist of signatures only
		if sig, _ := f.Type.(*ast.FuncType); sig != nil && iface {
			writeSigExpr(buf, sig)
			continue
		}

		// named fields are separated with a blank from the field type
		if len(f.Names) > 0 {
			buf.WriteByte(' ')
		}

		WriteExpr(buf, f.Type)

		// ignore tag
	}
}