README
¶
Golang structural data formatter
import "gopkg.in/structformat.v0"
This module gives you greater control over how to format structual data instead of using Golang's default Printf
formatting mechanism. It supports outputing to io.Writer interface so large data can be formatted in streaming fashion
instead of returning a large string to reduce memory footprint.
Usage
To support structual formatting for your data types, implement the structformat.Formatter interface.
import "gopkg.in/structformat.v0"
type Person struct {
FirstName string
LastName string
Hobbies []string
}
func (p Person) StructFormat(w structformat.Writer) (n int, err error) {
// Describe your structual data using structformat's built-in formatters
f := structformat.Struct("Person",
structformat.KV("Full Name", structformat.Printf("%s %s", p.FirstName, p.LastName)))
hobbies := structformat.Bracket()
for _, hobby := range p.Hobbies {
hobbies.Items = append(hobbies.Items, structformat.String(hobby))
}
f.Items = append(f.Items, structformat.KV("Hobbies", hobbies))
return f.StructFormat(w)
}
func main() {
person := &Person{
FirstName: "Adam",
LastName: "Brody",
Hobbies: []string{
"Movies",
"Singing",
"Surfing",
},
}
// Format your structual data using structformat.FormatString() or structformat.Format()
formatted, err := structformat.FormatString(person)
if err != nil {
panic(err)
}
fmt.Println(formatted)
}
And you get the following formatted output:
Person {
Full Name: Adam Brody
Hobbies: [
Movies
Singing
Surfing
]
}
Documentation
¶
Index ¶
- Constants
- func Format(writer io.Writer, formatter Formatter, options ...FormatOption) (n int, err error)
- func FormatString(formatter Formatter, options ...FormatOption) (s string, err error)
- type BlockFormatter
- type BoolFormatter
- type FormatOption
- type Formatter
- type HexBytesFormatter
- type HexdumpFormatter
- type KVFormatter
- type KVOption
- type PrintfFormatter
- type StringFormatter
- type StructFormatter
- type Writer
Constants ¶
const DefaultIndent = " "
Variables ¶
This section is empty.
Functions ¶
func FormatString ¶
func FormatString(formatter Formatter, options ...FormatOption) (s string, err error)
Format a structual data and return the formatted string.
Types ¶
type BlockFormatter ¶
func Block ¶
func Block(items ...Formatter) *BlockFormatter
func Bracket ¶
func Bracket(items ...Formatter) *BlockFormatter
func (*BlockFormatter) StructFormat ¶
func (f *BlockFormatter) StructFormat(w Writer) (n int, err error)
type BoolFormatter ¶
type BoolFormatter bool
func Bool ¶
func Bool(value bool) BoolFormatter
Return a BoolFormatter that just outputs true or false.
func (BoolFormatter) StructFormat ¶
func (f BoolFormatter) StructFormat(w Writer) (n int, err error)
type FormatOption ¶
type FormatOption func(*indentWriter)
func WithIndent ¶
func WithIndent(indent string) FormatOption
Use the provided string for each indent level
type Formatter ¶
type Formatter interface {
// Format the structual data and write to the Writer interface. Returns the number of bytes written in `n`.
StructFormat(Writer) (n int, err error)
}
Implement this interface in your data types to support sturctual formatting.
type HexBytesFormatter ¶
type HexBytesFormatter []byte
func HexBytes ¶
func HexBytes(data []byte) HexBytesFormatter
Return a HexBytesFormatter that formats the bytes data using hex.Encoder.
func (HexBytesFormatter) StructFormat ¶
func (f HexBytesFormatter) StructFormat(w Writer) (n int, err error)
type HexdumpFormatter ¶
type HexdumpFormatter []byte
func Hexdump ¶
func Hexdump(data []byte) HexdumpFormatter
Returns a HexdumpFormatter that format the bytes data using hex.Dumper().
func (HexdumpFormatter) StructFormat ¶
func (f HexdumpFormatter) StructFormat(w Writer) (n int, err error)
type KVFormatter ¶
func KV ¶
func KV(name string, value Formatter, options ...KVOption) *KVFormatter
Return a KVFormatter represents a key-value pair. Oftenly used inside the StructFormatter for form a map like structure.
func (*KVFormatter) StructFormat ¶
func (f *KVFormatter) StructFormat(w Writer) (n int, err error)
type PrintfFormatter ¶
type PrintfFormatter struct {
Fmt string
Args []interface{}
}
func Printf ¶
func Printf(format string, args ...interface{}) *PrintfFormatter
Return a PrintfFormatter that apply Printf template to the arguments and format them as a string.
func (*PrintfFormatter) StructFormat ¶
func (f *PrintfFormatter) StructFormat(w Writer) (n int, err error)
type StringFormatter ¶
type StringFormatter string
func String ¶
func String(s string) StringFormatter
Return a StringFormatter for a string. New lines will be indented according to the current indent level of the formatter.
func (StringFormatter) StructFormat ¶
func (f StringFormatter) StructFormat(w Writer) (n int, err error)
type StructFormatter ¶
func Struct ¶
func Struct(name string, items ...Formatter) *StructFormatter
Return a StructFormatter that has a name and arbitrary number of items.
func (*StructFormatter) StructFormat ¶
func (f *StructFormatter) StructFormat(w Writer) (n int, err error)
type Writer ¶
type Writer interface {
io.Writer
IndentString() string
LineNum() int
LineOffset() int
NonIndentLineOffset() int
IsEmpty() bool
// Return a new writer with indent level set to be current
// indent level plus levelDelta. If levelDelta is 0, indent
// is reset to empty level.
Indent(levelDelta int) Writer
EmptyCheck(prependIfNotEmpty string) Writer
RemoveTrailingNewLines() Writer
}
Source Files