Documentation
¶
Overview ¶
Package pretty pretty-prints Go structures.
This package uses reflection to examine a Go value and can print out in a nice, aligned fashion. It supports three modes (normal, compact, and extended) for advanced use.
See the Reflect and Print examples for what the output looks like.
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var DefaultConfig = &Config{}
Functions ¶
func Compare ¶
func Compare(got, want interface{}) string
Compare returns a string containing a line-by-line unified diff of the values in got and want. Compare includes unexported fields.
Each line in the output is prefixed with '+', '-', or ' ' to indicate if it should be added to, removed from, or is correct for the "got" value with respect to the "want" value.
Example ¶
package main
import (
"fmt"
"github.com/kylelemons/godebug/pretty"
)
func main() {
type ShipManifest struct {
Name string
Crew map[string]string
Androids int
Stolen bool
}
reported := &ShipManifest{
Name: "Spaceship Heart of Gold",
Crew: map[string]string{
"Zaphod Beeblebrox": "Galactic President",
"Trillian": "Human",
"Ford Prefect": "A Hoopy Frood",
"Arthur Dent": "Along for the Ride",
},
Androids: 1,
Stolen: true,
}
expected := &ShipManifest{
Name: "Spaceship Heart of Gold",
Crew: map[string]string{
"Rowan Artosok": "Captain",
},
Androids: 1,
Stolen: false,
}
fmt.Println(pretty.Compare(reported, expected))
}
Output: { Name: "Spaceship Heart of Gold", Crew: { - Arthur Dent: "Along for the Ride", - Ford Prefect: "A Hoopy Frood", - Trillian: "Human", - Zaphod Beeblebrox: "Galactic President", + Rowan Artosok: "Captain", }, Androids: 1, - Stolen: true, + Stolen: false, }
func Fprint ¶
Fprint writes the representation of the given value to the writer according to the default config.
func Print ¶
func Print(vals ...interface{})
Print writes the default representation of the given values to standard output.
Example ¶
package main
import (
"github.com/kylelemons/godebug/pretty"
)
func main() {
type ShipManifest struct {
Name string
Crew map[string]string
Androids int
Stolen bool
}
manifest := &ShipManifest{
Name: "Spaceship Heart of Gold",
Crew: map[string]string{
"Zaphod Beeblebrox": "Galactic President",
"Trillian": "Human",
"Ford Prefect": "A Hoopy Frood",
"Arthur Dent": "Along for the Ride",
},
Androids: 1,
Stolen: true,
}
pretty.Print(manifest)
}
Output: {Name: "Spaceship Heart of Gold", Crew: {Arthur Dent: "Along for the Ride", Ford Prefect: "A Hoopy Frood", Trillian: "Human", Zaphod Beeblebrox: "Galactic President"}, Androids: 1, Stolen: true}
Types ¶
type Config ¶
type Config struct {
// Verbosity options
Compact bool // One-line output. Overrides Diffable.
Diffable bool // Adds extra newlines for more easily diffable output.
// Field and value options
IncludeUnexported bool // Include unexported fields in output
PrintStringers bool // Call String on a fmt.Stringer
// Output transforms
ShortList int // Maximum character length for short lists if nonzero.
}
A Config represents optional configuration parameters for formatting.
Some options, notably ShortList, dramatically increase the overhead of pretty-printing a value.
func (*Config) Fprint ¶
Fprint writes the representation of the given value to the writer according to the cfg.
func (*Config) Print ¶
func (cfg *Config) Print(vals ...interface{})
Print writes the configured presentation of the given values to standard output.
func (*Config) Sprint ¶
Sprint returns a string representation of the given value according to cfg.
Example ¶
package main
import (
"fmt"
"github.com/kylelemons/godebug/pretty"
)
func main() {
type Pair [2]int
type Map struct {
Name string
Players map[string]Pair
Obstacles map[Pair]string
}
m := Map{
Name: "Rock Creek",
Players: map[string]Pair{
"player1": {1, 3},
"player2": {0, -1},
},
Obstacles: map[Pair]string{
Pair{0, 0}: "rock",
Pair{2, 1}: "pond",
Pair{1, 1}: "stream",
Pair{0, 1}: "stream",
},
}
// Specific output formats
compact := &pretty.Config{
Compact: true,
}
diffable := &pretty.Config{
Diffable: true,
}
// Print out a summary
fmt.Printf("Players: %s\n", compact.Sprint(m.Players))
// Print diffable output
fmt.Printf("Map State:\n%s", diffable.Sprint(m))
}
Output: Players: {player1:[1,3],player2:[0,-1]} Map State: { Name: "Rock Creek", Players: { player1: [ 1, 3, ], player2: [ 0, -1, ], }, Obstacles: { [0,0]: "rock", [0,1]: "stream", [1,1]: "stream", [2,1]: "pond", }, }
Source Files