format

package module
v0.0.2 Latest Latest
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 Go to latest Published: Sep 16, 2019 License: MIT Imports: 8 Imported by: 2

README

go-format

Build Status

Simple string formatting tool with date arithmetics and format (strftime) support

Installation
go get github.com/sirkon/go-format

or

dep ensure -add github.com/sirkon/go-format
Rationale behind

In analytical systems you need to deal with time intervals. This formatter helps to achieve this right at the configuration file level.

Examples
Positional parameters, you can use ${1}, ${2} to address specific parameter (by number)
res := format.Formatp("$ ${} $1 ${0}", 1, 2)
// res = "1 2 2 1"
Named parameters via map[string]interface{}
res := format.Formatm("${name} $count ${weight|1.2}", format.Values{
	"name": "name",
	"count": 12,
	"weight": 0.79,
})
// res = "name 12 0.79"
Named parameters via type guesses
var s struct {
	A string
	Field int
}
s.A = "str"
s.Field = 12
res := format.Formatg("$A $Field", s)

Substructures are supported. Also, any kind of map with keys being one of

  1. string
  2. any kind of integer, signed or unsigned
  3. fmt.Stringer is supported as well.
type t struct {
	A     string
	Field int
}
var s = t{
	A:     "str",
	Field: 12,
}
var d struct {
	F     t
	Entry float64
}
d.F = s
d.Entry = 0.5
res := format.Formatg("$F.A $F.Field $Entry", d)
// res = "str 12 0.500000"

v := map[int]string{
	1: "bc",
	12: "bd"
}
res := format.Formatg("$1-$12")
// res = "bc-bc"
Use given func(string) string function as a source of values

It is possible to use function like os.Getenv as a source of values. Use format.Formatf function for this:

res := format.Formatf("${HOSTTYPE} ${COLUMNS}", os.Getenv)
// res = "x86_64 80"

Check:

pic

Of course, you can use every func(string) string function, not just os.Getenv

Date arithmetics
t := time.Date(2018, 1, 18, 22, 57, 37, 12, time.UTC)
res := format.Formatm("${ date + 1 day | %Y-%m-%d %H:%M:%S }", format.Values{
	"date": t,
})
// res = "2018-01-19 22:57:37"

Date arithmetics allows following expression values:

  • year/years
  • month/months
  • week/weeks
  • day/days
  • hour/hours
  • minute/minutes
  • second/seconds

Where year and years (and other couples) are equivalent (5 years is nicer than 5 year, just like 1 year is prefered over 1 years). There's a limitation though, longer period must precedes shorter one, i.e. following expressions are valid.

+ 1 year + 5 weeks + 3 days + 12 seconds
+ 25 years + 3 months
- 17 days - 16 hours
+ 2 year + 15 weeks + 1 second

and this one is invalid

+ 1 week + 5 months

as a month must precedes a week

Low level usage, how it is doing in the background
package main

import (
	"fmt"
	"time"
	
	"github.com/sirkon/go-format"
)

func main() {
	bctx := format.NewContextBuilder()
	bctx.AddString("name", "explosion")
	bctx.AddInt("count", 15)
	bctx.AddTime("time", time.Date(2006, 1, 2, 3, 4, 5, 0, time.UTC))
	ctx, err := bctx.Build()
	if err != nil {
		panic(err)
	}
	
	res, err := format.Format(
		"${name} will be registered by $count independent sources in ${ time + 1 day | %Y-%m-%d } at ${ time | %H:%M:%S }",
		ctx)
	if err != nil {
		panic(err)
	}
	fmt.Println(res)
}

It is probably to be used for most typical usecases.

Documentation

Index

Constants

This section is empty.

Variables

This section is empty.

Functions

func Format 

func Format(format string, context Context) (string, error)

Format function

func Formatf 

func Formatf(format string, data func(string) string) string

Formatf is a formatting where values are taken form given func(string) string function

func Formatg 

func Formatg(format string, data interface{}) string

Formatg is a formatting with type guessing

func Formatm 

func Formatm(format string, data Values) string

Formatm is a formatting with keys from given map

func Formatp 

func Formatp(format string, a ...interface{}) string

Formatp is a formatting with positional arguments

Types

type Context 

type Context interface {
	GetFormatter(name string) (Formatter, error)
}

Context ...

type ContextBuilder 

type ContextBuilder struct {
	// contains filtered or unexported fields
}

ContextBuilder formatting context builder

func NewContextBuilder 

func NewContextBuilder() *ContextBuilder

NewContextBuilder ...

func (*ContextBuilder) Add 

func (c *ContextBuilder) Add(name string, value interface{}) *ContextBuilder

Add adds formatter with type guessing

func (*ContextBuilder) AddFloat32 

func (c *ContextBuilder) AddFloat32(name string, value float32) *ContextBuilder

AddFloat adds floating point number formatter

func (*ContextBuilder) AddFloat64 

func (c *ContextBuilder) AddFloat64(name string, value float64) *ContextBuilder

AddFloat adds floating point number formatter

func (*ContextBuilder) AddFormatter 

func (c *ContextBuilder) AddFormatter(name string, formatter Formatter) *ContextBuilder

AddFormatter ...

func (*ContextBuilder) AddInt 

func (c *ContextBuilder) AddInt(name string, value int) *ContextBuilder

AddInt adds int formatter

func (*ContextBuilder) AddInt16 

func (c *ContextBuilder) AddInt16(name string, value int16) *ContextBuilder

AddInt16 adds int16 formatter

func (*ContextBuilder) AddInt32 

func (c *ContextBuilder) AddInt32(name string, value int32) *ContextBuilder

AddInt32 adds int32 formatter

func (*ContextBuilder) AddInt64 

func (c *ContextBuilder) AddInt64(name string, value int64) *ContextBuilder

AddInt64 adds int64 formatter

func (*ContextBuilder) AddInt8 

func (c *ContextBuilder) AddInt8(name string, value int8) *ContextBuilder

AddInt8 adds int8 formatter

func (*ContextBuilder) AddString 

func (c *ContextBuilder) AddString(name, value string) *ContextBuilder

AddString adds string formatter

func (*ContextBuilder) AddTime 

func (c *ContextBuilder) AddTime(name string, datetime time.Time) *ContextBuilder

AddTime adds time formatter

func (*ContextBuilder) AddUint 

func (c *ContextBuilder) AddUint(name string, value uint) *ContextBuilder

AddUint adds uint formatter

func (*ContextBuilder) AddUint16 

func (c *ContextBuilder) AddUint16(name string, value uint16) *ContextBuilder

AddUint16 adds uint16 formatter

func (*ContextBuilder) AddUint32 

func (c *ContextBuilder) AddUint32(name string, value uint32) *ContextBuilder

AddUint32 adds uint32 formatter

func (*ContextBuilder) AddUint64 

func (c *ContextBuilder) AddUint64(name string, value uint64) *ContextBuilder

AddUint64 adds uint64 formatter

func (*ContextBuilder) AddUint8 

func (c *ContextBuilder) AddUint8(name string, value uint8) *ContextBuilder

AddUint8 adds uint8 formatter

func (*ContextBuilder) AddValue 

func (c *ContextBuilder) AddValue(name string, value interface{}) *ContextBuilder

AddValue adds formatter to format it as %...v

func (*ContextBuilder) Build 

func (c *ContextBuilder) Build() (Context, error)

Build retrieves context object from the builder

type Formatter 

type Formatter interface {
	Clarify(string) (Formatter, error)
	Format(string) (string, error)
}

Formatter generic formatting piece

type Splitter 

type Splitter struct {
	// contains filtered or unexported fields
}

Splitter splits the string

func NewSplitter 

func NewSplitter(text string, context Context) *Splitter

NewSplitter ...

func (*Splitter) Err 

func (s *Splitter) Err() error

Err ...

func (*Splitter) Split 

func (s *Splitter) Split() bool

Split cut the next chunk and apply context formatting once it is a piece of format

func (*Splitter) Text 

func (s *Splitter) Text() string

Text ...

type Values 

type Values = map[string]interface{}

Values is easier than map[string]interface{}

Source Files

View all Source files

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