regroup

Match regex group into go struct using struct tags and automatic parsing

Programming language: Go

License: Apache License 2.0

Tags: Utility     Text Processing    

README

regroup

Simple library to match regex expression named groups into go struct using struct tags and automatic parsing

Installing

go get github.com/oriser/regroup

Example

Named groups map

package main

import (
    "fmt"
    "github.com/oriser/regroup"
)

var re = regroup.MustCompile(`(?P<duration>.*?)\s+(?P<num>\d+)\s+(?P<foo>.*)`)

func main() {
    matches, err := re.Groups("5s 123 bar")
    if err != nil {
        panic(err)
    }
    fmt.Printf("%+v\n", matches)
}

Will output: map[duration:5s foo:bar num:123]

Single match

package main

import (
    "fmt"
    "github.com/oriser/regroup"
    "time"
)

var re = regroup.MustCompile(`(?P<duration>.*?)\s+(?P<num>\d+)\s+(?P<foo>.*)`)

type B struct {
    Str string `regroup:"foo"`
}

type A struct {
    Number        int           `regroup:"num"`
    Dur           time.Duration `regroup:"duration"`
    AnotherStruct B
}

func main() {
    a := &A{}
    if err := re.MatchToTarget("5s 123 bar", a); err != nil {
        panic(err)
    }
    fmt.Printf("%+v\n", a)
}

Will output: &{Number:123 Dur:5s AnotherStruct:{Str:bar}}

Multiple matches

You can also get all matches parsed as given target struct. The return value in this case will be an array of interfaces, you should cast it to the target type in order to access its fields.

package main

import (
    "fmt"
    "github.com/oriser/regroup"
    "time"
)

var re = regroup.MustCompile(`\s*(?P<duration>.*?)\s+(?P<num>\d+)\s+(?P<foo>.*)`)

type B struct {
    Str string `regroup:"foo"`
}

type A struct {
    Number        int           `regroup:"num"`
    Dur           time.Duration `regroup:"duration"`
    AnotherStruct B
}

func main() {
    a := &A{}
    s := `5s 123 bar1
          1m 456 bar2
          10h 789 bar3`
    rets, err := re.MatchAllToTarget(s, -1, a)
    if err != nil {
        panic(err)
    }
    for _, elem := range rets {
        fmt.Printf("%+v\n", elem.(*A))
    }
}

Will output:

&{Number:123 Dur:5s AnotherStruct:{Str:bar1}}
&{Number:456 Dur:1m0s AnotherStruct:{Str:bar2}}
&{Number:789 Dur:10h0m0s AnotherStruct:{Str:bar3}}

Required groups

You can specify that a specific group is required, means that it can't be empty.

If a required group is empty, an error (*regroup.RequiredGroupIsEmpty) will be returned .

package main

import (
    "fmt"
    "github.com/oriser/regroup"
    "time"
)

var re = regroup.MustCompile(`(?P<duration>.*?)\s+(?P<num>\d+)\s+(?P<foo>.*)`)

type B struct {
    Str string `regroup:"foo,required"`
}

type A struct {
    Number        int           `regroup:"num"`
    Dur           time.Duration `regroup:"duration"`
    AnotherStruct B
}

func main() {
    a := &A{}
    if err := re.MatchToTarget("5s 123 ", a); err != nil {
        panic(err)
    }
    fmt.Printf("%+v\n", a)
}

Will return an error: required regroup "foo" is empty for field "Str"

Supported struct field types

• time.Duration
• bool
• string
• int
• int8
• int16
• int32
• int64
• uint
• uint8
• uint16
• uint32
• uint64
• float32
• float64

Pointers and nested structs are also supported, both on single match and multiple matches