commander

Command evaluator and parser

Features

• Matches commands against provided text
• Extracts parameters from matching input
• Provides default values for missing parameters
• Supports String, Integer, Float and Boolean parameters
• Supports "word" {} vs "sentence" <> parameter matching

Dependencies

• proper github.com/slack-io/proper

Examples

Example 1

In this example, we are matching a few strings against a command format, then parsing parameters if found or returning default values.

package main

import (
	"fmt"
	"github.com/slack-io/commander"
)

func main() {
	properties, isMatch := commander.NewCommand("ping").Match("ping")
	fmt.Println(isMatch)            // true
	fmt.Println(properties)         // {}

	properties, isMatch = commander.NewCommand("ping").Match("pong")
	fmt.Println(isMatch)            // false
	fmt.Println(properties)         // nil

	properties, isMatch = commander.NewCommand("echo {word}").Match("echo hello world!")
	fmt.Println(isMatch)                               // true
	fmt.Println(properties.StringParam("word", ""))    // hello

	properties, isMatch = commander.NewCommand("echo <sentence>").Match("echo hello world!")
	fmt.Println(isMatch)                                   // true
	fmt.Println(properties.StringParam("sentence", ""))    // hello world!

	properties, isMatch = commander.NewCommand("repeat {word} {number}").Match("repeat hey 5")
	fmt.Println(isMatch)                                 // true
	fmt.Println(properties.StringParam("word", ""))      // hey
	fmt.Println(properties.IntegerParam("number", 0))    // 5

	properties, isMatch = commander.NewCommand("repeat {word} {number}").Match("repeat hey")
	fmt.Println(isMatch)                                 // true
	fmt.Println(properties.StringParam("word", ""))      // hey
	fmt.Println(properties.IntegerParam("number", 0))    // 0

	properties, isMatch = commander.NewCommand("search <stuff> {size}").Match("search hello there everyone 10")
	fmt.Println(isMatch)                                // true
	fmt.Println(properties.StringParam("stuff", ""))    // hello there everyone
	fmt.Println(properties.IntegerParam("size", 0))     // 10
}

Example 2

In this example, we are tokenizing the command format and returning each token with a number that determines whether it is a parameter (word vs sentence) or not

package main

import (
	"fmt"
	"github.com/slack-io/commander"
)

func main() {
	tokens := commander.NewCommand("echo {word} <sentence>").Tokenize()
	for _, token := range tokens {
		fmt.Println(token)
	}
}

Output:

&{echo NOT_PARAMETER}
&{word WORD_PARAMETER}
&{sentence SENTENCE_PARAMETER}