example-statement-parser

An statement parser with participle.

Install

go get github.com/dsxack/example-statement-parser

Usage example

package main

import (
	"fmt"
	"log"
	"reflect"

	"github.com/dsxack/example-statement-parser"
)

func Example() {
	stmt := parser.Statement{}
	err := parser.Parse(`#{ ${insecure} ? "http" : "https" }://${domain}/${basepath}`, &stmt)
	if err != nil {
		log.Fatal(err)
	}

	stringP := func(value string) *string { return &value }

	result := reflect.DeepEqual(stmt, parser.Statement{
		Fragments: []parser.Fragment{
			{IfStatement: &parser.IfStatement{
				Cond: parser.Expr{Left: &parser.Cond{Left: parser.Term{Variable: stringP("insecure")}}},
				Then: parser.Term{Value: &parser.Value{String: stringP("http")}},
				Else: parser.Term{Value: &parser.Value{String: stringP("https")}},
			}},
			{Literal: stringP("://")},
			{Variable: stringP("domain")},
			{Literal: stringP("/")},
			{Variable: stringP("basepath")},
		},
	})

	fmt.Println(result)

	// output: true
}

Example of statements

• some value 5"
• ${some.variable}"
• #{ true ? "yes" : "no" }
• #{ ${insecure} ? ${var1} : ${var2} }
• #{ true ? true : false }
• #{ 5 ? 10 : 0 }
• #{ ${cond1} or ${cond2} ? ${var1} : ${var2} }
• #{ ${cond1} || ${cond2} ? ${var1} : ${var2} }
• #{ ${cond1} and ${cond2} ? ${var1} : ${var2} }
• #{ ${cond1} && ${cond2} ? ${var1} : ${var2} }
• #{ ${foo} == "bar" ? ${var1} : ${var2} }
• #{ (${cond1} or ${cond2}) and ${cond3} ? ${var1} : ${var2} }
• #{ ${cond1} and (${cond2} or ${cond3}) ? ${var1} : ${var2} }
• #{ ${cond1} and (${cond2} > 5 or ${cond3}) ? ${var1} : ${var2} }
• #{ ${insecure} ? "http" : "https" }://${domain}/${basepath}

Parser railway diagram