Original post

I want to check the string between {} in my statement, in JavaScript I can use:
Negative Lookahead to matches characters of the A to Z range as [a-zA-Z]+(?![^{]*})
Or Negated Match if words will include whitespace or have other characters that need to be allowed or unsure of the type of input as [^}]+(?![^{]*})

Here is a live example to check the below text

{con}descens{ion}
lumberjack
tim{ing}
{tox}{icity}
fish
{dis}pel

I tried to do same in GO as;

package main

import (
        "fmt"
        "regexp"
)

func main() {
        r, err := regexp.Compile('[a-zA-Z]+(?![^{]*})')
        if err != nil {
                fmt.Println(err)
                return
        }
        fmt.Println(r.ReplaceAllString(`{con}descens{ion}
                                                                        lumberjack
                                                                        tim{ing}
                                                                        {tox}{icity}
                                                                        fish
                                                                        {dis}pel`,
                                                                        "found this"))
}

But got the below error:

# command-line-arguments
.reg.go:9:46: unknown escape