package main
import (
"regexp"
"fmt"
)
func main() {
var re = regexp.MustCompile(`(?m)(?<=[0-9])\s+(?=(?:st|[rn]d|th)(?: [^\W\d_]|$))`)
var str = `10 th elementary
1 st grade
133 rd anniversary
abc123 th 33333 rddccc
10 thetree
20 street
`
var substitution = ""
fmt.Println(re.ReplaceAllString(str, substitution))
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/