拆分字符串时，如何在输出中包括运算符？

Question

Yesterday I asked this question about splitting a string in python. I've since decided to do this project in Go instead. I have the following:

input := "house-width + 3 - y ^ (5 * house length)"
s := regexp.MustCompile(" ([+-/*^]) ").Split(input, -1)
log.Println(s)  //  [house-width 3 y (5 house length)]

How do I include the operators in this output? e.g. I'd like the following output:

['house-width', '+', '3', '-', 'y', '^', '(5', '*', 'house length)']

EDIT: To clarify I am splitting on the space-separated operators and not just the operator. The operator must have a space on both ends to differentiate it from a dash/hyphen. Please refer to my original python question I linked to for clarification if needed.

Answer 1

You can get the operands of your expression using regexp.Split() (just as you did) and you can get the operators (the separators) using regexp.FindAllString().

By doing this you will have 2 separate []string slices, you can merge these 2 slices if you want the result in one []string slice.

input := "house-width + 3 - y ^ (5 * house length)"

r := regexp.MustCompile(`\s([+\-/*^])\s`)

s1 := r.Split(input, -1)
s2 := r.FindAllString(input, -1)

fmt.Printf("%q
", s1)
fmt.Printf("%q
", s2)

all := make([]string, len(s1)+len(s2))
for i := range s1 {
    all[i*2] = s1[i]
    if i < len(s2) {
        all[i*2+1] = s2[i]
    }
}
fmt.Printf("%q
", all)

Output (try it on the Go Playground):

["house-width" "3" "y" "(5" "house length)"]
[" + " " - " " ^ " " * "]
["house-width" " + " "3" " - " "y" " ^ " "(5" " * " "house length)"]

Note:

If you want to trim the spaces from the operators, you can use the strings.TrimSpace() function for that:

for i, v := range s2 {
    all[i*2+1] = strings.TrimSpace(v)
}
fmt.Printf("%q
", all)

Output:

["house-width" "+" "3" "-" "y" "^" "(5" "*" "house length)"]