String Utility Library

A string manipulation utility to complement the golang standard strings library.

Escape

You want to substitute all occurances of a word or character in a string with something else (Escape), then do the reverse (Unescape) to get back the original string. But what if that original string already contains the substitute?

src := "a %reserved% message for john & cage llc"

// a &1reserved&1 message for john &2 cage llc
escaped := strutil.Escape(src, "%", "&")

// a %reserved% message for john & cage llc
recovered := strutil.Unescape(escaped, "%", "&")

Substring

Get the first/last n characters without worrying about out of range error or negative index:

strutil.Prefix("foobar", 300)  // foobar
strutil.Suffix("foobar", 1)    // r
strutil.Prefix("foobar", -2)   // ar

Get everything before/after a substring without messing with runes:

strutil.Before("hello world", " w") // hello
strutil.After("hello world", " ")   // world

Get substring sandwiched between other substrings. Performs better than regex:

src := "we have <tag1> and <tag2> to extract"
strutil.Between(src, []string{"<"}, []string{">"}, -1) // [tag1, tag2]

String slice

Remove empty in slice:

src := []string{"fish", "cow", "bird", "", "banana", "", "coffee", ""}
strutil.RemoveEmpty(&src)
// value of src: [fish, cow, bird, banana, coffee]

A more generic select function:

src := []string{"fish", "cow", "bird", "", "banana", "", "coffee", ""}
strutil.Select(&src, func(s string) bool {
	return len(s) > 4
})
// value of src: [banana, coffee]