CSS hsl() / hsla() Color in GO
Match CSS hsl() and hsla() color functions, capturing hue (0–360), saturation, lightness, and optional alpha.
Try it in the GO tester →Pattern
regexGO
hsla?\(\s*(\d{1,3})\s*,\s*(\d{1,3})%\s*,\s*(\d{1,3})%(?:\s*,\s*(?:0|1|0?\.\d+))?\s*\) (flags: gi)Go (RE2) code
goGo
package main
import (
"fmt"
"regexp"
)
func main() {
re := regexp.MustCompile(`(?i)hsla?\(\s*(\d{1,3})\s*,\s*(\d{1,3})%\s*,\s*(\d{1,3})%(?:\s*,\s*(?:0|1|0?\.\d+))?\s*\)`)
input := `hsl(200, 100%, 50%)`
for _, match := range re.FindAllString(input, -1) {
fmt.Println(match)
}
}Uses `regexp.MustCompile` (panics on bad patterns at startup) and `FindAllString` for all matches.
How the pattern works
hsla? matches hsl or hsla. The three numeric groups capture hue (degrees), saturation %, and lightness %. The optional fourth group captures an alpha value of 0, 1, or a decimal like 0.75. Whitespace is allowed around all values.
Examples
Input
hsl(200, 100%, 50%)Matches
hsl(200, 100%, 50%)
Input
hsla(120, 60%, 70%, 0.8)Matches
hsla(120, 60%, 70%, 0.8)
Input
color: blue;No match
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