Other fixes to display, better support for color

internal/color/color.go

@@ -84,6 +84,32 @@ func Fmt(color string) string {
 	return SGRStart + color + SGREnd
 }
 
+// Trim accepts a string including arbitrary escaped sequences at arbitrary
+// index positions, and returns the first 'n' printable characters in this
+// string, including all escape codes found between and immediately around
+// those characters (including surrounding 1st and 80th ones).
+func Trim(input string, maxPrintableLength int) string {
+	if len(input) < maxPrintableLength {
+		return input
+	}
+
+	// Find all escape sequences in the input
+	escapeIndices := re.FindAllStringIndex(input, -1)
+
+	// Iterate over escape sequences to find the
+	// last escape index within maxPrintableLength
+	for _, indices := range escapeIndices {
+		if indices[0] <= maxPrintableLength {
+			maxPrintableLength += indices[1] - indices[0]
+		} else {
+			break
+		}
+	}
+
+	// Determine the end index for limiting printable content
+	return input[:maxPrintableLength]
+}
+
 // UnquoteRC removes the `\e` escape used in readline .inputrc
 // configuration values and replaces it with the printable escape.
 func UnquoteRC(color string) string {
@@ -173,14 +199,3 @@ var re = regexp.MustCompile(ansi)
 func Strip(str string) string {
 	return re.ReplaceAllString(str, "")
 }
-
-// wrong: reapplies fg/bg escapes regardless of the string passed.
-// Users should be in charge of applying any effect as they wish.
-// func SGR(color string, fg bool) string {
-// 	if fg {
-// 		return SGRStart + FgColorStart + color + SGREnd
-// 		// return SGRStart + color + SGREnd
-// 	}
-//
-// 	return SGRStart + BgColorStart + color + SGREnd
-// }

internal/completion/group.go

@@ -365,8 +365,9 @@ func (g *group) trimDisplay(comp Candidate, pad, col int) (candidate, padded str
 	}
 
 	if comp.displayLen > maxDisplayWidth {
-		val = val[:maxDisplayWidth-3] + "..." // 3 dots = -3
-		val = g.listSep() + sanitizer.Replace(val)
+		val = color.Trim(val, maxDisplayWidth-4)
+		val += "..." // 3 dots + 1 safety space = -3
+		val = sanitizer.Replace(val)
 
 		return val, " "
 	}
@@ -380,12 +381,18 @@ func (g *group) trimDesc(val Candidate, pad int) (desc, padded string) {
 		return desc, padSpace(pad)
 	}
 
+	// We don't compare against the terminal width:
+	// the correct padding should have been computed
+	// based on the space taken by all candidates
+	// described by our current string.
 	if pad > g.maxDescAllowed {
 		pad = g.maxDescAllowed - val.descLen
 	}
 
+	// Trim the description accounting for escapes.
 	if val.descLen > g.maxDescAllowed && g.maxDescAllowed > 0 {
-		desc = desc[:g.maxDescAllowed-3] + "..."
+		desc = color.Trim(desc, g.maxDescAllowed-3)
+		desc += "..." // 3 dots =  -3
 		desc = g.listSep() + sanitizer.Replace(desc)
 
 		return desc, ""