Throw error instead of panicking if regex doesn't compile

Reviewed-on: #1

color.go

@@ -43,8 +43,8 @@ var possibleColors map[string]color = map[string]color{
 	"WHITE":   {"WHITE", colorData.New(colorData.FgWhite)},
 	"GRAY":    {"GRAY", colorData.New(colorData.FgWhite, colorData.Faint)},
 	// Last three numbers are RGB. Reference https://en.wikipedia.org/wiki/ANSI_escape_code for what the first two numbers mean.
-//	"ORANGE":   {"ORANGE", colorData.New(38, 2, 255, 153, 28)},
-//	"DARKBLUE": {"DARKBLUE", colorData.New(38, 2, 0, 112, 255)},
+	//	"ORANGE":   {"ORANGE", colorData.New(38, 2, 255, 153, 28)},
+	//	"DARKBLUE": {"DARKBLUE", colorData.New(38, 2, 0, 112, 255)},
 	"NONE": {"NONE", colorData.New()},
 }
 
@@ -157,7 +157,7 @@ func stringToRGB(rgbString string) (*RGB, error) {
 func loadColorsFromFile(filepath string) error {
 	data, err := os.ReadFile(filepath)
 	if err != nil {
-		panic(err)
+		return err
 	}
 	// Read color config file into a MapSlice
 	tempMapSlice := yaml.MapSlice{}

config.go

@@ -3,6 +3,7 @@ package main
 import (
 	"embed"
 	"errors"
+	"fmt"
 	"io/fs"
 	"os"
 	"path/filepath"
@@ -88,7 +89,10 @@ func loadConfig(configFilename string) (stack.Stack[regColor], error) {
 	//  returned.
 	regColorStack := stack.NewStack[regColor](len(strings.Split(string(configFile), "\n"))) // The stack will have the same size as the number of lines in the file
 	for _, item := range tempMapSlice {
-		re := regex.MustCompile(item.Key.(string), regex.RE_MULTILINE, regex.RE_SINGLE_LINE)
+		re, err := regex.Compile(item.Key.(string), regex.RE_MULTILINE, regex.RE_SINGLE_LINE)
+		if err != nil {
+			return *stack.NewStack[regColor](0), fmt.Errorf("%v: '%s'", err, item.Key.(string))
+		}
 		clr, err := newColor(item.Value.(string))
 		if err != nil {
 			return *stack.NewStack[regColor](0), err

main.go

@@ -79,7 +79,7 @@ func main() {
 	// Check if config exists. If it doesn't, generate the config files.
 	userHomeDir, err := os.UserHomeDir() // Get current user's home directory, to construct config path
 	if err != nil {
-		panic(err)
+		printErrAndExit("Unable to retrieve user home directory")
 	}
 	configPath := filepath.Join(userHomeDir + "/.config/ccat/")
 	if _, err := os.Stat(configPath); os.IsNotExist(err) {
@@ -107,7 +107,7 @@ func main() {
 	// the program.
 	finfo, err := os.Stat(fileName)
 	if err != nil {
-		panic(err)
+		printErrAndExit("Unable to read file")
 	}
 	if finfo.Size() == 0 {
 		os.Exit(0)