Made thos errors better

config/config.go

@@ -1,8 +1,8 @@
 package config
 
+import "io"
 import "os"
 import "bufio"
-import "errors"
 import "strings"
 import "strconv"
 import "image/color"
@@ -20,12 +20,52 @@ const (
 	// ErrorIllegalName is thrown when an application name contains illegal
 	// characters such as a slash.
 	ErrorIllegalName Error = iota
+
+	// ErrorNoSeparator is thrown when a configuration file has an
+	// incorrectly formatted key-value pair.
+	ErrorNoSeparator
+
+	// ErrorUnknownParameter is thrown when an unknown key is encountered in
+	// a configuration file.
+	ErrorUnknownParameter
+
+	// ErrorWrongColorLength is thrown when a configuration file has a color
+	// literal with a total length unequal to 7.
+	ErrorWrongColorLength
+
+	// ErrorMalformedColorLiteral is thrown when a configuration file has an
+	// improperly formatted color literal, or a color literal was expected
+	// and something else was encountered.
+	ErrorMalformedColorLiteral
+	
+	// ErrorMalformedIntegerLiteral is thrown when a configuration file has
+	// an improperly formatted integer literal, or an integer literal was
+	// expected and something else was encountered.
+	ErrorMalformedIntegerLiteral
+	
+	// ErrorMalformedFloatLiteral is thrown when a configuration file has
+	// an improperly formatted float literal, or a float literal was
+	// expected and something else was encountered.
+	ErrorMalformedFloatLiteral
 )
 
+// Error returns a description of the error.
 func (err Error) Error () (description string) {
 	switch err {
 	case ErrorIllegalName:
 		description = "name contains illegal characters"
+	case ErrorNoSeparator:
+		description = "key:value pair has no separator"
+	case ErrorUnknownParameter:
+		description = "unknown parameter"
+	case ErrorWrongColorLength:
+		description = "color literal has the wrong length"
+	case ErrorMalformedColorLiteral:
+		description = "malformed color literal"
+	case ErrorMalformedIntegerLiteral:
+		description = "malformed integer literal"
+	case ErrorMalformedFloatLiteral:
+		description = "malformed float literal"
 	}
 
 	return
@@ -36,10 +76,12 @@ type Type int
 
 const (
 	// string
+	// It is just a basic string with inner whitespace preserved. No quotes
+	// should be used in the file.
 	TypeString Type = iota
 
 	// Type: image/color.RGBA
-	// Represented as a 24 bit hexidecimal number (case insensitive)
+	// Represented as a 24 bit hexadecimal number (case insensitive)
 	// preceded with a # sign where the first two digits represent the red
 	// channel, the middle two digits represent the green channel, and the
 	// last two digits represent the blue channel.
@@ -112,16 +154,24 @@ func (config *Config) Load (name string) (err error) {
 	configDirs = append(configDirs, configHome)
 
 	for _, directory := range configDirs {
-		config.loadFile(filepath.Join(directory, name, name + ".conf"))
+		path := filepath.Join(directory, name, name + ".conf")
+		
+		file, fileErr := os.Open(path)
+		if fileErr != nil { continue }
+		parseErr := config.loadFile(file)
+		defer file.Close()
+		
+		if parseErr != nil {
+			println (
+				"config: error in file", path +
+				":", parseErr.Error())
+		}
 	}
 
 	return
 }
 
-func (config *Config) loadFile (path string) {
-	file, err := os.Open(path)
-	if err != nil { return }
-
+func (config *Config) loadFile (file io.Reader) (err error) {
 	scanner := bufio.NewScanner(file)
 	for scanner.Scan() {
 		line := strings.TrimSpace(scanner.Text())
@@ -136,22 +186,16 @@ func (config *Config) loadFile (path string) {
 	
 		key, value, found := strings.Cut(scanner.Text(), ":")
 		if !found {
-			println (
-				"config: error in file", path +
-				": key-value separator missing")
-			println(scanner.Text())
-			continue
+			err = ErrorNoSeparator
+			return
 		}
 		key   = strings.TrimSpace(key)
 		value = strings.TrimSpace(value)
 
 		what, isKnown := config.LegalParameters[key]
 		if !isKnown {
-			println (
-				"config: error in file", path +
-				": unknown parameter")
-			println(scanner.Text())
-			continue
+			err = ErrorUnknownParameter
+			return
 		}
 
 		switch what {
@@ -161,24 +205,15 @@ func (config *Config) loadFile (path string) {
 		case TypeColor:
 			var valueColor color.Color
 			valueColor, err = parseColor(value)
-			if err != nil {
-				println (
-					"config: error in file", path +
-					":", err)
-				println(scanner.Text())
-				continue
-			}
+			if err != nil { return }
 			config.Parameters[key] = valueColor
 		
 		case TypeInteger:
 			var valueInt int
 			valueInt, err = strconv.Atoi(value)
 			if err != nil {
-				println (
-					"config: error in file", path +
-					": malformed integer literal")
-				println(scanner.Text())
-				continue
+				err = ErrorMalformedIntegerLiteral
+				return
 			}
 			config.Parameters[key] = valueInt
 			
@@ -186,11 +221,8 @@ func (config *Config) loadFile (path string) {
 			var valueFloat float64
 			valueFloat, err = strconv.ParseFloat(value, 64)
 			if err != nil {
-				println (
-					"config: error in file", path +
-					": malformed float literal")
-				println(scanner.Text())
-				continue
+				err = ErrorMalformedFloatLiteral
+				return
 			}
 			config.Parameters[key] = valueFloat
 			
@@ -211,14 +243,14 @@ func (config *Config) loadFile (path string) {
 func parseColor (value string) (valueColor color.Color, err error) {
 	if value[0] == '#' {
 		if len(value) != 7  {
-			err = errors.New("wrong length color literal")
+			err = ErrorWrongColorLength
 			return
 		}
 
 		var colorInt uint64
 		colorInt, err = strconv.ParseUint(value[1:7], 16, 24)
 		if err != nil  {
-			err = errors.New("malformed color literal")
+			err = ErrorMalformedColorLiteral
 			return
 		}
 
@@ -229,7 +261,7 @@ func parseColor (value string) (valueColor color.Color, err error) {
 			A: 0xFF,
 		}
 	} else {
-		err = errors.New("malformed color literal")
+		err = ErrorMalformedColorLiteral
 		return
 	}