Implemented SubWordRight, SubWordLeft, SelectSubWordRight, SelectSubWordLeft and DeleteSubWordRight, DeleteSubWordLeft

internal/util/util.go

@@ -219,18 +219,69 @@ func FSize(f *os.File) int64 {
 }
 
 // IsWordChar returns whether or not a rune is a 'word character'
-// Word characters are defined as numbers, letters or '_'
+// Word characters are defined as numbers, letters or sub-word delimiters
 func IsWordChar(r rune) bool {
-	return unicode.IsLetter(r) || unicode.IsNumber(r) || r == '_'
+	return IsAlphanumeric(r) || IsSubwordDelimiter(r)
 }
 
 // IsNonWordChar returns whether or not a rune is not a 'word character'
-// Non word characters are defined as all characters not being numbers, letters or '_'
+// Non word characters are defined as all characters not being numbers, letters or sub-word delimiters
 // See IsWordChar()
 func IsNonWordChar(r rune) bool {
 	return !IsWordChar(r)
 }
 
+// IsUpperWordChar returns whether or not a rune is an 'upper word character'
+// Upper word characters are defined as numbers, upper-case letters or sub-word delimiters
+func IsUpperWordChar(r rune) bool {
+	return IsUpperAlphanumeric(r) || IsSubwordDelimiter(r)
+}
+
+// IsLowerWordChar returns whether or not a rune is a 'lower word character'
+// Lower word characters are defined as numbers, lower-case letters or sub-word delimiters
+func IsLowerWordChar(r rune) bool {
+	return IsLowerAlphanumeric(r) || IsSubwordDelimiter(r)
+}
+
+// IsSubwordDelimiter returns whether or not a rune is a 'sub-word delimiter character'
+// i.e. is considered a part of the word and is used as a delimiter between sub-words of the word.
+// For now the only sub-word delimiter character is '_'.
+func IsSubwordDelimiter(r rune) bool {
+	return r == '_'
+}
+
+// IsAlphanumeric returns whether or not a rune is an 'alphanumeric character'
+// Alphanumeric characters are defined as numbers or letters
+func IsAlphanumeric(r rune) bool {
+	return unicode.IsLetter(r) || unicode.IsNumber(r)
+}
+
+// IsUpperAlphanumeric returns whether or not a rune is an 'upper alphanumeric character'
+// Upper alphanumeric characters are defined as numbers or upper-case letters
+func IsUpperAlphanumeric(r rune) bool {
+	return IsUpperLetter(r) || unicode.IsNumber(r)
+}
+
+// IsLowerAlphanumeric returns whether or not a rune is a 'lower alphanumeric character'
+// Lower alphanumeric characters are defined as numbers or lower-case letters
+func IsLowerAlphanumeric(r rune) bool {
+	return IsLowerLetter(r) || unicode.IsNumber(r)
+}
+
+// IsUpperLetter returns whether or not a rune is an 'upper letter character'
+// Upper letter characters are defined as upper-case letters
+func IsUpperLetter(r rune) bool {
+	// unicode.IsUpper() returns true for letters only
+	return unicode.IsUpper(r)
+}
+
+// IsLowerLetter returns whether or not a rune is a 'lower letter character'
+// Lower letter characters are defined as lower-case letters
+func IsLowerLetter(r rune) bool {
+	// unicode.IsLower() returns true for letters only
+	return unicode.IsLower(r)
+}
+
 // Spaces returns a string with n spaces
 func Spaces(n int) string {
 	return strings.Repeat(" ", n)