Move all byte(s) related constant and functions from package text to bytes

5 files changed, 284 insertions, 3 deletions

diff --git a/lib/bytes/bytes.go b/lib/bytes/bytes.go
index 549d82db..ad777180 100644
--- a/lib/bytes/bytes.go
+++ b/lib/bytes/bytes.go
@@ -2,13 +2,31 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Packages bytes contains common functions to manipulate slice of bytes.
+// Packages bytes provide a library for working with byte or slice of bytes.
 package bytes
 
 import (
 	"fmt"
 )
 
+const (
+	// ASCIILetters contains list of lower and upper case characters in
+	// ASCII.
+	ASCIILetters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	// HexaLETTERS contains list of hexadecimal characters in upper cases.
+	HexaLETTERS = "0123456789ABCDEF"
+	// HexaLetters contains list of hexadecimal characters in lower and
+	// upper cases.
+	HexaLetters = "0123456789abcedfABCDEF"
+	// HexaLetters contains list of hexadecimal characters in lower cases.
+	Hexaletters = "0123456789abcedf"
+)
+
+var (
+	// ASCIISpaces contains list of white spaces in ASCII.
+	ASCIISpaces = []byte{'\t', '\n', '\v', '\f', '\r', ' '}
+)
+
 //
 // PrintHex will print each byte in slice as hexadecimal value into N column
 // length.
diff --git a/lib/bytes/bytes_test.go b/lib/bytes/bytes_test.go
index d4fef2a6..50669c4f 100644
--- a/lib/bytes/bytes_test.go
+++ b/lib/bytes/bytes_test.go
@@ -5,7 +5,6 @@ import (
 	"testing"
 
 	"github.com/shuLhan/share/lib/test"
-	libtext "github.com/shuLhan/share/lib/text"
 )
 
 func TestToLower(t *testing.T) {
@@ -35,7 +34,7 @@ func TestToLower(t *testing.T) {
 	}
 }
 
-var randomInput256 = libtext.Random([]byte(libtext.HexaLetters), 256)
+var randomInput256 = Random([]byte(HexaLetters), 256)
 
 func BenchmarkToLowerStd(b *testing.B) {
 	in := make([]byte, len(randomInput256))
diff --git a/lib/bytes/is.go b/lib/bytes/is.go
new file mode 100644
index 00000000..4ad06805
--- /dev/null
+++ b/lib/bytes/is.go
@@ -0,0 +1,70 @@
+// Copyright 2018, Shulhan <ms@kilabit.info>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bytes
+
+//
+// IsAlpha will return true if byte is ASCII alphabet character, otherwise
+// it will return false.
+//
+func IsAlpha(b byte) bool {
+	if (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') {
+		return true
+	}
+	return false
+}
+
+//
+// IsAlnum will return true if byte is ASCII alphanumeric character, otherwise
+// it will return false.
+//
+func IsAlnum(b byte) bool {
+	return IsAlpha(b) || IsDigit(b)
+}
+
+//
+// IsDigit will return true if byte is ASCII digit, otherwise it will return
+// false.
+//
+func IsDigit(b byte) bool {
+	if b >= '0' && b <= '9' {
+		return true
+	}
+	return false
+}
+
+//
+// IsDigits will return true if all bytes are ASCII digit, otherwise it will
+// return false.
+//
+func IsDigits(data []byte) bool {
+	for x := 0; x < len(data); x++ {
+		if !IsDigit(data[x]) {
+			return false
+		}
+	}
+	return true
+}
+
+//
+// IsHex will return true if byte is hexadecimal number, otherwise it will
+// return false.
+//
+func IsHex(b byte) bool {
+	if (b >= '1' && b <= '9') || (b >= 'a' && b <= 'f') || (b >= 'A' && b <= 'F') {
+		return true
+	}
+	return false
+}
+
+//
+// IsSpace will return true if byte is ASCII white spaces character,
+// otherwise it will return false.
+//
+func IsSpace(b byte) bool {
+	if b == '\t' || b == '\n' || b == '\v' || b == '\f' || b == '\r' || b == ' ' {
+		return true
+	}
+	return false
+}
diff --git a/lib/bytes/json.go b/lib/bytes/json.go
new file mode 100644
index 00000000..1a296a3b
--- /dev/null
+++ b/lib/bytes/json.go
@@ -0,0 +1,172 @@
+// Copyright 2018, Shulhan <ms@kilabit.info>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bytes
+
+import (
+	"bytes"
+	"fmt"
+	"strconv"
+)
+
+const (
+	errInvalidSyntax = "%s: invalid syntax at %d"
+)
+
+const (
+	bDoubleQuote = '"'
+	bRevSolidus  = '\\'
+	bSolidus     = '/'
+	bBackspace   = '\b'
+	bFormFeed    = '\f'
+	bLineFeed    = '\n'
+	bCarReturn   = '\r'
+	bTab         = '\t'
+)
+
+//
+// JSONEscape escape the following character: `"` (quotation mark),
+// `\` (reverse solidus), `/` (solidus), `\b` (backspace), `\f` (formfeed),
+// `\n` (newline), `\r` (carriage return`), `\t` (horizontal tab), and control
+// character from 0 - 31.
+//
+// References:
+//
+// * https://tools.ietf.org/html/rfc7159#page-8
+//
+func JSONEscape(in []byte) []byte {
+	var buf bytes.Buffer
+
+	for x := 0; x < len(in); x++ {
+		if in[x] == bDoubleQuote || in[x] == bRevSolidus || in[x] == bSolidus {
+			buf.WriteByte(bRevSolidus)
+			buf.WriteByte(in[x])
+			continue
+		}
+		if in[x] == bBackspace {
+			buf.WriteByte(bRevSolidus)
+			buf.WriteByte('b')
+			continue
+		}
+		if in[x] == bFormFeed {
+			buf.WriteByte(bRevSolidus)
+			buf.WriteByte('f')
+			continue
+		}
+		if in[x] == bLineFeed {
+			buf.WriteByte(bRevSolidus)
+			buf.WriteByte('n')
+			continue
+		}
+		if in[x] == bCarReturn {
+			buf.WriteByte(bRevSolidus)
+			buf.WriteByte('r')
+			continue
+		}
+		if in[x] == bTab {
+			buf.WriteByte(bRevSolidus)
+			buf.WriteByte('t')
+			continue
+		}
+		if in[x] <= 31 {
+			buf.WriteString(fmt.Sprintf("\\u%04X", in[x]))
+			continue
+		}
+
+		buf.WriteByte(in[x])
+	}
+
+	return buf.Bytes()
+}
+
+//
+// JSONUnescape unescape JSON bytes, reversing what BytesJSONEscape do.
+//
+// If strict is true, any unknown control character will be returned as error.
+// For example, in string "\x", "x" is not valid control character, and the
+// function will return empty string and error.
+// If strict is false, it will return "x".
+//
+func JSONUnescape(in []byte, strict bool) ([]byte, error) {
+	var (
+		buf bytes.Buffer
+		uni bytes.Buffer
+		esc bool
+	)
+
+	for x := 0; x < len(in); x++ {
+		if esc {
+			if in[x] == 'u' {
+				uni.Reset()
+				x++
+
+				for y := 0; y < 4 && x < len(in); x++ {
+					uni.WriteByte(in[x])
+					y++
+				}
+
+				dec, err := strconv.ParseUint(uni.String(), 16, 32)
+				if err != nil {
+					return nil, err
+				}
+
+				if dec <= 31 {
+					buf.WriteByte(byte(dec))
+				} else {
+					buf.WriteRune(rune(dec))
+				}
+
+				esc = false
+				x--
+				continue
+			}
+			if in[x] == 't' {
+				buf.WriteByte(bTab)
+				esc = false
+				continue
+			}
+			if in[x] == 'r' {
+				buf.WriteByte(bCarReturn)
+				esc = false
+				continue
+			}
+			if in[x] == 'n' {
+				buf.WriteByte(bLineFeed)
+				esc = false
+				continue
+			}
+			if in[x] == 'f' {
+				buf.WriteByte(bFormFeed)
+				esc = false
+				continue
+			}
+			if in[x] == 'b' {
+				buf.WriteByte(bBackspace)
+				esc = false
+				continue
+			}
+			if in[x] == bDoubleQuote || in[x] == bRevSolidus || in[x] == bSolidus {
+				buf.WriteByte(in[x])
+				esc = false
+				continue
+			}
+
+			if strict {
+				err := fmt.Errorf(errInvalidSyntax, "BytesJSONUnescape", x)
+				return nil, err
+			}
+
+			buf.WriteByte(in[x])
+			esc = false
+			continue
+		}
+		if in[x] == bRevSolidus {
+			esc = true
+			continue
+		}
+		buf.WriteByte(in[x])
+	}
+
+	return buf.Bytes(), nil
+}
diff --git a/lib/bytes/random.go b/lib/bytes/random.go
new file mode 100644
index 00000000..73945788
--- /dev/null
+++ b/lib/bytes/random.go
@@ -0,0 +1,22 @@
+// Copyright 2018, Shulhan <ms@kilabit.info>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bytes
+
+import (
+	"math/rand"
+)
+
+//
+// Random generate random sequence of value from seed with fixed length.
+//
+// This function assume that random generator has been seeded.
+//
+func Random(seed []byte, n int) []byte {
+	b := make([]byte, n)
+	for x := 0; x < n; x++ {
+		b[x] = seed[rand.Intn(len(seed))]
+	}
+	return b
+}