From f628b40dc66467db2e299f115ea9bac75a297900 Mon Sep 17 00:00:00 2001
From: Arda Serdar Pektezol <1669855+pektezol@users.noreply.github.com>
Date: Fri, 11 Nov 2022 08:59:19 +0300
Subject: add ReadBitsToSlice() function

---
 README.md    | 16 +++++++++++-----
 bitreader.go | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 1093153..2bc00e7 100644
--- a/README.md
+++ b/README.md
@@ -28,16 +28,22 @@ err := reader.SkipBits(8)
 err := reader.SkipBytes(4)
 
 // Read Bits/Bytes
-value, err := reader.ReadBytes(4)
-value, err := reader.ReadBits(64) // up to 64 bits
+value, err := reader.ReadBytes(4)       // up to 8 bytes
+value, err := reader.ReadBits(64)       // up to 64 bits
 
 // Read String
-text, err := reader.ReadString() // null-terminated
-text, err := reader.ReadStringLen(256) // length-specified
+text, err := reader.ReadString()        // null-terminated
+text, err := reader.ReadStringLen(256)  // length-specified
+
+// Read Bits/Bytes into Slice
+arr, err := reader.ReadBitsToSlice(128)
+arr, err := reader.ReadBytesToSlice(64)
 
 // Wrapper functions
 text := reader.TryReadString()      // string
 text := reader.TryReadStringLen(64) // string
+arr := reader.ReadBitsToSlice(128)  // []byte
+arr := reader.ReadBytesToSlice(64)  // []byte
 state := reader.TryReadBool()       // bool
 value := reader.TryReadInt1()       // uint8
 value := reader.TryReadInt8()       // uint8
@@ -51,7 +57,7 @@ value := reader.TryReadBytes(8)     // uint64
 ```
 
 ## Error Handling
-ReadBits(x), ReadBytes(x), ReadBool(), ReadString(), ReadStringLen(x) SkipBits(x) and SkipBytes(x) functions returns an error message when they don't work as expected. It is advised to always handle errors. \
+ReadBits(x), ReadBytes(x), ReadBool(), ReadString(), ReadStringLen(x), ReadBitsToSlice(x), ReadBytesToSlice(x), SkipBits(x) and SkipBytes(x) functions returns an error message when they don't work as expected. It is advised to always handle errors. \
 Wrapper functions, however, only returns the value and panics if an error is encountered.
 
 ## Bug Report / Feature Request
diff --git a/bitreader.go b/bitreader.go
index b9ac772..5c7dc04 100644
--- a/bitreader.go
+++ b/bitreader.go
@@ -152,6 +152,29 @@ func (reader *ReaderType) TryReadStringLen(length int) string {
 	return text
 }
 
+// TryReadBytesToSlice is a wrapper function that reads the specified amount of bits
+// from the parameter and puts each bit into a slice and returns this slice.
+func (reader *ReaderType) TryReadBitsToSlice(bits int) []byte {
+	bytes := (bits / 8) + (bits % 8)
+	out := make([]byte, bytes)
+	for i := 0; i < bytes; i++ {
+		if bits/8 > 0 {
+			val, err := reader.ReadBytes(1)
+			if err != nil {
+				panic(err)
+			}
+			out[i] = byte(val)
+		} else { // Not enough to fill a whole byte
+			val, err := reader.ReadBits(bits % 8)
+			if err != nil {
+				panic(err)
+			}
+			out[i] = byte(val)
+		}
+	}
+	return out
+}
+
 // TryReadBytesToSlice is a wrapper function that reads the specified amount of bytes
 // from the parameter and puts each byte into a slice and returns this slice.
 func (reader *ReaderType) TryReadBytesToSlice(bytes int) []byte {
@@ -289,6 +312,31 @@ func (reader *ReaderType) ReadBytes(bytes int) (uint64, error) {
 	return value, nil
 }
 
+// ReadBitsToSlice is a function that reads the specified amount of bits
+// from the parameter and puts each bit into a slice and returns this slice.
+//
+// Returns an error if there are no remaining bits.
+func (reader *ReaderType) ReadBitsToSlice(bits int) ([]byte, error) {
+	bytes := (bits / 8) + (bits % 8)
+	out := make([]byte, bytes)
+	for i := 0; i < bytes; i++ {
+		if bits/8 > 0 {
+			val, err := reader.ReadBytes(1)
+			if err != nil {
+				return out, err
+			}
+			out[i] = byte(val)
+		} else { // Not enough to fill a whole byte
+			val, err := reader.ReadBits(bits % 8)
+			if err != nil {
+				panic(err)
+			}
+			out[i] = byte(val)
+		}
+	}
+	return out, nil
+}
+
 // ReadBytesToSlice is a function that reads the specified amount of bytes
 // from the parameter and puts each byte into a slice and returns this slice.
 //
-- 
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