From 857efdf601798cf4b9399ce713d46cf1551b6e6c Mon Sep 17 00:00:00 2001
From: Charles Iliya Krempeaux <iamreiver@gmail.com>
Date: Sun, 13 Nov 2022 20:55:41 -0800
Subject: [PATCH] initial commits

---
 copyline.go | 117 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 copyline.go

diff --git a/copyline.go b/copyline.go
new file mode 100644
index 0000000..2d7e62f
--- /dev/null
+++ b/copyline.go
@@ -0,0 +1,117 @@
+package netln
+
+import (
+	"errors"
+	"io"
+)
+
+// CopyLine reads in a line from ‘reader’ and writes that line to ‘writer’ (without the line terminator).
+//
+// For CopyLine, a line is terminated by the "\r\n" characters.
+//
+// So, for example, if from ‘reader’ CopyLine read in:
+//
+//	"Hello world!\r\n"
+//
+// Then what CopyLine would write to ‘writer’ is:
+//
+//	"Hello world!"
+//
+// (Notice that the "\r\n" at the end is missing.)
+//
+// Note that ‘n64’ represents how many bytes were written, not read.
+func CopyLine(writer io.Writer, reader io.Reader) (n64 int64, err error) {
+
+	for {
+		var eof bool
+
+		var r0 rune
+		var size0 int
+		{
+			r0, size0, err = readRune(reader)
+			eof = errors.Is(err, io.EOF)
+			if nil != err && !eof {
+/////////////////////////////// RETURN
+				return
+			}
+		}
+
+		if size0 <= 0 {
+	/////////////// BREAK
+			break
+		}
+
+		if '\r' != r0 || eof {
+
+			err = writeRune(writer, r0, size0)
+			if nil != err {
+/////////////////////////////// RETURN
+				return
+			}
+			n64 += int64(size0)
+
+			if eof {
+	/////////////////////// BREAK
+				break
+			} else {
+	/////////////////////// CONTINUE
+				continue
+			}
+		}
+
+		var r1 rune
+		var size1 int
+		{
+			r1, size1, err = readRune(reader)
+			eof = errors.Is(err, io.EOF)
+			if nil != err && !eof {
+/////////////////////////////// RETURN
+				return
+			}
+		}
+
+		if size1 <= 0 {
+			err = writeRune(writer, r0, size0)
+			if nil != err {
+/////////////////////////////// RETURN
+				return
+			}
+			n64 += int64(size0)
+	/////////////// BREAK
+			break
+		}
+
+		if '\n' != r1 {
+			{
+				err = writeRune(writer, r0, size0)
+				if nil != err {
+/////////////////////////////////////// RETURN
+					return
+				}
+				n64 += int64(size0)
+			}
+
+			{
+				err = writeRune(writer, r1, size1)
+				if nil != err {
+/////////////////////////////////////// RETURN
+					return
+				}
+				n64 += int64(size1)
+			}
+
+			if eof {
+/////////////////////////////// BREAK
+				break
+			} else {
+/////////////////////////////// CONTINUE
+				continue
+			}
+		}
+
+	/////// BREAK
+		break
+	}
+
+	return n64, nil
+}