Bug 1106 – Using Stream.readLine() and Stream.read(ubyte[]) requires understanding implementation details

There is a bug in the Stream class. If you mix, readLine() and read(ubyte[]) calls to a stream, readLine() may not appear to perform as documented. As documented, readLine() stop at "some combination of carriage return [CR] and line feed [LF]". However, this is not necessarily true. If the stream is non-seekable, readLine() will stop at CR and set a prevCr flag indicating that a LF should be consumed on the next read. However, this only takes place in the getc() method and methods using getc(). Some methods, like read(ubyte[]), read the stream directly and the prevCr flag is not processed. At first, I thought this might just be odd behavior rather than a bug, but I decided that it is a bug. In order to understand how to use the stream effectively, one must understand the implementation details. One must know that the behavior for seekable streams is different that non-seekable streams, and adjust the client code accordingly. For this reason, it should be considered a bug. Code example: import std.stream; void main() { char[] testString = "line one\r\nline two\r\n"; File testFile = new File("testFile", FileMode.OutNew); testFile.writeString(testString); testFile.close(); File input = new File("testFile", FileMode.In); input.seekable = false; char[] line1 = input.readLine(); assert(line1 == "line one"); // correct ubyte[1] b; input.read(b); assert(b[0] == '\n'); // incorrect }

std.stream is deprecated and will be removed in 2016