lua-users home
lua-l archive

[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index] [Thread Index]


Hi there,

I'm designing a library which has a Buffer module that allows to contain binary data. Think of it as a string just with less features :-P ... except it is mutable. Now I'm writing a companion module called Buffer.Segment that allows access to just a limited part of the buffer which is defined by an offset and a length. I'd plan the API look like this:

b  = Buffer( 1024 )      -- buffer with 124 bytes
s = Segment( b ) -- creates a segment starting at the first byte of the buffer as long as the buffer itself
s1 = Segment( 128, 256 ) -- Segment with 128 byte offset and 256 bytes length
s2 = Segment( 439 )      -- this is the question, shall this be:

Here is what I ended up implementing:

 b = Buffer( 1024 )        -- buffer with 124 bytes
 s = b:Segment()           -- Segment covering entire buffer
 s = b:Segment( 256 )      -- Segment starting @256 covering to end of buffer
s = b:Segment( 256, 128 ) -- Segment starting @256 covering 128bytes of buffer
 s.buffer                  -- Buffer instance Segment refers to (immutable)
 s.size                    -- Length of Segment, same as #s but mutable
s.start -- First byte of Segment in regards to Buffer; mutable -- First byte that's NOT in Segment; muatble. That's
                              in line with string.sub() or Pythons slicing
 s[ 34 ]                   -- byte value of 34th byte in Segment; mutable

Thanks for your input.