API Design

[tobias@...]

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:

                     - a segment starting at byte 439 and have a  
length to the end of the buffer, or
                     - a segment starting at first byte being 439 bytes long

I don't think there is a 'right' answer, but to all those people who  
work with this kind of stuff, what would feel more natural to you?
Also, does Segment( offset, length ) makes more sense than Segment(  
length, offset ) ?

Thanks for the input,

 - Tobias