array of vertex attributes

Hi,

I wonder why doesn’t GLSL allow arrays for vertex attributes:
in at_pos[4]

You can have in/out variables as arrays, if they are not attributes.
You can have uniform values/structures arrays.
But you are not allowed to have an attribute array. Why?

Could be pretty useful for me:
App-1: texture coordinate channels
App-2: attributes passed as bones for skinning