make size of a product iterator concatenate the sizes of its components

this removes an extra layer of wrapping with `IteratorND`

add some inline declarations for `Generator` iteration

Author: JeffBezanson

base/generator.jl

@@ -15,9 +15,10 @@ Generator(f, c1, c...) = Generator(a->f(a...), zip(c1, c...))
 
 Generator{T,I}(::Type{T}, iter::I) = Generator{I,Type{T}}(T, iter)
 
-start(g::Generator) = start(g.iter)
-done(g::Generator, s) = done(g.iter, s)
+start(g::Generator) = (@_inline_meta; start(g.iter))
+done(g::Generator, s) = (@_inline_meta; done(g.iter, s))
 function next(g::Generator, s)
+    @_inline_meta
     v, s2 = next(g.iter, s)
     g.f(v), s2
 end

base/iterator.jl

@@ -370,12 +370,16 @@ iteratorsize{I1,I2}(::Type{Prod{I1,I2}}) = prod_iteratorsize(iteratorsize(I1),it
     ((x[1][1],x[1][2]...), x[2])
 end
 
-prod_iteratorsize(::Union{HasLength,HasShape}, ::Union{HasLength,HasShape}) = HasLength()
+prod_iteratorsize(::Union{HasLength,HasShape}, ::Union{HasLength,HasShape}) = HasShape()
 prod_iteratorsize(a, ::IsInfinite) = IsInfinite() # products can have an infinite last iterator (which moves slowest)
 prod_iteratorsize(a, b) = SizeUnknown()
 
-_size(p::Prod2) = (length(p.a), length(p.b))
-_size(p::Prod) = (length(p.a), _size(p.b)...)
+it_size(it) = it_size(it, iteratorsize(it))
+it_size(it, ::HasLength) = (length(it),)
+it_size(it, ::HasShape) = size(it)
+
+size(p::Prod2) = (it_size(p.a)..., it_size(p.b)...)
+size(p::Prod) = (it_size(p.a)..., size(p.b)...)
 
 """
     IteratorND(iter, dims)
@@ -396,7 +400,6 @@ immutable IteratorND{I,N}
         end
         new{I,N}(iter, shape)
     end
-    (::Type{IteratorND}){I<:AbstractProdIterator}(p::I) = IteratorND(p, _size(p))
 end
 
 start(i::IteratorND) = start(i.iter)

src/julia-syntax.scm

@@ -2009,7 +2009,7 @@
           `(call (top Generator) (-> ,argname (block ,@splat ,expr))
                  ,(if (length= ranges 1)
                       (car ranges)
-                      `(call (top IteratorND) (call (top product) ,@ranges))))))))
+                      `(call (top product) ,@ranges)))))))
 
    'comprehension
    (lambda (e) (expand-forms