I have a function, littered with macros, which when I call macroexpand on
it returns the following Expr:
quote # /home/tlycken/.julia/v0.3/Interpolations/src/linear.jl, line 12:
begin
begin
ix_1 = ifloor(x_1)
fx_1 = x_1 - convert(typeof(x_1),ix_1)
end
end # line 13:
begin
ixp_1 = ix_1 + 1
end # line 14:
begin
$(Expr(:boundscheck, false))
begin
ret = (one(fx_1) - fx_1) * itp.coefs[ix_1] + fx_1 * itp.coefs[ixp_1]
$(Expr(:boundscheck, :(Base.pop)))
end
end # line 15:
ret
end
Now, for my own sanity when I try to reason about this code, it would be
much easier if I could be sure that the above Expr is equivalent with this
one (except for the removal of an @inbounds block):
quote # /home/tlycken/.julia/v0.3/Interpolations/src/linear.jl, line 12:
ix_1 = ifloor(x_1)
fx_1 = x_1 - convert(typeof(x_1),ix_1)
ixp_1 = ix_1 + 1
ret = (one(fx_1) - fx_1) * itp.coefs[ix_1] + fx_1 * itp.coefs[ixp_1] # this
line previously had @inbounds as well
ret
end
I *think* that the man page on scoping
<http://julia.readthedocs.org/en/latest/manual/variables-and-scoping/>, and
specifically the line *“Notably missing from this list are begin blocks
<http://julia.readthedocs.org/en/latest/manual/control-flow/#man-compound-expressions>,
which do not introduce new scope blocks”*, indicate that I’m right, but I’m
not certain. Could someone confirm this for me? Since I’m not assigning the
results of the expressions to anything, the implications of begin ... end
in this context is still a little shady to me.
// T
