Speed-up Chebyshev ldirichlet indexing (#266)

* Speed-up Chebyshev ldirichlet indexing

* use isodd instead of iseven

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "ApproxFunOrthogonalPolynomials"
 uuid = "b70543e2-c0d9-56b8-a290-0d4d6d4de211"
-version = "0.6.34"
+version = "0.6.35"
 
 [deps]
 ApproxFunBase = "fbd15aa5-315a-5a7d-a8a4-24992e37be05"

src/Spaces/Chebyshev/ChebyshevOperators.jl

@@ -84,7 +84,7 @@ function _getindex_eval_leftendpoint(op::ConcreteEvaluation{<:Chebyshev{<:Interv
 
     ret = Array{T}(undef, n)
     for (ind, j) in enumerate(k)
-        ret[ind]=(-1)^(p+1)*(-one(T))^j
+        ret[ind] = iseven(p+j) ? -1 : 1
     end
 
     for m in 0:p-1