From 70817a8fbcfa28e8c9cfb0c33275ffbb18640714 Mon Sep 17 00:00:00 2001
From: kalmar <kalmar@amu.edu.pl>
Date: Tue, 16 May 2017 18:46:30 +0200
Subject: [PATCH] reverse_dict function for fast basis element lookup

---
 src/GroupAlgebras.jl | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/GroupAlgebras.jl b/src/GroupAlgebras.jl
index aedfa98..1b82536 100644
--- a/src/GroupAlgebras.jl
+++ b/src/GroupAlgebras.jl
@@ -191,6 +191,8 @@ function rationalize{T<:Integer, S<:Number}(::Type{T}, X::GroupRingElem{S};
    return GroupRingElem(v, parent(X))
 end
 
+function reverse_dict(a::AbstractVector)
+   return Dict{eltype(a), Int}(x => i for (i,x) in enumerate(a))
 end