From 2f3e2849a24719317f187e30dbd48f59e98e3b60 Mon Sep 17 00:00:00 2001
From: Matt Fishman <mtfishman@users.noreply.github.com>
Date: Wed, 23 Dec 2020 16:25:06 -0500
Subject: [PATCH] Allow longer gate names by using Symbol instead of
 SmallString (#161)

---
 Project.toml          |  4 ++--
 src/circuits/gates.jl | 35 +++++++++--------------------------
 test/gates.jl         | 12 +++++++++++-
 3 files changed, 22 insertions(+), 29 deletions(-)

diff --git a/Project.toml b/Project.toml
index 4fe65767..28d7a065 100644
--- a/Project.toml
+++ b/Project.toml
@@ -2,7 +2,7 @@ name = "PastaQ"
 uuid = "30b07047-aa8b-4c78-a4e8-24d720215c19"
 authors = ["Giacomo Torlai <torlaigiacomo@gmail.com>",
            "Matthew Fishman <mfishman@flatironinstitute.org>"]
-version = "0.0.2"
+version = "0.0.3"
 
 [deps]
 HDF5 = "f67ccb44-e63f-5c2f-98bd-6dc0ccc4ba2f"
@@ -14,6 +14,6 @@ StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
 
 [compat]
 HDF5 = "0.13.1, 0.14"
-ITensors = "0.1.33"
+ITensors = "0.1.34"
 StatsBase = "0.33"
 julia = "1.4"
diff --git a/src/circuits/gates.jl b/src/circuits/gates.jl
index b150c614..07897973 100644
--- a/src/circuits/gates.jl
+++ b/src/circuits/gates.jl
@@ -6,7 +6,7 @@
 const GateName = OpName
 
 macro GateName_str(s)
-  GateName{ITensors.SmallString(s)}
+  GateName{Symbol(s)}
 end
 
 #
@@ -311,7 +311,7 @@ function gate(::GateName"AD"; γ::Number)
 end
 
 # To accept the gate name "amplitude_damping"
-gate(::GateName"amplitud"; kwargs...) = gate("AD"; kwargs...)
+gate(::GateName"amplitude_damping"; kwargs...) = gate("AD"; kwargs...)
 
 function gate(::GateName"PD"; γ::Number)
   kraus = zeros(2,2,2)
@@ -323,10 +323,10 @@ function gate(::GateName"PD"; γ::Number)
 end
 
 # To accept the gate name "phase_damping"
-gate(::GateName"phase_da"; kwargs...) = gate("PD"; kwargs...)
+gate(::GateName"phase_damping"; kwargs...) = gate("PD"; kwargs...)
 
 # To accept the gate name "dephasing"
-gate(::GateName"dephasin"; kwargs...) = gate("PD"; kwargs...)
+gate(::GateName"dephasing"; kwargs...) = gate("PD"; kwargs...)
 
 function gate(::GateName"DEP"; p::Number)
   kraus = zeros(Complex{Float64},2,2,4)
@@ -342,7 +342,7 @@ function gate(::GateName"DEP"; p::Number)
 end
 
 # To accept the gate name "depolarizing"
-gate(::GateName"depolari"; kwargs...) = gate("DEP"; kwargs...)
+gate(::GateName"depolarizing"; kwargs...) = gate("DEP"; kwargs...)
 
 gate(::GateName"noiseDEP"; kwargs...) =
   gate("DEP";kwargs...)
@@ -397,15 +397,6 @@ end
 # Get an ITensor gate from a gate definition
 #
 
-function Base.startswith(ss::ITensors.SmallString, st::String)
-  for j in 1:length(st)
-    if ss[j] ≠ st[j]
-      return false
-    end
-  end
-  return true
-end
-
 function gate(::GateName{gn}; kwargs...) where {gn}
   gn_st = String(gn)
   if startswith(gn_st, "basis")
@@ -441,12 +432,8 @@ function gate(gn::GateName, s1::Index, ss::Index...; kwargs...)
   error("Gate definitions must be either Vector{T} (for a state), Matrix{T} (for a gate) or Array{T,3} (for a noise model). For gate name $gn, gate size is $(size(g)).") 
 end
 
-function gate(gn::String, s::Index...; kwargs...)
-  if length(gn) > 8
-    gn = gn[1:8]
-  end
-  return gate(GateName(gn), s...; kwargs...)
-end
+gate(gn::String, s::Index...; kwargs...) =
+  gate(GateName(gn), s...; kwargs...)
 
 gate(gn::String, s::Vector{<: Index}, ns::Int...; kwargs...) =
   gate(gn, s[[ns...]]...; kwargs...)
@@ -456,10 +443,6 @@ gate(gn::String, s::Vector{<: Index}, ns::Int...; kwargs...) =
 # definitions of the "Qubit" site type
 #
 
-function ITensors.op(gn::GateName,
-                     ::SiteType"Qubit",
-                     s::Index...;
-                     kwargs...)
-  return gate(gn, s...; kwargs...)
-end
+ITensors.op(gn::GateName, ::SiteType"Qubit", s::Index...; kwargs...) =
+  gate(gn, s...; kwargs...)
 
diff --git a/test/gates.jl b/test/gates.jl
index b4d18c5f..80a2ccdf 100644
--- a/test/gates.jl
+++ b/test/gates.jl
@@ -1,5 +1,5 @@
 using PastaQ
-using ITensors
+using PastaQ.ITensors
 using Test
 using LinearAlgebra
 
@@ -144,5 +144,15 @@ using LinearAlgebra
     end
   end
 
+  @testset "Custom gate with long name" begin
+    PastaQ.gate(::GateName"my_favorite_gate") = [0.11 0.12; 0.21 0.22]
+    s = Index(2, "Qubit, Site")
+    gate("my_favorite_gate", s)
+    g = gate("my_favorite_gate", s)
+    @test g[s'=>1, s=>1] == 0.11
+    @test g[s'=>1, s=>2] == 0.12
+    @test g[s'=>2, s=>1] == 0.21
+    @test g[s'=>2, s=>2] == 0.22
+  end
 end