From 325c5542d1dda2074f4ad591bb803893dbc3b572 Mon Sep 17 00:00:00 2001
From: mtfishman <mfishman@flatironinstitute.org>
Date: Wed, 21 May 2025 10:42:43 -0400
Subject: [PATCH] Define get and getindex

---
 Project.toml         |  2 +-
 src/backend_types.jl |  5 +++++
 test/Project.toml    |  1 +
 test/test_basics.jl  | 22 ++++++++++++++++------
 4 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/Project.toml b/Project.toml
index 6e030ef..e512743 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "BackendSelection"
 uuid = "680c2d7c-f67a-4cc9-ae9c-da132b1447a5"
 authors = ["ITensor developers <support@itensor.org> and contributors"]
-version = "0.1.5"
+version = "0.1.6"
 
 [compat]
 julia = "1.10"
diff --git a/src/backend_types.jl b/src/backend_types.jl
index f39d03b..217e265 100644
--- a/src/backend_types.jl
+++ b/src/backend_types.jl
@@ -30,8 +30,13 @@ function generate_backend_type_expr(type::Symbol)
       backend_string(::$type{Back}) where {Back} = string(Back)
       parameters(backend::$type) = getfield(backend, :kwargs)
 
+      # NamedTuple interface functions.
       Base.getproperty(backend::$type, name::Symbol) = parameters(backend)[name]
       Base.propertynames(backend::$type) = propertynames(parameters(backend))
+      Base.getindex(backend::$type, name::Symbol) = parameters(backend)[name]
+      function Base.get(backend::$type, name::Symbol, default)
+        get(parameters(backend), name, default)
+      end
 
       function Base.show(io::IO, backend::$type)
         return print(
diff --git a/test/Project.toml b/test/Project.toml
index b80f121..9e6585e 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -4,6 +4,7 @@ BackendSelection = "680c2d7c-f67a-4cc9-ae9c-da132b1447a5"
 SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 Suppressor = "fd094767-a336-5f1f-9728-57cf17d0bbfb"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+TestExtras = "5ed8adda-3752-4e41-b88a-e8b09835ee3a"
 
 [compat]
 Aqua = "0.8"
diff --git a/test/test_basics.jl b/test/test_basics.jl
index 30a9271..2245155 100644
--- a/test/test_basics.jl
+++ b/test/test_basics.jl
@@ -1,24 +1,34 @@
 using BackendSelection: BackendSelection, @Algorithm_str, @Backend_str, Algorithm, Backend
 using Test: @test, @testset
+using TestExtras: @constinferred
 
 @testset "BackendSelection" begin
   for type in (Algorithm, Backend)
     @testset "$type" begin
+      # Note: constructing from a string is not type stable.
       @test type("backend") isa type{:backend}
-      @test type(:backend) isa type{:backend}
-      backend = type("backend"; x=2, y=3)
+      @test @constinferred(type(:backend)) isa type{:backend}
+      backend = @constinferred type(:backend; x=2, y=3)
+      @test backend === type("backend"; x=2, y=3)
       @test backend isa type{:backend}
       @test backend.x == 2
       @test backend.y == 3
-      @test propertynames(backend) == (:x, :y)
+      @test @constinferred(getproperty(backend, :x)) == 2
+      @test @constinferred(getproperty(backend, :y)) == 3
+      @test @constinferred(backend[:x]) == 2
+      @test @constinferred(backend[:y]) == 3
+      @test @constinferred(get(backend, :x, "default")) == 2
+      @test @constinferred(get(backend, :y, "default")) == 3
+      @test @constinferred(get(backend, :z, "default")) == "default"
+      @test @constinferred(propertynames(backend)) == (:x, :y)
       (; x, y) = backend
       @test x == 2
       @test y == 3
-      @test BackendSelection.parameters(backend) === (; x=2, y=3)
+      @test @constinferred(BackendSelection.parameters(backend)) === (; x=2, y=3)
     end
   end
   # Macro syntax.
-  @test Algorithm"backend"(; x=2, y=3) === Algorithm("backend"; x=2, y=3)
-  @test Backend"backend"(; x=2, y=3) === Backend("backend"; x=2, y=3)
+  @test @constinferred(Algorithm"backend"(; x=2, y=3)) === Algorithm("backend"; x=2, y=3)
+  @test @constinferred(Backend"backend"(; x=2, y=3)) === Backend("backend"; x=2, y=3)
   @test isnothing(show(Algorithm("")))
 end