Add message about ITensorMPS.jl to News in README

.github/dependabot.yml

@@ -0,0 +1,7 @@
+# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/" # Location of package manifests
+    schedule:
+      interval: "weekly"

.github/workflows/CompatHelper.yml

@@ -1,7 +1,7 @@
 name: CompatHelper
 on:
   schedule:
-    - cron: '00 00 * * *'
+    - cron: 0 0 * * *
   workflow_dispatch:
 jobs:
   CompatHelper:
@@ -12,4 +12,5 @@ jobs:
       - name: CompatHelper.main()
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          COMPATHELPER_PRIV: ${{ secrets.DOCUMENTER_KEY }}
         run: julia -e 'using CompatHelper; CompatHelper.main(; subdirs=["", "NDTensors"])'

.github/workflows/Downstream.yml

@@ -0,0 +1,57 @@
+name: IntegrationTest
+on:
+  push:
+    branches: [main]
+    tags: [v*]
+  pull_request:
+
+jobs:
+  test:
+    name: ${{ matrix.package.repo }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        julia-version: [1]
+        os: [ubuntu-latest]
+        package:
+          - {user: ITensor, repo: ITensorGaussianMPS.jl}
+          - {user: ITensor, repo: ITensorTDVP.jl}
+          - {user: ITensor, repo: ITensorUnicodePlots.jl}
+          - {user: ITensor, repo: ITensorVisualizationBase.jl}
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: julia-actions/setup-julia@v2
+        with:
+          version: ${{ matrix.julia-version }}
+          arch: x64
+      - uses: julia-actions/julia-buildpkg@latest
+      - name: Clone Downstream
+        uses: actions/checkout@v4
+        with:
+          repository: ${{ matrix.package.user }}/${{ matrix.package.repo }}
+          path: downstream
+      - name: Load this and run the downstream tests
+        shell: julia --color=yes --project=downstream {0}
+        run: |
+          using Pkg
+          try
+            # force it to use this PR's version of the package
+            Pkg.develop(PackageSpec(path="."))  # resolver may fail with main deps
+            Pkg.update()
+            Pkg.test(coverage=true)  # resolver may fail with test time deps
+          catch err
+            err isa Pkg.Resolve.ResolverError || rethrow()
+            # If we can't resolve that means this is incompatible by SemVer and this is fine
+            # It means we marked this as a breaking change, so we don't need to worry about
+            # Mistakenly introducing a breaking change, as we have intentionally made one
+            @info "Not compatible with this release. No problem." exception=err
+            exit(0)  # Exit immediately, as a success
+          end
+##      - uses: julia-actions/julia-processcoverage@v1
+##      - uses: codecov/codecov-action@v4
+##        with:
+##          token: ${{ secrets.CODECOV_TOKEN }}
+##          file: lcov.info
+##          fail_ci_if_error: true

.github/workflows/register.yml → .github/workflows/Register.yml

@@ -8,6 +8,8 @@ on:
 jobs:
   register:
     runs-on: ubuntu-latest
+    permissions:
+        contents: write
     steps:
       - uses: julia-actions/RegisterAction@latest
         with:

.github/workflows/TagBot.yml

@@ -4,6 +4,22 @@ on:
     types:
       - created
   workflow_dispatch:
+    inputs:
+      lookback:
+        default: "3"
+permissions:
+  actions: read
+  checks: read
+  contents: write
+  deployments: read
+  issues: read
+  discussions: read
+  packages: read
+  pages: read
+  pull-requests: read
+  repository-projects: read
+  security-events: read
+  statuses: read
 jobs:
   TagBot:
     if: github.event_name == 'workflow_dispatch' || github.actor == 'JuliaTagBot'

.github/workflows/comment_trigger_example.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Get PR branch
-        uses: xt0rted/pull-request-comment-branch@v1
+        uses: xt0rted/pull-request-comment-branch@v2
         id: comment-branch
       - name: Set latest commit status as pending
         uses: myrotvorets/set-commit-status-action@master
@@ -22,7 +22,7 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
           status: pending
       - name: Checkout PR branch
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # https://github.com/actions/checkout/issues/331#issuecomment-1438220926
           ref: refs/pull/${{ github.event.issue.number }}/head
@@ -41,7 +41,7 @@ jobs:
           token: ${{ secrets.GITHUB_TOKEN }}
           status: ${{ job.status }}
       - name: Add comment to PR
-        uses: actions/github-script@v6
+        uses: actions/github-script@v7
         if: always()
         with:
           script: |

.github/workflows/documentation.yml

@@ -18,7 +18,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@latest
         with:
           version: '1'

.github/workflows/format_check.yml

@@ -10,8 +10,8 @@ jobs:
     name: "Format Check"
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-      - uses: julia-actions/setup-julia@v1
+      - uses: actions/checkout@v4
+      - uses: julia-actions/setup-julia@v2
         with:
           version: 1
       - name: Install JuliaFormatter and format

.github/workflows/format_pr.yml

@@ -6,7 +6,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Install JuliaFormatter and format
         run: |
           julia  -e 'import Pkg; Pkg.add("JuliaFormatter")'
@@ -15,7 +15,7 @@ jobs:
       # https://github.com/peter-evans/create-pull-request#reference-example
       - name: Create Pull Request
         id: cpr
-        uses: peter-evans/create-pull-request@v3
+        uses: peter-evans/create-pull-request@v6
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           commit-message: Format .jl files

.github/workflows/format_suggestions.yml

@@ -13,7 +13,7 @@ jobs:
   format:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@latest
         with:
           version: 1

.github/workflows/main_test_itensors_base_macos_windows.yml

@@ -27,7 +27,7 @@ jobs:
           # MacOS not available on x86
           - {os: 'macOS-latest', arch: 'x86'}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@latest
         with:
           version: ${{ matrix.version }}

.github/workflows/test_itensormps_ubuntu.yml

@@ -28,7 +28,7 @@ jobs:
           # MacOS not available on x86
           - {os: 'macOS-latest', arch: 'x86'}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@latest
         with:
           version: ${{ matrix.version }}

.github/workflows/test_itensors_base_ubuntu.yml

@@ -28,7 +28,7 @@ jobs:
           # MacOS not available on x86
           - {os: 'macOS-latest', arch: 'x86'}
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@latest
         with:
           version: ${{ matrix.version }}

.github/workflows/test_ndtensors.yml

@@ -25,7 +25,7 @@ jobs:
         arch:
           - x64
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@latest
         with:
           version: ${{ matrix.version }}

Project.toml

@@ -1,7 +1,7 @@
 name = "ITensors"
 uuid = "9136182c-28ba-11e9-034c-db9fb085ebd5"
 authors = ["Matthew Fishman <[email protected]>", "Miles Stoudenmire <[email protected]>"]
-version = "0.5.8"
+version = "0.6.0"
 
 [deps]
 Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"

docs/src/index.md

@@ -31,6 +31,8 @@ Development of ITensor is supported by the Flatiron Institute, a division of the
 
 - May 9, 2024: A new package ITensorMPS.jl has been released. We plan to move all of the MPS/MPO code in ITensors.jl to ITensorMPS.jl. For now, ITensorMPS.jl just re-exports the MPS/MPO functionality of ITensors.jl (as well as of [ITensorTDVP.jl](https://github.com/ITensor/ITensorTDVP.jl)), such as `dmrg`, `siteinds`, `MPS`, `MPO`, etc. To prepare for the change over to ITensorMPS.jl, please change `using ITensors` to `using ITensors, ITensorMPS` in any code that makes use of MPS/MPO functionality, and if you are using ITensorTDVP.jl change `using ITensorTDVP` to `using ITensorMPS` in your code.
 
+- May 8, 2024: ITensors.jl v0.6 has been released. This version deletes the experimental "combine-contract" contraction backend, which was enabled by `ITensors.enable_combine_contract()`. This feature enabled performing ITensor contractions by first combining indices and then performing contractions as matrix multiplications, which potentially could lead to speedups for certain contractions involving higher-order QN-conserving tensors. However, the speedups weren't consistent with the current implementation, and this feature will be incorporated into the library in a more systematic way when we release our new non-abelian symmetric tensor backend.
+
 - May 2, 2024: ITensors.jl v0.5 has been released. This version removes PackageCompiler.jl as a dependency and moves the package compilation functionality into a package extension. In order to use the `ITensors.compile()` function going forward, you need to install the PackageCompiler.jl package with `using Pkg: Pkg; Pkg.add("PackageCompiler")` and put `using PackageCompiler` together with `using ITensors` in your code.
 
 - April 16, 2024: ITensors.jl v0.4 has been released. This version removes HDF5.jl as a dependency and moves the HDF5 read and write functions for ITensor, MPS, MPO, and other associated types into a package extension. To enable ITensor HDF5 features, install the HDF5.jl package with `using Pkg: Pkg; Pkg.add("HDF5")` and put `using HDF5` together with `using ITensors` in your code. Other recent changes include support for multiple GPU backends using package extensions.

src/deprecated.jl

@@ -1,13 +1,10 @@
 
 # global_variables.jl
-@deprecate disable_combine_contract!() ITensors.disable_combine_contract()
 @deprecate disable_tblis!() ITensors.disable_tblis()
 @deprecate disable_warn_order!() ITensors.disable_warn_order()
-@deprecate enable_combine_contract!() ITensors.enable_combine_contract()
 @deprecate enable_tblis!() ITensors.enable_tblis()
 @deprecate reset_warn_order!() ITensors.reset_warn_order()
 @deprecate set_warn_order!(N) ITensors.set_warn_order(N)
-@deprecate use_combine_contract() ITensors.using_combine_contract()
 @deprecate use_debug_checks() ITensors.using_debug_checks()
 
 # index.jl

src/global_variables.jl

@@ -166,24 +166,6 @@ $(NDTensors.enable_threaded_blocksparse_docstring(@__MODULE__))
 """
 disable_threaded_blocksparse() = NDTensors._disable_threaded_blocksparse()
 
-#
-# Turn enable or disable combining QN ITensors before contracting
-#
-
-const _using_combine_contract = Ref(false)
-
-using_combine_contract() = _using_combine_contract[]
-
-function enable_combine_contract()
-  _using_combine_contract[] = true
-  return nothing
-end
-
-function disable_combine_contract()
-  _using_combine_contract[] = false
-  return nothing
-end
-
 #
 # Turn debug checks on and off
 #

src/tensor_operations/tensor_algebra.jl

@@ -23,36 +23,6 @@ function _contract(A::ITensor, B::ITensor)::ITensor
   return C
 end
 
-_contract(T::ITensor, ::Nothing) = T
-
-function can_combine_contract(A::ITensor, B::ITensor)::Bool
-  return hasqns(A) &&
-         hasqns(B) &&
-         !iscombiner(A) &&
-         !iscombiner(B) &&
-         !isdiag(A) &&
-         !isdiag(B)
-end
-
-function combine_contract(A::ITensor, B::ITensor)::ITensor
-  # Combine first before contracting
-  C::ITensor = if can_combine_contract(A, B)
-    uniqueindsA = uniqueinds(A, B)
-    uniqueindsB = uniqueinds(B, A)
-    commonindsAB = commoninds(A, B)
-    combinerA = isempty(uniqueindsA) ? nothing : combiner(uniqueindsA)
-    combinerB = isempty(uniqueindsB) ? nothing : combiner(uniqueindsB)
-    combinerAB = isempty(commonindsAB) ? nothing : combiner(commonindsAB)
-    AC = _contract(_contract(A, combinerA), combinerAB)
-    BC = _contract(_contract(B, combinerB), dag(combinerAB))
-    CC = _contract(AC, BC)
-    _contract(_contract(CC, dag(combinerA)), dag(combinerB))
-  else
-    _contract(A, B)
-  end
-  return C
-end
-
 """
     A::ITensor * B::ITensor
     contract(A::ITensor, B::ITensor)
@@ -100,10 +70,8 @@ function contract(A::ITensor, B::ITensor)::ITensor
     return iscombiner(A) ? _contract(A, B) : A[] * B
   elseif NB == 0
     return iscombiner(B) ? _contract(B, A) : B[] * A
-  else
-    C = using_combine_contract() ? combine_contract(A, B) : _contract(A, B)
-    return C
   end
+  return _contract(A, B)
 end
 
 function optimal_contraction_sequence(A::Union{Vector{<:ITensor},Tuple{Vararg{ITensor}}})