initial commit

.editorconfig

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+root = true
+
+[*.go]
+indent_style = tab
+indent_size = 2
+max_line_length = 80
+
+[*.md]
+indent_style = space
+indent_size = 4
+max_line_length = 120
+
+[*.{yml|yaml}]
+indent_style = space
+indent_size = 4
+max_line_length = 120

.github/workflows/go.yml

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+name: Go
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: [ '1.21' ]
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup Go ${{ matrix.go-version }}
+        uses: actions/setup-go@v4
+        with:
+          go-version: ${{ matrix.go-version }}
+      - name: Install dependencies
+        run: go mod tidy
+      - name: Test
+        run: go test ./...

.github/workflows/linter.yml

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+name: Linter
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: [ '1.21' ]
+
+    steps:
+      - name: Install Task
+        uses: arduino/setup-task@v1
+      - uses: actions/checkout@v4
+      - uses: ruby/setup-ruby@ec02537da5712d66d4d50a0f33b7eb52773b5ed1
+        with:
+          ruby-version: '3.1'
+      - name: Setup Go ${{ matrix.go-version }}
+        uses: actions/setup-go@v4
+        with:
+          go-version: ${{ matrix.go-version }}
+      - name: Install dependencies
+        run: task install-deps
+      - name: Linter
+        run: task lint

.gitignore

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+# Jetbrains IDEs
+.idea
+
+# Vim
+*.swp
+*.swn
+*.swo
+
+# MacOS system file
+.DS_Store
+
+# Environment variable files
+*.env
+
+# PEM files
+*.pem
+
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Binaries compiled by Go
+build/
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool
+*.new
+*.old
+*.out
+
+# Dependency directories
+vendor/
+
+# Redis
+*.rdb
+
+# Go workspace file
+go.work
+
+# local dev
+/.dev
+/pkg/debugger
+/docs/cookbook.md

.golangci.yml

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+run:
+  skip-files:
+    - "examples/.*"
+    - "pkg/debugger/.*"
+
+linters:
+  enable:
+    - lll
+
+linters-settings:
+  lll:
+    line-length: 80
+    tab-width: 2

.mdl_style.rb

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+all
+rule 'MD013', :line_length => 120
+rule 'MD029', :style => :ordered

.mdlrc

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+style "#{File.dirname(__FILE__)}/.mdl_style.rb"

LICENSE

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+MIT License
+
+Copyright (c) 2019 Kentaro Hibino
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

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+# asyncmachine-go
+
+`asyncmachine-go` is a minimal implementation of [AsyncMachine](https://github.com/TobiaszCudnik/asyncmachine) in
+Golang using _channels_ and _context_. It aims at simplicity and speed.
+
+It can be used as a lightweight in-memory [Temporal](https://github.com/temporalio/temporal) alternative, worker for
+[Asynq](https://github.com/hibiken/asynq), or to write simple consensus engines, stateful firewalls, telemetry, bots,
+etc.
+
+AsyncMachine is a relational state machine which never blocks.
+
+## Examples
+
+- [Expense Workflow](/examples/temporal-expense/expense_test.go) \|
+  [Temporal version](https://github.com/temporalio/samples-go/blob/main/expense/) \| [Go playground](https://goplay.tools/snippet/KAxlf3gm7pH)
+
+```go
+am.States{
+    // CreateExpenseActivity
+    "CreatingExpense": {
+        Remove: am.S{"ExpenseCreated"},
+    },
+    "ExpenseCreated": {
+        Remove: am.S{"CreatingExpense"},
+    },
+    // WaitForDecisionActivity
+    "WaitingForApproval": {
+        Auto:    true,
+        Require: am.S{"ExpenseCreated"},
+        Remove:  am.S{"ApprovalGranted"},
+    },
+    "ApprovalGranted": {
+        Require: am.S{"ExpenseCreated"},
+        Remove:  am.S{"WaitingForApproval"},
+    },
+    // PaymentActivity
+    "PaymentInProgress": {
+        Auto:    true,
+        Require: am.S{"ApprovalGranted"},
+        Remove:  am.S{"PaymentCompleted"},
+    },
+    "PaymentCompleted": {
+        Require: am.S{"ExpenseCreated", "ApprovalGranted"},
+        Remove:  am.S{"PaymentInProgress"},
+    },
+}
+```
+
+- [FileProcessing workflow](/examples/temporal-fileprocessing/fileprocessing.go) \|
+  [Temporal version](https://github.com/temporalio/samples-go/blob/main/fileprocessing/) \| [Go playground](https://goplay.tools/snippet/aTo4hsyJZck)
+
+```go
+am.States{
+    // DownloadFileActivity
+    "DownloadingFile": {
+        Remove: am.S{"FileDownloaded"},
+    },
+    "FileDownloaded": {
+        Remove: am.S{"DownloadingFile"},
+    },
+    // ProcessFileActivity
+    "ProcessingFile": {
+        Auto:    true,
+        Require: am.S{"FileDownloaded"},
+        Remove:  am.S{"FileProcessed"},
+    },
+    "FileProcessed": {
+        Remove: am.S{"ProcessingFile"},
+    },
+    // UploadFileActivity
+    "UploadingFile": {
+        Auto:    true,
+        Require: am.S{"FileProcessed"},
+        Remove:  am.S{"FileUploaded"},
+    },
+    "FileUploaded": {
+        Remove: am.S{"UploadingFile"},
+    },
+}
+```
+
+- [FileProcessing in an Asynq worker](examples/asynq-fileprocessing/fileprocessing_task.go)
+
+```go
+func HandleFileProcessingTask(ctx context.Context, t *asynq.Task) error {
+    var p FileProcessingPayload
+    if err := json.Unmarshal(t.Payload(), &p); err != nil {
+        return fmt.Errorf("json.Unmarshal failed: %v: %w", err, asynq.SkipRetry)
+    }
+    log.Printf("Processing file %s", p.Filename)
+    machine, err := processor.FileProcessingFlow(ctx, log.Printf, p.Filename)
+    if err != nil {
+        return err
+    }
+    // save the machine state as the result
+    ret := machine.String()
+    if _, err := t.ResultWriter().Write([]byte(ret)); err != nil {
+        return fmt.Errorf("failed to write task result: %v", err)
+    }
+    return nil
+}
+```
+
+## Documentation
+
+- [API godoc](https://godoc.org/github.com/pancsta/asyncmachine-go/pkg/machine)
+- [Manual](/docs/manual.md)
+   - [States](/docs/manual.md#states)
+      - [State Clocks](/docs/manual.md#state-clocks)
+      - [Auto States](/docs/manual.md#auto-states)
+   - [Transitions](/docs/manual.md#transitions)
+      - [Negotiation](/docs/manual.md#negotiation-handlers)
+   - [Relations](/docs/manual.md#relations)
+   - [Queue](/docs/manual.md#queue)
+
+## Status
+
+**Beta** - although the ideas behind AsyncMachine have been proven to work, the golang implementation is fairly fresh
+and may suffer from bugs, memory leaks, race conditions and even panics.
+[Please report bugs](https://github.com/pancsta/asyncmachine-go/issues/new).

Taskfile.yml

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+version: '3'
+
+dotenv: ['.env']
+
+tasks:
+
+  demo:
+    cmds:
+      - task: install-deps
+      - task: build-protobufs
+      - task: test
+      - task: start
+
+  build:
+    cmds:
+      - go build src/machine/*
+    silent: true
+
+  test:
+    cmds:
+      - task: clean
+      - go test ./...
+
+  test-verbose:
+    cmds:
+      - go test ./... -v
+
+  clean:
+    cmds:
+      - go clean -testcache
+
+  cloc:
+    cmds:
+      - gocloc pkg/machine --not-match=_test\.go
+      - gocloc pkg/machine/*_test.go
+      - gocloc examples
+      - gocloc --include-lang=md docs
+
+  format:
+    cmds:
+      - gofumpt -w pkg/machine/*.go
+      - gofumpt -w examples/*/*.go
+      - goimports -w pkg/**
+
+  lint:
+    cmds:
+      - task: lint-go
+      - task: lint-md
+      # https://github.com/markdownlint/markdownlint/issues/136
+      - |
+        if grep -q "]()" docs/*.md; then
+          echo "Error: Empty links" >&2
+          exit 1
+        fi
+
+  lint-go:
+    cmds:
+      - golangci-lint run
+
+  lint-md:
+    cmds:
+      # TODO -g
+      - mdl -c .mdlrc .
+
+  install-deps:
+    cmds:
+      - go mod tidy
+      - curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin v1.55.2
+      - go install mvdan.cc/gofumpt@latest
+      - go install golang.org/x/tools/cmd/goimports@latest
+      - gem install mdl