support go 1.18 onwards

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: ['1.22.x', '1.23.x', '1.24.x', '1.25.x']
+        go-version: ['1.18.x', '1.19.x', '1.20.x', '1.21.x', '1.22.x', '1.23.x', '1.24.x', '1.25.x']
 
     steps:
     - name: Checkout code
@@ -29,36 +29,38 @@ jobs:
       run: go mod download
 
     - name: Run tests
+      run: go test -v -race ./...
+
+    - name: Run tests with coverage (Go 1.23 only)
+      if: matrix.go-version == '1.23.x'
       run: go test -v -race -coverprofile=coverage.out ./...
 
     - name: Upload coverage
       uses: codecov/codecov-action@v4
-      if: matrix.go-version == '1.25.x'
+      if: matrix.go-version == '1.23.x'
       with:
         file: ./coverage.out
         flags: unittests
         fail_ci_if_error: false
 
-  # lint:
-  #   name: Lint
-  #   runs-on: ubuntu-latest
-  #   # Skipped for now - golangci-lint doesn't support Go 1.25 yet
-  #   # Will re-enable once golangci-lint releases a version built with Go 1.25
-  #   steps:
-  #   - name: Checkout code
-  #     uses: actions/checkout@v4
-  #
-  #   - name: Set up Go
-  #     uses: actions/setup-go@v5
-  #     with:
-  #       go-version: '1.24.x'
-  #       cache: true
-  #
-  #   - name: golangci-lint
-  #     uses: golangci/golangci-lint-action@v6
-  #     with:
-  #       version: latest
-  #       args: --timeout=5m
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: '1.23.x'
+        cache: true
+
+    - name: golangci-lint
+      uses: golangci/golangci-lint-action@v6
+      with:
+        version: latest
+        args: --timeout=5m
 
   build:
     name: Build
@@ -71,7 +73,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v5
       with:
-        go-version: '1.25.x'
+        go-version: '1.23.x'
         cache: true
 
     - name: Build

.golangci.yml

@@ -2,6 +2,7 @@ run:
   timeout: 5m
   tests: true
   modules-download-mode: readonly
+  go: '1.18'
 
 linters:
   enable:

go.mod

@@ -1,3 +1,3 @@
 module github.com/anish749/lazy
 
-go 1.25
+go 1.18

lazy.go

@@ -5,10 +5,10 @@ import "sync"
 // Lazy represents a value that is initialized on first access.
 // It ensures the initialization function is called only once, even in concurrent scenarios.
 type Lazy[T any, E error] struct {
-	once  sync.Once
 	value T
 	err   E
 	init  func() (T, E)
+	once  sync.Once
 }
 
 // NewLazy creates a new lazy value with the provided initialization function.
@@ -29,14 +29,20 @@ func InitializedLazy[T any, E error](value T) *Lazy[T, E] {
 	}
 }
 
-func (l *Lazy[T, E]) Get() (T, E) {
+// Get retrieves the lazy value, initializing it on first call if needed.
+// The initialization function is guaranteed to be called at most once,
+// even when Get is called concurrently from multiple goroutines.
+// Returns the computed value and any error from initialization.
+func (l *Lazy[T, E]) Get() (value T, err E) {
 	// Skip once.Do if init is nil, meaning the value was pre-initialized
 	if l.init != nil {
 		l.once.Do(func() {
 			l.value, l.err = l.init()
 		})
 	}
-	return l.value, l.err
+	value = l.value
+	err = l.err
+	return
 }
 
 // lazyType is an interface constraint for lazy value getters