refactor and use generic types

.github/workflows/test.yaml

@@ -0,0 +1,32 @@
+name: Test
+on:
+  push:
+    branches:
+      - "*"
+    paths-ignore:
+      - "README.md"
+    tags-ignore:
+      - "*"
+env:
+  GO_VERSION: "1.22.5"
+  GOFLAGS: -buildvcs=false
+  GOPROXY: https://proxy.golang.org,direct
+jobs:
+  lint:
+    name: Run make lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+      - run: make lint
+  test:
+    name: Run make test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: ${{ env.GO_VERSION }}
+      - run: make test

.gitignore

@@ -30,7 +30,7 @@
 ### Go Patch ###
 /vendor/
 /Godeps/
-go.sum
+/bin
 
 ### Vim ###
 # Swap

.golangci.yml

@@ -0,0 +1,34 @@
+run:
+  timeout: 5m
+  allow-parallel-runners: true
+
+issues:
+  exclude-use-default: false
+linters:
+  disable-all: true
+  enable:
+    - bidichk
+    - bodyclose
+    - containedctx
+    - errcheck
+    - exportloopref
+    - ginkgolinter
+    - goconst
+    - gocritic
+    - gocyclo
+    - gofmt
+    - goimports
+    - gosimple
+    - govet
+    - inamedparam
+    - ineffassign
+    - misspell
+    - nakedret
+    - prealloc
+    - staticcheck
+    - tenv
+    - typecheck
+    - unconvert
+    - unparam
+    - unused
+    - whitespace

Makefile

@@ -0,0 +1,28 @@
+.PHONY: fmt
+fmt:
+	go fmt ./...
+
+.PHONY: vet
+vet:
+	go vet ./...
+
+.PHONY: test
+test:
+	go test -race -cover ./...
+
+.PHONY: lint
+lint: golangci-lint
+	$(GOLANGCI_LINT) run
+
+LOCALBIN ?= $(shell pwd)/bin
+$(LOCALBIN):
+	mkdir -p $(LOCALBIN)
+
+GOLANGCI_LINT = $(shell pwd)/bin/golangci-lint
+GOLANGCI_LINT_VERSION ?= v1.59.1
+.PHONY: golangci-lint
+golangci-lint:
+	@[ -f $(GOLANGCI_LINT) ] || { \
+		set -e ;\
+		curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(shell dirname $(GOLANGCI_LINT)) $(GOLANGCI_LINT_VERSION) ;\
+	}

README.md

@@ -1,8 +1,8 @@
 # Goterator
 
-[![Test and Build](https://github.com/yaa110/goterator/workflows/Test%20and%20Build/badge.svg)](https://github.com/yaa110/goterator/actions?query=workflow%3A"Test+and+Build") [![PkgGoDev](https://pkg.go.dev/badge/github.com/yaa110/goterator)](https://pkg.go.dev/github.com/yaa110/goterator) [![GoDoc](https://img.shields.io/badge/godoc-goterator-blue)](https://godoc.org/github.com/yaa110/goterator) [![Go Report](https://goreportcard.com/badge/github.com/yaa110/goterator)](https://goreportcard.com/report/github.com/yaa110/goterator) [![Coverage](https://gocover.io/_badge/github.com/yaa110/goterator)](https://gocover.io/github.com/yaa110/goterator)
+[![Test](https://github.com/yaa110/goterator/actions/workflows/test.yaml/badge.svg)](https://github.com/yaa110/goterator/actions/workflows/test.yaml) [![PkgGoDev](https://pkg.go.dev/badge/github.com/yaa110/goterator)](https://pkg.go.dev/github.com/yaa110/goterator) [![Go Report](https://goreportcard.com/badge/github.com/yaa110/goterator)](https://goreportcard.com/report/github.com/yaa110/goterator)
 
-Iterator implementation for Golang to provide map and reduce functionalities.
+**Lazy iterator** implementation for Golang to provide map and reduce functionalities.
 
 ## Package
 
@@ -13,20 +13,32 @@ import (
 )
 ```
 
+## Example
+
+```go
+generator := generator.NewSlice([]string{"a", "b", "c"})
+
+// values = []string["A", "B", "C"]
+values := goterator.
+    New(generator).
+    Map(strings.ToUpper).
+    Collect()
+```
+
 ## Getting Started
 
 - Create a generator from slices
 
 ```go
-words := []interface{}{"an", "example", "of", "goterator"}
+words := []string{"an", "example", "of", "goterator"}
 
 gen := generator.NewSlice(words)
 ```
 
 - Create a generator from channels
 
 ```go
-chn := make(chan interface{}, 4)
+chn := make(chan string, 4)
 chn <- "an"
 chn <- "example"
 chn <- "of"
@@ -54,7 +66,7 @@ func (g *TestGenerator) Next() bool {
     return true
 }
 
-func (g *TestGenerator) Value() interface{} {
+func (g *TestGenerator) Value() string {
     return g.value
 }
 
@@ -68,11 +80,6 @@ gen := &TestGenerator{
 - Iterate over generators
 
 ```go
-lengths := goterator.New(gen).Map(func(word interface{}) interface{} {
-    return len(word.(string))
-}).Collect()
-
-assert.Equal([]interface{}{2, 7, 2, 9}, lengths)
+upperCases := goterator.New(gen).Map(strings.ToUpper).Collect()
+assert.Equal([]string{"AN", "EXAMPLE", "OF", "GOTERATOR"}, upperCases)
 ```
-
-Please for more information about mappers and reducers (consumers) check the [documentation](https://godoc.org/github.com/yaa110/goterator).