2 files changed, 80 insertions, 0 deletions
diff --git a/cmd/maleeni-go/generate.go b/cmd/maleeni-go/generate.go
new file mode 100644
index 0000000..d37defd
--- /dev/null
+++ b/cmd/maleeni-go/generate.go
@@ -0,0 +1,68 @@
+package main
+
+import (
+	_ "embed"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/nihei9/maleeni/driver"
+	"github.com/nihei9/maleeni/spec"
+	"github.com/spf13/cobra"
+)
+
+func Execute() error {
+	err := generateCmd.Execute()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%v\n", err)
+		return err
+	}
+
+	return nil
+}
+
+var generateFlags = struct {
+	pkgName *string
+}{}
+
+var generateCmd = &cobra.Command{
+	Use:           "maleeni-go",
+	Short:         "Generate a lexer for Go",
+	Long:          `maleeni-go generates a lexer for Go. The lexer recognizes the lexical specification specified as the argument.`,
+	Example:       `  maleeni-go clexspec.json > lexer.go`,
+	Args:          cobra.ExactArgs(1),
+	RunE:          runGenerate,
+	SilenceErrors: true,
+	SilenceUsage:  true,
+}
+
+func init() {
+	generateFlags.pkgName = generateCmd.Flags().StringP("package", "p", "main", "package name")
+}
+
+func runGenerate(cmd *cobra.Command, args []string) (retErr error) {
+	clspec, err := readCompiledLexSpec(args[0])
+	if err != nil {
+		return fmt.Errorf("Cannot read a compiled lexical specification: %w", err)
+	}
+
+	return driver.GenLexer(clspec, *generateFlags.pkgName)
+}
+
+func readCompiledLexSpec(path string) (*spec.CompiledLexSpec, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	data, err := ioutil.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+	clspec := &spec.CompiledLexSpec{}
+	err = json.Unmarshal(data, clspec)
+	if err != nil {
+		return nil, err
+	}
+	return clspec, nil
+}
diff --git a/cmd/maleeni-go/main.go b/cmd/maleeni-go/main.go
new file mode 100644
index 0000000..701f02f
--- /dev/null
+++ b/cmd/maleeni-go/main.go
@@ -0,0 +1,12 @@
+package main
+
+import (
+	"os"
+)
+
+func main() {
+	err := Execute()
+	if err != nil {
+		os.Exit(1)
+	}
+}