2 files changed, 112 insertions, 0 deletions
diff --git a/src/urubu/cmd/vartan-go/generate.go b/src/urubu/cmd/vartan-go/generate.go
new file mode 100644
index 0000000..8f2da84
--- /dev/null
+++ b/src/urubu/cmd/vartan-go/generate.go
@@ -0,0 +1,98 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+
+	"urubu/driver/lexer"
+	"urubu/driver/parser"
+	spec "urubu/spec/grammar"
+)
+
+func runGenerate(args []string) error {
+	cgram, err := readCompiledGrammar(args[0])
+	if err != nil {
+		return fmt.Errorf("Cannot read a compiled grammar: %w", err)
+	}
+
+	{
+		b, err := lexer.GenLexer(cgram.Lexical, "main")
+		if err != nil {
+			return fmt.Errorf("Failed to generate a lexer: %w", err)
+		}
+
+		filePath := fmt.Sprintf("%v_lexer.go", cgram.Name)
+
+		f, err := os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+		if err != nil {
+			return fmt.Errorf("Failed to create an output file: %v", err)
+		}
+		defer f.Close()
+
+		_, err = f.Write(b)
+		if err != nil {
+			return fmt.Errorf("Failed to write lexer source code: %v", err)
+		}
+	}
+
+	{
+		b, err := parser.GenParser(cgram, "main")
+		if err != nil {
+			return fmt.Errorf("Failed to generate a parser: %w", err)
+		}
+
+		filePath := fmt.Sprintf("%v_parser.go", cgram.Name)
+
+		f, err := os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+		if err != nil {
+			return fmt.Errorf("Failed to create an output file: %v", err)
+		}
+		defer f.Close()
+
+		_, err = f.Write(b)
+		if err != nil {
+			return fmt.Errorf("Failed to write parser source code: %v", err)
+		}
+	}
+
+	{
+		b, err := parser.GenSemanticAction("main")
+		if err != nil {
+			return fmt.Errorf("Failed to generate a semantic action set: %w", err)
+		}
+
+		filePath := fmt.Sprintf("%v_semantic_action.go", cgram.Name)
+
+		f, err := os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+		if err != nil {
+			return fmt.Errorf("Failed to create an output file: %v", err)
+		}
+		defer f.Close()
+
+		_, err = f.Write(b)
+		if err != nil {
+			return fmt.Errorf("Failed to write semantic action source code: %v", err)
+		}
+	}
+
+	return nil
+}
+
+func readCompiledGrammar(path string) (*spec.CompiledGrammar, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	data, err := io.ReadAll(f)
+	if err != nil {
+		return nil, err
+	}
+	cgram := &spec.CompiledGrammar{}
+	err = json.Unmarshal(data, cgram)
+	if err != nil {
+		return nil, err
+	}
+	return cgram, nil
+}
diff --git a/src/urubu/cmd/vartan-go/main.go b/src/urubu/cmd/vartan-go/main.go
new file mode 100644
index 0000000..315e7b3
--- /dev/null
+++ b/src/urubu/cmd/vartan-go/main.go
@@ -0,0 +1,14 @@
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func main() {
+	err := runGenerate(os.Args[1:])
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}