initial version of "tengo" CLI tool

cmd/tengo/main.go

@@ -0,0 +1,135 @@
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/d5/tengo"
+	"github.com/d5/tengo/compiler"
+	"github.com/d5/tengo/vm"
+)
+
+var (
+	compile    bool
+	outputFile = flag.String("o", "", "Output file")
+)
+
+func init() {
+	flag.BoolVar(&compile, "compile", false, "Compile input file")
+	flag.BoolVar(&compile, "c", false, "Compile input file")
+	flag.Parse()
+}
+
+func main() {
+	inputFile := flag.Arg(0)
+	if inputFile == "" {
+		doHelp()
+		os.Exit(2)
+	}
+
+	inputData, err := ioutil.ReadFile(inputFile)
+	if err != nil {
+		_, _ = fmt.Fprintf(os.Stderr, "Error reading input file: %s", err.Error())
+		os.Exit(1)
+	}
+
+	if compile {
+		if err := doCompile(inputData, inputFile, *outputFile); err != nil {
+			_, _ = fmt.Fprintln(os.Stderr, err.Error())
+			os.Exit(1)
+		}
+	} else {
+		if err := doRun(inputData, inputFile, *outputFile); err != nil {
+			_, _ = fmt.Fprintln(os.Stderr, err.Error())
+			os.Exit(1)
+		}
+	}
+}
+
+func doHelp() {
+	fmt.Println("Tengo is a tool to compile Tengo source code or execute compiled Tengo binary.")
+	fmt.Println()
+	fmt.Println("Usage:")
+	fmt.Println()
+	fmt.Println("	tengo [flags] input-file")
+	fmt.Println()
+	fmt.Println("Flags:")
+	fmt.Println()
+	fmt.Println("	-compile/-c compile source file")
+	fmt.Println("	-o          output file")
+	fmt.Println()
+	fmt.Println("Examples:")
+	fmt.Println()
+	fmt.Println("	tengo -c -o program.out program.tengo")
+	fmt.Println("	            : Compile program.tengo and write compiled binary to program.out file")
+	fmt.Println()
+	fmt.Println("	tengo program.out")
+	fmt.Println("	            : Execute compiled binary program.out")
+	fmt.Println()
+	fmt.Println()
+}
+
+func doCompile(data []byte, inputFile, outputFile string) (err error) {
+	bytecode, err := tengo.Compile(data, filepath.Base(inputFile))
+	if err != nil {
+		return
+	}
+
+	if outputFile == "" {
+		outputFile = basename(inputFile) + ".out"
+	}
+
+	out, err := os.OpenFile(outputFile, os.O_CREATE|os.O_WRONLY, os.ModePerm)
+	if err != nil {
+		return
+	}
+	defer func() {
+		if err != nil {
+			_ = out.Close()
+		} else {
+			err = out.Close()
+		}
+	}()
+
+	err = bytecode.Encode(out)
+	if err != nil {
+		return
+	}
+
+	fmt.Println(outputFile)
+
+	return
+}
+
+func doRun(data []byte, _, _ string) (err error) {
+	bytecode := &compiler.Bytecode{}
+	err = bytecode.Decode(bytes.NewReader(data))
+	if err != nil {
+		return
+	}
+
+	machine := vm.NewVM(bytecode, nil)
+
+	err = machine.Run()
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+func basename(s string) string {
+	s = filepath.Base(s)
+
+	n := strings.LastIndexByte(s, '.')
+	if n > 0 {
+		return s[:n]
+	}
+
+	return s
+}

tengo.go

@@ -1,21 +1,19 @@
 package tengo
 
 import (
-	"fmt"
-
 	"github.com/d5/tengo/compiler"
 	"github.com/d5/tengo/parser"
 	"github.com/d5/tengo/scanner"
 	"github.com/d5/tengo/vm"
 )
 
-func Compile(input []byte) (*compiler.Bytecode, error) {
+func Compile(input []byte, filename string) (*compiler.Bytecode, error) {
 	fileSet := scanner.NewFileSet()
 
-	p := parser.NewParser(fileSet.AddFile("", -1, len(input)), input, nil)
+	p := parser.NewParser(fileSet.AddFile(filename, -1, len(input)), input, nil)
 	file, err := p.ParseFile()
 	if err != nil {
-		return nil, fmt.Errorf("parse error: %s", err.Error())
+		return nil, err
 	}
 
 	c := compiler.NewCompiler(nil, nil)