feat: add main method

cmd/brainfuck/main.go

@@ -0,0 +1,67 @@
+// Copyright © 2021 Rak Laptudirm <raklaptudirm@gmail.com>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"laptudirm.com/x/brainfuck/pkg/lexer"
+	"laptudirm.com/x/brainfuck/pkg/parser"
+	"laptudirm.com/x/brainfuck/pkg/token"
+	"laptudirm.com/x/brainfuck/pkg/vm"
+)
+
+const Memory = 30000
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Fprintln(os.Stderr, "usage: brainfuck [filename]")
+		os.Exit(1)
+	}
+
+	filename := os.Args[1]
+	file, err := os.ReadFile(filename)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+	}
+
+	var l lexer.Lexer
+	l.Init(string(file), handleErr)
+
+	var p parser.Parser
+	p.Init(&l, handleErr)
+
+	program := p.ParseProgram()
+
+	if l.ErrorCount > 0 || p.ErrorCount > 0 {
+		os.Exit(1)
+	}
+
+	m := vm.New(Memory)
+	err = m.Execute(program)
+	if err != nil {
+		printErr(err.Error())
+		os.Exit(1)
+	}
+}
+
+func handleErr(p token.Position, e string) {
+	printErr("%s: %v\n", p, e)
+}
+
+func printErr(format string, a ...interface{}) error {
+	_, err := fmt.Fprintf(os.Stderr, format, a...)
+	return err
+}