Improved build and added version support. Added support for executing files and some cli options

.gitignore

@@ -1,4 +1,5 @@
-*~*
+*~
 *.bak
 *.txt
-monkey
+
+/monkey-lang

Makefile

@@ -1,16 +1,33 @@
-.PHONY: build test deps clean
+.PHONY: dev build install image profile bench test clean
 
-all: build
-	@./monkey
+CGO_ENABLED=0
+COMMIT=$(shell git rev-parse --short HEAD)
 
-deps:
-	@go get ./...
+all: dev
 
-build:
-	@go build -o monkey .
+dev: build
+	@./monkey-lang -d
+
+build: clean
+	@go build \
+		-tags "netgo static_build" -installsuffix netgo \
+		-ldflags "-w -X $(shell go list)/version/.GitCommit=$(COMMIT)" \
+		.
+
+install: build
+	@go install
+
+image:
+	@docker build -t prologic/monkey-lang .
+
+profile:
+	@go test -cpuprofile cpu.prof -memprofile mem.prof -v -bench ./...
+
+bench:
+	@go test -v -bench ./...
 
 test:
-	@go test -v -cover -coverprofile=coverage.txt -covermode=atomic ./...
+	@go test -v -cover -coverprofile=coverage.txt -covermode=atomic -coverpkg=./... -race ./...
 
 clean:
 	@git clean -f -d -X

examples/hello.monkey

@@ -0,0 +1 @@
+puts("Hello World!")

main.go

@@ -1,23 +1,64 @@
 package main
 
-// Package main implements the main process which invokes the interpreter's
+// Package main implements the main process which executes a program if
+// a filename is supplied as an argument or invokes the interpreter's
 // REPL and waits for user input before lexing, parsing nad evaulating.
 
 import (
+	"flag"
 	"fmt"
+	"log"
 	"os"
 	"os/user"
+	"path"
 
 	"github.com/prologic/monkey-lang/repl"
 )
 
+var (
+	interactive bool
+	version     bool
+	debug       bool
+)
+
+func init() {
+	flag.Usage = func() {
+		fmt.Fprintf(flag.CommandLine.Output(), "Usage: %s [options] [<filename>]", path.Base(os.Args[0]))
+		flag.PrintDefaults()
+		os.Exit(0)
+	}
+
+	flag.BoolVar(&version, "v", false, "display version information")
+	flag.BoolVar(&debug, "d", false, "enable debug mode")
+
+	flag.BoolVar(&interactive, "i", false, "enable interactive mode")
+}
+
 func main() {
+	flag.Parse()
+
+	if version {
+		fmt.Printf("%s %s", path.Base(os.Args[0]), FullVersion())
+		os.Exit(0)
+	}
+
 	user, err := user.Current()
 	if err != nil {
-		panic(err)
+		log.Fatalf("could not determine current user: %s", err)
+	}
+
+	if flag.NArg() == 1 {
+		f, err := os.Open(flag.Arg(0))
+		if err != nil {
+			log.Fatalf("could not open source file %s: %s", flag.Arg(0), err)
+		}
+		env := repl.Exec(f)
+		if interactive {
+			repl.Start(os.Stdin, os.Stdout, env)
+		}
+	} else {
+		fmt.Printf("Hello %s! This is the Monkey programming language!\n", user.Username)
+		fmt.Printf("Feel free to type in commands\n")
+		repl.Start(os.Stdin, os.Stdout, nil)
 	}
-	fmt.Printf("Hello %s! This is the Monkey programming language!\n",
-		user.Username)
-	fmt.Printf("Feel free to type in commands\n")
-	repl.Start(os.Stdin, os.Stdout)
 }

repl/repl.go

@@ -7,6 +7,8 @@ import (
 	"bufio"
 	"fmt"
 	"io"
+	"io/ioutil"
+	"os"
 
 	"github.com/prologic/monkey-lang/eval"
 	"github.com/prologic/monkey-lang/lexer"
@@ -32,10 +34,37 @@ const MonkeyFace = `            __,__
            '-----'
 `
 
+// Exec parses and executes the program given by f and returns the resulting
+// environment, any errors are printed to stderr
+func Exec(f io.Reader) (env *object.Environment) {
+	env = object.NewEnvironment()
+
+	b, err := ioutil.ReadAll(f)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error reading source file: %s", err)
+		return
+	}
+
+	l := lexer.New(string(b))
+	p := parser.New(l)
+
+	program := p.ParseProgram()
+	if len(p.Errors()) != 0 {
+		printParserErrors(os.Stderr, p.Errors())
+		return
+	}
+
+	eval.Eval(program, env)
+	return
+}
+
 // Start starts the REPL in a continious loop
-func Start(in io.Reader, out io.Writer) {
+func Start(in io.Reader, out io.Writer, env *object.Environment) {
 	scanner := bufio.NewScanner(in)
-	env := object.NewEnvironment()
+
+	if env == nil {
+		env = object.NewEnvironment()
+	}
 
 	for {
 		fmt.Printf(PROMPT)

version.go

@@ -0,0 +1,18 @@
+package main
+
+import (
+	"fmt"
+)
+
+var (
+	// Version release version
+	Version = "0.0.1"
+
+	// GitCommit will be overwritten automatically by the build system
+	GitCommit = "HEAD"
+)
+
+// FullVersion returns the full version and commit hash
+func FullVersion() string {
+	return fmt.Sprintf("%s@%s", Version, GitCommit)
+}