Builtin program parser output

README.md

@@ -32,6 +32,8 @@ for performance comparison see no_optimisation branch.
       bf [option] source.bf [input]
 
     Options:
+      -dump
+            dump parsed program
       -eight
     	    eight bit execution
       -version

cmd/bfg/main.go

@@ -14,6 +14,7 @@ import (
 func main() {
 	version := flag.Bool("version", false, "display version")
 	eight := flag.Bool("eight", false, "eight bit execution")
+	dump := flag.Bool("dump", false, "dump parsed program")
 
 	flag.Usage = func() {
 		fmt.Printf("Usage:\n  %s [option] source.bf [input]\n", os.Args[0])
@@ -48,7 +49,9 @@ func main() {
 		fmt.Println("error compiling program: err:", err)
 		os.Exit(1)
 	}
-	if *eight {
+	if *dump {
+		parser.Dump(program, outputBuf)
+	} else if *eight {
 		data := make([]byte, parser.DataSize)
 		parser.Execute(data, program, inputBuf, outputBuf)
 	} else {

parser/dump.go

@@ -0,0 +1,24 @@
+package parser
+
+import (
+	"bufio"
+	"fmt"
+	"strings"
+)
+
+// Dump prints out the parsed program.
+func Dump(program []Instruction, writer *bufio.Writer) {
+	depth := 0
+	startLoop := NewInstruction('[')
+	endLoop := NewInstruction(']')
+	for idx, inst := range program {
+		if inst.SameOp(endLoop) {
+			depth--
+		}
+		fmt.Fprintln(writer, idx, strings.Repeat("\t", depth), inst.String())
+		if inst.SameOp(startLoop) {
+			depth++
+		}
+	}
+	writer.Flush()
+}

parser/dump_test.go

@@ -0,0 +1,31 @@
+package parser
+
+import (
+	"bufio"
+	"bytes"
+	"reflect"
+	"testing"
+)
+
+func TestDump(t *testing.T) {
+	program := []Instruction{
+		{opNoop, 0},
+		{opAddDp, 5},
+		{opSetVal, 0},
+		{opAddVal, 5},
+		{opMove, 2},
+		{opJmpZ, 7},
+		{opIn, 1},
+		{opJmpNz, 5},
+		{opAddDp, 2},
+	}
+	var buf bytes.Buffer
+	outputBuf := bufio.NewWriter(&buf)
+	Dump(program, outputBuf)
+	got := buf.String()
+	want := "0  nop: 0\n1  ptr: 5\n2  set: 0\n3  add: 5\n4  mov: 2\n5  jmp: 7\n6 \t inp: 1\n7  jnz: 5\n8  ptr: 2\n"
+
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("got %v want %v", got, want)
+	}
+}

parser/instruction.go

@@ -34,13 +34,13 @@ func (inst Instruction) String() string {
 		"add",
 		"set",
 		"out",
-		"in",
-		"jmpz",
-		"jmpnz",
+		"inp",
+		"jmp",
+		"jnz",
 		"mov",
-		"skip",
+		"skp",
 	}
-	return fmt.Sprintf("%s:%v", opName[inst.operator], inst.operand)
+	return fmt.Sprintf("%s: %v", opName[inst.operator], inst.operand)
 }
 
 // NewInstruction created from a sourcecode byte