vm: remove dependency on package github.com/pkg/errors

cmd/retro/main.go

@@ -24,7 +24,6 @@ import (
 	"os"
 
 	"github.com/db47h/ngaro/vm"
-	"github.com/pkg/errors"
 )
 
 var fileName = flag.String("image", "retroImage", "Use `filename` as the image to load")
@@ -103,9 +102,7 @@ func main() {
 	if err != nil {
 		return
 	}
-	err = proc.Run()
-	// filter out EOF
-	if e := errors.Cause(err); e == io.EOF {
+	if err = proc.Run(); err == io.EOF {
 		err = nil
 	}
 }

vm/core.go

@@ -16,8 +16,6 @@
 
 package vm
 
-import "github.com/pkg/errors"
-
 // Opcode represents an Ngaro VM opcode.
 type Opcode Cell
 
@@ -99,7 +97,6 @@ func (i *Instance) Run() (err error) {
 			if err, ok = e.(error); !ok {
 				panic(e)
 			}
-			err = errors.Wrap(err, "VM abort")
 		}
 	}()
 	i.insCount = 0

vm/example_test.go

@@ -0,0 +1,103 @@
+// This file is part of ngaro - https://github.com/db47h/ngaro
+//
+// Copyright 2016 Denis Bernard <db047h@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 vm_test
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"github.com/db47h/ngaro/vm"
+)
+
+// Shows how to load an image, setup the VM with multiple readers/init code.
+func ExampleInstance_Run() {
+	imageFile := "testdata/retroImage"
+	img, err := vm.Load(imageFile, 50000)
+	if err != nil {
+		panic(err)
+	}
+
+	// output capture buffer
+	output := bytes.NewBuffer(nil)
+
+	// Setup the VM instance with os.Stdin as first reader, and we push another
+	// reader with some custom init code that will include and run the retro core tests.
+	i, err := vm.New(img, imageFile,
+		vm.Input(os.Stdin),
+		vm.Input(strings.NewReader("\"testdata/core.rx\" :include\n")),
+		vm.Output(output, false))
+
+	// run it
+	if err == nil {
+		err = i.Run()
+	}
+	if err != nil {
+		// in interactive use, err may be io.EOF if any of the IO channels gets closed
+		// in which case this would be a normal exit condition
+		panic(err)
+	}
+
+	// filter output to get the retro core test results.
+	b := bytes.Split(output.Bytes(), []byte{'\n'})
+	fmt.Printf("%s\n", b[len(b)-5])
+	fmt.Printf("%s\n", b[len(b)-4])
+
+	// Output:
+	// 360 tests run: 360 passed, 0 failed.
+	// 186 words checked, 0 words unchecked, 37 i/o words ignored.
+}
+
+// Shows how to setup a port handler.
+func ExampleOutHandler() {
+	imageFile := "testdata/retroImage"
+	img, err := vm.Load(imageFile, 0)
+	if err != nil {
+		panic(err)
+	}
+
+	// we will use a buffered stdout
+	output := bufio.NewWriter(os.Stdout)
+	// so according to the spec, we should flush the output as soon as port 3
+	// is written to:
+	outputHandler := func(v vm.Cell) (vm.Cell, error) {
+		output.Flush()
+		return 0, nil
+	}
+
+	i, err := vm.New(img, imageFile,
+		vm.Input(strings.NewReader("6 7 * putn\n")),
+		vm.Output(output, false),
+		vm.OutHandler(3, outputHandler))
+	if err != nil {
+		panic(err)
+	}
+
+	if err = i.Run(); err != nil && err != io.EOF {
+		fmt.Fprintf(os.Stderr, "%+v\n", err)
+	}
+	// Retro 11.7.1
+	//
+	// ok  6
+	// ok  7
+	// ok  *
+	// ok  putn 42
+	// ok
+}

vm/image.go

@@ -18,10 +18,9 @@ package vm
 
 import (
 	"encoding/binary"
+	"fmt"
 	"os"
 	"unsafe"
-
-	"github.com/pkg/errors"
 )
 
 // Image encapsulates a VM's memory
@@ -32,16 +31,16 @@ type Image []Cell
 func Load(fileName string, minSize int) (Image, error) {
 	f, err := os.Open(fileName)
 	if err != nil {
-		return nil, errors.Wrap(err, "Load")
+		return nil, err
 	}
 	defer f.Close()
 	st, err := f.Stat()
 	if err != nil {
-		return nil, errors.Wrap(err, "Load")
+		return nil, err
 	}
 	sz := st.Size()
 	if sz > int64((^uint(0))>>1) { // MaxInt
-		return nil, errors.Errorf("Load %v: file too large", fileName)
+		return nil, fmt.Errorf("Load %v: file too large", fileName)
 	}
 	var t Cell
 	sz /= int64(unsafe.Sizeof(t))
@@ -54,7 +53,7 @@ func Load(fileName string, minSize int) (Image, error) {
 	i := make(Image, sz)
 	err = binary.Read(f, binary.LittleEndian, i[:fileCells])
 	if err != nil {
-		return nil, errors.Wrap(err, "Load")
+		return nil, err
 	}
 	return i, nil
 }
@@ -64,14 +63,14 @@ func Load(fileName string, minSize int) (Image, error) {
 func (i Image) Save(fileName string, shrink bool) error {
 	f, err := os.OpenFile(fileName, os.O_WRONLY|os.O_CREATE, 0666)
 	if err != nil {
-		return errors.Wrap(err, "Save image")
+		return err
 	}
 	defer f.Close()
 
 	if shrink {
 		i = i[0:i[3]]
 	}
-	return errors.Wrap(binary.Write(f, binary.LittleEndian, i), "Save image")
+	return binary.Write(f, binary.LittleEndian, i)
 }
 
 // DecodeString returns the 0 terminated string starting at position pos in the image.

vm/io.go

@@ -22,8 +22,6 @@ import (
 	"time"
 	"unicode/utf8"
 	"unsafe"
-
-	"github.com/pkg/errors"
 )
 
 // readWriter wraps the WriteRune method. Works the same ad bufio.Writer.WriteRune.
@@ -188,7 +186,7 @@ func (i *Instance) ioWait() error {
 			} else {
 				i.out(utf8.RuneError, 1)
 				if err != nil {
-					return errors.Wrap(err, "ioWait input")
+					return err
 				}
 			}
 		case nil:
@@ -212,7 +210,7 @@ func (i *Instance) ioWait() error {
 					}
 				}
 				if err != nil {
-					return errors.Wrap(err, "ioWait output")
+					return err
 				}
 			}
 			i.out(0, 2)
@@ -247,7 +245,7 @@ func (i *Instance) ioWait() error {
 				var f *os.File
 				f, err = os.Open(i.Image.DecodeString(int(i.Pop())))
 				if err != nil {
-					return errors.Wrap(err, "Include failed")
+					return err
 				}
 				i.PushInput(f)
 			default:

vm/vm.go

@@ -33,7 +33,7 @@ import (
 type Cell int32
 
 const (
-	portCount   = 64
+	portCount   = 1024
 	dataSize    = 1024
 	addressSize = 1024
 )

vm/vm_test.go

@@ -1,10 +1,22 @@
+// This file is part of ngaro - https://github.com/db47h/ngaro
 //
+// Copyright 2016 Denis Bernard <db047h@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 vm_test
 
 import (
-	"bufio"
-	"bytes"
 	"fmt"
 	"io"
 	"os"
@@ -13,7 +25,6 @@ import (
 	"time"
 
 	"github.com/db47h/ngaro/vm"
-	"github.com/pkg/errors"
 )
 
 type C []vm.Cell
@@ -44,7 +55,7 @@ func check(t *testing.T, i *vm.Instance, ip int, stack C, rstack C) {
 		ip = len(i.Image)
 	}
 	if ip != i.PC {
-		t.Errorf("%+v", errors.Errorf("Bad IP %d != %d", i.PC, ip))
+		t.Errorf("%v", fmt.Errorf("Bad IP %d != %d", i.PC, ip))
 	}
 	stk := i.Data()
 	diff := len(stk) != len(stack)
@@ -57,7 +68,7 @@ func check(t *testing.T, i *vm.Instance, ip int, stack C, rstack C) {
 		}
 	}
 	if diff {
-		t.Errorf("%+v", errors.Errorf("Stack error: expected %d, got %d", stack, stk))
+		t.Errorf("%v", fmt.Errorf("Stack error: expected %d, got %d", stack, stk))
 	}
 	stk = i.Address()
 	diff = len(stk) != len(rstack)
@@ -70,7 +81,7 @@ func check(t *testing.T, i *vm.Instance, ip int, stack C, rstack C) {
 		}
 	}
 	if diff {
-		t.Errorf("%+v", errors.Errorf("Return stack error: expected %d, got %d", rstack, stk))
+		t.Errorf("%v", fmt.Errorf("Return stack error: expected %d, got %d", rstack, stk))
 	}
 }
 
@@ -118,81 +129,6 @@ func TestLoop(t *testing.T) {
 
 // TODO: make more...
 
-// Shows how to load an image, setup the VM with multiple readers/init code.
-func ExampleInstance_Run() {
-	imageFile := "testdata/retroImage"
-	img, err := vm.Load(imageFile, 50000)
-	if err != nil {
-		panic(err)
-	}
-
-	// output capture buffer
-	output := bytes.NewBuffer(nil)
-
-	// Setup the VM instance with os.Stdin as first reader, and we push another
-	// reader with some custom init code that will include and run the retro core tests.
-	i, err := vm.New(img, imageFile,
-		vm.Input(os.Stdin),
-		vm.Input(strings.NewReader("\"testdata/core.rx\" :include\n")),
-		vm.Output(output, false))
-
-	// run it
-	if err == nil {
-		err = i.Run()
-	}
-	if err != nil {
-		// in interactive use, err may be io.EOF if any of the IO channels gets closed
-		// in which case this would be a normal exit condition
-		panic(err)
-	}
-
-	// filter output to get the retro core test results.
-	b := bytes.Split(output.Bytes(), []byte{'\n'})
-	fmt.Printf("%s\n", b[len(b)-5])
-	fmt.Printf("%s\n", b[len(b)-4])
-
-	// Output:
-	// 360 tests run: 360 passed, 0 failed.
-	// 186 words checked, 0 words unchecked, 37 i/o words ignored.
-}
-
-// Shows how to setup a port handler.
-func ExampleOutHandler() {
-	imageFile := "testdata/retroImage"
-	img, err := vm.Load(imageFile, 0)
-	if err != nil {
-		panic(err)
-	}
-
-	// we will use a buffered stdout
-	output := bufio.NewWriter(os.Stdout)
-	// so according to the spec, we should flush the output as soon as port 3
-	// is written to:
-	outputHandler := func(v vm.Cell) (vm.Cell, error) {
-		output.Flush()
-		return 0, nil
-	}
-
-	i, err := vm.New(img, imageFile,
-		vm.Input(strings.NewReader("6 7 * putn\n")),
-		vm.Output(output, false),
-		vm.OutHandler(3, outputHandler))
-	if err != nil {
-		panic(err)
-	}
-
-	if err = i.Run(); err != nil && errors.Cause(err) != io.EOF {
-		fmt.Fprintf(os.Stderr, "%+v\n", err)
-	}
-	// Retro 11.7.1
-	//
-	// ok  6
-	// ok  7
-	// ok  *
-	// ok  putn 42
-	// ok
-}
-
 var fib = []vm.Opcode{
 	vm.OpPush,
 	vm.OpLit, 0,
@@ -350,7 +286,7 @@ func BenchmarkRun(b *testing.B) {
 
 		fmt.Printf("Executed %d instructions in %.3fs. Perf: %.2f MIPS\n", c, el, float64(c)/1e6/el)
 		if err != nil {
-			switch errors.Cause(err) {
+			switch err {
 			case io.EOF: // stdin or stdout closed
 			default:
 				b.Errorf("%+v\n", err)