Handle empty translation strings as untranslated as defined in https://www.gnu.org/software/gettext/manual/html_node/Untranslated-Entries.html. Fixes #9

use kinako instead of anko

.travis.yml

@@ -1,7 +1,16 @@
 language: go
-script: go test -v -race ./...
 
 go:
-  - 1.5
   - 1.6
+  - 1.7
+  - 1.8
   - tip
+
+before_install:
+  - go get -t -v ./...
+
+script: go test -v -race -coverprofile=coverage.txt -covermode=atomic .
+
+after_success:
+  - bash <(curl -s https://codecov.io/bash)
+

Godeps/Godeps.json

@@ -0,0 +1,18 @@
+{
+	"ImportPath": "github.com/leonelquinteros/gotext",
+	"GoVersion": "devel +be9d7f6d87 Fri Jun 16 00:31:25 2017 +0000",
+	"Deps": [
+		{
+			"ImportPath": "github.com/mattn/kinako/ast",
+			"Rev": "fbc18625ec69b28ae03b4eea4c349f215840ee09"
+		},
+		{
+			"ImportPath": "github.com/mattn/kinako/parser",
+			"Rev": "fbc18625ec69b28ae03b4eea4c349f215840ee09"
+		},
+		{
+			"ImportPath": "github.com/mattn/kinako/vm",
+			"Rev": "fbc18625ec69b28ae03b4eea4c349f215840ee09"
+		}
+	]
+}

Godeps/Readme

@@ -0,0 +1,5 @@
+This directory tree is generated automatically by godep.
+
+Please do not edit.
+
+See https://github.com/tools/godep for more information.

README.md

@@ -1,12 +1,14 @@
+[![GitHub release](https://img.shields.io/github/release/leonelquinteros/gotext.svg)](https://github.com/leonelquinteros/gotext)
+[![MIT license](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE)
 [![GoDoc](https://godoc.org/github.com/leonelquinteros/gotext?status.svg)](https://godoc.org/github.com/leonelquinteros/gotext)
 [![Build Status](https://travis-ci.org/leonelquinteros/gotext.svg?branch=master)](https://travis-ci.org/leonelquinteros/gotext)
+[![codecov](https://codecov.io/gh/leonelquinteros/gotext/branch/master/graph/badge.svg)](https://codecov.io/gh/leonelquinteros/gotext)
+[![Go Report Card](https://goreportcard.com/badge/github.com/leonelquinteros/gotext)](https://goreportcard.com/report/github.com/leonelquinteros/gotext)
 
 # Gotext
 
 [GNU gettext utilities](https://www.gnu.org/software/gettext) for Go. 
 
-Version: [v1.1.0](https://github.com/leonelquinteros/gotext/releases/tag/v1.1.0)
-
 
 # Features
 
@@ -261,7 +263,7 @@ PO format supports defining one or more plural forms for the same translation.
 Relying on the PO file headers, a Plural-Forms formula can be set on the translation file
 as defined in (https://www.gnu.org/savannah-checkouts/gnu/gettext/manual/html_node/Plural-forms.html)
 
-Plural formulas are parsed and evaluated using [Anko](https://github.com/mattn/anko)
+Plural formulas are parsed and evaluated using [Kinako](https://github.com/mattn/kinako)
 
 ```go
 import "github.com/leonelquinteros/gotext"

gotext_test.go

@@ -32,8 +32,8 @@ func TestGettersSetters(t *testing.T) {
 func TestPackageFunctions(t *testing.T) {
 	// Set PO content
 	str := `
-msgid ""
-msgstr ""
+# msgid ""
+# msgstr ""
 # Initial comment
 # Headers below
 "Language: en\n"

locale_test.go

@@ -9,8 +9,8 @@ import (
 func TestLocale(t *testing.T) {
 	// Set PO content
 	str := `
-msgid ""
-msgstr ""
+# msgid ""
+# msgstr ""
 # Initial comment
 # Headers below
 "Language: en\n"
@@ -106,12 +106,115 @@ msgstr "More translation"
 		t.Errorf("Expected 'This one is the plural: Variable' but got '%s'", tr)
 	}
 
+	// Test context translations
+	v = "Test"
+	tr = l.GetDC("my_domain", "One with var: %s", "Ctx", v)
+	if tr != "This one is the singular in a Ctx context: Test" {
+		t.Errorf("Expected 'This one is the singular in a Ctx context: Test' but got '%s'", tr)
+	}
+
+	// Test plural
+	tr = l.GetNDC("my_domain", "One with var: %s", "Several with vars: %s", 3, "Ctx", v)
+	if tr != "This one is the plural in a Ctx context: Test" {
+		t.Errorf("Expected 'This one is the plural in a Ctx context: Test' but got '%s'", tr)
+	}
+
+	// Test last translation
+	tr = l.GetD("my_domain", "More")
+	if tr != "More translation" {
+		t.Errorf("Expected 'More translation' but got '%s'", tr)
+	}
+}
+
+func TestLocaleFails(t *testing.T) {
+	// Set PO content
+	str := `
+msgid ""
+msgstr ""
+# Initial comment
+# Headers below
+"Language: en\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+
+# Some comment
+msgid "My text"
+msgstr "Translated text"
+
+# More comments
+msgid "Another string"
+msgstr ""
+
+msgid "One with var: %s"
+msgid_plural "Several with vars: %s"
+msgstr[0] "This one is the singular: %s"
+msgstr[1] "This one is the plural: %s"
+msgstr[2] "And this is the second plural form: %s"
+
+msgid "This one has invalid syntax translations"
+msgid_plural "Plural index"
+msgstr[abc] "Wrong index"
+msgstr[1 "Forgot to close brackets"
+msgstr[0] "Badly formatted string'
+
+msgid "Invalid formatted id[] with no translations
+
+msgctxt "Ctx"
+msgid "One with var: %s"
+msgid_plural "Several with vars: %s"
+msgstr[0] "This one is the singular in a Ctx context: %s"
+msgstr[1] "This one is the plural in a Ctx context: %s"
+
+msgid "Some random"
+msgstr "Some random translation"
+
+msgctxt "Ctx"
+msgid "Some random in a context"
+msgstr "Some random translation in a context"
+
+msgid "More"
+msgstr "More translation"
+
+	`
+
+	// Create Locales directory with simplified language code
+	dirname := path.Join("/tmp", "en", "LC_MESSAGES")
+	err := os.MkdirAll(dirname, os.ModePerm)
+	if err != nil {
+		t.Fatalf("Can't create test directory: %s", err.Error())
+	}
+
+	// Write PO content to file
+	filename := path.Join(dirname, "my_domain.po")
+
+	f, err := os.Create(filename)
+	if err != nil {
+		t.Fatalf("Can't create test file: %s", err.Error())
+	}
+	defer f.Close()
+
+	_, err = f.WriteString(str)
+	if err != nil {
+		t.Fatalf("Can't write to test file: %s", err.Error())
+	}
+
+	// Create Locale with full language code
+	l := NewLocale("/tmp", "en_US")
+
+	// Force nil domain storage
+	l.domains = nil
+
+	// Add domain
+	l.AddDomain("my_domain")
+
 	// Test non-existent "deafult" domain responses
-	tr = l.Get("My text")
+	tr := l.Get("My text")
 	if tr != "My text" {
 		t.Errorf("Expected 'My text' but got '%s'", tr)
 	}
 
+	v := "Variable"
 	tr = l.GetN("One with var: %s", "Several with vars: %s", 2, v)
 	if tr != "Several with vars: Variable" {
 		t.Errorf("Expected 'Several with vars: Variable' but got '%s'", tr)
@@ -138,25 +241,6 @@ msgstr "More translation"
 	if tr != "This are tests" {
 		t.Errorf("Expected 'Plural index' but got '%s'", tr)
 	}
-
-	// Test context translations
-	v = "Test"
-	tr = l.GetDC("my_domain", "One with var: %s", "Ctx", v)
-	if tr != "This one is the singular in a Ctx context: Test" {
-		t.Errorf("Expected 'This one is the singular in a Ctx context: Test' but got '%s'", tr)
-	}
-
-	// Test plural
-	tr = l.GetNDC("my_domain", "One with var: %s", "Several with vars: %s", 3, "Ctx", v)
-	if tr != "This one is the plural in a Ctx context: Test" {
-		t.Errorf("Expected 'This one is the plural in a Ctx context: Test' but got '%s'", tr)
-	}
-
-	// Test last translation
-	tr = l.GetD("my_domain", "More")
-	if tr != "More translation" {
-		t.Errorf("Expected 'More translation' but got '%s'", tr)
-	}
 }
 
 func TestLocaleRace(t *testing.T) {

po.go

@@ -3,18 +3,19 @@ package gotext
 import (
 	"bufio"
 	"fmt"
-	"github.com/leonelquinteros/anko/vm"
 	"io/ioutil"
 	"net/textproto"
 	"os"
 	"strconv"
 	"strings"
 	"sync"
+
+	"github.com/mattn/kinako/vm"
 )
 
 type translation struct {
 	id       string
-	pluralId string
+	pluralID string
 	trs      map[int]string
 }
 
@@ -28,8 +29,10 @@ func newTranslation() *translation {
 func (t *translation) get() string {
 	// Look for translation index 0
 	if _, ok := t.trs[0]; ok {
+		if t.trs[0] != "" {
 			return t.trs[0]
 		}
+	}
 
 	// Return unstranlated id by default
 	return t.id
@@ -38,11 +41,13 @@ func (t *translation) get() string {
 func (t *translation) getN(n int) string {
 	// Look for translation index
 	if _, ok := t.trs[n]; ok {
+		if t.trs[n] != "" {
 			return t.trs[n]
 		}
+	}
 
 	// Return unstranlated plural by default
-	return t.pluralId
+	return t.pluralID
 }
 
 /*
@@ -86,8 +91,22 @@ type Po struct {
 
 	// Sync Mutex
 	sync.RWMutex
+
+	// Parsing buffers
+	trBuffer  *translation
+	ctxBuffer string
 }
 
+type parseState int
+
+const (
+	head parseState = iota
+	msgCtxt
+	msgID
+	msgIDPlural
+	msgStr
+)
+
 // ParseFile tries to read the file by its provided path (f) and parse its content as a .po file.
 func (po *Po) ParseFile(f string) {
 	// Check if file exists
@@ -125,89 +144,111 @@ func (po *Po) Parse(str string) {
 	// Get lines
 	lines := strings.Split(str, "\n")
 
-	// Translation buffer
-	tr := newTranslation()
-
-	// Context buffer
-	ctx := ""
+	// Init buffer
+	po.trBuffer = newTranslation()
+	po.ctxBuffer = ""
 
+	state := head
 	for _, l := range lines {
 		// Trim spaces
 		l = strings.TrimSpace(l)
 
-		// Skip empty lines
-		if l == "" {
-			continue
-		}
-
 		// Skip invalid lines
-		if !strings.HasPrefix(l, "\"") && !strings.HasPrefix(l, "msgctxt") && !strings.HasPrefix(l, "msgid") && !strings.HasPrefix(l, "msgid_plural") && !strings.HasPrefix(l, "msgstr") {
+		if !po.isValidLine(l) {
 			continue
 		}
 
 		// Buffer context and continue
 		if strings.HasPrefix(l, "msgctxt") {
-			// Save current translation buffer.
-			// No context
-			if ctx == "" {
-				po.translations[tr.id] = tr
-			} else {
-				// Save context
-				if _, ok := po.contexts[ctx]; !ok {
-					po.contexts[ctx] = make(map[string]*translation)
-				}
-				po.contexts[ctx][tr.id] = tr
-			}
-
-			// Flush buffer
-			tr = newTranslation()
-			ctx = ""
-
-			// Buffer context
-			ctx, _ = strconv.Unquote(strings.TrimSpace(strings.TrimPrefix(l, "msgctxt")))
-
-			// Loop
+			po.parseContext(l)
+			state = msgCtxt
 			continue
 		}
 
 		// Buffer msgid and continue
 		if strings.HasPrefix(l, "msgid") && !strings.HasPrefix(l, "msgid_plural") {
-			// Save current translation buffer if not inside a context.
-			if ctx == "" {
-				po.translations[tr.id] = tr
-
-				// Flush buffer
-				tr = newTranslation()
-				ctx = ""
-			} else if ctx != "" && tr.id != "" {
-				// Save current translation buffer inside a context
-				if _, ok := po.contexts[ctx]; !ok {
-					po.contexts[ctx] = make(map[string]*translation)
-				}
-				po.contexts[ctx][tr.id] = tr
-
-				// Flush buffer
-				tr = newTranslation()
-				ctx = ""
-			}
-
-			// Set id
-			tr.id, _ = strconv.Unquote(strings.TrimSpace(strings.TrimPrefix(l, "msgid")))
-
-			// Loop
+			po.parseID(l)
+			state = msgID
 			continue
 		}
 
 		// Check for plural form
 		if strings.HasPrefix(l, "msgid_plural") {
-			tr.pluralId, _ = strconv.Unquote(strings.TrimSpace(strings.TrimPrefix(l, "msgid_plural")))
-
-			// Loop
+			po.parsePluralID(l)
+			state = msgIDPlural
 			continue
 		}
 
 		// Save translation
 		if strings.HasPrefix(l, "msgstr") {
+			po.parseMessage(l)
+			state = msgStr
+			continue
+		}
+
+		// Multi line strings and headers
+		if strings.HasPrefix(l, "\"") && strings.HasSuffix(l, "\"") {
+			state = po.parseString(l, state)
+			continue
+		}
+	}
+
+	// Save last translation buffer.
+	po.saveBuffer()
+
+	// Parse headers
+	po.parseHeaders()
+}
+
+// saveBuffer takes the context and translation buffers
+// and saves it on the translations collection
+func (po *Po) saveBuffer() {
+	// If we have something to save...
+	if po.trBuffer.id != "" {
+		// With no context...
+		if po.ctxBuffer == "" {
+			po.translations[po.trBuffer.id] = po.trBuffer
+		} else {
+			// With context...
+			if _, ok := po.contexts[po.ctxBuffer]; !ok {
+				po.contexts[po.ctxBuffer] = make(map[string]*translation)
+			}
+			po.contexts[po.ctxBuffer][po.trBuffer.id] = po.trBuffer
+		}
+
+		// Flush buffer
+		po.trBuffer = newTranslation()
+		po.ctxBuffer = ""
+	}
+}
+
+// parseContext takes a line starting with "msgctxt",
+// saves the current translation buffer and creates a new context.
+func (po *Po) parseContext(l string) {
+	// Save current translation buffer.
+	po.saveBuffer()
+
+	// Buffer context
+	po.ctxBuffer, _ = strconv.Unquote(strings.TrimSpace(strings.TrimPrefix(l, "msgctxt")))
+}
+
+// parseID takes a line starting with "msgid",
+// saves the current translation and creates a new msgid buffer.
+func (po *Po) parseID(l string) {
+	// Save current translation buffer.
+	po.saveBuffer()
+
+	// Set id
+	po.trBuffer.id, _ = strconv.Unquote(strings.TrimSpace(strings.TrimPrefix(l, "msgid")))
+}
+
+// parsePluralID saves the plural id buffer from a line starting with "msgid_plural"
+func (po *Po) parsePluralID(l string) {
+	po.trBuffer.pluralID, _ = strconv.Unquote(strings.TrimSpace(strings.TrimPrefix(l, "msgid_plural")))
+}
+
+// parseMessage takes a line starting with "msgstr" and saves it into the current buffer.
+func (po *Po) parseMessage(l string) {
 	l = strings.TrimSpace(strings.TrimPrefix(l, "msgstr"))
 
 	// Check for indexed translation forms
@@ -215,69 +256,82 @@ func (po *Po) Parse(str string) {
 		idx := strings.Index(l, "]")
 		if idx == -1 {
 			// Skip wrong index formatting
-					continue
+			return
 		}
 
 		// Parse index
 		i, err := strconv.Atoi(l[1:idx])
 		if err != nil {
 			// Skip wrong index formatting
-					continue
+			return
 		}
 
 		// Parse translation string
-				tr.trs[i], _ = strconv.Unquote(strings.TrimSpace(l[idx+1:]))
+		po.trBuffer.trs[i], _ = strconv.Unquote(strings.TrimSpace(l[idx+1:]))
 
 		// Loop
-				continue
+		return
 	}
 
 	// Save single translation form under 0 index
-			tr.trs[0], _ = strconv.Unquote(l)
-
-			// Loop
-			continue
+	po.trBuffer.trs[0], _ = strconv.Unquote(l)
 }
 
-		// Multi line strings and headers
-		if strings.HasPrefix(l, "\"") && strings.HasSuffix(l, "\"") {
+// parseString takes a well formatted string without prefix
+// and creates headers or attach multi-line strings when corresponding
+func (po *Po) parseString(l string, state parseState) parseState {
+	switch state {
+	case msgStr:
 		// Check for multiline from previously set msgid
-			if tr.id != "" {
+		if po.trBuffer.id != "" {
 			// Append to last translation found
 			uq, _ := strconv.Unquote(l)
-				tr.trs[len(tr.trs)-1] += uq
+			po.trBuffer.trs[len(po.trBuffer.trs)-1] += uq
 
-				// Loop
-				continue
 		}
-
+	case msgID:
+		// Multiline msgid - Append to current id
+		uq, _ := strconv.Unquote(l)
+		po.trBuffer.id += uq
+	case msgIDPlural:
+		// Multiline msgid - Append to current id
+		uq, _ := strconv.Unquote(l)
+		po.trBuffer.pluralID += uq
+	case msgCtxt:
+		// Multiline context - Append to current context
+		ctxt, _ := strconv.Unquote(l)
+		po.ctxBuffer += ctxt
+	default:
 		// Otherwise is a header
-			h, err := strconv.Unquote(strings.TrimSpace(l))
-			if err != nil {
-				continue
-			}
-
+		h, _ := strconv.Unquote(strings.TrimSpace(l))
 		po.RawHeaders += h
-			continue
-		}
+		return head
 	}
 
-	// Save last translation buffer.
-	if tr.id != "" {
-		if ctx == "" {
-			po.translations[tr.id] = tr
-		} else {
-			// Save context
-			if _, ok := po.contexts[ctx]; !ok {
-				po.contexts[ctx] = make(map[string]*translation)
-			}
-			po.contexts[ctx][tr.id] = tr
-		}
+	return state
 }
 
-	// Parse headers
+// isValidLine checks for line prefixes to detect valid syntax.
+func (po *Po) isValidLine(l string) bool {
+	// Skip empty lines
+	if l == "" {
+		return false
+	}
+
+	// Check prefix
+	if !strings.HasPrefix(l, "\"") && !strings.HasPrefix(l, "msgctxt") && !strings.HasPrefix(l, "msgid") && !strings.HasPrefix(l, "msgid_plural") && !strings.HasPrefix(l, "msgstr") {
+		return false
+	}
+
+	return true
+}
+
+// parseHeaders retrieves data from previously parsed headers
+func (po *Po) parseHeaders() {
+	// Make sure we end with 2 carriage returns.
 	po.RawHeaders += "\n\n"
 
+	// Read
 	reader := bufio.NewReader(strings.NewReader(po.RawHeaders))
 	tp := textproto.NewReader(reader)
 
@@ -340,9 +394,9 @@ func (po *Po) pluralForm(n int) int {
 	if plural.Type().Name() == "bool" {
 		if plural.Bool() {
 			return 1
-		} else {
-			return 0
 		}
+		// Else
+		return 0
 	}
 
 	if int(plural.Int()) > po.nplurals {
@@ -382,7 +436,9 @@ func (po *Po) GetN(str, plural string, n int, vars ...interface{}) string {
 		}
 	}
 
-	// Return the plural string we received by default
+	if n == 1 {
+		return fmt.Sprintf(str, vars...)
+	}
 	return fmt.Sprintf(plural, vars...)
 }
 
@@ -424,6 +480,8 @@ func (po *Po) GetNC(str, plural string, n int, ctx string, vars ...interface{})
 		}
 	}
 
-	// Return the plural string we received by default
+	if n == 1 {
+		return fmt.Sprintf(str, vars...)
+	}
 	return fmt.Sprintf(plural, vars...)
 }

po_test.go

@@ -9,8 +9,6 @@ import (
 func TestPo(t *testing.T) {
 	// Set PO content
 	str := `
-msgid ""
-msgstr ""
 # Initial comment
 # Headers below
 "Language: en\n"
@@ -26,6 +24,19 @@ msgstr "Translated text"
 msgid "Another string"
 msgstr ""
 
+# Multi-line msgid
+msgid "multi"
+"line"
+"id"
+msgstr "id with multiline content"
+
+# Multi-line msgid_plural
+msgid "multi"
+"line"
+"plural"
+"id"
+msgstr "plural id with multiline content"
+
 #Multi-line string
 msgid "Multi-line"
 msgstr "Multi "
@@ -58,8 +69,17 @@ msgctxt "Ctx"
 msgid "Some random in a context"
 msgstr "Some random translation in a context"
 
+msgid "Empty translation"
+msgstr ""
+
+msgid "Empty plural form singular"
+msgid_plural "Empty plural form"
+msgstr[0] "Singular translated"
+msgstr[1] "
+
 msgid "More"
 msgstr "More translation"
+"
 	`
 
 	// Write PO content to file
@@ -97,6 +117,18 @@ msgstr "More translation"
 		t.Errorf("Expected 'This one is the singular: Variable' but got '%s'", tr)
 	}
 
+	// Test multi-line id
+	tr = po.Get("multilineid")
+	if tr != "id with multiline content" {
+		t.Errorf("Expected 'id with multiline content' but got '%s'", tr)
+	}
+
+	// Test multi-line plural id
+	tr = po.Get("multilinepluralid")
+	if tr != "plural id with multiline content" {
+		t.Errorf("Expected 'plural id with multiline content' but got '%s'", tr)
+	}
+
 	// Test multi-line
 	tr = po.Get("Multi-line")
 	if tr != "Multi line" {
@@ -122,8 +154,8 @@ msgstr "More translation"
 
 	// Test syntax error parsed translations
 	tr = po.Get("This one has invalid syntax translations")
-	if tr != "" {
-		t.Errorf("Expected '' but got '%s'", tr)
+	if tr != "This one has invalid syntax translations" {
+		t.Errorf("Expected 'This one has invalid syntax translations' but got '%s'", tr)
 	}
 
 	tr = po.GetN("This one has invalid syntax translations", "This are tests", 4)
@@ -144,19 +176,47 @@ msgstr "More translation"
 		t.Errorf("Expected 'This one is the plural in a Ctx context: Test' but got '%s'", tr)
 	}
 
+	// Test default plural vs singular return responses
+	tr = po.GetN("Original", "Original plural", 4)
+	if tr != "Original plural" {
+		t.Errorf("Expected 'Original plural' but got '%s'", tr)
+	}
+	tr = po.GetN("Original", "Original plural", 1)
+	if tr != "Original" {
+		t.Errorf("Expected 'Original' but got '%s'", tr)
+	}
+
+	// Test empty translation strings
+	tr = po.Get("Empty translation")
+	if tr != "Empty translation" {
+		t.Errorf("Expected 'Empty translation' but got '%s'", tr)
+	}
+
+	tr = po.Get("Empty plural form singular")
+	if tr != "Singular translated" {
+		t.Errorf("Expected 'Singular translated' but got '%s'", tr)
+	}
+
+	tr = po.GetN("Empty plural form singular", "Empty plural form", 1)
+	if tr != "Singular translated" {
+		t.Errorf("Expected 'Singular translated' but got '%s'", tr)
+	}
+
+	tr = po.GetN("Empty plural form singular", "Empty plural form", 2)
+	if tr != "Empty plural form" {
+		t.Errorf("Expected 'Empty plural form' but got '%s'", tr)
+	}
+
 	// Test last translation
 	tr = po.Get("More")
 	if tr != "More translation" {
 		t.Errorf("Expected 'More translation' but got '%s'", tr)
 	}
-
 }
 
 func TestPoHeaders(t *testing.T) {
 	// Set PO content
 	str := `
-msgid ""
-msgstr ""
 # Initial comment
 # Headers below
 "Language: en\n"
@@ -186,7 +246,7 @@ msgstr "Translated example"
 	}
 }
 
-func TestPluralForms(t *testing.T) {
+func TestPluralFormsSingle(t *testing.T) {
 	// Single form
 	str := `
 "Plural-Forms: nplurals=1; plural=0;"
@@ -227,10 +287,11 @@ msgstr[3] "Plural form 3"
 	if n != 0 {
 		t.Errorf("Expected 0 for pluralForm(50), got %d", n)
 	}
+}
 
-	// ------------------------------------------------------------------------
+func TestPluralForms2(t *testing.T) {
 	// 2 forms
-	str = `
+	str := `
 "Plural-Forms: nplurals=2; plural=n != 1;"
 
 # Some comment
@@ -243,13 +304,13 @@ msgstr[3] "Plural form 3"
 	`
 
 	// Create po object
-	po = new(Po)
+	po := new(Po)
 
 	// Parse
 	po.Parse(str)
 
 	// Check plural form
-	n = po.pluralForm(0)
+	n := po.pluralForm(0)
 	if n != 1 {
 		t.Errorf("Expected 1 for pluralForm(0), got %d", n)
 	}
@@ -265,10 +326,11 @@ msgstr[3] "Plural form 3"
 	if n != 1 {
 		t.Errorf("Expected 1 for pluralForm(3), got %d", n)
 	}
+}
 
-	// ------------------------------------------------------------------------
+func TestPluralForms3(t *testing.T) {
 	// 3 forms
-	str = `
+	str := `
 "Plural-Forms: nplurals=3; plural=n%10==1 && n%100!=11 ? 0 : n != 0 ? 1 : 2;"
 
 # Some comment
@@ -281,13 +343,13 @@ msgstr[3] "Plural form 3"
 	`
 
 	// Create po object
-	po = new(Po)
+	po := new(Po)
 
 	// Parse
 	po.Parse(str)
 
 	// Check plural form
-	n = po.pluralForm(0)
+	n := po.pluralForm(0)
 	if n != 2 {
 		t.Errorf("Expected 2 for pluralForm(0), got %d", n)
 	}
@@ -311,10 +373,11 @@ msgstr[3] "Plural form 3"
 	if n != 1 {
 		t.Errorf("Expected 1 for pluralForm(3), got %d", n)
 	}
+}
 
-	// ------------------------------------------------------------------------
+func TestPluralFormsSpecial(t *testing.T) {
 	// 3 forms special
-	str = `
+	str := `
 "Plural-Forms: nplurals=3;"
 "plural=(n==1) ? 0 : (n>=2 && n<=4) ? 1 : 2;"
 
@@ -328,13 +391,13 @@ msgstr[3] "Plural form 3"
 	`
 
 	// Create po object
-	po = new(Po)
+	po := new(Po)
 
 	// Parse
 	po.Parse(str)
 
 	// Check plural form
-	n = po.pluralForm(1)
+	n := po.pluralForm(1)
 	if n != 0 {
 		t.Errorf("Expected 0 for pluralForm(1), got %d", n)
 	}

vendor/github.com/mattn/kinako/ast/expr.go

@@ -0,0 +1,104 @@
+package ast
+
+type Token struct {
+	Tok int
+	Lit string
+}
+
+// Position provides interface to store code locations.
+type Position struct {
+	Line   int
+	Column int
+}
+
+// Expr provides all of interfaces for expression.
+type Expr interface {
+	expr()
+}
+
+// ExprImpl provide commonly implementations for Expr.
+type ExprImpl struct {
+}
+
+// expr provide restraint interface.
+func (x *ExprImpl) expr() {}
+
+// NumberExpr provide Number expression.
+type NumberExpr struct {
+	ExprImpl
+	Lit string
+}
+
+// UnaryExpr provide unary minus expression. ex: -1, ^1, ~1.
+type UnaryExpr struct {
+	ExprImpl
+	Operator string
+	Expr     Expr
+}
+
+// IdentExpr provide identity expression.
+type IdentExpr struct {
+	ExprImpl
+	Lit string
+}
+
+// Stmt provides all of interfaces for statement.
+type Stmt interface {
+	stmt()
+}
+
+// StmtImpl provide commonly implementations for Stmt..
+type StmtImpl struct {
+}
+
+// stmt provide restraint interface.
+func (x *StmtImpl) stmt() {}
+
+// LetsStmt provide multiple statement of let.
+type LetsStmt struct {
+	StmtImpl
+	Lhss     []Expr
+	Operator string
+	Rhss     []Expr
+}
+
+// StringExpr provide String expression.
+type StringExpr struct {
+	ExprImpl
+	Lit string
+}
+
+type TernaryOpExpr struct {
+	ExprImpl
+	Expr Expr
+	Lhs  Expr
+	Rhs  Expr
+}
+
+// ParenExpr provide parent block expression.
+type ParenExpr struct {
+	ExprImpl
+	SubExpr Expr
+}
+
+// BinOpExpr provide binary operator expression.
+type BinOpExpr struct {
+	ExprImpl
+	Lhs      Expr
+	Operator string
+	Rhs      Expr
+}
+
+// ExprStmt provide expression statement.
+type ExprStmt struct {
+	StmtImpl
+	Expr Expr
+}
+
+// LetStmt provide statement of let.
+type LetStmt struct {
+	StmtImpl
+	Lhs      Expr
+	Operator string
+	Rhs      Expr
+}

vendor/github.com/mattn/kinako/parser/Makefile

@@ -0,0 +1,4 @@
+all : parser.go
+
+parser.go : parser.go.y
+	goyacc -o $@ parser.go.y

vendor/github.com/mattn/kinako/parser/lexer.go

@@ -0,0 +1,427 @@
+package parser
+
+import (
+	"errors"
+	"fmt"
+	"unicode"
+
+	"github.com/mattn/kinako/ast"
+)
+
+const (
+	EOF = -1   // End of file.
+	EOL = '\n' // End of line.
+)
+
+// Error provides a convenient interface for handling runtime error.
+// It can be Error inteface with type cast which can call Pos().
+type Error struct {
+	Message  string
+	Filename string
+	Fatal    bool
+}
+
+// Error returns the error message.
+func (e *Error) Error() string {
+	return e.Message
+}
+
+// Scanner stores informations for lexer.
+type Scanner struct {
+	src      []rune
+	offset   int
+	lineHead int
+	line     int
+}
+
+// Init resets code to scan.
+func (s *Scanner) Init(src string) {
+	s.src = []rune(src)
+}
+
+// Scan analyses token, and decide identify or literals.
+func (s *Scanner) Scan() (tok int, lit string, pos ast.Position, err error) {
+retry:
+	s.skipBlank()
+	pos = s.pos()
+	switch ch := s.peek(); {
+	case isLetter(ch):
+		tok = IDENT
+		lit, err = s.scanIdentifier()
+		if err != nil {
+			return
+		}
+	case isDigit(ch):
+		tok = NUMBER
+		lit, err = s.scanNumber()
+		if err != nil {
+			return
+		}
+	case ch == '"':
+		tok = STRING
+		lit, err = s.scanString('"')
+		if err != nil {
+			return
+		}
+	case ch == '\'':
+		tok = STRING
+		lit, err = s.scanString('\'')
+		if err != nil {
+			return
+		}
+	case ch == '`':
+		tok = STRING
+		lit, err = s.scanRawString()
+		if err != nil {
+			return
+		}
+	default:
+		switch ch {
+		case EOF:
+			tok = EOF
+		case '#':
+			for !isEOL(s.peek()) {
+				s.next()
+			}
+			goto retry
+		case '!':
+			s.next()
+			switch s.peek() {
+			case '=':
+				tok = NEQ
+				lit = "!="
+			default:
+				s.back()
+				tok = int(ch)
+				lit = string(ch)
+			}
+		case '=':
+			s.next()
+			switch s.peek() {
+			case '=':
+				tok = EQEQ
+				lit = "=="
+			default:
+				s.back()
+				tok = int(ch)
+				lit = string(ch)
+			}
+		case '+':
+			tok = int(ch)
+			lit = string(ch)
+		case '-':
+			tok = int(ch)
+			lit = string(ch)
+		case '*':
+			tok = int(ch)
+			lit = string(ch)
+		case '/':
+			tok = int(ch)
+			lit = string(ch)
+		case '>':
+			s.next()
+			switch s.peek() {
+			case '=':
+				tok = GE
+				lit = ">="
+			case '>':
+				tok = SHIFTRIGHT
+				lit = ">>"
+			default:
+				s.back()
+				tok = int(ch)
+				lit = string(ch)
+			}
+		case '<':
+			s.next()
+			switch s.peek() {
+			case '=':
+				tok = LE
+				lit = "<="
+			case '<':
+				tok = SHIFTLEFT
+				lit = "<<"
+			default:
+				s.back()
+				tok = int(ch)
+				lit = string(ch)
+			}
+		case '|':
+			s.next()
+			switch s.peek() {
+			case '|':
+				tok = OROR
+				lit = "||"
+			default:
+				s.back()
+				tok = int(ch)
+				lit = string(ch)
+			}
+		case '&':
+			s.next()
+			switch s.peek() {
+			case '&':
+				tok = ANDAND
+				lit = "&&"
+			default:
+				s.back()
+				tok = int(ch)
+				lit = string(ch)
+			}
+		case '.':
+			tok = int(ch)
+			lit = string(ch)
+		case '\n':
+			tok = int(ch)
+			lit = string(ch)
+		case '(', ')', ':', ';', '%', '?', '{', '}', ',', '[', ']', '^':
+			tok = int(ch)
+			lit = string(ch)
+		default:
+			err = fmt.Errorf(`syntax error "%s"`, string(ch))
+			tok = int(ch)
+			lit = string(ch)
+			return
+		}
+		s.next()
+	}
+	return
+}
+
+// isLetter returns true if the rune is a letter for identity.
+func isLetter(ch rune) bool {
+	return unicode.IsLetter(ch) || ch == '_'
+}
+
+// isDigit returns true if the rune is a number.
+func isDigit(ch rune) bool {
+	return '0' <= ch && ch <= '9'
+}
+
+// isHex returns true if the rune is a hex digits.
+func isHex(ch rune) bool {
+	return ('0' <= ch && ch <= '9') || ('a' <= ch && ch <= 'f') || ('A' <= ch && ch <= 'F')
+}
+
+// isEOL returns true if the rune is at end-of-line or end-of-file.
+func isEOL(ch rune) bool {
+	return ch == '\n' || ch == -1
+}
+
+// isBlank returns true if the rune is empty character..
+func isBlank(ch rune) bool {
+	return ch == ' ' || ch == '\t' || ch == '\r'
+}
+
+// peek returns current rune in the code.
+func (s *Scanner) peek() rune {
+	if s.reachEOF() {
+		return EOF
+	}
+	return s.src[s.offset]
+}
+
+// next moves offset to next.
+func (s *Scanner) next() {
+	if !s.reachEOF() {
+		if s.peek() == '\n' {
+			s.lineHead = s.offset + 1
+			s.line++
+		}
+		s.offset++
+	}
+}
+
+// current returns the current offset.
+func (s *Scanner) current() int {
+	return s.offset
+}
+
+// offset sets the offset value.
+func (s *Scanner) set(o int) {
+	s.offset = o
+}
+
+// back moves back offset once to top.
+func (s *Scanner) back() {
+	s.offset--
+}
+
+// reachEOF returns true if offset is at end-of-file.
+func (s *Scanner) reachEOF() bool {
+	return len(s.src) <= s.offset
+}
+
+// pos returns the position of current.
+func (s *Scanner) pos() ast.Position {
+	return ast.Position{Line: s.line + 1, Column: s.offset - s.lineHead + 1}
+}
+
+// skipBlank moves position into non-black character.
+func (s *Scanner) skipBlank() {
+	for isBlank(s.peek()) {
+		s.next()
+	}
+}
+
+// scanIdentifier returns identifier begining at current position.
+func (s *Scanner) scanIdentifier() (string, error) {
+	var ret []rune
+	for {
+		if !isLetter(s.peek()) && !isDigit(s.peek()) {
+			break
+		}
+		ret = append(ret, s.peek())
+		s.next()
+	}
+	return string(ret), nil
+}
+
+// scanNumber returns number begining at current position.
+func (s *Scanner) scanNumber() (string, error) {
+	var ret []rune
+	ch := s.peek()
+	ret = append(ret, ch)
+	s.next()
+	if ch == '0' && s.peek() == 'x' {
+		ret = append(ret, s.peek())
+		s.next()
+		for isHex(s.peek()) {
+			ret = append(ret, s.peek())
+			s.next()
+		}
+	} else {
+		for isDigit(s.peek()) || s.peek() == '.' {
+			ret = append(ret, s.peek())
+			s.next()
+		}
+		if s.peek() == 'e' {
+			ret = append(ret, s.peek())
+			s.next()
+			if isDigit(s.peek()) || s.peek() == '+' || s.peek() == '-' {
+				ret = append(ret, s.peek())
+				s.next()
+				for isDigit(s.peek()) || s.peek() == '.' {
+					ret = append(ret, s.peek())
+					s.next()
+				}
+			}
+			for isDigit(s.peek()) || s.peek() == '.' {
+				ret = append(ret, s.peek())
+				s.next()
+			}
+		}
+		if isLetter(s.peek()) {
+			return "", errors.New("identifier starts immediately after numeric literal")
+		}
+	}
+	return string(ret), nil
+}
+
+// scanRawString returns raw-string starting at current position.
+func (s *Scanner) scanRawString() (string, error) {
+	var ret []rune
+	for {
+		s.next()
+		if s.peek() == EOF {
+			return "", errors.New("unexpected EOF")
+			break
+		}
+		if s.peek() == '`' {
+			s.next()
+			break
+		}
+		ret = append(ret, s.peek())
+	}
+	return string(ret), nil
+}
+
+// scanString returns string starting at current position.
+// This handles backslash escaping.
+func (s *Scanner) scanString(l rune) (string, error) {
+	var ret []rune
+eos:
+	for {
+		s.next()
+		switch s.peek() {
+		case EOL:
+			return "", errors.New("unexpected EOL")
+		case EOF:
+			return "", errors.New("unexpected EOF")
+		case l:
+			s.next()
+			break eos
+		case '\\':
+			s.next()
+			switch s.peek() {
+			case 'b':
+				ret = append(ret, '\b')
+				continue
+			case 'f':
+				ret = append(ret, '\f')
+				continue
+			case 'r':
+				ret = append(ret, '\r')
+				continue
+			case 'n':
+				ret = append(ret, '\n')
+				continue
+			case 't':
+				ret = append(ret, '\t')
+				continue
+			}
+			ret = append(ret, s.peek())
+			continue
+		default:
+			ret = append(ret, s.peek())
+		}
+	}
+	return string(ret), nil
+}
+
+// Lexer provides inteface to parse codes.
+type Lexer struct {
+	s     *Scanner
+	lit   string
+	pos   ast.Position
+	e     error
+	stmts []ast.Stmt
+}
+
+// Lex scans the token and literals.
+func (l *Lexer) Lex(lval *yySymType) int {
+	tok, lit, pos, err := l.s.Scan()
+	if err != nil {
+		l.e = &Error{Message: fmt.Sprintf("%s", err.Error()), Fatal: true}
+	}
+	lval.tok = ast.Token{Tok: tok, Lit: lit}
+	l.lit = lit
+	l.pos = pos
+	return tok
+}
+
+// Error sets parse error.
+func (l *Lexer) Error(msg string) {
+	l.e = &Error{Message: msg, Fatal: false}
+}
+
+// Parser provides way to parse the code using Scanner.
+func Parse(s *Scanner) ([]ast.Stmt, error) {
+	l := Lexer{s: s}
+	if yyParse(&l) != 0 {
+		return nil, l.e
+	}
+	return l.stmts, l.e
+}
+
+func EnableErrorVerbose() {
+	yyErrorVerbose = true
+}
+
+// ParserSrc provides way to parse the code from source.
+func ParseSrc(src string) ([]ast.Stmt, error) {
+	scanner := &Scanner{
+		src: []rune(src),
+	}
+	return Parse(scanner)
+}

vendor/github.com/mattn/kinako/parser/parser.go

@@ -0,0 +1,752 @@
+//line parser.go.y:2
+package parser
+
+import __yyfmt__ "fmt"
+
+//line parser.go.y:2
+import (
+	"github.com/mattn/kinako/ast"
+)
+
+//line parser.go.y:15
+type yySymType struct {
+	yys       int
+	compstmt  []ast.Stmt
+	stmts     []ast.Stmt
+	stmt      ast.Stmt
+	expr      ast.Expr
+	tok       ast.Token
+	term      ast.Token
+	terms     ast.Token
+	opt_terms ast.Token
+}
+
+const IDENT = 57346
+const NUMBER = 57347
+const STRING = 57348
+const EQEQ = 57349
+const NEQ = 57350
+const GE = 57351
+const LE = 57352
+const OROR = 57353
+const ANDAND = 57354
+const POW = 57355
+const SHIFTLEFT = 57356
+const SHIFTRIGHT = 57357
+const PLUSPLUS = 57358
+const MINUSMINUS = 57359
+const UNARY = 57360
+
+var yyToknames = [...]string{
+	"$end",
+	"error",
+	"$unk",
+	"IDENT",
+	"NUMBER",
+	"STRING",
+	"EQEQ",
+	"NEQ",
+	"GE",
+	"LE",
+	"OROR",
+	"ANDAND",
+	"POW",
+	"'='",
+	"'?'",
+	"':'",
+	"','",
+	"'>'",
+	"'<'",
+	"SHIFTLEFT",
+	"SHIFTRIGHT",
+	"'+'",
+	"'-'",
+	"PLUSPLUS",
+	"MINUSMINUS",
+	"'*'",
+	"'/'",
+	"'%'",
+	"UNARY",
+	"'!'",
+	"'^'",
+	"'('",
+	"')'",
+	"'|'",
+	"'&'",
+	"';'",
+	"'\\n'",
+}
+var yyStatenames = [...]string{}
+
+const yyEofCode = 1
+const yyErrCode = 2
+const yyInitialStackSize = 16
+
+//line parser.go.y:194
+
+//line yacctab:1
+var yyExca = [...]int{
+	-1, 1,
+	1, -1,
+	-2, 0,
+	-1, 49,
+	7, 0,
+	8, 0,
+	-2, 20,
+	-1, 50,
+	7, 0,
+	8, 0,
+	-2, 21,
+}
+
+const yyNprod = 36
+const yyPrivate = 57344
+
+var yyTokenNames []string
+var yyStates []string
+
+const yyLast = 249
+
+var yyAct = [...]int{
+
+	9, 6, 7, 33, 35, 4, 22, 23, 3, 18,
+	24, 25, 26, 37, 38, 39, 2, 40, 33, 35,
+	17, 42, 43, 44, 45, 46, 47, 48, 49, 50,
+	51, 52, 53, 54, 55, 56, 57, 58, 27, 28,
+	30, 32, 34, 36, 8, 1, 21, 60, 0, 29,
+	31, 0, 0, 22, 23, 5, 0, 24, 25, 26,
+	19, 61, 0, 41, 0, 33, 35, 27, 28, 30,
+	32, 34, 36, 0, 19, 21, 0, 0, 29, 31,
+	0, 0, 22, 23, 0, 0, 24, 25, 26, 0,
+	0, 0, 0, 59, 33, 35, 27, 28, 30, 32,
+	34, 36, 0, 20, 21, 0, 0, 29, 31, 0,
+	0, 22, 23, 0, 0, 24, 25, 26, 0, 0,
+	0, 0, 0, 33, 35, 27, 28, 30, 32, 34,
+	36, 0, 0, 21, 0, 0, 29, 31, 0, 0,
+	22, 23, 0, 0, 24, 25, 26, 0, 0, 0,
+	0, 0, 33, 35, 27, 28, 30, 32, 0, 36,
+	0, 0, 0, 0, 0, 29, 31, 0, 0, 22,
+	23, 0, 0, 24, 25, 26, 27, 28, 30, 32,
+	0, 33, 35, 0, 0, 0, 0, 29, 31, 0,
+	0, 22, 23, 0, 0, 24, 25, 26, 30, 32,
+	10, 11, 15, 33, 35, 0, 0, 29, 31, 0,
+	0, 22, 23, 0, 0, 24, 25, 26, 0, 12,
+	10, 11, 15, 33, 35, 0, 13, 14, 16, 24,
+	25, 26, 6, 7, 0, 0, 0, 33, 35, 12,
+	0, 0, 0, 0, 0, 0, 13, 14, 16,
+}
+var yyPact = [...]int{
+
+	-35, -1000, 216, -35, -35, -1000, -1000, -1000, -1000, 89,
+	-1000, -1000, 216, 216, 216, -1000, 216, -1000, 196, -1000,
+	216, 216, 216, 216, 216, 216, 216, 216, 216, 216,
+	216, 216, 216, 216, 216, 216, 216, -31, -31, -31,
+	60, -1000, 118, 31, 203, 203, -31, -31, -31, 189,
+	189, -16, -16, -16, -16, 118, 147, 118, 169, -1000,
+	216, 118,
+}
+var yyPgo = [...]int{
+
+	0, 45, 8, 44, 0, 16, 5, 55,
+}
+var yyR1 = [...]int{
+
+	0, 1, 1, 2, 2, 3, 3, 4, 4, 4,
+	4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+	4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+	5, 5, 6, 6, 7, 7,
+}
+var yyR2 = [...]int{
+
+	0, 1, 2, 2, 3, 3, 1, 1, 1, 2,
+	2, 2, 1, 5, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	0, 1, 1, 2, 1, 1,
+}
+var yyChk = [...]int{
+
+	-1000, -1, -5, -2, -6, -7, 36, 37, -3, -4,
+	4, 5, 23, 30, 31, 6, 32, -5, -6, -7,
+	14, 15, 22, 23, 26, 27, 28, 7, 8, 18,
+	9, 19, 10, 34, 11, 35, 12, -4, -4, -4,
+	-4, -3, -4, -4, -4, -4, -4, -4, -4, -4,
+	-4, -4, -4, -4, -4, -4, -4, -4, -4, 33,
+	16, -4,
+}
+var yyDef = [...]int{
+
+	30, -2, 1, 30, 31, 32, 34, 35, 3, 6,
+	7, 8, 0, 0, 0, 12, 0, 2, 31, 33,
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	0, 0, 0, 0, 0, 0, 0, 9, 10, 11,
+	0, 4, 5, 0, 15, 16, 17, 18, 19, -2,
+	-2, 22, 23, 24, 25, 26, 27, 28, 29, 14,
+	0, 13,
+}
+var yyTok1 = [...]int{
+
+	1, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	37, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 30, 3, 3, 3, 28, 35, 3,
+	32, 33, 26, 22, 17, 23, 3, 27, 3, 3,
+	3, 3, 3, 3, 3, 3, 3, 3, 16, 36,
+	19, 14, 18, 15, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 31, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+	3, 3, 3, 3, 34,
+}
+var yyTok2 = [...]int{
+
+	2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
+	12, 13, 20, 21, 24, 25, 29,
+}
+var yyTok3 = [...]int{
+	0,
+}
+
+var yyErrorMessages = [...]struct {
+	state int
+	token int
+	msg   string
+}{}
+
+//line yaccpar:1
+
+/*	parser for yacc output	*/
+
+var (
+	yyDebug        = 0
+	yyErrorVerbose = false
+)
+
+type yyLexer interface {
+	Lex(lval *yySymType) int
+	Error(s string)
+}
+
+type yyParser interface {
+	Parse(yyLexer) int
+	Lookahead() int
+}
+
+type yyParserImpl struct {
+	lval  yySymType
+	stack [yyInitialStackSize]yySymType
+	char  int
+}
+
+func (p *yyParserImpl) Lookahead() int {
+	return p.char
+}
+
+func yyNewParser() yyParser {
+	return &yyParserImpl{}
+}
+
+const yyFlag = -1000
+
+func yyTokname(c int) string {
+	if c >= 1 && c-1 < len(yyToknames) {
+		if yyToknames[c-1] != "" {
+			return yyToknames[c-1]
+		}
+	}
+	return __yyfmt__.Sprintf("tok-%v", c)
+}
+
+func yyStatname(s int) string {
+	if s >= 0 && s < len(yyStatenames) {
+		if yyStatenames[s] != "" {
+			return yyStatenames[s]
+		}
+	}
+	return __yyfmt__.Sprintf("state-%v", s)
+}
+
+func yyErrorMessage(state, lookAhead int) string {
+	const TOKSTART = 4
+
+	if !yyErrorVerbose {
+		return "syntax error"
+	}
+
+	for _, e := range yyErrorMessages {
+		if e.state == state && e.token == lookAhead {
+			return "syntax error: " + e.msg
+		}
+	}
+
+	res := "syntax error: unexpected " + yyTokname(lookAhead)
+
+	// To match Bison, suggest at most four expected tokens.
+	expected := make([]int, 0, 4)
+
+	// Look for shiftable tokens.
+	base := yyPact[state]
+	for tok := TOKSTART; tok-1 < len(yyToknames); tok++ {
+		if n := base + tok; n >= 0 && n < yyLast && yyChk[yyAct[n]] == tok {
+			if len(expected) == cap(expected) {
+				return res
+			}
+			expected = append(expected, tok)
+		}
+	}
+
+	if yyDef[state] == -2 {
+		i := 0
+		for yyExca[i] != -1 || yyExca[i+1] != state {
+			i += 2
+		}
+
+		// Look for tokens that we accept or reduce.
+		for i += 2; yyExca[i] >= 0; i += 2 {
+			tok := yyExca[i]
+			if tok < TOKSTART || yyExca[i+1] == 0 {
+				continue
+			}
+			if len(expected) == cap(expected) {
+				return res
+			}
+			expected = append(expected, tok)
+		}
+
+		// If the default action is to accept or reduce, give up.
+		if yyExca[i+1] != 0 {
+			return res
+		}
+	}
+
+	for i, tok := range expected {
+		if i == 0 {
+			res += ", expecting "
+		} else {
+			res += " or "
+		}
+		res += yyTokname(tok)
+	}
+	return res
+}
+
+func yylex1(lex yyLexer, lval *yySymType) (char, token int) {
+	token = 0
+	char = lex.Lex(lval)
+	if char <= 0 {
+		token = yyTok1[0]
+		goto out
+	}
+	if char < len(yyTok1) {
+		token = yyTok1[char]
+		goto out
+	}
+	if char >= yyPrivate {
+		if char < yyPrivate+len(yyTok2) {
+			token = yyTok2[char-yyPrivate]
+			goto out
+		}
+	}
+	for i := 0; i < len(yyTok3); i += 2 {
+		token = yyTok3[i+0]
+		if token == char {
+			token = yyTok3[i+1]
+			goto out
+		}
+	}
+
+out:
+	if token == 0 {
+		token = yyTok2[1] /* unknown char */
+	}
+	if yyDebug >= 3 {
+		__yyfmt__.Printf("lex %s(%d)\n", yyTokname(token), uint(char))
+	}
+	return char, token
+}
+
+func yyParse(yylex yyLexer) int {
+	return yyNewParser().Parse(yylex)
+}
+
+func (yyrcvr *yyParserImpl) Parse(yylex yyLexer) int {
+	var yyn int
+	var yyVAL yySymType
+	var yyDollar []yySymType
+	_ = yyDollar // silence set and not used
+	yyS := yyrcvr.stack[:]
+
+	Nerrs := 0   /* number of errors */
+	Errflag := 0 /* error recovery flag */
+	yystate := 0
+	yyrcvr.char = -1
+	yytoken := -1 // yyrcvr.char translated into internal numbering
+	defer func() {
+		// Make sure we report no lookahead when not parsing.
+		yystate = -1
+		yyrcvr.char = -1
+		yytoken = -1
+	}()
+	yyp := -1
+	goto yystack
+
+ret0:
+	return 0
+
+ret1:
+	return 1
+
+yystack:
+	/* put a state and value onto the stack */
+	if yyDebug >= 4 {
+		__yyfmt__.Printf("char %v in %v\n", yyTokname(yytoken), yyStatname(yystate))
+	}
+
+	yyp++
+	if yyp >= len(yyS) {
+		nyys := make([]yySymType, len(yyS)*2)
+		copy(nyys, yyS)
+		yyS = nyys
+	}
+	yyS[yyp] = yyVAL
+	yyS[yyp].yys = yystate
+
+yynewstate:
+	yyn = yyPact[yystate]
+	if yyn <= yyFlag {
+		goto yydefault /* simple state */
+	}
+	if yyrcvr.char < 0 {
+		yyrcvr.char, yytoken = yylex1(yylex, &yyrcvr.lval)
+	}
+	yyn += yytoken
+	if yyn < 0 || yyn >= yyLast {
+		goto yydefault
+	}
+	yyn = yyAct[yyn]
+	if yyChk[yyn] == yytoken { /* valid shift */
+		yyrcvr.char = -1
+		yytoken = -1
+		yyVAL = yyrcvr.lval
+		yystate = yyn
+		if Errflag > 0 {
+			Errflag--
+		}
+		goto yystack
+	}
+
+yydefault:
+	/* default state action */
+	yyn = yyDef[yystate]
+	if yyn == -2 {
+		if yyrcvr.char < 0 {
+			yyrcvr.char, yytoken = yylex1(yylex, &yyrcvr.lval)
+		}
+
+		/* look through exception table */
+		xi := 0
+		for {
+			if yyExca[xi+0] == -1 && yyExca[xi+1] == yystate {
+				break
+			}
+			xi += 2
+		}
+		for xi += 2; ; xi += 2 {
+			yyn = yyExca[xi+0]
+			if yyn < 0 || yyn == yytoken {
+				break
+			}
+		}
+		yyn = yyExca[xi+1]
+		if yyn < 0 {
+			goto ret0
+		}
+	}
+	if yyn == 0 {
+		/* error ... attempt to resume parsing */
+		switch Errflag {
+		case 0: /* brand new error */
+			yylex.Error(yyErrorMessage(yystate, yytoken))
+			Nerrs++
+			if yyDebug >= 1 {
+				__yyfmt__.Printf("%s", yyStatname(yystate))
+				__yyfmt__.Printf(" saw %s\n", yyTokname(yytoken))
+			}
+			fallthrough
+
+		case 1, 2: /* incompletely recovered error ... try again */
+			Errflag = 3
+
+			/* find a state where "error" is a legal shift action */
+			for yyp >= 0 {
+				yyn = yyPact[yyS[yyp].yys] + yyErrCode
+				if yyn >= 0 && yyn < yyLast {
+					yystate = yyAct[yyn] /* simulate a shift of "error" */
+					if yyChk[yystate] == yyErrCode {
+						goto yystack
+					}
+				}
+
+				/* the current p has no shift on "error", pop stack */
+				if yyDebug >= 2 {
+					__yyfmt__.Printf("error recovery pops state %d\n", yyS[yyp].yys)
+				}
+				yyp--
+			}
+			/* there is no state on the stack with an error shift ... abort */
+			goto ret1
+
+		case 3: /* no shift yet; clobber input char */
+			if yyDebug >= 2 {
+				__yyfmt__.Printf("error recovery discards %s\n", yyTokname(yytoken))
+			}
+			if yytoken == yyEofCode {
+				goto ret1
+			}
+			yyrcvr.char = -1
+			yytoken = -1
+			goto yynewstate /* try again in the same state */
+		}
+	}
+
+	/* reduction by production yyn */
+	if yyDebug >= 2 {
+		__yyfmt__.Printf("reduce %v in:\n\t%v\n", yyn, yyStatname(yystate))
+	}
+
+	yynt := yyn
+	yypt := yyp
+	_ = yypt // guard against "declared and not used"
+
+	yyp -= yyR2[yyn]
+	// yyp is now the index of $0. Perform the default action. Iff the
+	// reduced production is ε, $1 is possibly out of range.
+	if yyp+1 >= len(yyS) {
+		nyys := make([]yySymType, len(yyS)*2)
+		copy(nyys, yyS)
+		yyS = nyys
+	}
+	yyVAL = yyS[yyp+1]
+
+	/* consult goto table to find next state */
+	yyn = yyR1[yyn]
+	yyg := yyPgo[yyn]
+	yyj := yyg + yyS[yyp].yys + 1
+
+	if yyj >= yyLast {
+		yystate = yyAct[yyg]
+	} else {
+		yystate = yyAct[yyj]
+		if yyChk[yystate] != -yyn {
+			yystate = yyAct[yyg]
+		}
+	}
+	// dummy call; replaced with literal code
+	switch yynt {
+
+	case 1:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line parser.go.y:43
+		{
+			yyVAL.compstmt = nil
+		}
+	case 2:
+		yyDollar = yyS[yypt-2 : yypt+1]
+		//line parser.go.y:47
+		{
+			yyVAL.compstmt = yyDollar[1].stmts
+		}
+	case 3:
+		yyDollar = yyS[yypt-2 : yypt+1]
+		//line parser.go.y:53
+		{
+			yyVAL.stmts = []ast.Stmt{yyDollar[2].stmt}
+			if l, ok := yylex.(*Lexer); ok {
+				l.stmts = yyVAL.stmts
+			}
+		}
+	case 4:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:60
+		{
+			if yyDollar[3].stmt != nil {
+				yyVAL.stmts = append(yyDollar[1].stmts, yyDollar[3].stmt)
+				if l, ok := yylex.(*Lexer); ok {
+					l.stmts = yyVAL.stmts
+				}
+			}
+		}
+	case 5:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:71
+		{
+			yyVAL.stmt = &ast.LetStmt{Lhs: yyDollar[1].expr, Operator: "=", Rhs: yyDollar[3].expr}
+		}
+	case 6:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line parser.go.y:75
+		{
+			yyVAL.stmt = &ast.ExprStmt{Expr: yyDollar[1].expr}
+		}
+	case 7:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line parser.go.y:81
+		{
+			yyVAL.expr = &ast.IdentExpr{Lit: yyDollar[1].tok.Lit}
+		}
+	case 8:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line parser.go.y:85
+		{
+			yyVAL.expr = &ast.NumberExpr{Lit: yyDollar[1].tok.Lit}
+		}
+	case 9:
+		yyDollar = yyS[yypt-2 : yypt+1]
+		//line parser.go.y:89
+		{
+			yyVAL.expr = &ast.UnaryExpr{Operator: "-", Expr: yyDollar[2].expr}
+		}
+	case 10:
+		yyDollar = yyS[yypt-2 : yypt+1]
+		//line parser.go.y:93
+		{
+			yyVAL.expr = &ast.UnaryExpr{Operator: "!", Expr: yyDollar[2].expr}
+		}
+	case 11:
+		yyDollar = yyS[yypt-2 : yypt+1]
+		//line parser.go.y:97
+		{
+			yyVAL.expr = &ast.UnaryExpr{Operator: "^", Expr: yyDollar[2].expr}
+		}
+	case 12:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line parser.go.y:101
+		{
+			yyVAL.expr = &ast.StringExpr{Lit: yyDollar[1].tok.Lit}
+		}
+	case 13:
+		yyDollar = yyS[yypt-5 : yypt+1]
+		//line parser.go.y:105
+		{
+			yyVAL.expr = &ast.TernaryOpExpr{Expr: yyDollar[1].expr, Lhs: yyDollar[3].expr, Rhs: yyDollar[5].expr}
+		}
+	case 14:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:109
+		{
+			yyVAL.expr = &ast.ParenExpr{SubExpr: yyDollar[2].expr}
+		}
+	case 15:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:113
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "+", Rhs: yyDollar[3].expr}
+		}
+	case 16:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:117
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "-", Rhs: yyDollar[3].expr}
+		}
+	case 17:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:121
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "*", Rhs: yyDollar[3].expr}
+		}
+	case 18:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:125
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "/", Rhs: yyDollar[3].expr}
+		}
+	case 19:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:129
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "%", Rhs: yyDollar[3].expr}
+		}
+	case 20:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:133
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "==", Rhs: yyDollar[3].expr}
+		}
+	case 21:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:137
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "!=", Rhs: yyDollar[3].expr}
+		}
+	case 22:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:141
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: ">", Rhs: yyDollar[3].expr}
+		}
+	case 23:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:145
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: ">=", Rhs: yyDollar[3].expr}
+		}
+	case 24:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:149
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "<", Rhs: yyDollar[3].expr}
+		}
+	case 25:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:153
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "<=", Rhs: yyDollar[3].expr}
+		}
+	case 26:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:157
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "|", Rhs: yyDollar[3].expr}
+		}
+	case 27:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:161
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "||", Rhs: yyDollar[3].expr}
+		}
+	case 28:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:165
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "&", Rhs: yyDollar[3].expr}
+		}
+	case 29:
+		yyDollar = yyS[yypt-3 : yypt+1]
+		//line parser.go.y:169
+		{
+			yyVAL.expr = &ast.BinOpExpr{Lhs: yyDollar[1].expr, Operator: "&&", Rhs: yyDollar[3].expr}
+		}
+	case 32:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line parser.go.y:179
+		{
+		}
+	case 33:
+		yyDollar = yyS[yypt-2 : yypt+1]
+		//line parser.go.y:182
+		{
+		}
+	case 34:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line parser.go.y:187
+		{
+		}
+	case 35:
+		yyDollar = yyS[yypt-1 : yypt+1]
+		//line parser.go.y:190
+		{
+		}
+	}
+	goto yystack /* stack new state and value */
+}

vendor/github.com/mattn/kinako/parser/parser.go.y

@@ -0,0 +1,195 @@
+%{
+package parser
+
+import (
+	"github.com/mattn/kinako/ast"
+)
+
+%}
+
+%type<compstmt> compstmt
+%type<stmts> stmts
+%type<stmt> stmt
+%type<expr> expr
+
+%union{
+	compstmt               []ast.Stmt
+	stmts                  []ast.Stmt
+	stmt                   ast.Stmt
+	expr                   ast.Expr
+	tok                    ast.Token
+	term                   ast.Token
+	terms                  ast.Token
+	opt_terms              ast.Token
+}
+
+%token<tok> IDENT NUMBER STRING EQEQ NEQ GE LE OROR ANDAND POW
+
+%right '='
+%right '?' ':'
+%left OROR
+%left ANDAND
+%left IDENT
+%nonassoc EQEQ NEQ ','
+%left '>' GE '<' LE SHIFTLEFT SHIFTRIGHT
+
+%left '+' '-' PLUSPLUS MINUSMINUS
+%left '*' '/' '%'
+%right UNARY
+
+%%
+
+compstmt : opt_terms
+	{
+		$$ = nil
+	}
+	| stmts opt_terms
+	{
+		$$ = $1
+	}
+
+stmts :
+	opt_terms stmt
+	{
+		$$ = []ast.Stmt{$2}
+		if l, ok := yylex.(*Lexer); ok {
+			l.stmts = $$
+		}
+	}
+	| stmts terms stmt
+	{
+		if $3 != nil {
+			$$ = append($1, $3)
+			if l, ok := yylex.(*Lexer); ok {
+				l.stmts = $$
+			}
+		}
+	}
+
+stmt :
+	expr '=' expr
+	{
+		$$ = &ast.LetStmt{Lhs: $1, Operator: "=", Rhs: $3}
+	}
+	| expr
+	{
+		$$ = &ast.ExprStmt{Expr: $1}
+	}
+
+expr :
+	IDENT
+	{
+		$$ = &ast.IdentExpr{Lit: $1.Lit}
+	}
+	| NUMBER
+	{
+		$$ = &ast.NumberExpr{Lit: $1.Lit}
+	}
+	| '-' expr %prec UNARY
+	{
+		$$ = &ast.UnaryExpr{Operator: "-", Expr: $2}
+	}
+	| '!' expr %prec UNARY
+	{
+		$$ = &ast.UnaryExpr{Operator: "!", Expr: $2}
+	}
+	| '^' expr %prec UNARY
+	{
+		$$ = &ast.UnaryExpr{Operator: "^", Expr: $2}
+	}
+	| STRING
+	{
+		$$ = &ast.StringExpr{Lit: $1.Lit}
+	}
+	| expr '?' expr ':' expr
+	{
+		$$ = &ast.TernaryOpExpr{Expr: $1, Lhs: $3, Rhs: $5}
+	}
+	| '(' expr ')'
+	{
+		$$ = &ast.ParenExpr{SubExpr: $2}
+	}
+	| expr '+' expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "+", Rhs: $3}
+	}
+	| expr '-' expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "-", Rhs: $3}
+	}
+	| expr '*' expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "*", Rhs: $3}
+	}
+	| expr '/' expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "/", Rhs: $3}
+	}
+	| expr '%' expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "%", Rhs: $3}
+	}
+	| expr EQEQ expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "==", Rhs: $3}
+	}
+	| expr NEQ expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "!=", Rhs: $3}
+	}
+	| expr '>' expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: ">", Rhs: $3}
+	}
+	| expr GE expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: ">=", Rhs: $3}
+	}
+	| expr '<' expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "<", Rhs: $3}
+	}
+	| expr LE expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "<=", Rhs: $3}
+	}
+	| expr '|' expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "|", Rhs: $3}
+	}
+	| expr OROR expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "||", Rhs: $3}
+	}
+	| expr '&' expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "&", Rhs: $3}
+	}
+	| expr ANDAND expr
+	{
+		$$ = &ast.BinOpExpr{Lhs: $1, Operator: "&&", Rhs: $3}
+	}
+
+opt_terms : /* none */
+	| terms
+	;
+
+
+terms : term
+	{
+	}
+	| terms term
+	{
+	}
+	;
+
+term : ';'
+	{
+	}
+	| '\n'
+	{
+	}
+	;
+
+%%
+

vendor/github.com/mattn/kinako/vm/env.go

@@ -0,0 +1,258 @@
+package vm
+
+import (
+	"fmt"
+	"reflect"
+	"strings"
+	"sync"
+
+	"github.com/mattn/kinako/parser"
+)
+
+// Env provides interface to run VM. This mean function scope and blocked-scope.
+// If stack goes to blocked-scope, it will make new Env.
+type Env struct {
+	name      string
+	env       map[string]reflect.Value
+	typ       map[string]reflect.Type
+	parent    *Env
+	interrupt *bool
+	sync.RWMutex
+}
+
+// NewEnv creates new global scope.
+func NewEnv() *Env {
+	b := false
+
+	return &Env{
+		env:       make(map[string]reflect.Value),
+		typ:       make(map[string]reflect.Type),
+		parent:    nil,
+		interrupt: &b,
+	}
+}
+
+// NewEnv creates new child scope.
+func (e *Env) NewEnv() *Env {
+	return &Env{
+		env:       make(map[string]reflect.Value),
+		typ:       make(map[string]reflect.Type),
+		parent:    e,
+		name:      e.name,
+		interrupt: e.interrupt,
+	}
+}
+
+func NewPackage(n string) *Env {
+	b := false
+
+	return &Env{
+		env:       make(map[string]reflect.Value),
+		typ:       make(map[string]reflect.Type),
+		parent:    nil,
+		name:      n,
+		interrupt: &b,
+	}
+}
+
+func (e *Env) NewPackage(n string) *Env {
+	return &Env{
+		env:       make(map[string]reflect.Value),
+		typ:       make(map[string]reflect.Type),
+		parent:    e,
+		name:      n,
+		interrupt: e.interrupt,
+	}
+}
+
+// Destroy deletes current scope.
+func (e *Env) Destroy() {
+	e.Lock()
+	defer e.Unlock()
+
+	if e.parent == nil {
+		return
+	}
+	for k, v := range e.parent.env {
+		if v.IsValid() && v.Interface() == e {
+			delete(e.parent.env, k)
+		}
+	}
+	e.parent = nil
+	e.env = nil
+}
+
+// NewModule creates new module scope as global.
+func (e *Env) NewModule(n string) *Env {
+	m := &Env{
+		env:    make(map[string]reflect.Value),
+		parent: e,
+		name:   n,
+	}
+	e.Define(n, m)
+	return m
+}
+
+// SetName sets a name of the scope. This means that the scope is module.
+func (e *Env) SetName(n string) {
+	e.Lock()
+	e.name = n
+	e.Unlock()
+}
+
+// GetName returns module name.
+func (e *Env) GetName() string {
+	e.RLock()
+	defer e.RUnlock()
+
+	return e.name
+}
+
+// Addr returns pointer value which specified symbol. It goes to upper scope until
+// found or returns error.
+func (e *Env) Addr(k string) (reflect.Value, error) {
+	e.RLock()
+	defer e.RUnlock()
+
+	if v, ok := e.env[k]; ok {
+		return v.Addr(), nil
+	}
+	if e.parent == nil {
+		return NilValue, fmt.Errorf("Undefined symbol '%s'", k)
+	}
+	return e.parent.Addr(k)
+}
+
+// Type returns type which specified symbol. It goes to upper scope until
+// found or returns error.
+func (e *Env) Type(k string) (reflect.Type, error) {
+	e.RLock()
+	defer e.RUnlock()
+
+	if v, ok := e.typ[k]; ok {
+		return v, nil
+	}
+	if e.parent == nil {
+		return NilType, fmt.Errorf("Undefined type '%s'", k)
+	}
+	return e.parent.Type(k)
+}
+
+// Get returns value which specified symbol. It goes to upper scope until
+// found or returns error.
+func (e *Env) Get(k string) (reflect.Value, error) {
+	e.RLock()
+	defer e.RUnlock()
+
+	if v, ok := e.env[k]; ok {
+		return v, nil
+	}
+	if e.parent == nil {
+		return NilValue, fmt.Errorf("Undefined symbol '%s'", k)
+	}
+	return e.parent.Get(k)
+}
+
+// Set modifies value which specified as symbol. It goes to upper scope until
+// found or returns error.
+func (e *Env) Set(k string, v interface{}) error {
+	e.Lock()
+	defer e.Unlock()
+
+	if _, ok := e.env[k]; ok {
+		val, ok := v.(reflect.Value)
+		if !ok {
+			val = reflect.ValueOf(v)
+		}
+		e.env[k] = val
+		return nil
+	}
+	if e.parent == nil {
+		return fmt.Errorf("Unknown symbol '%s'", k)
+	}
+	return e.parent.Set(k, v)
+}
+
+// DefineGlobal defines symbol in global scope.
+func (e *Env) DefineGlobal(k string, v interface{}) error {
+	if e.parent == nil {
+		return e.Define(k, v)
+	}
+	return e.parent.DefineGlobal(k, v)
+}
+
+// DefineType defines type which specifis symbol in global scope.
+func (e *Env) DefineType(k string, t interface{}) error {
+	if strings.Contains(k, ".") {
+		return fmt.Errorf("Unknown symbol '%s'", k)
+	}
+	global := e
+	keys := []string{k}
+
+	e.RLock()
+	for global.parent != nil {
+		if global.name != "" {
+			keys = append(keys, global.name)
+		}
+		global = global.parent
+	}
+	e.RUnlock()
+
+	for i, j := 0, len(keys)-1; i < j; i, j = i+1, j-1 {
+		keys[i], keys[j] = keys[j], keys[i]
+	}
+
+	typ, ok := t.(reflect.Type)
+	if !ok {
+		typ = reflect.TypeOf(t)
+	}
+
+	global.Lock()
+	global.typ[strings.Join(keys, ".")] = typ
+	global.Unlock()
+
+	return nil
+}
+
+// Define defines symbol in current scope.
+func (e *Env) Define(k string, v interface{}) error {
+	if strings.Contains(k, ".") {
+		return fmt.Errorf("Unknown symbol '%s'", k)
+	}
+	val, ok := v.(reflect.Value)
+	if !ok {
+		val = reflect.ValueOf(v)
+	}
+
+	e.Lock()
+	e.env[k] = val
+	e.Unlock()
+
+	return nil
+}
+
+// String return the name of current scope.
+func (e *Env) String() string {
+	e.RLock()
+	defer e.RUnlock()
+
+	return e.name
+}
+
+// Dump show symbol values in the scope.
+func (e *Env) Dump() {
+	e.RLock()
+	for k, v := range e.env {
+		fmt.Printf("%v = %#v\n", k, v)
+	}
+	e.RUnlock()
+}
+
+// Execute parses and runs source in current scope.
+func (e *Env) Execute(src string) (reflect.Value, error) {
+	stmts, err := parser.ParseSrc(src)
+	if err != nil {
+		return NilValue, err
+	}
+	return Run(stmts, e)
+}

vendor/github.com/mattn/kinako/vm/vm.go

@@ -0,0 +1,409 @@
+package vm
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"reflect"
+	"strconv"
+	"strings"
+
+	"github.com/mattn/kinako/ast"
+)
+
+var (
+	NilValue   = reflect.ValueOf((*interface{})(nil))
+	NilType    = reflect.TypeOf((*interface{})(nil))
+	TrueValue  = reflect.ValueOf(true)
+	FalseValue = reflect.ValueOf(false)
+)
+
+// Error provides a convenient interface for handling runtime error.
+// It can be Error interface with type cast which can call Pos().
+type Error struct {
+	Message string
+}
+
+var (
+	BreakError     = errors.New("Unexpected break statement")
+	ContinueError  = errors.New("Unexpected continue statement")
+	ReturnError    = errors.New("Unexpected return statement")
+	InterruptError = errors.New("Execution interrupted")
+)
+
+// Error returns the error message.
+func (e *Error) Error() string {
+	return e.Message
+}
+
+// Func is function interface to reflect functions internaly.
+type Func func(args ...reflect.Value) (reflect.Value, error)
+
+func (f Func) String() string {
+	return fmt.Sprintf("[Func: %p]", f)
+}
+
+func ToFunc(f Func) reflect.Value {
+	return reflect.ValueOf(f)
+}
+
+// Run executes statements in the specified environment.
+func Run(stmts []ast.Stmt, env *Env) (reflect.Value, error) {
+	rv := NilValue
+	var err error
+	for _, stmt := range stmts {
+		rv, err = RunSingleStmt(stmt, env)
+		if err != nil {
+			return rv, err
+		}
+	}
+	return rv, nil
+}
+
+// Interrupts the execution of any running statements in the specified environment.
+//
+// Note that the execution is not instantly aborted: after a call to Interrupt,
+// the current running statement will finish, but the next statement will not run,
+// and instead will return a NilValue and an InterruptError.
+func Interrupt(env *Env) {
+	env.Lock()
+	*(env.interrupt) = true
+	env.Unlock()
+}
+
+// RunSingleStmt executes one statement in the specified environment.
+func RunSingleStmt(stmt ast.Stmt, env *Env) (reflect.Value, error) {
+	env.Lock()
+	if *(env.interrupt) {
+		*(env.interrupt) = false
+		env.Unlock()
+
+		return NilValue, InterruptError
+	}
+	env.Unlock()
+
+	switch stmt := stmt.(type) {
+	case *ast.ExprStmt:
+		rv, err := invokeExpr(stmt.Expr, env)
+		if err != nil {
+			return rv, err
+		}
+		return rv, nil
+	case *ast.LetStmt:
+		rv := NilValue
+		var err error
+		rv, err = invokeExpr(stmt.Rhs, env)
+		if err != nil {
+			return rv, err
+		}
+		_, err = invokeLetExpr(stmt.Lhs, rv, env)
+		if err != nil {
+			return rv, err
+		}
+		return rv, nil
+	default:
+		return NilValue, errors.New("unknown statement")
+	}
+}
+
+// toString converts all reflect.Value-s into string.
+func toString(v reflect.Value) string {
+	if v.Kind() == reflect.Interface {
+		v = v.Elem()
+	}
+	if v.Kind() == reflect.String {
+		return v.String()
+	}
+	if !v.IsValid() {
+		return "nil"
+	}
+	return fmt.Sprint(v.Interface())
+}
+
+// toBool converts all reflect.Value-s into bool.
+func toBool(v reflect.Value) bool {
+	if v.Kind() == reflect.Interface {
+		v = v.Elem()
+	}
+
+	switch v.Kind() {
+	case reflect.Float32, reflect.Float64:
+		return v.Float() != 0.0
+	case reflect.Int, reflect.Int32, reflect.Int64:
+		return v.Int() != 0
+	case reflect.Bool:
+		return v.Bool()
+	case reflect.String:
+		if v.String() == "true" {
+			return true
+		}
+		if toInt64(v) != 0 {
+			return true
+		}
+	}
+	return false
+}
+
+// toFloat64 converts all reflect.Value-s into float64.
+func toFloat64(v reflect.Value) float64 {
+	if v.Kind() == reflect.Interface {
+		v = v.Elem()
+	}
+	switch v.Kind() {
+	case reflect.Float32, reflect.Float64:
+		return v.Float()
+	case reflect.Int, reflect.Int32, reflect.Int64:
+		return float64(v.Int())
+	}
+	return 0.0
+}
+
+func isNil(v reflect.Value) bool {
+	if !v.IsValid() || v.Kind().String() == "unsafe.Pointer" {
+		return true
+	}
+	if (v.Kind() == reflect.Interface || v.Kind() == reflect.Ptr) && v.IsNil() {
+		return true
+	}
+	return false
+}
+
+func isNum(v reflect.Value) bool {
+	switch v.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr, reflect.Float32, reflect.Float64:
+		return true
+	}
+	return false
+}
+
+// equal returns true when lhsV and rhsV is same value.
+func equal(lhsV, rhsV reflect.Value) bool {
+	lhsIsNil, rhsIsNil := isNil(lhsV), isNil(rhsV)
+	if lhsIsNil && rhsIsNil {
+		return true
+	}
+	if (!lhsIsNil && rhsIsNil) || (lhsIsNil && !rhsIsNil) {
+		return false
+	}
+	if lhsV.Kind() == reflect.Interface || lhsV.Kind() == reflect.Ptr {
+		lhsV = lhsV.Elem()
+	}
+	if rhsV.Kind() == reflect.Interface || rhsV.Kind() == reflect.Ptr {
+		rhsV = rhsV.Elem()
+	}
+	if !lhsV.IsValid() || !rhsV.IsValid() {
+		return true
+	}
+	if isNum(lhsV) && isNum(rhsV) {
+		if rhsV.Type().ConvertibleTo(lhsV.Type()) {
+			rhsV = rhsV.Convert(lhsV.Type())
+		}
+	}
+	if lhsV.CanInterface() && rhsV.CanInterface() {
+		return reflect.DeepEqual(lhsV.Interface(), rhsV.Interface())
+	}
+	return reflect.DeepEqual(lhsV, rhsV)
+}
+
+// toInt64 converts all reflect.Value-s into int64.
+func toInt64(v reflect.Value) int64 {
+	if v.Kind() == reflect.Interface {
+		v = v.Elem()
+	}
+	switch v.Kind() {
+	case reflect.Float32, reflect.Float64:
+		return int64(v.Float())
+	case reflect.Int, reflect.Int32, reflect.Int64:
+		return v.Int()
+	case reflect.String:
+		s := v.String()
+		var i int64
+		var err error
+		if strings.HasPrefix(s, "0x") {
+			i, err = strconv.ParseInt(s, 16, 64)
+		} else {
+			i, err = strconv.ParseInt(s, 10, 64)
+		}
+		if err == nil {
+			return int64(i)
+		}
+	}
+	return 0
+}
+
+func invokeLetExpr(expr ast.Expr, rv reflect.Value, env *Env) (reflect.Value, error) {
+	switch lhs := expr.(type) {
+	case *ast.IdentExpr:
+		if env.Set(lhs.Lit, rv) != nil {
+			if strings.Contains(lhs.Lit, ".") {
+				return NilValue, fmt.Errorf("Undefined symbol '%s'", lhs.Lit)
+			}
+			env.Define(lhs.Lit, rv)
+		}
+		return rv, nil
+	}
+	return NilValue, errors.New("Invalid operation")
+}
+
+// invokeExpr evaluates one expression.
+func invokeExpr(expr ast.Expr, env *Env) (reflect.Value, error) {
+	switch e := expr.(type) {
+	case *ast.NumberExpr:
+		if strings.Contains(e.Lit, ".") || strings.Contains(e.Lit, "e") {
+			v, err := strconv.ParseFloat(e.Lit, 64)
+			if err != nil {
+				return NilValue, err
+			}
+			return reflect.ValueOf(float64(v)), nil
+		}
+		var i int64
+		var err error
+		if strings.HasPrefix(e.Lit, "0x") {
+			i, err = strconv.ParseInt(e.Lit[2:], 16, 64)
+		} else {
+			i, err = strconv.ParseInt(e.Lit, 10, 64)
+		}
+		if err != nil {
+			return NilValue, err
+		}
+		return reflect.ValueOf(i), nil
+	case *ast.IdentExpr:
+		return env.Get(e.Lit)
+	case *ast.StringExpr:
+		return reflect.ValueOf(e.Lit), nil
+	case *ast.UnaryExpr:
+		v, err := invokeExpr(e.Expr, env)
+		if err != nil {
+			return v, err
+		}
+		switch e.Operator {
+		case "-":
+			if v.Kind() == reflect.Float64 {
+				return reflect.ValueOf(-v.Float()), nil
+			}
+			return reflect.ValueOf(-v.Int()), nil
+		case "^":
+			return reflect.ValueOf(^toInt64(v)), nil
+		case "!":
+			return reflect.ValueOf(!toBool(v)), nil
+		default:
+			return NilValue, errors.New("Unknown operator ''")
+		}
+	case *ast.ParenExpr:
+		v, err := invokeExpr(e.SubExpr, env)
+		if err != nil {
+			return v, err
+		}
+		return v, nil
+	case *ast.BinOpExpr:
+		lhsV := NilValue
+		rhsV := NilValue
+		var err error
+
+		lhsV, err = invokeExpr(e.Lhs, env)
+		if err != nil {
+			return lhsV, err
+		}
+		if lhsV.Kind() == reflect.Interface {
+			lhsV = lhsV.Elem()
+		}
+		if e.Rhs != nil {
+			rhsV, err = invokeExpr(e.Rhs, env)
+			if err != nil {
+				return rhsV, err
+			}
+			if rhsV.Kind() == reflect.Interface {
+				rhsV = rhsV.Elem()
+			}
+		}
+		switch e.Operator {
+		case "+":
+			if lhsV.Kind() == reflect.String || rhsV.Kind() == reflect.String {
+				return reflect.ValueOf(toString(lhsV) + toString(rhsV)), nil
+			}
+			if (lhsV.Kind() == reflect.Array || lhsV.Kind() == reflect.Slice) && (rhsV.Kind() != reflect.Array && rhsV.Kind() != reflect.Slice) {
+				return reflect.Append(lhsV, rhsV), nil
+			}
+			if (lhsV.Kind() == reflect.Array || lhsV.Kind() == reflect.Slice) && (rhsV.Kind() == reflect.Array || rhsV.Kind() == reflect.Slice) {
+				return reflect.AppendSlice(lhsV, rhsV), nil
+			}
+			if lhsV.Kind() == reflect.Float64 || rhsV.Kind() == reflect.Float64 {
+				return reflect.ValueOf(toFloat64(lhsV) + toFloat64(rhsV)), nil
+			}
+			return reflect.ValueOf(toInt64(lhsV) + toInt64(rhsV)), nil
+		case "-":
+			if lhsV.Kind() == reflect.Float64 || rhsV.Kind() == reflect.Float64 {
+				return reflect.ValueOf(toFloat64(lhsV) - toFloat64(rhsV)), nil
+			}
+			return reflect.ValueOf(toInt64(lhsV) - toInt64(rhsV)), nil
+		case "*":
+			if lhsV.Kind() == reflect.String && (rhsV.Kind() == reflect.Int || rhsV.Kind() == reflect.Int32 || rhsV.Kind() == reflect.Int64) {
+				return reflect.ValueOf(strings.Repeat(toString(lhsV), int(toInt64(rhsV)))), nil
+			}
+			if lhsV.Kind() == reflect.Float64 || rhsV.Kind() == reflect.Float64 {
+				return reflect.ValueOf(toFloat64(lhsV) * toFloat64(rhsV)), nil
+			}
+			return reflect.ValueOf(toInt64(lhsV) * toInt64(rhsV)), nil
+		case "/":
+			return reflect.ValueOf(toFloat64(lhsV) / toFloat64(rhsV)), nil
+		case "%":
+			return reflect.ValueOf(toInt64(lhsV) % toInt64(rhsV)), nil
+		case "==":
+			return reflect.ValueOf(equal(lhsV, rhsV)), nil
+		case "!=":
+			return reflect.ValueOf(equal(lhsV, rhsV) == false), nil
+		case ">":
+			return reflect.ValueOf(toFloat64(lhsV) > toFloat64(rhsV)), nil
+		case ">=":
+			return reflect.ValueOf(toFloat64(lhsV) >= toFloat64(rhsV)), nil
+		case "<":
+			return reflect.ValueOf(toFloat64(lhsV) < toFloat64(rhsV)), nil
+		case "<=":
+			return reflect.ValueOf(toFloat64(lhsV) <= toFloat64(rhsV)), nil
+		case "|":
+			return reflect.ValueOf(toInt64(lhsV) | toInt64(rhsV)), nil
+		case "||":
+			if toBool(lhsV) {
+				return lhsV, nil
+			}
+			return rhsV, nil
+		case "&":
+			return reflect.ValueOf(toInt64(lhsV) & toInt64(rhsV)), nil
+		case "&&":
+			if toBool(lhsV) {
+				return rhsV, nil
+			}
+			return lhsV, nil
+		case "**":
+			if lhsV.Kind() == reflect.Float64 {
+				return reflect.ValueOf(math.Pow(toFloat64(lhsV), toFloat64(rhsV))), nil
+			}
+			return reflect.ValueOf(int64(math.Pow(toFloat64(lhsV), toFloat64(rhsV)))), nil
+		case ">>":
+			return reflect.ValueOf(toInt64(lhsV) >> uint64(toInt64(rhsV))), nil
+		case "<<":
+			return reflect.ValueOf(toInt64(lhsV) << uint64(toInt64(rhsV))), nil
+		default:
+			return NilValue, errors.New("Unknown operator")
+		}
+	case *ast.TernaryOpExpr:
+		rv, err := invokeExpr(e.Expr, env)
+		if err != nil {
+			return rv, err
+		}
+		if toBool(rv) {
+			lhsV, err := invokeExpr(e.Lhs, env)
+			if err != nil {
+				return lhsV, err
+			}
+			return lhsV, nil
+		}
+		rhsV, err := invokeExpr(e.Rhs, env)
+		if err != nil {
+			return rhsV, err
+		}
+		return rhsV, nil
+	default:
+		return NilValue, errors.New("Unknown expression")
+	}
+}