Plural-Forms formula support. Headers parsing. Multiline strings support.

.travis.yml

@@ -0,0 +1,9 @@
+language: go
+script: go test -v -race ./...
+
+go:
+  - 1.3
+  - 1.4
+  - 1.5
+  - 1.6
+  - tip

README.md

@@ -4,16 +4,17 @@
 
 [GNU gettext utilities](https://www.gnu.org/software/gettext) for Go. 
 
-Version: [v1.0.1](https://github.com/leonelquinteros/gotext/releases/tag/v1.0.1)
+Version: [v1.1.0](https://github.com/leonelquinteros/gotext/releases/tag/v1.1.0)
 
 
 # Features
 
 - Implements GNU gettext support in native Go.
-- Complete support for [PO files](https://www.gnu.org/software/gettext/manual/html_node/PO-Files.html).
+- Complete support for [PO files](https://www.gnu.org/software/gettext/manual/html_node/PO-Files.html) including:
-- Support for [pluralization rules](https://www.gnu.org/software/gettext/manual/html_node/Plural-forms.html).
+  - Support for multiline strings and headers.
-- Support for [message context](https://www.gnu.org/software/gettext/manual/html_node/Contexts.html).
+  - Support for variables inside translation strings using Go's [fmt syntax](https://golang.org/pkg/fmt/).
-- Support for variables inside translation strings using Go's [fmt package syntax](https://golang.org/pkg/fmt/).
+  - Support for [pluralization rules](https://www.gnu.org/software/gettext/manual/html_node/Translating-plural-forms.html).
+  - Support for [message contexts](https://www.gnu.org/software/gettext/manual/html_node/Contexts.html).
 - Thread-safe: This package is safe for concurrent use across multiple goroutines. 
 - It works with UTF-8 encoding as it's the default for Go language.
 - Unit tests available.
@@ -256,6 +257,10 @@ msgstr "This one sets the var: %s"
 ## Use plural forms of translations
 
 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)
 
 ```go
 import "github.com/leonelquinteros/gotext"
@@ -263,6 +268,12 @@ import "github.com/leonelquinteros/gotext"
 func main() {
     // Set PO content
     str := `
+msgid ""
+msgstr ""
+
+# Header below
+"Plural-Forms: nplurals=2; plural=(n != 1);\n"
+
 msgid "Translate this"
 msgstr "Translated text"
 
@@ -273,15 +284,14 @@ 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"
 `
     
     // Create Po object
     po := new(Po)
     po.Parse(str)
     
-    println(po.GetN("One with var: %s", "Several with vars: %s", 2, v))
+    println(po.GetN("One with var: %s", "Several with vars: %s", 54, v))
-    // "And this is the second plural form: Variable"
+    // "This one is the plural: Variable"
 }
 ```
 

gotext.go

@@ -100,8 +100,7 @@ func Get(str string, vars ...interface{}) string {
 	return GetD(domain, str, vars...)
 }
 
-// GetN retrieves the (N)th plural form translation for the given string in the "default" domain.
+// GetN retrieves the (N)th plural form of translation for the given string in the "default" domain.
-// If n == 0, usually the singular form of the string is returned as defined in the PO file.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func GetN(str, plural string, n int, vars ...interface{}) string {
 	return GetND("default", str, plural, n, vars...)
@@ -110,10 +109,10 @@ func GetN(str, plural string, n int, vars ...interface{}) string {
 // GetD returns the corresponding translation in the given domain for a given string.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func GetD(dom, str string, vars ...interface{}) string {
-	return GetND(dom, str, str, 0, vars...)
+	return GetND(dom, str, str, 1, vars...)
 }
 
-// GetND retrieves the (N)th plural form translation in the given domain for a given string.
+// GetND retrieves the (N)th plural form of translation in the given domain for a given string.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func GetND(dom, str, plural string, n int, vars ...interface{}) string {
 	// Try to load default package Locale storage
@@ -129,8 +128,7 @@ func GetC(str, ctx string, vars ...interface{}) string {
 	return GetDC(domain, str, ctx, vars...)
 }
 
-// GetNC retrieves the (N)th plural form translation for the given string in the given context in the "default" domain.
+// GetNC retrieves the (N)th plural form of translation for the given string in the given context in the "default" domain.
-// If n == 0, usually the singular form of the string is returned as defined in the PO file.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func GetNC(str, plural string, n int, ctx string, vars ...interface{}) string {
 	return GetNDC("default", str, plural, n, ctx, vars...)
@@ -139,10 +137,10 @@ func GetNC(str, plural string, n int, ctx string, vars ...interface{}) string {
 // GetDC returns the corresponding translation in the given domain for the given string in the given context.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func GetDC(dom, str, ctx string, vars ...interface{}) string {
-	return GetNDC(dom, str, str, 0, ctx, vars...)
+	return GetNDC(dom, str, str, 1, ctx, vars...)
 }
 
-// GetNDC retrieves the (N)th plural form translation in the given domain for a given string.
+// GetNDC retrieves the (N)th plural form of translation in the given domain for a given string.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func GetNDC(dom, str, plural string, n int, ctx string, vars ...interface{}) string {
 	// Try to load default package Locale storage

gotext_test.go

@@ -31,7 +31,17 @@ func TestGettersSetters(t *testing.T) {
 
 func TestPackageFunctions(t *testing.T) {
 	// Set PO content
-	str := `# Some comment
+	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"
 
@@ -109,8 +119,8 @@ msgstr "More translation"
 
 	// Test plural
 	tr = GetN("One with var: %s", "Several with vars: %s", 2, v)
-	if tr != "And this is the second plural form: Variable" {
+	if tr != "This one is the plural: Variable" {
-		t.Errorf("Expected 'And this is the second plural form: Variable' but got '%s'", tr)
+		t.Errorf("Expected 'This one is the plural: Variable' but got '%s'", tr)
 	}
 
 	// Test context translations
@@ -125,7 +135,7 @@ msgstr "More translation"
 		t.Errorf("Expected 'This one is the singular in a Ctx context: Variable' but got '%s'", tr)
 	}
 
-	tr = GetNC("One with var: %s", "Several with vars: %s", 1, "Ctx", v)
+	tr = GetNC("One with var: %s", "Several with vars: %s", 19, "Ctx", v)
 	if tr != "This one is the plural in a Ctx context: Variable" {
 		t.Errorf("Expected 'This one is the plural in a Ctx context: Variable' but got '%s'", tr)
 	}

locale.go

@@ -107,8 +107,7 @@ func (l *Locale) Get(str string, vars ...interface{}) string {
 	return l.GetD("default", str, vars...)
 }
 
-// GetN retrieves the (N)th plural form translation for the given string in the "default" domain.
+// GetN retrieves the (N)th plural form of translation for the given string in the "default" domain.
-// If n == 0, usually the singular form of the string is returned as defined in the PO file.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (l *Locale) GetN(str, plural string, n int, vars ...interface{}) string {
 	return l.GetND("default", str, plural, n, vars...)
@@ -117,11 +116,10 @@ func (l *Locale) GetN(str, plural string, n int, vars ...interface{}) string {
 // GetD returns the corresponding translation in the given domain for the given string.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (l *Locale) GetD(dom, str string, vars ...interface{}) string {
-	return l.GetND(dom, str, str, 0, vars...)
+	return l.GetND(dom, str, str, 1, vars...)
 }
 
-// GetND retrieves the (N)th plural form translation in the given domain for the given string.
+// GetND retrieves the (N)th plural form of translation in the given domain for the given string.
-// If n == 0, usually the singular form of the string is returned as defined in the PO file.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (l *Locale) GetND(dom, str, plural string, n int, vars ...interface{}) string {
 	// Sync read
@@ -146,8 +144,7 @@ func (l *Locale) GetC(str, ctx string, vars ...interface{}) string {
 	return l.GetDC("default", str, ctx, vars...)
 }
 
-// GetNC retrieves the (N)th plural form translation for the given string in the given context in the "default" domain.
+// GetNC retrieves the (N)th plural form of translation for the given string in the given context in the "default" domain.
-// If n == 0, usually the singular form of the string is returned as defined in the PO file.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (l *Locale) GetNC(str, plural string, n int, ctx string, vars ...interface{}) string {
 	return l.GetNDC("default", str, plural, n, ctx, vars...)
@@ -156,11 +153,10 @@ func (l *Locale) GetNC(str, plural string, n int, ctx string, vars ...interface{
 // GetDC returns the corresponding translation in the given domain for the given string in the given context.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (l *Locale) GetDC(dom, str, ctx string, vars ...interface{}) string {
-	return l.GetNDC(dom, str, str, 0, ctx, vars...)
+	return l.GetNDC(dom, str, str, 1, ctx, vars...)
 }
 
-// GetNDC retrieves the (N)th plural form translation in the given domain for the given string in the given context.
+// GetNDC retrieves the (N)th plural form of translation in the given domain for the given string in the given context.
-// If n == 0, usually the singular form of the string is returned as defined in the PO file.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (l *Locale) GetNDC(dom, str, plural string, n int, ctx string, vars ...interface{}) string {
 	// Sync read

locale_test.go

@@ -8,7 +8,17 @@ import (
 
 func TestLocale(t *testing.T) {
 	// Set PO content
-	str := `# Some comment
+	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"
 
@@ -91,9 +101,9 @@ msgstr "More translation"
 	}
 
 	// Test plural
-	tr = l.GetND("my_domain", "One with var: %s", "Several with vars: %s", 2, v)
+	tr = l.GetND("my_domain", "One with var: %s", "Several with vars: %s", 7, v)
-	if tr != "And this is the second plural form: Variable" {
+	if tr != "This one is the plural: Variable" {
-		t.Errorf("Expected 'And this is the second plural form: Variable' but got '%s'", tr)
+		t.Errorf("Expected 'This one is the plural: Variable' but got '%s'", tr)
 	}
 
 	// Test non-existent "deafult" domain responses
@@ -137,7 +147,7 @@ msgstr "More translation"
 	}
 
 	// Test plural
-	tr = l.GetNDC("my_domain", "One with var: %s", "Several with vars: %s", 1, "Ctx", v)
+	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)
 	}

po.go

@@ -1,8 +1,11 @@
 package gotext
 
 import (
+	"bufio"
 	"fmt"
+	"github.com/mattn/anko/vm"
 	"io/ioutil"
+	"net/textproto"
 	"os"
 	"strconv"
 	"strings"
@@ -44,8 +47,8 @@ func (t *translation) getN(n int) string {
 
 /*
 Po parses the content of any PO file and provides all the translation functions needed.
-It's the base object used by all packafe methods.
+It's the base object used by all package methods.
-And it's safe for concurrent use by multiple goroutines by using the sync package for write locking.
+And it's safe for concurrent use by multiple goroutines by using the sync package for locking.
 
 Example:
 
@@ -64,6 +67,19 @@ Example:
 
 */
 type Po struct {
+	// Headers
+	RawHeaders string
+
+	// Language header
+	Language string
+
+	// Plural-Forms header
+	PluralForms string
+
+	// Parsed Plural-Forms header values
+	nplurals int
+	plural   string
+
 	// Storage
 	translations map[string]*translation
 	contexts     map[string]map[string]*translation
@@ -123,7 +139,7 @@ func (po *Po) Parse(str string) {
 		}
 
 		// Skip invalid lines
-		if !strings.HasPrefix(l, "msgctxt") && !strings.HasPrefix(l, "msgid") && !strings.HasPrefix(l, "msgid_plural") && !strings.HasPrefix(l, "msgstr") {
+		if !strings.HasPrefix(l, "\"") && !strings.HasPrefix(l, "msgctxt") && !strings.HasPrefix(l, "msgid") && !strings.HasPrefix(l, "msgid_plural") && !strings.HasPrefix(l, "msgstr") {
 			continue
 		}
 
@@ -198,21 +214,21 @@ func (po *Po) Parse(str string) {
 
 			// Check for indexed translation forms
 			if strings.HasPrefix(l, "[") {
-				in := strings.Index(l, "]")
+				idx := strings.Index(l, "]")
-				if in == -1 {
+				if idx == -1 {
 					// Skip wrong index formatting
 					continue
 				}
 
 				// Parse index
-				i, err := strconv.Atoi(l[1:in])
+				i, err := strconv.Atoi(l[1:idx])
 				if err != nil {
 					// Skip wrong index formatting
 					continue
 				}
 
 				// Parse translation string
-				tr.trs[i], _ = strconv.Unquote(strings.TrimSpace(l[in+1:]))
+				tr.trs[i], _ = strconv.Unquote(strings.TrimSpace(l[idx+1:]))
 
 				// Loop
 				continue
@@ -220,6 +236,31 @@ func (po *Po) Parse(str string) {
 
 			// Save single translation form under 0 index
 			tr.trs[0], _ = strconv.Unquote(l)
+
+			// Loop
+			continue
+		}
+
+		// Multi line strings and headers
+		if strings.HasPrefix(l, "\"") && strings.HasSuffix(l, "\"") {
+			// Check for multiline from previously set msgid
+			if tr.id != "" {
+				// Append to last translation found
+				uq, _ := strconv.Unquote(l)
+				tr.trs[len(tr.trs)-1] += uq
+
+				// Loop
+				continue
+			}
+
+			// Otherwise is a header
+			h, err := strconv.Unquote(strings.TrimSpace(l))
+			if err != nil {
+				continue
+			}
+
+			po.RawHeaders += h
+			continue
 		}
 	}
 
@@ -237,6 +278,79 @@ func (po *Po) Parse(str string) {
 		}
 		po.Unlock()
 	}
+
+	// Parse headers
+	po.RawHeaders += "\n\n"
+	reader := bufio.NewReader(strings.NewReader(po.RawHeaders))
+	tp := textproto.NewReader(reader)
+
+	mimeHeader, err := tp.ReadMIMEHeader()
+	if err != nil {
+		return
+	}
+
+	// Get/save needed headers
+	po.Language = mimeHeader.Get("Language")
+	po.PluralForms = mimeHeader.Get("Plural-Forms")
+
+	// Parse Plural-Forms formula
+	if po.PluralForms == "" {
+		return
+	}
+
+	// Split plural form header value
+	pfs := strings.Split(po.PluralForms, ";")
+
+	// Parse values
+	for _, i := range pfs {
+		vs := strings.SplitN(i, "=", 2)
+		if len(vs) != 2 {
+			continue
+		}
+
+		switch strings.TrimSpace(vs[0]) {
+		case "nplurals":
+			po.nplurals, _ = strconv.Atoi(vs[1])
+
+		case "plural":
+			po.plural = vs[1]
+		}
+	}
+}
+
+// pluralForm calculates the plural form index corresponding to n.
+// Returns 0 on error
+func (po *Po) pluralForm(n int) int {
+	// Failsafe
+	if po.nplurals < 1 {
+		return 0
+	}
+	if po.plural == "" {
+		return 0
+	}
+
+	// Init compiler
+	var env = vm.NewEnv()
+	env.Define("n", n)
+
+	// Run script
+	plural, err := env.Execute(po.plural)
+	if err != nil {
+		return 0
+	}
+	if plural.Type().Name() == "bool" {
+		if plural.Bool() {
+			return 1
+		} else {
+			return 0
+		}
+	}
+
+	if int(plural.Int()) > po.nplurals {
+		return 0
+	}
+
+	return int(plural.Int())
 }
 
 // Get retrieves the corresponding translation for the given string.
@@ -256,8 +370,7 @@ func (po *Po) Get(str string, vars ...interface{}) string {
 	return fmt.Sprintf(str, vars...)
 }
 
-// GetN retrieves the (N)th plural form translation for the given string.
+// GetN retrieves the (N)th plural form of translation for the given string.
-// If n == 0, usually the singular form of the string is returned as defined in the PO file.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (po *Po) GetN(str, plural string, n int, vars ...interface{}) string {
 	// Sync read
@@ -266,7 +379,7 @@ func (po *Po) GetN(str, plural string, n int, vars ...interface{}) string {
 
 	if po.translations != nil {
 		if _, ok := po.translations[str]; ok {
-			return fmt.Sprintf(po.translations[str].getN(n), vars...)
+			return fmt.Sprintf(po.translations[str].getN(po.pluralForm(n)), vars...)
 		}
 	}
 
@@ -295,8 +408,7 @@ func (po *Po) GetC(str, ctx string, vars ...interface{}) string {
 	return fmt.Sprintf(str, vars...)
 }
 
-// GetNC retrieves the (N)th plural form translation for the given string in the given context.
+// GetNC retrieves the (N)th plural form of translation for the given string in the given context.
-// If n == 0, usually the singular form of the string is returned as defined in the PO file.
 // Supports optional parameters (vars... interface{}) to be inserted on the formatted string using the fmt.Printf syntax.
 func (po *Po) GetNC(str, plural string, n int, ctx string, vars ...interface{}) string {
 	// Sync read
@@ -307,7 +419,7 @@ func (po *Po) GetNC(str, plural string, n int, ctx string, vars ...interface{})
 		if _, ok := po.contexts[ctx]; ok {
 			if po.contexts[ctx] != nil {
 				if _, ok := po.contexts[ctx][str]; ok {
-					return fmt.Sprintf(po.contexts[ctx][str].getN(n), vars...)
+					return fmt.Sprintf(po.contexts[ctx][str].getN(po.pluralForm(n)), vars...)
 				}
 			}
 		}

po_test.go

@@ -8,7 +8,17 @@ import (
 
 func TestPo(t *testing.T) {
 	// Set PO content
-	str := `# Some comment
+	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"
 
@@ -16,6 +26,11 @@ msgstr "Translated text"
 msgid "Another string"
 msgstr ""
 
+#Multi-line string
+msgid "Multi-line"
+msgstr "Multi "
+"line"
+
 msgid "One with var: %s"
 msgid_plural "Several with vars: %s"
 msgstr[0] "This one is the singular: %s"
@@ -82,10 +97,16 @@ msgstr "More translation"
 		t.Errorf("Expected 'This one is the singular: Variable' but got '%s'", tr)
 	}
 
+	// Test multi-line
+	tr = po.Get("Multi-line")
+	if tr != "Multi line" {
+		t.Errorf("Expected 'Multi line' but got '%s'", tr)
+	}
+
 	// Test plural
 	tr = po.GetN("One with var: %s", "Several with vars: %s", 2, v)
-	if tr != "And this is the second plural form: Variable" {
+	if tr != "This one is the plural: Variable" {
-		t.Errorf("Expected 'And this is the second plural form: Variable' but got '%s'", tr)
+		t.Errorf("Expected 'This one is the plural: Variable' but got '%s'", tr)
 	}
 
 	// Test inexistent translations
@@ -94,7 +115,7 @@ msgstr "More translation"
 		t.Errorf("Expected 'This is a test' but got '%s'", tr)
 	}
 
-	tr = po.GetN("This is a test", "This are tests", 1)
+	tr = po.GetN("This is a test", "This are tests", 100)
 	if tr != "This are tests" {
 		t.Errorf("Expected 'This are tests' but got '%s'", tr)
 	}
@@ -105,7 +126,7 @@ msgstr "More translation"
 		t.Errorf("Expected '' but got '%s'", tr)
 	}
 
-	tr = po.GetN("This one has invalid syntax translations", "This are tests", 1)
+	tr = po.GetN("This one has invalid syntax translations", "This are tests", 4)
 	if tr != "Plural index" {
 		t.Errorf("Expected 'Plural index' but got '%s'", tr)
 	}
@@ -118,7 +139,7 @@ msgstr "More translation"
 	}
 
 	// Test plural
-	tr = po.GetNC("One with var: %s", "Several with vars: %s", 1, "Ctx", v)
+	tr = po.GetNC("One with var: %s", "Several with vars: %s", 17, "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)
 	}
@@ -131,6 +152,210 @@ msgstr "More translation"
 
 }
 
+func TestPoHeaders(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 "Example"
+msgstr "Translated example"
+    `
+
+	// Create po object
+	po := new(Po)
+
+	// Parse
+	po.Parse(str)
+
+	// Check headers expected
+	if po.Language != "en" {
+		t.Errorf("Expected 'Language: en' but got '%s'", po.Language)
+	}
+
+	// Check headers expected
+	if po.PluralForms != "nplurals=2; plural=(n != 1);" {
+		t.Errorf("Expected 'Plural-Forms: nplurals=2; plural=(n != 1);' but got '%s'", po.PluralForms)
+	}
+}
+
+func TestPluralForms(t *testing.T) {
+	// Single form
+	str := `
+"Plural-Forms: nplurals=1; plural=0;"
+
+# Some comment
+msgid "Singular"
+msgid_plural "Plural"
+msgstr[0] "Singular form"
+msgstr[1] "Plural form 1"
+msgstr[2] "Plural form 2"
+msgstr[3] "Plural form 3"
+    `
+
+	// Create po object
+	po := new(Po)
+
+	// Parse
+	po.Parse(str)
+
+	// Check plural form
+	n := po.pluralForm(0)
+	if n != 0 {
+		t.Errorf("Expected 0 for pluralForm(0), got %d", n)
+	}
+	n = po.pluralForm(1)
+	if n != 0 {
+		t.Errorf("Expected 0 for pluralForm(1), got %d", n)
+	}
+	n = po.pluralForm(2)
+	if n != 0 {
+		t.Errorf("Expected 0 for pluralForm(2), got %d", n)
+	}
+	n = po.pluralForm(3)
+	if n != 0 {
+		t.Errorf("Expected 0 for pluralForm(3), got %d", n)
+	}
+	n = po.pluralForm(50)
+	if n != 0 {
+		t.Errorf("Expected 0 for pluralForm(50), got %d", n)
+	}
+
+	// ------------------------------------------------------------------------
+	// 2 forms
+	str = `
+"Plural-Forms: nplurals=2; plural=n != 1;"
+
+# Some comment
+msgid "Singular"
+msgid_plural "Plural"
+msgstr[0] "Singular form"
+msgstr[1] "Plural form 1"
+msgstr[2] "Plural form 2"
+msgstr[3] "Plural form 3"
+    `
+
+	// Create po object
+	po = new(Po)
+
+	// Parse
+	po.Parse(str)
+
+	// Check plural form
+	n = po.pluralForm(0)
+	if n != 1 {
+		t.Errorf("Expected 1 for pluralForm(0), got %d", n)
+	}
+	n = po.pluralForm(1)
+	if n != 0 {
+		t.Errorf("Expected 0 for pluralForm(1), got %d", n)
+	}
+	n = po.pluralForm(2)
+	if n != 1 {
+		t.Errorf("Expected 1 for pluralForm(2), got %d", n)
+	}
+	n = po.pluralForm(3)
+	if n != 1 {
+		t.Errorf("Expected 1 for pluralForm(3), got %d", n)
+	}
+
+	// ------------------------------------------------------------------------
+	// 3 forms
+	str = `
+"Plural-Forms: nplurals=3; plural=n%10==1 && n%100!=11 ? 0 : n != 0 ? 1 : 2;"
+
+# Some comment
+msgid "Singular"
+msgid_plural "Plural"
+msgstr[0] "Singular form"
+msgstr[1] "Plural form 1"
+msgstr[2] "Plural form 2"
+msgstr[3] "Plural form 3"
+    `
+
+	// Create po object
+	po = new(Po)
+
+	// Parse
+	po.Parse(str)
+
+	// Check plural form
+	n = po.pluralForm(0)
+	if n != 2 {
+		t.Errorf("Expected 2 for pluralForm(0), got %d", n)
+	}
+	n = po.pluralForm(1)
+	if n != 0 {
+		t.Errorf("Expected 0 for pluralForm(1), got %d", n)
+	}
+	n = po.pluralForm(2)
+	if n != 1 {
+		t.Errorf("Expected 1 for pluralForm(2), got %d", n)
+	}
+	n = po.pluralForm(3)
+	if n != 1 {
+		t.Errorf("Expected 1 for pluralForm(3), got %d", n)
+	}
+	n = po.pluralForm(100)
+	if n != 1 {
+		t.Errorf("Expected 1 for pluralForm(100), got %d", n)
+	}
+	n = po.pluralForm(49)
+	if n != 1 {
+		t.Errorf("Expected 1 for pluralForm(3), got %d", n)
+	}
+
+	// ------------------------------------------------------------------------
+	// 3 forms special
+	str = `
+"Plural-Forms: nplurals=3;"
+"plural=(n==1) ? 0 : (n>=2 && n<=4) ? 1 : 2;"
+
+# Some comment
+msgid "Singular"
+msgid_plural "Plural"
+msgstr[0] "Singular form"
+msgstr[1] "Plural form 1"
+msgstr[2] "Plural form 2"
+msgstr[3] "Plural form 3"
+    `
+
+	// Create po object
+	po = new(Po)
+
+	// Parse
+	po.Parse(str)
+
+	// Check plural form
+	n = po.pluralForm(1)
+	if n != 0 {
+		t.Errorf("Expected 0 for pluralForm(1), got %d", n)
+	}
+	n = po.pluralForm(2)
+	if n != 1 {
+		t.Errorf("Expected 1 for pluralForm(2), got %d", n)
+	}
+	n = po.pluralForm(4)
+	if n != 1 {
+		t.Errorf("Expected 4 for pluralForm(4), got %d", n)
+	}
+	n = po.pluralForm(0)
+	if n != 2 {
+		t.Errorf("Expected 2 for pluralForm(2), got %d", n)
+	}
+	n = po.pluralForm(1000)
+	if n != 2 {
+		t.Errorf("Expected 2 for pluralForm(1000), got %d", n)
+	}
+}
+
 func TestTranslationObject(t *testing.T) {
 	tr := newTranslation()
 	str := tr.get()