Add public package version parsing API

* BPackageVersion: Add respective constructor and SetTo().
* BPackageInfo: Add static ParseVersionString() utility method. It's
  only there because the parser lives in the BPackageInfo
  implementation.

headers/os/package/PackageInfo.h

@@ -141,6 +141,12 @@ public:
 	static	status_t			GetArchitectureByName(const BString& name,
 									BPackageArchitecture& _architecture);
 
+	static	status_t			ParseVersionString(const BString& string,
+									bool releaseIsOptional,
+									BPackageVersion& _version,
+									ParseErrorListener* listener = NULL);
+
+public:
 	static	const char*			kElementNames[];
 	static	const char*			kArchitectureNames[];
 

headers/os/package/PackageVersion.h

@@ -23,6 +23,8 @@ public:
 								BPackageVersion();
 								BPackageVersion(
 									const BPackageVersionData& data);
+								BPackageVersion(const BString& versionString,
+									bool releaseIsOptional = true);
 								BPackageVersion(const BString& major,
 									const BString& minor, const BString& micro,
 									const BString& preRelease, uint8 release);
@@ -41,6 +43,8 @@ public:
 			void				SetTo(const BString& major,
 									const BString& minor, const BString& micro,
 									const BString& preRelease, uint8 release);
+			status_t			SetTo(const BString& versionString,
+									bool releaseIsOptional = true);
 			void				Clear();
 
 			int					Compare(const BPackageVersion& other) const;

src/kits/package/PackageInfo.cpp

@@ -68,6 +68,10 @@ public:
 			status_t			Parse(const BString& packageInfoString,
 									BPackageInfo* packageInfo);
 
+			status_t			ParseVersion(const BString& versionString,
+									bool releaseIsOptional,
+									BPackageVersion& _version);
+
 private:
 			struct Token;
 			struct ListElementParser;
@@ -82,6 +86,9 @@ private:
 									BPackageArchitecture* value);
 			void				_ParseVersionValue(BPackageVersion* value,
 									bool releaseIsOptional);
+	static	void				_ParseVersionValue(Token& word,
+									BPackageVersion* value,
+									bool releaseIsOptional);
 			void				_ParseList(ListElementParser& elementParser,
 									bool allowSingleNonListElement);
 			void				_ParseStringList(BStringList* value,
@@ -206,6 +213,31 @@ BPackageInfo::Parser::Parse(const BString& packageInfoString,
 }
 
 
+status_t
+BPackageInfo::Parser::ParseVersion(const BString& versionString,
+	bool releaseIsOptional, BPackageVersion& _version)
+{
+	fPos = versionString.String();
+
+	try {
+		Token token(TOKEN_WORD, fPos, versionString.Length());
+		_ParseVersionValue(token, &_version, releaseIsOptional);
+	} catch (const ParseError& error) {
+		if (fListener != NULL) {
+			int32 offset = error.pos - versionString.String();
+			fListener->OnError(error.message, 1, offset);
+		}
+		return B_BAD_DATA;
+	} catch (const std::bad_alloc& e) {
+		if (fListener != NULL)
+			fListener->OnError("out of memory", 0, 0);
+		return B_NO_MEMORY;
+	}
+
+	return B_OK;
+}
+
+
 BPackageInfo::Parser::Token
 BPackageInfo::Parser::_NextToken()
 {
@@ -360,6 +392,14 @@ BPackageInfo::Parser::_ParseVersionValue(BPackageVersion* value,
 	bool releaseIsOptional)
 {
 	Token word = _NextToken();
+	_ParseVersionValue(word, value, releaseIsOptional);
+}
+
+
+/*static*/ void
+BPackageInfo::Parser::_ParseVersionValue(Token& word, BPackageVersion* value,
+	bool releaseIsOptional)
+{
 	if (word.type != TOKEN_WORD)
 		throw ParseError("expected word (a version)", word.pos);
 
@@ -1365,4 +1405,13 @@ BPackageInfo::GetArchitectureByName(const BString& name,
 	return B_NAME_NOT_FOUND;
 }
 
+
+/*static*/ status_t
+BPackageInfo::ParseVersionString(const BString& string, bool releaseIsOptional,
+	BPackageVersion& _version, ParseErrorListener* listener)
+{
+	return Parser(listener).ParseVersion(string, releaseIsOptional, _version);
+}
+
+
 }	// namespace BPackageKit

src/kits/package/PackageVersion.cpp

@@ -8,6 +8,7 @@
 
 #include <NaturalCompare.h>
 
+#include <package/PackageInfo.h>
 #include <package/hpkg/PackageInfoAttributeValue.h>
 
 
@@ -30,6 +31,13 @@ BPackageVersion::BPackageVersion(const BPackageVersionData& data)
 }
 
 
+BPackageVersion::BPackageVersion(const BString& versionString,
+	bool releaseIsOptional)
+{
+	SetTo(versionString, releaseIsOptional);
+}
+
+
 BPackageVersion::BPackageVersion(const BString& major, const BString& minor,
 	const BString& micro, const BString& preRelease, uint8 release)
 {
@@ -151,6 +159,15 @@ BPackageVersion::SetTo(const BString& major, const BString& minor,
 }
 
 
+status_t
+BPackageVersion::SetTo(const BString& versionString, bool releaseIsOptional)
+{
+	Clear();
+	return BPackageInfo::ParseVersionString(versionString, releaseIsOptional,
+		*this);
+}
+
+
 void
 BPackageVersion::Clear()
 {