range ';' RANGE_MASK ( ';' VERSION )

The range macro takes a version range mask/template and uses it calculate a range from a given version. The primary reason for the ${range} macro is to be used in the version policy. With the version policy we have a version of an exported package and we need to calculate the range for that. The rules come from the consumer or provider policy. However, this policy can be overridden on the Import-Package header by specifying the version as a range macro:

Import-Package: com.example.myownpolicy; version="${range;[==,=+)}", *

<foo ]>

Since the version for the exported package is set as ${@}, the macro will calculate the proper semantic range for a provider.

The syntax for the range macro is:

range ::= ( '\[' |'\( ) mask ',' mask ( '\)' | '\]' )
mask  ::= m ( m ( m )? )? q
m     ::= [0-9=+-~]
q     ::= [0-9=~Ss]

The meaning of the characters is:

= – Keep the version part
- – Decrement the version part
+ – Increment the version part
[0-9] – Replace the version part
~ – Ignore the version part
[Ss] – If the qualifier equals SNAPSHOT, then it will return a maven like snapshot version. Maven snapshot versions do not use the . as the separator but a - sign. The upper case S checks case sensitive, the lower case s is case insensitive. This template character will be treated as the last character in the template and return the version immediately. For example, ${versionmask;=S;1.2.3.SNAPSHOT} will return 1-SNAPSHOT.

/**
 * Schortcut for version policy
 * 
 * <pre>
 * -provide-policy : ${policy;[==,=+)}
 * -consume-policy : ${policy;[==,+)}
 * </pre>
 * 
 * @param args
 * @return
 */

static Pattern	RANGE_MASK		= Pattern.compile("(\\[|\\()(" + MASK_STRING + "),(" + MASK_STRING + ")(\\]|\\))");
static String	_rangeHelp		= "${range;<mask>[;<version>]}, range for version, if version not specified lookup ${@}\n"
										+ "<mask> ::= [ M [ M [ M [ MQ ]]]\n"
										+ "M ::= '+' | '-' | MQ\n"
										+ "MQ ::= '~' | '='";
static Pattern	_rangePattern[]	= new Pattern[] {
		null, RANGE_MASK
								};

public String _range(String args[]) {
	verifyCommand(args, _rangeHelp, _rangePattern, 2, 3);
	Version version = null;
	if (args.length >= 3)
		version = new Version(args[2]);
	else {
		String v = domain.getProperty("@");
		if (v == null)
			return null;
		version = new Version(v);
	}
	String spec = args[1];

	Matcher m = RANGE_MASK.matcher(spec);
	m.matches();
	String floor = m.group(1);
	String floorMask = m.group(2);
	String ceilingMask = m.group(3);
	String ceiling = m.group(4);

	String left = version(version, floorMask);
	String right = version(version, ceilingMask);
	StringBuilder sb = new StringBuilder();
	sb.append(floor);
	sb.append(left);
	sb.append(",");
	sb.append(right);
	sb.append(ceiling);

	String s = sb.toString();
	VersionRange vr = new VersionRange(s);
	if (!(vr.includes(vr.getHigh()) || vr.includes(vr.getLow()))) {
		domain.error("${range} macro created an invalid range %s from %s and mask %s", s, version, spec);
	}
	return sb.toString();
}