/**
* tests whether <code>this</code> matches a prefix of <code>s</code> starting at position <code>
* pos</code>.
*
* @return the length of the match or -1.
*/
public int atStartOf(CharSequence s, int pos) {
analyzed = false;
in.setSource(s, pos);
out.setLength(0);
try {
a = dfa.match(in, out, smd);
} catch (java.io.IOException e) {
throw new Error("impossible", e);
}
return (a != null && a != DfaRun.EOF) ? out.length() : -1;
}
/**
* returns a <code>TextStore</code> which contains submatches, if any, pertaining to the most
* recent match. The object returned should be treated read-only. Its contents are only valid
* until the next match operation.
*
* @throws IllegalStateException if the most recent application of <code>this</code> did not yield
* a match.
*/
public TextStore submatches() {
if (a == null || a == DfaRun.EOF) {
throw new IllegalStateException("no recent match available");
}
if (!analyzed) {
analyzed = true;
ts.clear();
ts.appendPart(out, 0, out.length());
smd.analyze(ts, a);
}
return ts;
}
/**
* checks if the whole input sequence starting at position <code>pos</code> can be matched.
*
* @return <code>true</code> iff the whole input sequence starting at position <code>pos</code>
* and ending at <code>s.length()</code> can be matched.
*/
public boolean matches(CharSequence s, int pos) {
return atStartOf(s, pos) != -1 && out.length() == s.length() - pos;
}
/**
* returns the number of characters matched by the most recent match call to any of <code>matches
* </code>, <code>atStartOf</code> or <code>find</code>.
*
* @throws IllegalStateException if the most recent application of <code>this</code> did not yield
* a match.
*/
public int length() {
if (a == null || a == DfaRun.EOF) {
throw new IllegalStateException("no recent match available");
}
return out.length();
}