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package bjc.utils.parserutils.defines;
import java.util.Arrays;
import java.util.Iterator;
import java.util.function.UnaryOperator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import bjc.data.CircularIterator;
import bjc.data.ResettableIterator;
/**
* An iterated find/replace, using a circular assortment of replacements.
*
* @author Ben Culkin
*/
public class IteratedDefine implements UnaryOperator<String> {
private Pattern patt;
private ResettableIterator<String> repls;
/**
* Create a new iterated define.
*
* @param pattern
* The pattern to use for matching.
* @param circular
* Whether or not to loop through the list of replacers, or
* just repeat the last one.
* @param replacers
* The set of replacement strings to use.
*/
public IteratedDefine(Pattern pattern, boolean circular, String... replacers) {
patt = pattern;
Iterator<String> tmp = new CircularIterator<>(Arrays.asList(replacers), circular);
repls = new ResettableIterator<>(tmp);
}
/**
* Create a new iterated define.
*
* @param pattern
* The pattern to use for matching.
* @param circular
* Whether or not to loop through the list of replacers, or
* just repeat the last one.
* @param replacers
* The set of replacement strings to use.
*/
public IteratedDefine(String pattern, boolean circular, String... replacers) {
this(Pattern.compile(pattern), circular, replacers);
}
@Override
public String apply(String ln) {
/*
* NOTE Oct 6 2020 - Ben Culkin - Should this be configurable to do/not do?
*/
/*
* Reset the iterator. This means that the fact that you iterated over a
* replacer previously, doesn't keep it from being used again.
*/
repls.reset();
Matcher mat = patt.matcher(ln);
StringBuffer sb = new StringBuffer();
while (mat.find()) {
/*
* @NOTE Oct 6, 2020 - Ben Culkin
*
* Policy question here. Should we throw an exception if we exhaust our
* replacers and we weren't supposed to?
*
* Other alternatives are:
*
* a) Default to the empty string
*
* b) Keep the last valid replacer. This seems to be what we do as of now, per
* the behavior of CircularIterator.
*
* c) Use the replacer "$0", which is the same as not doing a replace at all
*/
String repl = repls.next();
mat.appendReplacement(sb, repl);
}
mat.appendTail(sb);
return sb.toString();
}
}
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