/**
* Creates a mapping by merging two mappings. There must be no clashes.
*
* <p>Unlike {@link #append}, sources and targets are not shifted.
*
* <p>For example, <code>merge({0:0, 1:1}, {2:2, 3:3, 4:4})</code> yields <code>
* {0:0, 1:1, 2:2, 3:3, 4:4}</code>. <code>merge({0:0, 1:1}, {1:2, 2:3})</code> throws, because
* there are two entries with source=1.
*/
public static TargetMapping merge(TargetMapping mapping0, TargetMapping mapping1) {
final int s0 = mapping0.getSourceCount();
final int s1 = mapping1.getSourceCount();
final int sMin = Math.min(s0, s1);
final int sMax = Math.max(s0, s1);
final int t0 = mapping0.getTargetCount();
final int t1 = mapping1.getTargetCount();
final int tMax = Math.max(t0, t1);
final TargetMapping mapping = create(MappingType.INVERSE_SURJECTION, sMax, tMax);
for (int s = 0; s < sMin; s++) {
int t = mapping0.getTargetOpt(s);
if (t >= 0) {
mapping.set(s, t);
assert mapping1.getTargetOpt(s) < 0;
} else {
t = mapping1.getTargetOpt(s);
if (t >= 0) {
mapping.set(s, t);
}
}
}
for (int s = sMin; s < sMax; s++) {
int t = s < s0 ? mapping0.getTargetOpt(s) : -1;
if (t >= 0) {
mapping.set(s, t);
assert mapping1.getTargetOpt(s) < 0;
} else {
t = s < s1 ? mapping1.getTargetOpt(s) : -1;
if (t >= 0) {
mapping.set(s, t);
}
}
}
return mapping;
}
/**
* Creates a mapping that consists of a set of contiguous ranges.
*
* <p>For example,
*
* <pre>createShiftMapping(60,
* 100, 0, 3,
* 200, 50, 5);
* </pre>
*
* <p>creates
*
* <table>
* <caption>Example mapping</caption>
* <tr><th>Source</th><th>Target</th></tr>
* <tr><td>0</td><td>100</td></tr>
* <tr><td>1</td><td>101</td></tr>
* <tr><td>2</td><td>102</td></tr>
* <tr><td>3</td><td>-1</td></tr>
* <tr><td>...</td><td>-1</td></tr>
* <tr><td>50</td><td>200</td></tr>
* <tr><td>51</td><td>201</td></tr>
* <tr><td>52</td><td>202</td></tr>
* <tr><td>53</td><td>203</td></tr>
* <tr><td>54</td><td>204</td></tr>
* <tr><td>55</td><td>-1</td></tr>
* <tr><td>...</td><td>-1</td></tr>
* <tr><td>59</td><td>-1</td></tr>
* </table>
*
* @param sourceCount Maximum value of {@code source}
* @param ints Collection of ranges, each {@code (target, source, count)}
* @return Mapping that maps from source ranges to target ranges
*/
public static TargetMapping createShiftMapping(int sourceCount, int... ints) {
int targetCount = 0;
assert ints.length % 3 == 0;
for (int i = 0; i < ints.length; i += 3) {
final int target = ints[i];
final int length = ints[i + 2];
final int top = target + length;
targetCount = Math.max(targetCount, top);
}
final TargetMapping mapping =
create(
MappingType.INVERSE_SURJECTION,
sourceCount, // aCount + bCount + cCount,
targetCount); // cCount + bCount
for (int i = 0; i < ints.length; i += 3) {
final int target = ints[i];
final int source = ints[i + 1];
final int length = ints[i + 2];
assert source + length <= sourceCount;
for (int j = 0; j < length; j++) {
assert mapping.getTargetOpt(source + j) == -1;
mapping.set(source + j, target + j);
}
}
return mapping;
}
