1 files changed, 33 insertions, 4 deletions

diff --git a/src/main/java/sevenUnitsGUI/Presenter.java b/src/main/java/sevenUnitsGUI/Presenter.java
index 4feea44..f630a77 100644
--- a/src/main/java/sevenUnitsGUI/Presenter.java
+++ b/src/main/java/sevenUnitsGUI/Presenter.java
@@ -32,6 +32,7 @@ import java.util.Set;
 import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import sevenUnits.ProgramInfo;
 import sevenUnits.unit.BaseDimension;
@@ -195,6 +196,14 @@ public final class Presenter {
 	private Predicate<List<UnitPrefix>> prefixRepetitionRule = DefaultPrefixRepetitionRule.NO_RESTRICTION;
 	
 	/**
+	 * A rule that accepts a prefixless name-unit pair and returns a map mapping
+	 * names to prefixed versions of that unit (including the unit itself) that
+	 * should be searchable.
+	 */
+	private final Function<Map.Entry<String, LinearUnit>, Map<String, LinearUnit>> searchRule = e -> Map
+			.ofEntries(e);
+	
+	/**
 	 * The set of units that is considered neither metric nor nonmetric for the
 	 * purposes of the metric-imperial one-way conversion. These units are
 	 * included in both From and To, even if One Way Conversion is enabled.
@@ -275,6 +284,26 @@ public final class Presenter {
 	}
 	
 	/**
+	 * Applies a search rule to an entry in a name-unit map.
+	 *
+	 * @param e entry
+	 * @return stream of entries, ready for flat-mapping
+	 * @since 2022-07-06
+	 */
+	private final Stream<Map.Entry<String, Unit>> applySearchRule(
+			Map.Entry<String, Unit> e) {
+		final Unit u = e.getValue();
+		if (u instanceof LinearUnit) {
+			final String name = e.getKey();
+			final Map.Entry<String, LinearUnit> linearEntry = Map.entry(name,
+					(LinearUnit) u);
+			return this.searchRule.apply(linearEntry).entrySet().stream().map(
+					entry -> Map.entry(entry.getKey(), (Unit) entry.getValue()));
+		} else
+			return Stream.of(e);
+	}
+	
+	/**
 	 * Converts from the view's input expression to its output expression.
 	 * Displays an error message if any of the required fields are invalid.
 	 * 
@@ -761,10 +790,10 @@ public final class Presenter {
 			}
 			
 			// set unit names
-			ucview.setFromUnitNames(
-					fromUnits.map(Map.Entry::getKey).collect(Collectors.toSet()));
-			ucview.setToUnitNames(
-					toUnits.map(Map.Entry::getKey).collect(Collectors.toSet()));
+			ucview.setFromUnitNames(fromUnits.flatMap(this::applySearchRule)
+					.map(Map.Entry::getKey).collect(Collectors.toSet()));
+			ucview.setToUnitNames(toUnits.flatMap(this::applySearchRule)
+					.map(Map.Entry::getKey).collect(Collectors.toSet()));
 		}
 	}