Add named parsers

cloud-annotations/src/main/java/com/intellectualsites/commands/annotations/AnnotationParser.java

@@ -261,7 +261,10 @@ public final class AnnotationParser<C> {
         final TypeToken<?> token = TypeToken.of(parameter.getParameterizedType());
         final ParserParameters parameters = this.manager.getParserRegistry()
                                                         .parseAnnotations(token, annotations);
-        final ArgumentParser<C, ?> parser = this.manager.getParserRegistry()
+
+        final ArgumentParser<C, ?> parser;
+        if (argumentPair.getArgument().parserName().isEmpty()) {
+            parser = this.manager.getParserRegistry()
                                  .createParser(token, parameters)
                                  .orElseThrow(() -> new IllegalArgumentException(
                                          String.format("Parameter '%s' in method '%s' "
@@ -269,6 +272,17 @@ public final class AnnotationParser<C> {
                                                                + "for that type",
                                                        parameter.getName(), method.getName(),
                                                        token.toString())));
+        } else {
+            parser = this.manager.getParserRegistry()
+                                 .createParser(argumentPair.getArgument().parserName(), parameters)
+                                 .orElseThrow(() -> new IllegalArgumentException(
+                                         String.format("Parameter '%s' in method '%s' "
+                                                               + "has parser '%s' but no parser exists "
+                                                               + "for that type",
+                                                       parameter.getName(), method.getName(),
+                                                       token.toString())));
+        }
+
         if (syntaxFragment == null || syntaxFragment.getArgumentMode() == ArgumentMode.LITERAL) {
             throw new IllegalArgumentException(String.format(
                     "Invalid command argument '%s' in method '%s': "

cloud-annotations/src/test/java/com/intellectualsites/commands/annotations/AnnotationParserTest.java

@@ -26,6 +26,7 @@ package com.intellectualsites.commands.annotations;
 import com.intellectualsites.commands.Command;
 import com.intellectualsites.commands.CommandManager;
 import com.intellectualsites.commands.annotations.specifier.Range;
+import com.intellectualsites.commands.arguments.standard.StringArgument;
 import com.intellectualsites.commands.meta.SimpleCommandMeta;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.BeforeAll;
@@ -33,6 +34,7 @@ import org.junit.jupiter.api.Test;
 
 import javax.annotation.Nonnull;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.concurrent.CompletionException;
 
 class AnnotationParserTest {
@@ -44,6 +46,8 @@ class AnnotationParserTest {
     static void setup() {
         manager = new TestCommandManager();
         annotationParser = new AnnotationParser<>(manager, TestCommandSender.class, p -> SimpleCommandMeta.empty());
+        manager.getParserRegistry().registerNamedParserSupplier("potato", p -> new StringArgument.StringParser<>(
+                StringArgument.StringMode.SINGLE, (c, s) -> Collections.singletonList("potato")));
     }
 
     @Test
@@ -59,7 +63,8 @@ class AnnotationParserTest {
     @CommandMethod("test|t <int> [string]")
     public void testCommand(@Nonnull final TestCommandSender sender,
                             @Argument("int") @Range(max = "100") final int argument,
-                            @Nonnull @Argument(value = "string", defaultValue = "potato") final String string) {
+                            @Nonnull @Argument(value = "string", defaultValue = "potato", parserName = "potato")
+                                final String string) {
         System.out.printf("Received int: %d and string '%s'\n", argument, string);
     }
 

cloud-core/src/main/java/com/intellectualsites/commands/arguments/parser/ParserRegistry.java

@@ -52,6 +52,16 @@ public interface ParserRegistry<C> {
     <T> void registerParserSupplier(@Nonnull TypeToken<T> type,
                                     @Nonnull Function<ParserParameters, ArgumentParser<C, ?>> supplier);
 
+    /**
+     * Register a named parser supplier
+     *
+     * @param name     Parser name
+     * @param supplier The function that generates the parser. The map supplied my contain parameters used
+     *                 to configure the parser, many of which are documented in {@link StandardParameters}
+     */
+    void registerNamedParserSupplier(@Nonnull String name,
+                                     @Nonnull Function<ParserParameters, ArgumentParser<C, ?>> supplier);
+
     /**
      * Register a mapper that maps annotation instances to a map of parameter-object pairs
      *
@@ -88,4 +98,17 @@ public interface ParserRegistry<C> {
     <T> Optional<ArgumentParser<C, T>> createParser(@Nonnull TypeToken<T> type,
                                                     @Nonnull ParserParameters parserParameters);
 
+    /**
+     * Attempt to create a {@link ArgumentParser} for a specified type, using
+     * an instance of {@link ParserParameter} to configure the parser settings
+     *
+     * @param name             Parser
+     * @param parserParameters Parser parameters
+     * @param <T>              Generic type
+     * @return Parser, if one can be created
+     */
+    @Nonnull
+    <T> Optional<ArgumentParser<C, T>> createParser(@Nonnull String name,
+                                                    @Nonnull ParserParameters parserParameters);
+
 }

cloud-core/src/main/java/com/intellectualsites/commands/arguments/parser/StandardParserRegistry.java

@@ -65,6 +65,7 @@ public final class StandardParserRegistry<C> implements ParserRegistry<C> {
             .put(boolean.class, Boolean.class)
             .build();
 
+    private final Map<String, Function<ParserParameters, ArgumentParser<C, ?>>> namedParsers = new HashMap<>();
     private final Map<TypeToken<?>, Function<ParserParameters, ArgumentParser<C, ?>>> parserSuppliers = new HashMap<>();
     private final Map<Class<? extends Annotation>, BiFunction<? extends Annotation, TypeToken<?>, ParserParameters>>
             annotationMappers = new HashMap<>();
@@ -109,6 +110,12 @@ public final class StandardParserRegistry<C> implements ParserRegistry<C> {
         this.parserSuppliers.put(type, supplier);
     }
 
+    @Override
+    public void registerNamedParserSupplier(@Nonnull final String name,
+                                            @Nonnull final Function<ParserParameters, ArgumentParser<C, ?>> supplier) {
+        this.namedParsers.put(name, supplier);
+    }
+
     @Override
     public <A extends Annotation, T> void registerAnnotationMapper(@Nonnull final Class<A> annotation,
                                                                    @Nonnull final BiFunction<A, TypeToken<?>,
@@ -160,6 +167,19 @@ public final class StandardParserRegistry<C> implements ParserRegistry<C> {
         return Optional.of(parser);
     }
 
+    @Nonnull
+    @Override
+    public <T> Optional<ArgumentParser<C, T>> createParser(@Nonnull final String name,
+                                                           @Nonnull final ParserParameters parserParameters) {
+        final Function<ParserParameters, ArgumentParser<C, ?>> producer = this.namedParsers.get(name);
+        if (producer == null) {
+            return Optional.empty();
+        }
+        @SuppressWarnings("unchecked") final ArgumentParser<C, T> parser = (ArgumentParser<C, T>) producer.apply(
+                parserParameters);
+        return Optional.of(parser);
+    }
+
 
     private static final class RangeMapper<T> implements BiFunction<Range, TypeToken<?>, ParserParameters> {