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package org.codehaus.jparsec.examples.java.parser;
import static org.codehaus.jparsec.Parsers.between;
import static org.codehaus.jparsec.examples.java.parser.TerminalParser.phrase;
import static org.codehaus.jparsec.examples.java.parser.TerminalParser.term;
import java.util.Collections;
import java.util.List;
import org.codehaus.jparsec.Parser;
import org.codehaus.jparsec.Parsers;
import org.codehaus.jparsec.Terminals;
import org.codehaus.jparsec.examples.java.ast.type.ArrayTypeLiteral;
import org.codehaus.jparsec.examples.java.ast.type.LowerBoundWildcard;
import org.codehaus.jparsec.examples.java.ast.type.SimpleTypeLiteral;
import org.codehaus.jparsec.examples.java.ast.type.TypeLiteral;
import org.codehaus.jparsec.examples.java.ast.type.UpperBoundWildcard;
import org.codehaus.jparsec.functors.Maps;
import org.codehaus.jparsec.functors.Unary;
import org.codehaus.jparsec.misc.Mapper;
/**
* Parses any type literal.
*
* @author Ben Yu
*/
public final class TypeLiteralParser {
static final List<TypeLiteral> EMPTY_TYPE_ARGUMENT_LIST = Collections.<TypeLiteral>emptyList();
static final Parser<Unary<TypeLiteral>> ARRAY_OF =
phrase("[ ]").next(curry(ArrayTypeLiteral.class).unary());
static final Parser<TypeLiteral> ELEMENT_TYPE_LITERAL = TypeLiteralParser.elementTypeLiteral();
// at least one "[]" followed by any number of "[]".
static final Parser<TypeLiteral> ARRAY_TYPE_LITERAL = curry(ArrayTypeLiteral.class)
.sequence(ELEMENT_TYPE_LITERAL, phrase("[ ]")).postfix(ARRAY_OF);
// an element type optionally followed by some "[]".
static final Parser<TypeLiteral> TYPE_LITERAL = ELEMENT_TYPE_LITERAL.postfix(ARRAY_OF);
static Parser<TypeLiteral> elementTypeLiteral() {
Parser.Reference<TypeLiteral> ref = Parser.newReference();
Parser<TypeLiteral> lazy = ref.lazy();
Parser<TypeLiteral> arg = wildcard(lazy).or(lazy);
Parser<String> nativeTypeName = TerminalParser.oneOf(
"byte", "short", "int", "long", "boolean", "char", "float", "double", "void")
.map(Maps.mapToString());
Parser<String> typeName = nativeTypeName.or(Terminals.Identifier.PARSER);
Parser<TypeLiteral> parser = Mapper.<TypeLiteral>curry(SimpleTypeLiteral.class)
.sequence(typeName.sepBy1(term(".")), TypeLiteralParser.optionalTypeArgs(arg));
ref.set(parser.postfix(ARRAY_OF));
return parser;
}
static Parser<List<TypeLiteral>> optionalTypeArgs(Parser<TypeLiteral> parser) {
return between(term("<"), parser.sepBy1(term(",")), term(">"))
.optional(TypeLiteralParser.EMPTY_TYPE_ARGUMENT_LIST);
}
static Parser<TypeLiteral> wildcard(Parser<TypeLiteral> type) {
return Parsers.or(
curry(UpperBoundWildcard.class).sequence(phrase("? extends"), type),
curry(LowerBoundWildcard.class).sequence(phrase("? super"), type),
term("?").retn(new UpperBoundWildcard(null)));
}
private static Mapper<TypeLiteral> curry(
Class<? extends TypeLiteral> clazz, Object... curryArgs) {
return Mapper.curry(clazz, curryArgs);
}
}