// VoidMethodDeclaration ::= void id '(' ParameterList? ')' { Statement* }
private MethodDecl parseVoidMethodDeclaration(
boolean isPrivate, boolean isStatic, SourcePosition pos) {
SourcePosition currentPos = token.posn;
accept(TokenKind.VOID);
String methodName = accept(TokenKind.ID);
accept(TokenKind.LEFTPAREN);
// Initialize empty list in case there are no parameters
ParameterDeclList parameterDeclList = new ParameterDeclList();
if (token.kind != TokenKind.RIGHTPAREN) parameterDeclList = parseParameterList();
accept(TokenKind.RIGHTPAREN);
accept(TokenKind.LEFTBRACKET);
// Initialize empty list in case there are no statements
StatementList statementList = new StatementList();
while (token.kind != TokenKind.RIGHTBRACKET)
statementList.add(parseStatement(new BaseType(TypeKind.VOID, pos)));
accept(TokenKind.RIGHTBRACKET);
return new MethodDecl(
new FieldDecl(
isPrivate, isStatic, new BaseType(TypeKind.VOID, currentPos), methodName, pos),
parameterDeclList,
statementList,
pos);
}
/*
* Type id ( ; | '(' ParameterList? ')' '{' Statement* '}' )
*/
private Object parseFieldOrNonVoidMethodDeclaration(
boolean isPrivate, boolean isStatic, SourcePosition pos) {
Type type = parseType();
String name = accept(TokenKind.ID);
switch (token.kind) {
// Field declaration
case SEMICOLON:
accept(TokenKind.SEMICOLON);
return new FieldDecl(isPrivate, isStatic, type, name, pos);
// '(' ParameterList? ')' '{' Statement* '}'
// Method declaration
case LEFTPAREN:
{
accept(TokenKind.LEFTPAREN);
// Initialize empty list in case there are no parameters
ParameterDeclList parameterDeclList = new ParameterDeclList();
if (token.kind != TokenKind.RIGHTPAREN) {
parameterDeclList = parseParameterList();
}
accept(TokenKind.RIGHTPAREN);
accept(TokenKind.LEFTBRACKET);
// Initialize empty list in case there are no statements
StatementList statementList = new StatementList();
while (token.kind != TokenKind.RIGHTBRACKET) statementList.add(parseStatement(type));
accept(TokenKind.RIGHTBRACKET);
return new MethodDecl(
new FieldDecl(isPrivate, isStatic, type, name, pos),
parameterDeclList,
statementList,
pos);
}
default:
parseError("Invalid Term - expecting SEMICOLON or LEFTPAREN but found " + token.kind);
return null;
}
}
private Statement parseStatement(Type returnType) {
SourcePosition currentPos = token.posn;
switch (token.kind) {
// { Statement* }
case LEFTBRACKET:
accept(TokenKind.LEFTBRACKET);
StatementList statementList = new StatementList();
while (token.kind != TokenKind.RIGHTBRACKET) {
statementList.add(parseStatement(returnType));
}
accept(TokenKind.RIGHTBRACKET);
return new BlockStmt(statementList, currentPos);
case ID:
ClassType classType = new ClassType(new Identifier(token), currentPos);
IdRef idRef = new IdRef(new Identifier(token), currentPos);
acceptIt();
if (token.kind == TokenKind.LEFTSQUAREBRACKET) {
acceptIt();
// id[] id = Expression ;
if (token.kind == TokenKind.RIGHTSQUAREBRACKET) {
acceptIt();
return parseIDArrayDeclarationStatement(classType);
} else { // id [ Expression ] = Expression ;
return parseIDIndexedAssignStatement(idRef);
}
}
// id id = Expression ;
else if (token.kind == TokenKind.ID) {
String variableName = acceptIt();
return parseIDDeclarationStatement(classType, variableName);
}
// id ( . id)* ( = Expression | '('ArgumentList?')' ) ;
else if (token.kind == TokenKind.DOT
|| token.kind == TokenKind.ASSIGNMENTEQUAL
|| token.kind == TokenKind.LEFTPAREN) {
return parseQualifiedStatements(idRef);
} else {
parseError(
"Invalid Term - expecting LEFTSQUAREBRACKET, ID, DOT, or ASSIGNMENTEQUAL but found "
+ token.kind);
// Never reached
return null;
}
case INT:
return parseIntOrIntArrayDeclarationStatement();
case BOOLEAN:
return parseBooleanDeclarationStatement();
case THIS: // this ( . id )* ( = Expression | '('ArgumentList?')' ) ;
acceptIt();
Reference thisRef = new ThisRef(currentPos);
return parseQualifiedStatements(thisRef);
case RETURN:
return parseReturnStatement(returnType);
case IF:
return parseIfStatement(returnType);
case WHILE:
return parseWhileStatement(returnType);
default:
parseError(
"Invalid Term - expecting LEFTBRACKET, ID, INT, BOOLEAN, THIS, RETURN, IF, or WHILE but found "
+ token.kind);
return null;
}
}