// === Entry and Evaluation Control Methods ===
public void interpret(List <Stmt> statements)
{
try
{
foreach (Stmt statement in statements)
{
execute(statement);
}
}
catch (RuntimeError e)
{
AutonoCy_Main.runtimeError(e);
}
}
public override object CALL(Interpreter interpreter, List <object> arguments)
{
if (arguments[0] is string)
{
try
{
return(Double.Parse((string)arguments[0]));
}
catch (FormatException e)
{
AutonoCy_Main.runtimeError(new RuntimeError(new Token(TokenTypes.IDENTIFIER, "stringToNumber", null, -1), "stringToNumber - Unexpected formatting"));
return(null);
}
}
else
{
throw new RuntimeError(new Token(TokenTypes.IDENTIFIER, "stringToNumber", null, -1), "stringToNumber - unexpected argument type '" + arguments[0].GetType().ToString() + "', expecting type 'string'");
}
}
private ParseError error(Token token, string message)
{
AutonoCy_Main.error(token, message);
return(new ParseError());
}
void scanToken()
{
char c = advance();
switch (c)
{
// Single character lexemes
case '(': addToken(TokenTypes.LEFT_PAREN); break;
case ')': addToken(TokenTypes.RIGHT_PAREN); break;
case '{': addToken(TokenTypes.LEFT_BRACE); break;
case '}': addToken(TokenTypes.RIGHT_BRACE); break;
case '[': addToken(TokenTypes.LEFT_BRACKET); break;
case ']': addToken(TokenTypes.RIGHT_BRACKET); break;
case ',': addToken(TokenTypes.COMMA); break;
case '.': addToken(TokenTypes.DOT); break;
case '-': addToken(TokenTypes.MINUS); break;
case '+': addToken(TokenTypes.PLUS); break;
case ';': addToken(TokenTypes.SEMICOLON); break;
case '*': addToken(TokenTypes.STAR); break;
case '^': addToken(TokenTypes.CARET); break;
// Possibly double character lexemes
case '!': addToken(match('=') ? TokenTypes.BANG_EQUAL : TokenTypes.BANG); break;
case '=': addToken(match('=') ? TokenTypes.EQUAL_EQUAL : TokenTypes.EQUAL); break;
case '<': addToken(match('=') ? TokenTypes.LESS_EQUAL : TokenTypes.LESS); break;
case '>': addToken(match('=') ? TokenTypes.GREATER_EQUAL : TokenTypes.GREATER); break;
case '&':
if (match('&'))
{
addToken(TokenTypes.AND);
}
else
{
AutonoCy_Main.error(line, "Unsupported operator. Did you mean '&&'?");
}
break;
case '|':
if (match('|'))
{
addToken(TokenTypes.OR);
}
else
{
AutonoCy_Main.error(line, "Unsupported operator. Did you mean '||'?");
}
break;
// Longer lexemes
case '/':
if (match('/'))
{
// Ignore line because comment
while (peek() != '\n' && !isAtEnd())
{
advance();
}
}
else
{
addToken(TokenTypes.SLASH);
}
break;
// Whitespaces
case ' ':
case '\r':
case '\t':
// Ignore these
break;
case '\n':
// Increment line count, but don't do anything else
line++;
break;
// String Literal
case '"': stringL(); break;
default:
// Catch numbers here
if (isDigit(c))
{
numberL();
}
// Catch all Alphabetical things here
else if (isAlpha(c))
{
identifierL();
}
else
{
// Error from unexpected character
AutonoCy_Main.error(line, "Unexpected character.");
}
break;
}
}
void stringL()
{
char next;
string stringLiteral = "";
bool escape = false;
next = peek();
while (next != '"' && !isAtEnd())
{
if (next == '\\')
{
escape = true;
}
if (next == '\n')
{
line++;
}
if (!escape)
{
stringLiteral = stringLiteral + next;
}
else
{
if (!isAtEnd())
{
advance();
next = peek();
switch (next)
{
case 'n':
stringLiteral = stringLiteral + '\n';
break;
case '"':
stringLiteral = stringLiteral + '"';
break;
case '\\':
stringLiteral = stringLiteral + '\\';
break;
default:
AutonoCy_Main.error(line, "Unrecognized escape sequence.");
break;
}
escape = false;
}
}
advance();
next = peek();
}
if (isAtEnd())
{
AutonoCy_Main.error(line, "Unterminated string.");
return;
}
// Move past the closing "
advance();
// Trim the surrounding quotes
string value = source.Substring(start + 1, current - start - 2);
addToken(TokenTypes.STRING, stringLiteral);
}