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382 lines (337 loc) · 7.66 KB
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package crux;
import java.io.IOException;
import java.io.Reader;
import java.util.Iterator;
public class Scanner implements Iterable<Token> {
public static String studentName = "Ford Tang";
public static String studentID = "46564602";
public static String uciNetID = "FordT1";
private int lineNum; // current line count
private int charPos; // character offset for current line
private int nextChar; // contains the next char (-1 == EOF)
private Reader input;
Scanner(Reader reader) throws IOException
{
lineNum = 1;
charPos = 1;
input = reader;
nextChar = input.read();
}
// OPTIONAL: helper function for reading a single char from input
// can be used to catch and handle any IOExceptions,
// advance the charPos or lineNum, etc.
private int readChar() throws IOException
{
if (nextChar == '\n')
{
++lineNum;
charPos = 1;
nextChar = input.read();
}
else if (nextChar != -1)
{
++charPos;
nextChar = input.read();
}
return nextChar;
}
/* Invariants:
* 1. call assumes that nextChar is already holding an unread character
* 2. return leaves nextChar containing an untokenized character
*/
public Token next() throws IOException
{
while (nextChar != -1)
{
//System.out.println((char)nextChar);
String lexeme = "";
while (nextChar == ' ' || nextChar == '\n')
readChar();
if (nextChar == -1)
return Token.EOF(lineNum, charPos);
//if (nextChar == ' ' || nextChar == '\n')
// return new Token(lexeme, lineNum, charPos);
if (nextChar == '_' || (nextChar >= 'A' && nextChar <= 'Z') || (nextChar >= 'a' && nextChar <= 'z'))
{
int charNum = charPos;
lexeme += (char)nextChar;
readChar();
while (nextChar == '_' || (nextChar >= 'A' && nextChar <= 'Z') || (nextChar >= 'a' && nextChar <= 'z') || (nextChar >= '0' && nextChar <= '9'))
{
lexeme += (char)nextChar;
readChar();
}
switch (lexeme)
{
case "and":
case "or":
case "not":
case "let":
case "var":
case "array":
case "func":
case "if":
case "else":
case "while":
case "true":
case "false":
case "return":
return new Token(lexeme, lineNum, charNum);
default:
return Token.Identifier(lexeme, lineNum, charNum);
}
}
if (nextChar >= '0' && nextChar <= '9')
{
//System.out.println((char)nextChar);
int charNum = charPos;
while (nextChar >= '0' && nextChar <= '9')
{
lexeme += (char)nextChar;
readChar();
}
if (nextChar == '.')
{
lexeme += (char)nextChar;
readChar();
while (nextChar >= '0' && nextChar <= '9')
{
lexeme += (char)nextChar;
readChar();
}
return Token.Float(lexeme, lineNum, charNum);
}
return Token.Integer(lexeme, lineNum, charNum);
}
int charNum = charPos;
lexeme += (char)nextChar;
switch (lexeme)
{
case "(":
case ")":
case "{":
case "}":
case "[":
case "]":
case "+":
case "-":
case "*":
case ",":
case ";":
readChar();
return new Token(lexeme, lineNum, charNum);
case "/":
if (readChar() == '/')
{
int temp = lineNum + 1;
while (lineNum != temp && nextChar != -1)
readChar();
lexeme = "";
break;
}
else
return new Token(lexeme, lineNum, charNum);
case ">":
if (readChar() == '=')
{
lexeme += (char)nextChar;
readChar();
}
return new Token(lexeme, lineNum, charNum);
case "<":
if (readChar() == '=')
{
lexeme += (char)nextChar;
readChar();
}
return new Token(lexeme, lineNum, charNum);
case "!":
if (readChar() == '=')
{
lexeme += (char)nextChar;
readChar();
}
return new Token(lexeme, lineNum, charNum);
case "=":
if (readChar() == '=')
{
lexeme += (char)nextChar;
readChar();
}
return new Token(lexeme, lineNum, charNum);
case ":":
if (readChar() == ':')
{
lexeme += (char)nextChar;
readChar();
}
return new Token(lexeme, lineNum, charNum);
default:
readChar();
return new Token(lexeme, lineNum, charNum);
}
}
return Token.EOF(lineNum, charPos);
/*
while (nextChar != -1)
{
while(nextChar == ' ' || nextChar == '\n')
readChar();
if (nextChar == '/')
{
if (readChar() == '/')
{
int temp = lineNum + 1;
while (lineNum != temp || nextChar != -1)
readChar();
}
else
return Token.Div(lineNum, charPos); //check against comments
}
else if (nextChar == '(')
{
readChar();
return Token.OpenParen(lineNum, charPos);
}
else if (nextChar == ')')
{
readChar();
return Token.CloseParen(lineNum, charPos);
}
else if (nextChar == '{')
{
readChar();
return Token.OpenBrace(lineNum, charPos);
}
else if (nextChar == '}')
{
readChar();
return Token.CloseBrace(lineNum, charPos);
}
else if (nextChar == '[')
{
readChar();
return Token.OpenBracket(lineNum, charPos);
}
else if (nextChar == ']')
{
readChar();
return Token.CloseBracket(lineNum, charPos);
}
else if (nextChar == '+')
{
readChar();
return Token.Add(lineNum, charPos);
}
else if (nextChar == '-')
{
readChar();
return Token.Sub(lineNum, charPos);
}
else if (nextChar == '*')
{
readChar();
return Token.Mul(lineNum, charPos);
}
else if (nextChar == ',')
{
readChar();
return Token.Comma(lineNum, charPos);
}
else if (nextChar == ';')
{
readChar();
return Token.SemiColon(lineNum, charPos);
}
else if (nextChar == ':')
{
if (readChar() == ':')
{
readChar();
return Token.Call(lineNum, charPos);
}
return Token.Colon(lineNum, charPos);
}
else if (nextChar == '>')
{
if (readChar() == '=')
{
readChar();
return Token.GreaterEqual(lineNum, charPos);
}
return Token.GreaterThan(lineNum, charPos);
}
else if (nextChar == '<')
{
if (readChar() == '=')
{
readChar();
return Token.LesserEqual(lineNum, charPos);
}
return Token.LessThan(lineNum, charPos);
}
else if (nextChar == '!')
{
if (readChar() == '=')
{
readChar();
return Token.NotEqual(lineNum, charPos);
}
}
else if (nextChar == '=')
{
if (readChar() == '=')
{
readChar();
return Token.Equal(lineNum, charPos);
}
return Token.Assign(lineNum, charPos);
}
else
{
String lexeme = "";
if ((nextChar >= 'A' && nextChar <= 'Z') || (nextChar >= 'a' && nextChar <= 'z'))
{
while ((nextChar >= 'A' && nextChar <= 'Z') || (nextChar >= 'a' && nextChar <= 'z'))
{
lexeme += (char)nextChar;
readChar();
}
return new Token(lexeme, lineNum, charPos);
}
else if (nextChar >= '0' && nextChar <= '9')
{
while (nextChar >= '0' && nextChar <= '9')
{
lexeme += (char)nextChar;
readChar();
}
if (nextChar == '.')
{
lexeme += (char)nextChar;
readChar();
while (nextChar >= '0' && nextChar <= '9')
{
lexeme += (char)nextChar;
readChar();
}
}
return new Token(lexeme, lineNum, charPos);
}
else
{
lexeme += (char)nextChar;
readChar();
return new Token(lexeme, lineNum, charPos);
}
}
}
return Token.EOF(lineNum, charPos);
*/
}
public Iterator<Token> iterator()
{
return null;
}
// OPTIONAL: any other methods that you find convenient for implementation or testing
}