initial works on the lexer

src/main/cup/chocopy/pa1/ChocoPy.cup

@@ -144,6 +144,11 @@ action code {:
  */
 terminal NEWLINE;
 terminal String PLUS; 
+terminal String MINUS;
+terminal String MULTIPLY;
+terminal String DIVIDE;
+terminal String NAMES;
+
 terminal Integer NUMBER; 
 /* Returned by the lexer for erroneous tokens.  Since it does not appear in
  * the grammar, it indicates a syntax error. */

src/main/jflex/chocopy/pa1/ChocoPy.jflex

@@ -1,6 +1,6 @@
 package chocopy.pa1;
 import java_cup.runtime.*;
-
+import java.util.ArrayList;
 %%
 
 /*** Do not change the flags below unless you know what you are doing. ***/
@@ -8,7 +8,7 @@ import java_cup.runtime.*;
 %unicode
 %line
 %column
-
+%states AFTER
 %class ChocoPyLexer
 %public
 
@@ -32,11 +32,12 @@ import java_cup.runtime.*;
 
     /** Producer of token-related values for the parser. */
     final ComplexSymbolFactory symbolFactory = new ComplexSymbolFactory();
-
+    private int currIndent = 0;
+    private ArrayList<Integer> stack = new ArrayList<Integer>(20);
     /** Return a terminal symbol of syntactic category TYPE and no
      *  semantic value at the current source location. */
     private Symbol symbol(int type) {
-        return symbol(type, yytext());
+        return symbol(type);
     }
 
     /** Return a terminal symbol of syntactic category TYPE and semantic
@@ -47,7 +48,17 @@ import java_cup.runtime.*;
             new ComplexSymbolFactory.Location(yyline + 1,yycolumn + yylength()),
             value);
     }
-
+    private void push(int indent){
+        stack.add(indent);
+    }
+    private int pop(){
+        if(stack.isEmpty()) return 0;
+        return stack.remove(stack.size() - 1);
+    }
+    private int top(){
+        if(stack.isEmpty) return 0;
+        return stack.get(stack.size() - 1);
+    }
 %}
 
 /* Macros (regexes used in rules below) */
@@ -55,25 +66,119 @@ import java_cup.runtime.*;
 WhiteSpace = [ \t]
 LineBreak  = \r|\n|\r\n
 
-IntegerLiteral = 0 | [1-9][0-9]*
-
+IntegerLiteral = 0|[1-9][0-9]*
+StringLiteral = \"([^\"\\]|(\\\")|(\\t)|(\\r)|(\\n)|(\\\\))*\"
+Names = (_|[a-z]|[A-Z])(_|[a-z]|[A-Z])*
+Comments = #[^\r\n]*
 %%
 
-
-<YYINITIAL> {
+<YYINITIAL>{
+  {WhiteSpace}                
+  { 
+      String space = yytext();
+      if(space == "\t")
+        currIndent += 8;
+      else 
+        currIndent ++;
+  }
+  {LineBreak}
+  {
+      currIndent = 0;
+  }
+  {Comments}           { /* ignored */ }
+  [^ \t\r\n#]               
+  {
+      yypushback(1);
+      if(top() > currIndent)
+      {    
+          pop();
+          return symbol(ChocoPyTokens.DEDENT);
+      }
+      yystart(AFTER);
+      if(top()< currIndent)
+      {
+          push(currIndent);
+          return symbol(ChocoPyTokens.INDENT);
+      }
+  }
+}
+<AFTER> {
 
   /* Delimiters. */
-  {LineBreak}                 { return symbol(ChocoPyTokens.NEWLINE); }
+  {LineBreak}                 { return symbol(ChocoPyTokens.NEWLINE); yybegin(YYINITIAL); currIndent = 0;}
+  ":"                         { return symbol(ChocoPyTokens.COLON); }
+  ","                         { return symbol(ChocoPyTokens.COMMA); }
 
   /* Literals. */
   {IntegerLiteral}            { return symbol(ChocoPyTokens.NUMBER,
                                                  Integer.parseInt(yytext())); }
+  {StringLiteral}             { return symbol(ChocoPyTokens.STRING, yytext());}
+  "False"                        { return symbol(ChocoPyTokens.BOOL, false); }
+  "True"                         { return symbol(ChocoPyTokens.BOOL, true); }
+  "None"                         { return symbol(ChocoPyTokens.NONE); }
+
+  /*Keywords*/
+  "if"                          {return symbol(ChocoPyTokens.IF);}
+  "else"                          {return symbol(ChocoPyTokens.ELSE);}
+  "elif"                          {return symbol(ChocoPyTokens.ELIF);}
+  "while"                          {return symbol(ChocoPyTokens.WHILE);}
+  "class"                          {return symbol(ChocoPyTokens.CLASS);}
+  "def"                          {return symbol(ChocoPyTokens.DEF);}
+  "lambda"                          {return symbol(ChocoPyTokens.LAMBDA);}
+  "as"                           { return symbol(ChocoPyTokens.AS); }
+  "for"                          { return symbol(ChocoPyTokens.FOR); }
+  "global"                       { return symbol(ChocoPyTokens.GLOBAL); }
+  "in"                           { return symbol(ChocoPyTokens.IN); }
+  "nonlocal"                     { return symbol(ChocoPyTokens.NONLOCAL); }
+  "pass"                         { return symbol(ChocoPyTokens.PASS); }
+  "return"                       { return symbol(ChocoPyTokens.RETURN); }
+  "assert"                       { return symbol(ChocoPyTokens.ASSERT); }
+  "await"                        { return symbol(ChocoPyTokens.AWAIT); }
+  "break"                        { return symbol(ChocoPyTokens.BREAK); }
+  "continue"                     { return symbol(ChocoPyTokens.CONTINUE); }
+  "del"                          { return symbol(ChocoPyTokens.DEL); }
+  "except"                       { return symbol(ChocoPyTokens.EXCEPT); }
+  "finally"                      { return symbol(ChocoPyTokens.FINALLY); }
+  "from"                         { return symbol(ChocoPyTokens.FROM); }
+  "import"                       { return symbol(ChocoPyTokens.IMPORT); }
+  "raise"                        { return symbol(ChocoPyTokens.RAISE); }
+  "try"                          { return symbol(ChocoPyTokens.TRY); }
+  "with"                         { return symbol(ChocoPyTokens.WITH); }
+  "yield"                        { return symbol(ChocoPyTokens.YIELD); }
 
-  /* Operators. */
-  "+"                         { return symbol(ChocoPyTokens.PLUS, yytext()); }
 
+  /* Operators. */
+  "+"                         { return symbol(ChocoPyTokens.PLUS); }
+  "-"                         { return symbol(ChocoPyTokens.MINUS); }
+  "*"                         { return symbol(ChocoPyTokens.MUL); }
+  "//"                         { return symbol(ChocoPyTokens.DIV); }  
+  "/"                         { return symbol(ChocoPyTokens.DIV); }  
+  "%"                         { return symbol(ChocoPyTokens.MOD); }  
+  ">"                         { return symbol(ChocoPyTokens.GT); }
+  "<"                         { return symbol(ChocoPyTokens.LT); }
+  "=="                         { return symbol(ChocoPyTokens.EQUAL); }
+  "!="                         { return symbol(ChocoPyTokens.NEQ); }
+  ">="                         { return symbol(ChocoPyTokens.GEQ); }
+  "<="                         { return symbol(ChocoPyTokens.LEQ); }
+  "="                         { return symbol(ChocoPyTokens.ASSIGN); }
+  "and"                         { return symbol(ChocoPyTokens.AND); }
+  "or"                         { return symbol(ChocoPyTokens.OR); }
+  "not"                         { return symbol(ChocoPyTokens.NOT); }
+  "."                         { return symbol(ChocoPyTokens.DOT); }
+  "("                         { return symbol(ChocoPyTokens.LPAR); }
+  ")"                         { return symbol(ChocoPyTokens.RPAR); }
+  "["                         { return symbol(ChocoPyTokens.LBR); }
+  "]"                         { return symbol(ChocoPyTokens.RBR); }
+  "->"                           { return symbol(ChocoPyTokens.ARROW); }
+  "is"                           { return symbol(ChocoPyTokens.IS); }
+  
+ 
+  /*Identifiers*/
+  {Names}                     {return symbol(ChocoPyTokens.NAMES, yytext());}
   /* Whitespace. */
   {WhiteSpace}                { /* ignore */ }
+  /* Comment. */
+  {Comments}                  { /* ignore */ }
 }
 
 <<EOF>>                       { return symbol(ChocoPyTokens.EOF); }