// jBASIC lexer, JFlex version

import java_cup.runtime.*;

%%

%class Lexer
%unicode
%cup
%line
%column

//%char
//%type java_cup.runtime.Symbol
//%function next_token

%eofval{
  {return symbol(sym.EOF,null); }
%eofval}
/*
*/

%{

  /* copied from JFlex example */
  StringBuffer string = new StringBuffer();

  int mylinenum = 1;

  private java_cup.runtime.Symbol symbol(int type) {
    return new java_cup.runtime.Symbol(type, yyline, yycolumn);
  }
  private java_cup.runtime.Symbol symbol(int type, Object value) {
    return new java_cup.runtime.Symbol(type, yyline, yycolumn, value);
  }

%}

LineTerminator = \r|\n|\r\n
InputCharacter = [^\r\n]
WhiteSpace     = {LineTerminator} | [ \t\f]

/* comments */
Comment = {TraditionalComment} | {EndOfLineComment} | {DocumentationComment}

TraditionalComment   = "/*" [^*] ~"*/" | "/*" "*"+ "/"
EndOfLineComment     = "//" {InputCharacter}* {LineTerminator}
DocumentationComment = "/**" {CommentContent} "*"+ "/"
CommentContent       = ( [^*] | \*+ [^/*] )*

Identifier = [:jletter:] [:jletterdigit:]*

DecIntegerLiteral = 0 | [1-9][0-9]*

%state STRING

%%
/* keywords */
/* 
<YYINITIAL>{NONNEWLINE_WHITE_SPACE}+ {}
<YYINITIAL>\"{STRING_TEXT}\" { 
   // System.out.println("I found a string: " + changestring(yytext().substring(1,yytext().length() - 1)));
   return tok(sym.STRINGe, 
	      changestring(yytext().substring(1,yytext().length() - 1))); }
*/
/*<YYINITIAL>{LineTerminator} { System.err.println("line "+(mylinenum++)); }  */
<YYINITIAL>";"      { return symbol(sym.SEMI, null); }
<YYINITIAL>goto     { return symbol(sym.GOTO, null); }
<YYINITIAL>and      { return symbol(sym.ANDop, null); }
<YYINITIAL>label    { return symbol(sym.LABEL, null); }
<YYINITIAL>"("      { return symbol(sym.LPAREN, null); }
<YYINITIAL>")"      { return symbol(sym.RPAREN, null); }
<YYINITIAL>":="     { return symbol(sym.ASSIGN, null); }
<YYINITIAL>"="      { return symbol(sym.EQUAL, null); }
<YYINITIAL>true     { return symbol(sym.TRUE, null); }
<YYINITIAL>false    { return symbol(sym.FALSE, null); }
<YYINITIAL>if       { return symbol(sym.IF, null); }
<YYINITIAL>"+"      { return symbol(sym.PLUS, null); }
<YYINITIAL>"*"      { return symbol(sym.TIMES, null); }
<YYINITIAL>then     { return symbol(sym.THEN, null); }
<YYINITIAL>not      { return symbol(sym.NOT, null); }
<YYINITIAL>print    { // System.out.println("I found a print token!"); 
           return symbol(sym.PRINT, null); }
<YYINITIAL>while     { return symbol(sym.WHILE, null); }
<YYINITIAL>begin     { return symbol(sym.BEGIN, null); }
<YYINITIAL>end       { return symbol(sym.END, null); }

<YYINITIAL> {
{Identifier} { return symbol(sym.ID, yytext()); }
{DecIntegerLiteral} { return symbol(sym.NUM,new Integer(yytext())); }
{Comment} { /* ignore*/ }
{WhiteSpace} {/* ignore */}
}

<YYINITIAL>\"  { string.setLength(0); yybegin(STRING); }
/*<YYINITIAL>{DIGITS} { return symbol(sym.NUM, new Integer(yytext())); }
<YYINITIAL>[a-zA-Z]([a-zA-Z0-9]*)    { return symbol(sym.ID, yytext()); }
*/

<STRING> {
  \"                             { yybegin(YYINITIAL); 
                                   return symbol(sym.STRINGe, 
                                   string.toString()); }
  [^\n\r\"\\]+                   { string.append( yytext() ); }
  \\t                            { string.append('\t'); }
  \\n                            { string.append('\n'); }

  \\r                            { string.append('\r'); }
  \\\"                           { string.append('\"'); }
  \\                             { string.append('\\'); }
}

/* error fallback */
[^]                              { throw new Error("Illegal character <"+
                                                    yytext()+">"); }