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import java.lang.System;
class Sample {
public static void main(String argv[]) throws java.io.IOException {
Yylex yy = new Yylex(System.in);
Yytoken t;
while ((t = yy.yylex()) != null)
System.out.println(t);
}
}
class Utility {
public static void assert
(
boolean expr
)
{
if (false == expr) {
throw (new Error("Error: Assertion failed."));
}
}
private static final String errorMsg[] = {
"Error: Unmatched end-of-comment punctuation.",
"Error: Unmatched start-of-comment punctuation.",
"Error: Unclosed string.",
"Error: Illegal character."
};
public static final int E_ENDCOMMENT = 0;
public static final int E_STARTCOMMENT = 1;
public static final int E_UNCLOSEDSTR = 2;
public static final int E_UNMATCHED = 3;
public static void error
(
int code
)
{
System.out.println(errorMsg[code]);
}
}
class Yytoken {
Yytoken
(
int index,
String text,
int line,
int charBegin,
int charEnd
)
{
m_index = index;
m_text = new String(text);
m_line = line;
m_charBegin = charBegin;
m_charEnd = charEnd;
}
public int m_index;
public String m_text;
public int m_line;
public int m_charBegin;
public int m_charEnd;
public String toString() {
return "Token #"+m_index+": "+m_text+" (line "+m_line+")";
}
}
%%
%{
private int comment_count = 0;
%}
%line
%char
%state COMMENT
ALPHA=[A-Za-z]
DIGIT=[0-9]
NONNEWLINE_WHITE_SPACE_CHAR=[\ \t\b\012]
WHITE_SPACE_CHAR=[\n\ \t\b\012]
STRING_TEXT=(\\\"|[^\n\"]|\\{WHITE_SPACE_CHAR}+\\)*
COMMENT_TEXT=([^/*\n]|[^*\n]"/"[^*\n]|[^/\n]"*"[^/\n]|"*"[^/\n]|"/"[^*\n])*
%%
<YYINITIAL> "," { return (new Yytoken(0,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> ":" { return (new Yytoken(1,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> ";" { return (new Yytoken(2,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "(" { return (new Yytoken(3,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> ")" { return (new Yytoken(4,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "[" { return (new Yytoken(5,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "]" { return (new Yytoken(6,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "{" { return (new Yytoken(7,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "}" { return (new Yytoken(8,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "." { return (new Yytoken(9,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "+" { return (new Yytoken(10,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "-" { return (new Yytoken(11,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "*" { return (new Yytoken(12,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "/" { return (new Yytoken(13,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "=" { return (new Yytoken(14,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "<>" { return (new Yytoken(15,yytext(),yyline,yychar,yychar+2)); }
<YYINITIAL> "<" { return (new Yytoken(16,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "<=" { return (new Yytoken(17,yytext(),yyline,yychar,yychar+2)); }
<YYINITIAL> ">" { return (new Yytoken(18,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> ">=" { return (new Yytoken(19,yytext(),yyline,yychar,yychar+2)); }
<YYINITIAL> "&" { return (new Yytoken(20,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> "|" { return (new Yytoken(21,yytext(),yyline,yychar,yychar+1)); }
<YYINITIAL> ":=" { return (new Yytoken(22,yytext(),yyline,yychar,yychar+2)); }
<YYINITIAL> {NONNEWLINE_WHITE_SPACE_CHAR}+ { }
<YYINITIAL,COMMENT> \n { }
<YYINITIAL> "/*" { yybegin(COMMENT); comment_count = comment_count + 1; }
<COMMENT> "/*" { comment_count = comment_count + 1; }
<COMMENT> "*/" {
comment_count = comment_count - 1;
Utility.assert(comment_count >= 0);
if (comment_count == 0) {
yybegin(YYINITIAL);
}
}
<COMMENT> {COMMENT_TEXT} { }
<YYINITIAL> \"{STRING_TEXT}\" {
String str = yytext().substring(1,yytext().length() - 1);
Utility.assert(str.length() == yytext().length() - 2);
return (new Yytoken(40,str,yyline,yychar,yychar + str.length()));
}
<YYINITIAL> \"{STRING_TEXT} {
String str = yytext().substring(1,yytext().length());
Utility.error(Utility.E_UNCLOSEDSTR);
Utility.assert(str.length() == yytext().length() - 1);
return (new Yytoken(41,str,yyline,yychar,yychar + str.length()));
}
<YYINITIAL> {DIGIT}+ {
return (new Yytoken(42,yytext(),yyline,yychar,yychar + yytext().length()));
}
<YYINITIAL> {ALPHA}({ALPHA}|{DIGIT}|_)* {
return (new Yytoken(43,yytext(),yyline,yychar,yychar + yytext().length()));
}
<YYINITIAL,COMMENT> . {
System.out.println("Illegal character: <" + yytext() + ">");
Utility.error(Utility.E_UNMATCHED);
}
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