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Appendice B : Definizione Lexer Jflex
import java_cup.runtime.*; %% %class prova %unicode %cup %line %column %{
StringBuffer string = new StringBuffer();
private Symbol symbol(int type) {
return new Symbol(type, yyline, yycolumn); }
private Symbol symbol(int type, Object value) {
return new Symbol(type, yyline, yycolumn, value); } %} Terminatori = \r|\n|\r\n InputC = [^\r\n] Spazio = {Terminatori} | [ \t\f]* /*Commenti*/
Commenti = {Tradizionali} | {FineLinea} | {Documentazione} Tradizionali = "/*" [^*] ~"*/" | "/*" "*"+ "/"
FineLinea = "//" {InputC}* {Terminatori} Documentazione = "/**" {Contenuti} "*"+ "/"
95
Contenuti = ( [^*] | \*+ [^/*] )*
Identificatori = [a-zA-Z] [a-zA-Z0-9]*
Digits = [0-9]+ Char = '.' bool = true|false InteriDec = 0 | [1-9][0-9]* Razionali = {Digits}"."{Digits} %state TKSTRING %% <YYINITIAL> { /*Booleani*/
{bool} { return symbol(sym.TKBOOL, new Boolean(yytext())); }
/*Interi decimali*/
{InteriDec} { return symbol(sym.TKINT, new Integer(yytext())); }
/*Stringhe*/
\" { string.setLength(0); yybegin(TKSTRING); }
/*Singoli caratteri*/
{Char} { return symbol(sym.TKCHAR,new Character(yycharat(1))); }
/*Razionali*/
{Razionali} { return symbol(sym.TKREAL,
96 /*Simboli*/ ":=" { return symbol(sym.UPDATE); } "[" { return symbol(sym.LBRACK); } "]" { return symbol(sym.RBRACK); } "(" { return symbol(sym.LPAREN); } ")" { return symbol(sym.RPAREN); } "." { return symbol(sym.DOT); } "," { return symbol(sym.COMMA); } "=" { return symbol(sym.EQ); } "^" { return symbol(sym.EXT); } "let" { return symbol(sym.LET); } "in" { return symbol(sym.IN); } ":" { return symbol(sym.COLON); } "->" { return symbol(sym.ARROW); } ";" { return symbol(sym.SEMI); }
"INT" { return symbol(sym.INT); } "REAL" { return symbol(sym.REAL); } "STRING" { return symbol(sym.STRING); } "CHAR" { return symbol(sym.CHAR); } "BOOL" { return symbol(sym.BOOL); } "Type" { return symbol(sym.Type); } "epyT" { return symbol(sym.epyT); }
/*Identificatori*/
{Identificatori} { return symbol(sym.IDE, new String(yytext())); }
/*Commenti*/ {Commenti} { /* ignore */ } /*Spazio*/ {Spazio} { /* ignore */ } } <TKSTRING> {
97 \" { yybegin(YYINITIAL); return symbol(sym.TKSTRING, string.toString()); } [^\n\r\"\\]+ { string.append( yytext() ); } \\t { string.append( '\t' ); } \\n { string.append( '\n' ); } \\r { string.append( '\r' ); } \\\" { string.append( '\"' ); } \\ { string.append( '\\' ); } } /* Errore */ .|\n {
throw new RuntimeException("Carattere illegale \"" +yytext()+ "\" at line "+yyline+", column "+yycolumn); }
/*Fine file*/
