Implemented switch-case grammar.

mzweilin · Oct 26, 2013 · ce058e4 · ce058e4
1 parent 15844fd
commit ce058e4
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Showing 2 changed files with 23 additions and 3 deletions.
diff --git a/wx4ed/src/pp2/parser.y b/wx4ed/src/pp2/parser.y
@@ -87,7 +87,7 @@ void yyerror(const char *msg); // standard error-handling routine
 %token   T_And T_Or T_Null T_Extends T_This T_Interface T_Implements
 %token   T_While T_For T_If T_Else T_Return T_Break
 %token   T_New T_NewArray T_Print T_ReadInteger T_ReadLine
-%token   T_Incr T_Decr
+%token   T_Incr T_Decr T_Switch T_Case T_Default
 
 %token   <identifier> T_Identifier
 %token   <stringConstant> T_StringConstant 
@@ -126,6 +126,7 @@ void yyerror(const char *msg); // standard error-handling routine
 %type <breakStmt>       BreakStmt
 %type <returnStmt>      ReturnStmt
 %type <printStmt>       PrintStmt
+%type <switchStmt>      SwitchStmt
 
 %nonassoc '='
 %left     T_Or
@@ -260,6 +261,7 @@ Stmt      :     ExprOpt ';'
           |     BreakStmt
           |     ReturnStmt
           |     PrintStmt
+          |     SwitchStmt
           |     StmtBlock
 ;
 
@@ -282,6 +284,22 @@ BreakStmt :     T_Break ';'
 PrintStmt :     T_Print '(' ExprPlus ')' ';'
 ;
 
+SwitchStmt  :   T_Switch '(' Expr ')' '{' CaseStmts DefaultStmt '}'
+;
+
+CaseStmts   :   CaseStmts CaseStmt
+            |   CaseStmt
+;
+
+CaseStmt    :   T_Case T_IntConstant ':' StmtList
+            |   T_Case T_IntConstant ':'
+;
+
+DefaultStmt :   T_Default ':' StmtList
+            |   T_Default ':'
+            |   /* empty */
+;
+
 ExprOpt     :   Expr
             |   // empty
 ;

diff --git a/wx4ed/src/pp2/scanner.l b/wx4ed/src/pp2/scanner.l
@@ -51,7 +51,7 @@ DOUBLE            ({INTEGER}"."{DIGIT}*{EXPONENT}?)
 BEG_STRING        (\"[^"\n]*)
 STRING            ({BEG_STRING}\")
 IDENTIFIER        ([a-zA-Z][a-zA-Z_0-9]*)
-OPERATOR          ([-+/*%=.,;!<>()[\]{}])
+OPERATOR          ([-+/*%=.,:;!<>()[\]{}])
 BEG_COMMENT       ("/*")
 END_COMMENT       ("*/")
 SINGLE_COMMENT    ("//"[^\n]*)
@@ -102,7 +102,9 @@ SINGLE_COMMENT    ("//"[^\n]*)
 "Print"             { return T_Print;       }
 "ReadInteger"       { return T_ReadInteger; }
 "ReadLine"          { return T_ReadLine;    }
-
+"switch"            { return T_Switch;      }
+"case"              { return T_Case;        }
+"default"           { return T_Default;     }
 
 
  /* -------------------- Operators ----------------------------- */