1 files changed, 54 insertions, 0 deletions
diff --git a/sem3/osc/mm11/regn/regn.y b/sem3/osc/mm11/regn/regn.y
new file mode 100644
index 0000000..d0f67eb
--- /dev/null
+++ b/sem3/osc/mm11/regn/regn.y
@@ -0,0 +1,54 @@
+%{
+#include <stdio.h>
+#include <math.h>
+#include "symtab.h"
+#include <string.h>
+%}
+
+%union {
+	char           *string;
+	double          dval;
+}
+
+%token <string> VAR
+%token <dval> TAL
+%token LOG EXP SQRT VAR_BEGIN
+
+%left '-' '+'
+%right LOG EXP SQRT
+%left '*' '/'
+%right UMINUS
+
+%type <dval> expression
+
+%%
+
+statement_list: statement '\n'
+	  | statement_list statement '\n' ;
+
+statement:  expression					{printf("= %f\n",$1);}
+	  | VAR_BEGIN VAR '=' expression	{symnode_t *n = sym_lookup($2);
+										 if( !n ) {n = sym_insert($2); }
+										 n->value = $4;};
+
+expression: expression '+' expression   {$$ = $1 + $3;}
+	  | expression '-' expression   {$$ = $1 - $3;}
+	  | expression '*' expression   {$$ = $1 * $3;}
+	  | expression '/' expression   {if ($3 == 0.0) 
+                                           yyerror("divide dy zero");
+                                         else $$ = $1 / $3;}
+	  | '-' expression %prec UMINUS {$$ =  - $2;}
+	  | '(' expression ')'          {$$= $2;}
+	  | LOG expression				{$$ = log($2);}
+	  | EXP expression				{$$ = exp($2);}
+	  | SQRT expression				{$$ = sqrt($2);}
+          | TAL                         {$$ = $1;}
+	  | VAR							{symnode_t *n = sym_lookup($1);
+									 if( !n ) { yyerror("Var not found"); } else { $$ = n->value;} };
+%%
+
+int main()
+{ 
+  yyparse(); 
+}
+