diff --git a/src/bison/bison_parser.y b/src/bison/bison_parser.y
index e26ef28..b730d02 100644
--- a/src/bison/bison_parser.y
+++ b/src/bison/bison_parser.y
@@ -231,8 +231,8 @@ scalar_expr:
 	;
 
 unary_expr:
-		'-' expr { $$ = Expr::makeOpUnary(UMINUS, $2); }
-	|	NOT expr { $$ = Expr::makeOpUnary(NOT, $2); }
+		'-' expr { $$ = Expr::makeOpUnary(Expr::UMINUS, $2); }
+	|	NOT expr { $$ = Expr::makeOpUnary(Expr::NOT, $2); }
 	;
 
 binary_expr:
@@ -241,26 +241,26 @@ binary_expr:
 	|	expr '+' expr { $$ = Expr::makeOpBinary($1, '+', $3); }
 	|	expr '/' expr { $$ = Expr::makeOpBinary($1, '/', $3); }
 	|	expr '*' expr { $$ = Expr::makeOpBinary($1, '*', $3); }
-	|	expr AND expr { $$ = Expr::makeOpBinary($1, AND, $3); }
-	|	expr OR expr { $$ = Expr::makeOpBinary($1, OR, $3); }
+	|	expr AND expr { $$ = Expr::makeOpBinary($1, Expr::AND, $3); }
+	|	expr OR expr { $$ = Expr::makeOpBinary($1, Expr::OR, $3); }
 	;
 
 
 comp_expr:
 		expr EQUALS expr { $$ = Expr::makeOpBinary($1, '=', $3); }
-	|	expr NOTEQUALS expr { $$ = Expr::makeOpBinary($1, NOT_EQUALS, $3); }
+	|	expr NOTEQUALS expr { $$ = Expr::makeOpBinary($1, Expr::NOT_EQUALS, $3); }
 	|	expr LESS expr { $$ = Expr::makeOpBinary($1, '<', $3); }
 	|	expr GREATER expr { $$ = Expr::makeOpBinary($1, '>', $3); }
-	|	expr LESSEQ expr { $$ = Expr::makeOpBinary($1, LESS_EQ, $3); }
-	|	expr GREATEREQ expr { $$ = Expr::makeOpBinary($1, GREATER_EQ, $3); }
+	|	expr LESSEQ expr { $$ = Expr::makeOpBinary($1, Expr::LESS_EQ, $3); }
+	|	expr GREATEREQ expr { $$ = Expr::makeOpBinary($1, Expr::GREATER_EQ, $3); }
 	;
 
 function_expr:
-		NAME '(' expr ')' { $$ = makeFunctionRef($1, $3); }
+		NAME '(' expr ')' { $$ = Expr::makeFunctionRef($1, $3); }
 	;
 
 column_name:
-		NAME { $$ = makeColumnRef($1); }
+		NAME { $$ = Expr::makeColumnRef($1); }
 	;
 
 literal:
diff --git a/src/lib/Expr.cpp b/src/lib/Expr.cpp
index 2cf99bd..0f20b57 100644
--- a/src/lib/Expr.cpp
+++ b/src/lib/Expr.cpp
@@ -11,18 +11,6 @@ char* substr(const char* source, int from, int to) {
 	return copy;
 }
 
-Expr* makeColumnRef(char* name) {
-	ALLOC_EXPR(e, kExprColumnRef);
-	e->name = name;
-	return e;
-}
-
-Expr* makeFunctionRef(char* func_name, Expr* expr) {
-	ALLOC_EXPR(e, kExprFunctionRef);
-	e->name = func_name;
-	e->expr = expr;
-	return e;
-}
 
 
 
@@ -64,7 +52,7 @@ Expr* Expr::makeLiteral(int64_t val) {
 
 Expr* Expr::makeLiteral(double value) {
 	ALLOC_EXPR(e, kExprLiteralFloat);
-	e->float_literal = value;
+	e->fval = value;
 	return e;
 }
 
@@ -75,3 +63,16 @@ Expr* Expr::makeLiteral(char* string) {
 	return e;
 }
 
+
+Expr* Expr::makeColumnRef(char* name) {
+	ALLOC_EXPR(e, kExprColumnRef);
+	e->name = name;
+	return e;
+}
+
+Expr* Expr::makeFunctionRef(char* func_name, Expr* expr) {
+	ALLOC_EXPR(e, kExprFunctionRef);
+	e->name = func_name;
+	e->expr = expr;
+	return e;
+}
\ No newline at end of file
diff --git a/src/lib/Expr.h b/src/lib/Expr.h
index 18533df..4d4b071 100644
--- a/src/lib/Expr.h
+++ b/src/lib/Expr.h
@@ -3,8 +3,6 @@
 
 #include <stdlib.h>
 
-
-
 typedef enum {
 	kExprLiteralFloat,
 	kExprLiteralString,
@@ -15,32 +13,33 @@ typedef enum {
 	kExprOperator
 } ExprType;
 
-
-/**
- * Trivial types are those that can be descriped by a sigle character e.g:
- * + - * / < > = %
- * Non-trivial are:
- * <> <= >= LIKE ISNULL NOT
- */
-typedef enum {
-	SIMPLE_OP,
-	// Binary
-	NOT_EQUALS,
-	LESS_EQ,
-	GREATER_EQ,
-	LIKE,
-	AND,
-	OR,
-	// Unary
-	NOT,
-	UMINUS,
-	ISNULL
-} OperatorType;
-
-
-
 typedef struct Expr Expr;
+
 struct Expr {
+	/**
+	 * Operator types. These are important for expressions of type kExprOperator
+	 * Trivial types are those that can be descriped by a sigle character e.g:
+	 * + - * / < > = %
+	 * Non-trivial are:
+	 * <> <= >= LIKE ISNULL NOT
+	 */
+	typedef enum {
+		SIMPLE_OP,
+		// Binary
+		NOT_EQUALS,
+		LESS_EQ,
+		GREATER_EQ,
+		LIKE,
+		AND,
+		OR,
+		// Unary
+		NOT,
+		UMINUS,
+		ISNULL
+	} OperatorType;
+
+
+
 	Expr(ExprType type) : type(type) {};
 	
 	ExprType type;
@@ -48,7 +47,7 @@ struct Expr {
 	Expr* expr;
 	Expr* expr2;
 	char* name;
-	float float_literal;
+	float fval;
 	int64_t ival;
 
 	OperatorType op_type;
@@ -61,6 +60,9 @@ struct Expr {
 	static Expr* makeLiteral(int64_t val);
 	static Expr* makeLiteral(double val);
 	static Expr* makeLiteral(char* val);
+
+	static Expr* makeColumnRef(char* name);
+	static Expr* makeFunctionRef(char* func_name, Expr* expr);
 };
 
 // Zero initializes an Expr object and assigns it to a space in the heap
@@ -73,8 +75,4 @@ struct Expr {
 		*var = zero;				\
 	} while(0)
 
-
-Expr* makeColumnRef(char* name);
-Expr* makeFunctionRef(char* func_name, Expr* expr);
-
 #endif
diff --git a/src/lib/sqlhelper.cpp b/src/lib/sqlhelper.cpp
index 3a94efa..4f6d572 100644
--- a/src/lib/sqlhelper.cpp
+++ b/src/lib/sqlhelper.cpp
@@ -31,10 +31,10 @@ void printOperatorExpression(Expr* expr, uint num_indent) {
   if (expr == NULL) { inprint("null", num_indent); return; }
 
   switch (expr->op_type) {
-    case SIMPLE_OP: inprintC(expr->op_char, num_indent); break;
-    case AND: inprint("AND", num_indent); break;
-    case OR: inprint("OR", num_indent); break;
-    case NOT: inprint("NOT", num_indent); break;
+    case Expr::SIMPLE_OP: inprintC(expr->op_char, num_indent); break;
+    case Expr::AND: inprint("AND", num_indent); break;
+    case Expr::OR: inprint("OR", num_indent); break;
+    case Expr::NOT: inprint("NOT", num_indent); break;
     default: inprintU(expr->op_type, num_indent); break;
   }
   printExpression(expr->expr, num_indent+1);
@@ -45,7 +45,7 @@ void printExpression(Expr* expr, uint num_indent) {
   switch (expr->type) {
     case kExprStar: inprint("*", num_indent); break;
     case kExprColumnRef: inprint(expr->name, num_indent); break;
-    case kExprLiteralFloat: inprint(expr->float_literal, num_indent); break;
+    case kExprLiteralFloat: inprint(expr->fval, num_indent); break;
     case kExprLiteralInt: inprint(expr->ival, num_indent); break;
     case kExprLiteralString: inprint(expr->name, num_indent); break;
     case kExprFunctionRef: /* todo */ break;