X-Git-Url: http://shamusworld.gotdns.org/cgi-bin/gitweb.cgi?p=rmac;a=blobdiff_plain;f=expr.c;fp=expr.c;h=5a9155c67832c1ee049d899415a0c924b40b4a07;hp=2361817784d7c0eccab31b9060de867613c1ff7d;hb=3f937a2ab53c5fa20f5468e59c278da9d8c54b02;hpb=9aa8503cdc9933350f14299d326ec7ee379721b8

diff --git a/expr.c b/expr.c
index 2361817..5a9155c 100644
--- a/expr.c
+++ b/expr.c
@@ -93,24 +93,97 @@ void InitExpression(void)
 	symbolNum = 0;
 }
 
+extern int correctMathRules;
+int xor(void);
+int and(void);
+int rel(void);
+int shift(void);
+int sum(void);
+int product(void);
+
 //
-// Binary operators (all the same precedence)
+// Binary operators (all the same precedence,
+// except if -4 is passed to the command line)
 //
+#define precedence(HIERARCHY_HIGHER, HIERARCHY_CURRENT) \
+do \
+{ \
+	if (HIERARCHY_HIGHER() != OK) \
+		return ERROR; \
+	while (tokenClass[*tok] == HIERARCHY_CURRENT) \
+	{ \
+		TOKEN t = *tok++; \
+		if (HIERARCHY_HIGHER() != OK) \
+			return ERROR; \
+		*evalTokenBuffer.u32++ = t; \
+	} \
+}while (0)
+
 int expr0(void)
 {
-	if (expr1() != OK)
-		return ERROR;
-
-	while (tokenClass[*tok] >= MULT)
+	if ( correctMathRules == 0 )
 	{
-		TOKEN t = *tok++;
-
 		if (expr1() != OK)
 			return ERROR;
 
-		*evalTokenBuffer.u32++ = t;
+		while (tokenClass[*tok] >= MULT)
+		{
+			TOKEN t = *tok++;
+
+			if (expr1() != OK)
+				return ERROR;
+
+			*evalTokenBuffer.u32++ = t;
+		}
 	}
+	else
+	{
+		// The order of C precedence (lower to higher):
+		// bitwise XOR ^
+		// bitwise OR |
+		// bitwise AND &
+		// relational = < <= >= > !=
+		// shifts << >>
+		// sum + -
+		// product * /
+		precedence(xor, OR);
+	}
+	return OK;
+}
 
+int xor(void)
+{
+	precedence(and, XOR);
+	return OK;
+}
+
+int and(void)
+{
+	precedence(rel, AND);
+	return OK;
+}
+
+int rel(void)
+{
+	precedence(shift, REL);
+	return OK;
+}
+
+int shift(void)
+{
+	precedence(sum, SHIFT);
+	return OK;
+}
+
+int sum(void)
+{
+	precedence(product, ADD);
+	return OK;
+}
+
+int product(void)
+{
+	precedence(expr1, MULT);
 	return OK;
 }