lab2 feat: add constant folding

inc/expression.hpp

@@ -186,17 +186,22 @@ public:
 
 	std::shared_ptr<std::string> to_math_str(void) const
 	{
+		char buffer[128] = {0};
+
 		switch (t)
 		{
 		case VAR:
 			return v.s;
 		case CONST:
 		{
-			char buffer[128] = {0};
 			return std::make_shared<std::string>((std::ostringstream() << v.d).str());
 		}
 		case OPERATOR:
 			return std::make_shared<std::string>(op_math_str());
+		case CV:
+			return std::make_shared<std::string>((std::ostringstream() << "t" << v.cv.i).str());
+		case NAT:
+			return std::make_shared<std::string>("");
 		default:
 			return std::make_shared<std::string>("Not a valid token!");
 		}

inc/syntaxer.hpp

@@ -6,8 +6,9 @@
 namespace Syntax
 {
 
-int check_syntax(std::vector<Expression::Token>& tv);
-void apply_corrections(std::vector<Expression::Token>& tv);
+void pre_process(std::vector<Expression::Token>& tv);
+int check_syntax(const std::vector<Expression::Token>& tv);
+void post_process(std::vector<Expression::Token>& tv);
 std::vector<Expression::Operation> build_op_vector(const std::vector<Expression::Token>& tv);
 Expression::TreeNode ov_to_tree(const std::vector<Expression::Token> tv, const std::vector<Expression::Operation>& ov);
 void print_op_tree(const std::vector<Expression::Token> tv, const std::vector<Expression::Operation>& ov);

src/main.cpp

@@ -10,12 +10,14 @@ int main(int argc, char **argv)
 
 	std::vector<Expression::Token> tv = Parser::tokenize_input(argv[1]);
 
+	Syntax::pre_process(tv);
+
 	if (Syntax::check_syntax(tv))
 	{
 		return 0;
 	}
 
-	Syntax::apply_corrections(tv);
+	Syntax::post_process(tv);
 
 	std::vector<Expression::Operation> ov = Syntax::build_op_vector(tv);
 

src/syntaxer.cpp

@@ -5,9 +5,12 @@
 #include <queue>
 #include <stack>
 #include <vector>
+#include <cmath>
 
 namespace Syntax {
 
+static int add_bracket_to(std::vector<Expression::Token>& tv, const int location, const int direction);
+
 static void highlight_issue(const std::vector<Expression::Token>& tv, const int location)
 {
 	int start = location - 7 < 0 ? 0 : location - 7;
@@ -30,7 +33,62 @@ static void highlight_issue(const std::vector<Expression::Token>& tv, const int
 	std::cout << "\n";
 }
 
-int check_syntax(std::vector<Expression::Token>& tv)
+void pre_process(std::vector<Expression::Token>& tv)
+{
+	pr_debug("Pre-process: remove empty brackets");
+	for (int i = 0; i < tv.size() - 1; i++)
+	{
+		if (tv[i].t == Expression::Token::OPERATOR
+			&& tv[i].v.o == Expression::Token::OPA
+			&& tv[i+1].t == Expression::Token::OPERATOR
+			&& tv[i+1].v.o == Expression::Token::CPA)
+		{
+			std::vector<int> highlight;
+			highlight.emplace_back(i);
+			highlight.emplace_back(i+1);
+			Parser::print_math_vector(tv, highlight);
+
+			tv.erase(tv.begin() + i, tv.begin() + i + 2);
+			i--;
+		}
+	}
+
+	pr_debug("Pre-process: unary minus");
+	int change = 1;
+	while (change)
+	{
+		change = 0;
+
+		for (int i = 0; i < tv.size() - 2; i++)
+		{
+			if (tv[i].t == Expression::Token::OPERATOR
+				&& tv[i].v.o != Expression::Token::CPA
+				&& tv[i+1].t == Expression::Token::OPERATOR
+				&& tv[i+1].v.o == Expression::Token::SUB
+				&& (tv[i+2].t == Expression::Token::CONST
+					|| tv[i+2].t == Expression::Token::VAR
+					|| (tv[i+2].t == Expression::Token::OPERATOR
+						&& tv[i+2].v.o == Expression::Token::OPA)))
+			{
+				std::vector<int> highlight;
+
+				tv.insert(tv.begin() + i + 1, Expression::Token(0.0));
+				tv.insert(tv.begin() + i + 1, Expression::Token(Expression::Token::OPA));
+				highlight.emplace_back(add_bracket_to(tv, i + 3, 1));
+
+				highlight.emplace(highlight.begin(), i+2);
+				highlight.emplace(highlight.begin(), i+1);
+				Parser::print_math_vector(tv, highlight);
+
+				i += 4;
+
+				change++;
+			}
+		}
+	}
+}
+
+int check_syntax(const std::vector<Expression::Token>& tv)
 {
 	int problem_cnt = 0;
 
@@ -382,7 +440,7 @@ static int get_max_index(const std::vector<int>& v)
 
 static void write_operation(
 		std::vector<Expression::Operation>& ov,
-		const std::vector<Expression::Token>& tv,
+		std::vector<Expression::Token>& cv,
 		std::vector<Expression::Token>& mv,
 		std::vector<int>& mp,
 		int position)
@@ -391,10 +449,54 @@ static void write_operation(
 	int left_location = get_left_location(mv, location);
 	int right_location = get_right_location(mv, location);
 
+	std::vector<int> hl;
+	hl.emplace_back(left_location);
+	hl.emplace_back(location);
+	hl.emplace_back(right_location);
+	Parser::print_math_vector(mv, hl);
+
 	Expression::Token &o = mv[location],
 	      &l = mv[left_location],
 	      &r = mv[right_location];
 
+#if LAB2_EXCLUDE_COMPTIME_OP_WRITES == 1
+	if (l.t == Expression::Token::CONST && r.t == Expression::Token::CONST)
+	{
+		pr_debug("CONST folding");
+
+		switch (o.v.o)
+		{
+		case Expression::Token::ADD:
+			o.v.d = l.v.d + r.v.d;
+			break;
+		case Expression::Token::SUB:
+			o.v.d = l.v.d - r.v.d;
+			break;
+		case Expression::Token::MUL:
+			o.v.d = l.v.d * r.v.d;
+			break;
+		case Expression::Token::DIV:
+			o.v.d = l.v.d / r.v.d;
+			break;
+		case Expression::Token::POW:
+			o.v.d = std::pow(l.v.d, r.v.d);
+			break;
+		default:
+			pr_warn("Impossible operator, this is a bug!");
+			break;
+		}
+
+		l.t = Expression::Token::NAT;
+		r.t = Expression::Token::NAT;
+		o.t = Expression::Token::CONST;
+
+		// sync &cv operator
+		cv[location].t = Expression::Token::CONST;
+		cv[location].v.d = o.v.d;
+	}
+	else
+	{
+#endif
 		int this_op_weight = get_operator_weight(mv, location) + 1;
 
 		int il = l.t == Expression::Token::CV ? l.v.cv.i : left_location;
@@ -415,6 +517,9 @@ static void write_operation(
 		o.t = Expression::Token::CV;
 		o.v.cv.w = this_op_weight;
 		o.v.cv.i = this_ov_index;
+#if LAB2_EXCLUDE_COMPTIME_OP_WRITES == 1
+	}
+#endif
 
 	// update mp
 	mp.erase(mp.begin() + position, mp.begin() + position + 1);
@@ -639,7 +744,7 @@ static void weight_operators(std::vector<int>& operator_weights, const std::vect
 	}
 }
 
-void apply_corrections(std::vector<Expression::Token>& tv)
+void post_process(std::vector<Expression::Token>& tv)
 {
 	pr_debug("Post processing:");
 	Parser::print_math_vector(tv);
@@ -732,15 +837,14 @@ std::vector<Expression::Operation> build_op_vector(const std::vector<Expression:
 	std::vector<int> g_prios;
 	create_prios_vector(tv, g_prios);
 
-	for (int i = 0, l = g_prios.size(); i < l; i++)
-	{
-		pr_debug("prio=" << g_prios[i]);
-	}
+	pr_debug("Building operation vector");
+
+	std::vector<Expression::Token> cv = tv; // Constant sync Vector
 
 	// build operation vector
 	std::vector<Expression::Operation> ov;
 	{
-		std::vector<Expression::Token> mv = tv;
+		std::vector<Expression::Token> mv = tv; // Modifiable Vector
 		std::vector<int> mp = g_prios;
 
 		while (mp.size())
@@ -757,15 +861,20 @@ std::vector<Expression::Operation> build_op_vector(const std::vector<Expression:
 				std::vector<int> operator_weights;
 				weight_operators(operator_weights, mv, inner_top_ops, start);
 
-				write_operation(ov, tv, mv, mp, start + inner_top_ops[get_min_index(operator_weights)]);
+				write_operation(ov, cv, mv, mp, start + inner_top_ops[get_min_index(operator_weights)]);
 				finish--;
 			}
 
 			// process final operation w/out running selection algorithm
-			write_operation(ov, tv, mv, mp, start);
+			write_operation(ov, cv, mv, mp, start);
 		}
+
+		pr_debug("Final value:");
+		Parser::print_math_vector(mv);
 	}
 
+	pr_debug("Resulting operation vector:");
+
 	for (int i = 0, l = ov.size(); i < l; i++)
 	{
 		const Expression::Operation &o = ov[i];
@@ -774,16 +883,8 @@ std::vector<Expression::Operation> build_op_vector(const std::vector<Expression:
 
 		if (o.tl == Expression::Operation::NORMAL)
 		{
-			const Expression::Token &real_value = tv[o.il];
-
-			if (real_value.t == Expression::Token::VAR)
-			{
-				pri_debug(*real_value.v.s);
-			}
-			else
-			{
-				pri_debug(real_value.v.d);
-			}
+			const Expression::Token &real_value = cv[o.il];
+			pri_debug(*real_value.to_math_str());
 		}
 		else
 		{
@@ -794,16 +895,8 @@ std::vector<Expression::Operation> build_op_vector(const std::vector<Expression:
 
 		if (o.tr == Expression::Operation::NORMAL)
 		{
-			const Expression::Token &real_value = tv[o.ir];
-
-			if (real_value.t == Expression::Token::VAR)
-			{
-				pri_debug(*real_value.v.s);
-			}
-			else
-			{
-				pri_debug(real_value.v.d);
-			}
+			const Expression::Token &real_value = cv[o.ir];
+			pri_debug(*real_value.to_math_str());
 		}
 		else
 		{
@@ -860,13 +953,6 @@ Expression::TreeNode ov_to_tree(const std::vector<Expression::Token> tv, const s
 	return root;
 }
 
-#if 0
-static int get_tree_depth(const Expression::TreeNode& root)
-{
-	retur
-}
-#endif
-
 void print_op_tree(const Expression::TreeNode& root)
 {
 	std::vector<std::pair<Expression::TreeNode *, int>> items_to_display;

src/test-cases.cpp

@@ -99,7 +99,7 @@ TEST(tree_proper_test_1)
 TEST(tree_proper_test_2)
 {
 	std::vector<Expression::Token> o = Parser::tokenize_input("(1**5 * (1-2-3-4-5-6-7-8))");
-	Syntax::apply_corrections(o);
+	Syntax::post_process(o);
 	std::vector<Expression::Operation> ov = Syntax::build_op_vector(o);
 
 	return 0;