commit 2999c295aff2ea7af21e6c931a6f53efa2873aa1
Author: hasslesstech <hasslesstech@tutanota.com>
Date:   Fri Oct 2 20:31:24 2026 +0300

    initial commit

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..d378480
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,37 @@
+cmake_minimum_required(VERSION 3.10)
+
+SET(CMAKE_CXX_FLAGS_DEBUG "-g")
+
+project(pzks)
+
+set (GLOBAL_INC PRIVATE
+	${CMAKE_CURRENT_SOURCE_DIR}/inc
+	${CMAKE_CURRENT_SOURCE_DIR}
+)
+
+
+add_library(parser STATIC)
+
+target_sources(parser PRIVATE
+	src/parser.cpp
+)
+
+target_include_directories(parser PRIVATE
+	${GLOBAL_INC}
+)
+
+
+add_executable(tester)
+
+target_sources(tester PRIVATE
+	src/test.cpp
+)
+
+target_include_directories(tester PRIVATE
+	${GLOBAL_INC}
+	${CMAKE_CURRENT_SOURCE_DIR}/src
+)
+
+target_link_libraries(tester PRIVATE
+	parser
+)
diff --git a/config.h b/config.h
new file mode 100644
index 0000000..30759e6
--- /dev/null
+++ b/config.h
@@ -0,0 +1,3 @@
+#pragma once
+
+#define DEBUG 1
diff --git a/inc/expression.hpp b/inc/expression.hpp
new file mode 100644
index 0000000..11247a2
--- /dev/null
+++ b/inc/expression.hpp
@@ -0,0 +1,157 @@
+#pragma once
+
+#include <iostream>
+#include <memory>
+#include <string>
+
+namespace Expression {
+
+#if 0
+namespace TokenType {
+
+enum TokenType {
+	VAR,
+	CONST,
+	OPERATOR
+};
+
+}
+#endif
+
+class Token {
+public:
+	enum TokenType {
+		VAR,
+		CONST,
+		OPERATOR
+	} t;
+
+	enum Operator {
+		OPA, // opening parentheses
+		CPA, // closing parentheses
+		ADD,
+		SUB,
+		MUL,
+		DIV,
+		POW
+	};
+
+	union TokenValue {
+		std::shared_ptr<std::string> s;
+		double d;
+		Operator o;
+
+		explicit TokenValue(std::string& s)
+			: s(std::make_shared<std::string>(s))
+		{
+		}
+
+		explicit TokenValue(double d)
+			: d(d)
+		{
+		}
+
+		explicit TokenValue(enum Operator o)
+			: o(o)
+		{
+		}
+
+		explicit TokenValue(void)
+		{
+		}
+
+		~TokenValue(void)
+		{
+		}
+	} v;
+
+	Token(std::string s)
+		: v(s)
+	{
+		t = VAR;
+	}
+
+	Token(double d)
+		: v(d)
+	{
+		t = CONST;
+	}
+
+	Token(enum Operator o)
+		: v(o)
+	{
+		t = OPERATOR;
+	}
+
+	Token(Expression::Token&& other)
+	{
+		t = other.t;
+
+		switch (t)
+		{
+		case VAR:
+			v.s = other.v.s;
+			break;
+		case CONST:
+			v.d = other.v.d;
+			break;
+		case OPERATOR:
+			v.o = other.v.o;
+			break;
+		default:
+			std::cout << "Warning: token type is invalid\n";
+			break;
+		}
+	}
+
+	const char *type_str(void)
+	{
+		switch (t)
+		{
+		case VAR:
+			return "VAR";
+		case CONST:
+			return "CONST";
+		case OPERATOR:
+			return "OPERATOR";
+		default:
+			return "Not a valid type";
+		}
+	}
+
+	const char *op_str(void)
+	{
+		if (t != OPERATOR)
+		{
+			return "Token is not an operator!";
+		}
+
+		switch (v.o)
+		{
+		case OPA:
+			return "OPA";
+		case CPA:
+			return "CPA";
+		case ADD:
+			return "ADD";
+		case SUB:
+			return "SUB";
+		case MUL:
+			return "MUL";
+		case DIV:
+			return "DIV";
+		case POW:
+			return "POW";
+		default:
+			return "Invalid operator";
+		}
+	}
+};
+
+class TreeNode {
+	std::shared_ptr<Token> l; // left hand
+	std::shared_ptr<Token> o; // operation
+	std::shared_ptr<Token> r; // right hand
+};
+
+}
diff --git a/inc/parser.hpp b/inc/parser.hpp
new file mode 100644
index 0000000..45755d4
--- /dev/null
+++ b/inc/parser.hpp
@@ -0,0 +1,11 @@
+#pragma once
+
+#include <vector>
+#include "expression.hpp"
+
+namespace Parser {
+
+std::shared_ptr<std::vector<Expression::Token>> tokenize_input(char *input_string);
+int assert_same(std::vector<Expression::Token>& a, std::vector<Expression::Token>& b);
+
+}
diff --git a/inc/print.h b/inc/print.h
new file mode 100644
index 0000000..95725d8
--- /dev/null
+++ b/inc/print.h
@@ -0,0 +1,12 @@
+#pragma once
+
+#include <iostream>
+#include "config.h"
+
+#if DEBUG == 1
+#define pr_debug(...) std::cout << "[" << __func__ << ":" << __LINE__ << "] debug: " << __VA_ARGS__ << "\n"
+#else
+#define pr_debug(...) do {} while (0)
+#endif
+
+#define pr_warn(...) std::cout << "[" << __func__ << ":" << __LINE__ << "] warning: " << __VA_ARGS__ << "\n"
diff --git a/inc/test-tools.hpp b/inc/test-tools.hpp
new file mode 100644
index 0000000..7b0badf
--- /dev/null
+++ b/inc/test-tools.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <iostream>
+#include <vector>
+
+typedef int (*TestFunc)(void);
+
+extern std::vector<TestFunc> test_funcs;
+
+#define CHECK(a) do { \
+	if (a) { \
+		std::cout << "Failed check in " << __func__ << ":" << __LINE__ << "\n" \
+			  << #a << " does not hold\n"; \
+		return 1; \
+	} \
+} while (0)
+
+#define TEST(name) static int name(void)
+#define REGISTER(name) test_funcs.push_back(name)
diff --git a/src/parser.cpp b/src/parser.cpp
new file mode 100644
index 0000000..3eadbf9
--- /dev/null
+++ b/src/parser.cpp
@@ -0,0 +1,312 @@
+#include <iostream>
+#include <cctype>
+#include <cstring>
+#include <memory>
+#include <vector>
+#include "expression.hpp"
+#include "print.h"
+
+namespace Parser {
+
+class Parser
+{
+	enum State {
+		I, // idle
+		RC, // read constant
+		RV, // read variable
+		OP, // read operator
+	} s;
+
+	const char *state_str(enum State e)
+	{
+		switch (e)
+		{
+		case I:
+			return "I";
+		case RC:
+			return "RC";
+		case RV:
+			return "RV";
+		case OP:
+			return "OP";
+		default:
+			return "Not a valid state!";
+		}
+	}
+
+	void switch_state(enum State e)
+	{
+		pr_debug("Leaving " << state_str(s) << ", entering " << state_str(e));
+		switch (s)
+		{
+		case I:
+			leave_i();
+			break;
+		case RC:
+			leave_rc();
+			break;
+		case RV:
+			leave_rv();
+			break;
+		case OP:
+			leave_op();
+			break;
+		default:
+			pr_warn("Warning: broken state machine on leave");
+			break;
+		}
+
+		switch (e)
+		{
+		case I:
+			enter_i();
+			break;
+		case RC:
+			enter_rc();
+			break;
+		case RV:
+			enter_rv();
+			break;
+		case OP:
+			enter_op();
+			break;
+		default:
+			pr_warn("Warning: broken state machine on enter");
+			break;
+		}
+
+		s = e;
+	}
+
+public:
+	char buffer[256];
+	std::shared_ptr<std::vector<Expression::Token>>& pv;
+
+	Parser(std::shared_ptr<std::vector<Expression::Token>>& pv)
+		: s(I), pv(pv)
+	{
+		buf_clear();
+	}
+
+	void buf_clear(void)
+	{
+		memset(buffer, 0, 256);
+	}
+
+	void buf_push(char c)
+	{
+		buffer[strlen(buffer)] = c;
+	}
+
+	int dispatch_to_current(char c)
+	{
+		switch (s)
+		{
+		case I:
+			return parse_i(c);
+		case RC:
+			return parse_rc(c);
+		case RV:
+			return parse_rv(c);
+		case OP:
+			return parse_op(c);
+		default:
+			pr_warn("State machine is broken, unable to dispatch character " << c << ", returning 0");
+			return 0;
+		}
+	}
+
+	void enter_i(void) {}
+	int  parse_i(char c)
+	{
+		if (isdigit(c) || c == '.')
+		{
+			switch_state(RC);
+			return 1;
+		}
+		else if (isalpha(c))
+		{
+			switch_state(RV);
+			return 1;
+		}
+		else if (c == '+' || c == '-' || c == '*' || c == '/' || c == '(' || c == ')')
+		{
+			switch_state(OP);
+			return 1;
+		}
+		else
+		{
+			pr_warn("Unknown character skipped (" << c << "), still in idle");
+			return 0;
+		}
+	}
+	void leave_i(void) {}
+
+	void enter_rc(void)
+	{
+		buf_clear();
+	}
+	int  parse_rc(char c)
+	{
+		if (!(isdigit(c) || c == '.'))
+		{
+			switch_state(I);
+			return 1;
+		}
+		else
+		{
+			buf_push(c);
+			return 0;
+		}
+	}
+	void leave_rc(void)
+	{
+		double value;
+
+		if (!sscanf(buffer, "%lf", &value))
+		{
+			pr_warn("Invalid CONST: " << buffer);
+		}
+		else
+		{
+			pv->push_back(Expression::Token(value));
+		}
+	}
+
+	void enter_rv(void)
+	{
+		buf_clear();
+	}
+	int  parse_rv(char c)
+	{
+		if (!isalpha(c))
+		{
+			switch_state(I);
+			return 1;
+		}
+		else
+		{
+			buf_push(c);
+			return 0;
+		}
+	}
+	void leave_rv(void)
+	{
+		pv->push_back(Expression::Token(buffer));
+	}
+
+	void enter_op(void)
+	{
+		buf_clear();
+	}
+	int  parse_op(char c)
+	{
+		if (!(c == '+' || c == '-' || c == '*' || c == '/' || c == '(' || c == ')'))
+		{
+			switch_state(I);
+			return 1;
+		}
+		else
+		{
+			buf_push(c);
+			return 0;
+		}
+	}
+	void leave_op(void)
+	{
+		if      (!strcmp(buffer, "("))
+		{
+			pv->push_back(Expression::Token(Expression::Token::OPA));
+		}
+		else if (!strcmp(buffer, ")"))
+		{
+			pv->push_back(Expression::Token(Expression::Token::CPA));
+		}
+		else if (!strcmp(buffer, "+"))
+		{
+			pv->push_back(Expression::Token(Expression::Token::ADD));
+		}
+		else if (!strcmp(buffer, "-"))
+		{
+			pv->push_back(Expression::Token(Expression::Token::SUB));
+		}
+		else if (!strcmp(buffer, "*"))
+		{
+			pv->push_back(Expression::Token(Expression::Token::MUL));
+		}
+		else if (!strcmp(buffer, "/"))
+		{
+			pv->push_back(Expression::Token(Expression::Token::DIV));
+		}
+		else if (!strcmp(buffer, "**"))
+		{
+			pv->push_back(Expression::Token(Expression::Token::POW));
+		}
+		else
+		{
+			pr_warn("Skip unknown operator: " << buffer);
+		}
+	}
+};
+
+std::shared_ptr<std::vector<Expression::Token>> tokenize_input(char *input_string)
+{
+	std::shared_ptr<std::vector<Expression::Token>> pv = std::make_shared<std::vector<Expression::Token>>();
+
+	Parser p(pv);
+	for (int i = 0, l = strlen(input_string); i < l; i++)
+	{
+		i -= p.dispatch_to_current(input_string[i]);
+	}
+
+	(void) p.dispatch_to_current('\0');
+
+	return pv;
+}
+
+int assert_same(std::vector<Expression::Token>& a, std::vector<Expression::Token>& b)
+{
+	if (a.size() != b.size())
+	{
+		std::cout << "Vectors are of different lengths: " << a.size() << " != " << b.size() << "\n";
+		return 1;
+	}
+
+	for (int i = 0, l = a.size(); i < l; i++)
+	{
+		if (a[i].t != b[i].t)
+		{
+			std::cout << "Token " << i << " types differ: " << a[i].type_str() << " != " << b[i].type_str() << "\n";
+			return 1;
+		}
+
+		switch (a[i].t)
+		{
+		case Expression::Token::VAR:
+			if (strcmp((*(a[i].v.s)).c_str(),
+				   (*(b[i].v.s)).c_str()))
+			{
+				std::cout << "Variable names at " << i << " differ: " << (*(a[i].v.s)).c_str() << " != " << (*(b[i].v.s)).c_str() << "\n";
+				return 1;
+			}
+			break;
+		case Expression::Token::CONST:
+			if (a[i].v.d != b[i].v.d)
+			{
+				std::cout << "Constants at " << i << " differ: " << a[i].v.d << " != " << b[i].v.d << "\n";
+				return 1;
+			}
+			break;
+		case Expression::Token::OPERATOR:
+			if (a[i].v.o != b[i].v.o)
+			{
+				std::cout << "Operators at " << i << " differ: " << a[i].op_str() << " != " << b[i].op_str() << "\n";
+				return 1;
+			}
+			break;
+		}
+	}
+	return 0;
+}
+
+}
diff --git a/src/test-cases.cpp b/src/test-cases.cpp
new file mode 100644
index 0000000..08e7db5
--- /dev/null
+++ b/src/test-cases.cpp
@@ -0,0 +1,55 @@
+#include "test-tools.hpp"
+#include "parser.hpp"
+#include "expression.hpp"
+
+TEST(parser_proper_test_1)
+{
+	auto o = Parser::tokenize_input((char *) "(1+2-c)");
+	std::vector<Expression::Token> r;
+
+	r.push_back(Expression::Token(Expression::Token::OPA));
+	r.push_back(Expression::Token(1));
+	r.push_back(Expression::Token(Expression::Token::ADD));
+	r.push_back(Expression::Token(2));
+	r.push_back(Expression::Token(Expression::Token::SUB));
+	r.push_back(Expression::Token("c"));
+	r.push_back(Expression::Token(Expression::Token::CPA));
+
+	CHECK(Parser::assert_same(*o, r));
+
+	return 0;
+}
+
+TEST(parser_proper_test_2)
+{
+	auto o = Parser::tokenize_input((char *) "(1**5,-snake+marble*34*(35 / 63.2))");
+	std::vector<Expression::Token> r;
+
+	r.push_back(Expression::Token(Expression::Token::OPA));
+	r.push_back(Expression::Token(1));
+	r.push_back(Expression::Token(Expression::Token::POW));
+	r.push_back(Expression::Token(5));
+	r.push_back(Expression::Token(Expression::Token::SUB));
+	r.push_back(Expression::Token("snake"));
+	r.push_back(Expression::Token(Expression::Token::ADD));
+	r.push_back(Expression::Token("marble"));
+	r.push_back(Expression::Token(Expression::Token::MUL));
+	r.push_back(Expression::Token(34));
+	r.push_back(Expression::Token(Expression::Token::MUL));
+	r.push_back(Expression::Token(Expression::Token::OPA));
+	r.push_back(Expression::Token(35));
+	r.push_back(Expression::Token(Expression::Token::DIV));
+	r.push_back(Expression::Token(63.2));
+	r.push_back(Expression::Token(Expression::Token::CPA));
+	r.push_back(Expression::Token(Expression::Token::CPA));
+
+	CHECK(Parser::assert_same(*o, r));
+
+	return 0;
+}
+
+void register_tests(void)
+{
+	REGISTER(parser_proper_test_1);
+	REGISTER(parser_proper_test_2);
+}
diff --git a/src/test.cpp b/src/test.cpp
new file mode 100644
index 0000000..478c1d1
--- /dev/null
+++ b/src/test.cpp
@@ -0,0 +1,35 @@
+#include <iostream>
+#include <vector>
+
+#include "test-cases.cpp"
+
+typedef int (*TestFunc)(void);
+
+void register_tests(void);
+
+std::vector<TestFunc> test_funcs;
+
+int main(void)
+{
+	static unsigned long fails = 0,
+			     successes = 0;
+
+	register_tests();
+
+	for (int i = 0, l = test_funcs.size(); i < l; i++) {
+		std::cout << "--- Running test " << i + 1 << "/" << l << "\n";
+		if (test_funcs[i]())
+		{
+			std::cout << "Test failed.\n";
+			fails++;
+		}
+		else
+		{
+			successes++;
+		}
+	}
+
+	std::cout << "--- Finished testing: " << successes << " passed, " << fails << " failed\n";
+
+	return !!fails;
+}