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sys: Improved math evaluator

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This commit is contained in:
WerWolv 2022-03-04 19:20:21 +01:00
parent efe6137067
commit 57c449936f
2 changed files with 71 additions and 70 deletions
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18
plugins/builtin/include/math_evaluator.hpp
View File

@ -11,7 +11,8 @@
namespace hex {
enum class TokenType {
enum class TokenType
{
Number,
Variable,
Function,
@ -19,7 +20,8 @@ namespace hex {
Bracket
};
enum class Operator : u16 {
enum class Operator : u16
{
Invalid = 0x000,
Assign = 0x010,
Or = 0x020,
@ -47,7 +49,8 @@ namespace hex {
Not = 0x0F1
};
enum class BracketType : std::uint8_t {
enum class BracketType : std::uint8_t
{
Left,
Right
};
@ -66,19 +69,18 @@ namespace hex {
public:
MathEvaluator() = default;
std::optional<long double> evaluate(std::string input);
std::optional<long double> evaluate(const std::string &input);
void registerStandardVariables();
void registerStandardFunctions();
void setVariable(std::string name, long double value);
void setFunction(std::string name, std::function<std::optional<long double>(std::vector<long double>)> function, size_t minNumArgs, size_t maxNumArgs);
void setVariable(const std::string &name, long double value);
void setFunction(const std::string &name, const std::function<std::optional<long double>(std::vector<long double>)> &function, size_t minNumArgs, size_t maxNumArgs);
std::unordered_map<std::string, long double> &getVariables() { return this->m_variables; }
private:
std::queue<Token> parseInput(const char *input);
std::queue<Token> toPostfix(std::queue<Token> inputQueue);
std::queue<Token> parseInput(std::string input);
std::optional<long double> evaluate(std::queue<Token> postfixTokens);
std::unordered_map<std::string, long double> m_variables;

123
plugins/builtin/source/math_evaluator.cpp
View File

@ -7,19 +7,18 @@
#include <cmath>
#include <cstdint>
#include <optional>
#include <numbers>
namespace hex {
i16 comparePrecedence(const Operator &a, const Operator &b) {
return (static_cast<i8>(a) & 0x0F0) - (static_cast<i8>(b) & 0x0F0);
return static_cast<i16>((static_cast<i8>(a) & 0x0F0) - (static_cast<i8>(b) & 0x0F0));
}
bool isLeftAssociative(const Operator op) {
return (static_cast<u32>(op) & 0xF00) == 0;
}
std::pair<Operator, size_t> toOperator(std::string input) {
std::pair<Operator, size_t> toOperator(const std::string &input) {
if (input.starts_with("##")) return { Operator::Combine, 2 };
if (input.starts_with("==")) return { Operator::Equals, 2 };
if (input.starts_with("!=")) return { Operator::NotEquals, 2 };
@ -48,10 +47,59 @@ namespace hex {
return { Operator::Invalid, 0 };
}
std::queue<Token> MathEvaluator::parseInput(const char *input) {
static std::queue<Token> toPostfix(std::queue<Token> inputQueue) {
std::queue<Token> outputQueue;
std::stack<Token> operatorStack;
while (!inputQueue.empty()) {
Token currToken = inputQueue.front();
inputQueue.pop();
if (currToken.type == TokenType::Number || currToken.type == TokenType::Variable || currToken.type == TokenType::Function)
outputQueue.push(currToken);
else if (currToken.type == TokenType::Operator) {
while ((!operatorStack.empty()) && (operatorStack.top().type == TokenType::Operator && currToken.type == TokenType::Operator && (comparePrecedence(operatorStack.top().op, currToken.op) > 0) || (comparePrecedence(operatorStack.top().op, currToken.op) == 0 && isLeftAssociative(currToken.op))) && operatorStack.top().type != TokenType::Bracket) {
outputQueue.push(operatorStack.top());
operatorStack.pop();
}
operatorStack.push(currToken);
} else if (currToken.type == TokenType::Bracket) {
if (currToken.bracketType == BracketType::Left)
operatorStack.push(currToken);
else {
if (operatorStack.empty())
throw std::invalid_argument("Mismatching parenthesis!");
while (operatorStack.top().type != TokenType::Bracket || (operatorStack.top().type == TokenType::Bracket && operatorStack.top().bracketType != BracketType::Left)) {
if (operatorStack.empty())
throw std::invalid_argument("Mismatching parenthesis!");
outputQueue.push(operatorStack.top());
operatorStack.pop();
}
operatorStack.pop();
}
}
}
while (!operatorStack.empty()) {
auto top = operatorStack.top();
if (top.type == TokenType::Bracket)
throw std::invalid_argument("Mismatching parenthesis!");
outputQueue.push(top);
operatorStack.pop();
}
return outputQueue;
}
std::queue<Token> MathEvaluator::parseInput(std::string input) {
std::queue<Token> inputQueue;
char *prevPos = const_cast<char *>(input);
char *prevPos = input.data();
for (char *pos = prevPos; *pos != 0x00;) {
if (std::isdigit(*pos) || *pos == '.') {
auto number = std::strtold(pos, &pos);
@ -111,13 +159,13 @@ namespace hex {
pos++;
for (const auto &expression : expressions) {
if (expression == "" && expressions.size() > 1)
if (expression.empty() && expressions.size() > 1)
throw std::invalid_argument("Invalid function call syntax!");
else if (expression == "")
else if (expression.empty())
break;
auto inputQueue = parseInput(expression.c_str());
auto postfixTokens = toPostfix(inputQueue);
auto newInputQueue = parseInput(expression.c_str());
auto postfixTokens = toPostfix(newInputQueue);
auto result = evaluate(postfixTokens);
if (!result.has_value())
@ -145,55 +193,6 @@ namespace hex {
return inputQueue;
}
std::queue<Token> MathEvaluator::toPostfix(std::queue<Token> inputQueue) {
std::queue<Token> outputQueue;
std::stack<Token> operatorStack;
while (!inputQueue.empty()) {
Token currToken = inputQueue.front();
inputQueue.pop();
if (currToken.type == TokenType::Number || currToken.type == TokenType::Variable || currToken.type == TokenType::Function)
outputQueue.push(currToken);
else if (currToken.type == TokenType::Operator) {
while ((!operatorStack.empty()) && (operatorStack.top().type == TokenType::Operator && currToken.type == TokenType::Operator && (comparePrecedence(operatorStack.top().op, currToken.op) > 0) || (comparePrecedence(operatorStack.top().op, currToken.op) == 0 && isLeftAssociative(currToken.op))) && operatorStack.top().type != TokenType::Bracket) {
outputQueue.push(operatorStack.top());
operatorStack.pop();
}
operatorStack.push(currToken);
} else if (currToken.type == TokenType::Bracket) {
if (currToken.bracketType == BracketType::Left)
operatorStack.push(currToken);
else {
if (operatorStack.empty())
throw std::invalid_argument("Mismatching parenthesis!");
while (operatorStack.top().type != TokenType::Bracket || (operatorStack.top().type == TokenType::Bracket && operatorStack.top().bracketType != BracketType::Left)) {
if (operatorStack.empty())
throw std::invalid_argument("Mismatching parenthesis!");
outputQueue.push(operatorStack.top());
operatorStack.pop();
}
operatorStack.pop();
}
}
}
while (!operatorStack.empty()) {
auto top = operatorStack.top();
if (top.type == TokenType::Bracket)
throw std::invalid_argument("Mismatching parenthesis!");
outputQueue.push(top);
operatorStack.pop();
}
return outputQueue;
}
std::optional<long double> MathEvaluator::evaluate(std::queue<Token> postfixTokens) {
std::stack<long double> evaluationStack;
@ -227,7 +226,7 @@ namespace hex {
result = static_cast<i64>(leftOperand) && static_cast<i64>(rightOperand);
break;
case Operator::Or:
result = static_cast<i64>(leftOperand) && static_cast<i64>(rightOperand);
result = static_cast<i64>(leftOperand) || static_cast<i64>(rightOperand);
break;
case Operator::Xor:
result = (static_cast<i64>(leftOperand) ^ static_cast<i64>(rightOperand)) > 0;
@ -321,7 +320,7 @@ namespace hex {
}
std::optional<long double> MathEvaluator::evaluate(std::string input) {
std::optional<long double> MathEvaluator::evaluate(const std::string &input) {
auto inputQueue = parseInput(input.c_str());
std::string resultVariable = "ans";
@ -351,11 +350,11 @@ namespace hex {
return result;
}
void MathEvaluator::setVariable(std::string name, long double value) {
void MathEvaluator::setVariable(const std::string &name, long double value) {
this->m_variables[name] = value;
}
void MathEvaluator::setFunction(std::string name, std::function<std::optional<long double>(std::vector<long double>)> function, size_t minNumArgs, size_t maxNumArgs) {
void MathEvaluator::setFunction(const std::string &name, const std::function<std::optional<long double>(std::vector<long double>)> &function, size_t minNumArgs, size_t maxNumArgs) {
this->m_functions[name] = [minNumArgs, maxNumArgs, function](auto args) {
if (args.size() < minNumArgs || args.size() > maxNumArgs)
throw std::invalid_argument("Invalid number of function arguments!");