Initial commit

include/lexer_base.h

@@ -0,0 +1,26 @@
+#ifndef MCALC_LEXER_BASE_H
+#define MCALC_LEXER_BASE_H
+
+#include <string_view>
+
+#ifndef yyFlexLexerOnce
+#include <FlexLexer.h>
+#endif
+
+#include <parser.h>
+
+struct Scanner : public yyFlexLexer {
+    using value_type = yy::Parser::value_type;
+    using location_type = yy::Parser::location_type;
+
+    explicit Scanner(std::istream *in) : yyFlexLexer(in) {}
+
+    using FlexLexer::yylex;
+    virtual int yylex(value_type *lval, location_type * loc);
+
+    //double num{};
+    //std::string_view ident{};
+    //value_type *yylval = nullptr;
+};
+
+#endif //MCALC_LEXER_BASE_H

include/node.h

@@ -0,0 +1,53 @@
+#ifndef MCALC_NODE_H
+#define MCALC_NODE_H
+
+#include <optional>
+#include <string>
+#include <unordered_set>
+#include <memory>
+#include <memory_resource>
+
+struct State;
+
+struct Node {
+    enum class type {
+        NUM,
+        VAR,
+        NEG,
+        PLUS,
+        MINUS,
+        MUL,
+        DIV,
+        INVALID
+    } ty = type::INVALID;
+    double num = 0;
+    std::string var{};
+    std::unique_ptr<Node> a{}, b{};
+
+    void used_vars(std::unordered_set<std::string>*) const;
+    std::optional<double> eval(State*) const;
+};
+
+using parser_var_ty = std::variant<double, std::string, Node*>;
+
+template<Node::type ty>
+Node *new_node(const parser_var_ty& v) {
+    auto *node = new Node { .ty = ty };
+    if constexpr (ty == Node::type::NUM)
+        node->num = std::get<double>(v);
+    else if constexpr (ty == Node::type::VAR)
+        node->var = std::get<std::string>(v);
+    else
+        node->a.reset(std::get<Node*>(v));
+    return node;
+}
+
+template<Node::type ty>
+Node *new_node(const parser_var_ty& a, const parser_var_ty& b) {
+    auto *node = new Node { .ty = ty };
+    node->a.reset(std::get<Node*>(a));
+    node->b.reset(std::get<Node*>(b));
+    return node;
+}
+
+#endif //MCALC_NODE_H