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/* ************************************************************** * C++ Mathematical Expression Toolkit Library * * * * ExprTk Greatest Common Divisor Example * * Author: Arash Partow (1999-2024) * * URL: https://www.partow.net/programming/exprtk/index.html * * * * Copyright notice: * * Free use of the Mathematical Expression Toolkit Library is * * permitted under the guidelines and in accordance with the * * most current version of the MIT License. * * https://www.opensource.org/licenses/MIT * * SPDX-License-Identifier: MIT * * * ************************************************************** */ #include #include #include "exprtk.hpp" template T gcd_println(T x, T y, T z) { printf("gcd(%2d,%2d) = %2d\n", static_cast(x), static_cast(y), static_cast(z)); return T(0); } template void gcd() { typedef exprtk::symbol_table symbol_table_t; typedef exprtk::expression expression_t; typedef exprtk::parser parser_t; typedef exprtk::function_compositor compositor_t; typedef typename compositor_t::function function_t; symbol_table_t symbol_table; symbol_table.add_function("println",gcd_println); compositor_t compositor(symbol_table); // define function: gcd(x,y) compositor.add( function_t("gcd") .vars("x","y") .expression ( " switch " " { " " case 0 = x : 0; " " case 0 = y : x; " " case x = y : x; " " case x > y : gcd(x - y, y); " " default : gcd(x, y - x); " " } " )); const std::string gcd_program = " i := 0; " " while ((i += 1) < 100) " " { " " j := 0; " " repeat " " println(i, j, gcd(i,j)); " " until ((j += 1) >= 100); " " }; "; expression_t expression; expression.register_symbol_table(symbol_table); parser_t parser; parser.enable_unknown_symbol_resolver(); parser.compile(gcd_program,expression); expression.value(); } int main() { gcd(); return 0; }