C/C++表达式解析（可用于脚本解析功能实现）

Asimplecommandlinecalculatorthatusesarecursivedescentparser,writteninC.Madeasanexerciseintokenizingandparsing...##SupportedfeaturesBelowistheBNFoftheparser.ThefunctionsarenamedandbehavethesameasthosefoundinC64BASIC.expression=["+"|"-"]term{("+"