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1 files changed, 90 insertions, 0 deletions
| -rw-r--r-- | homework/81270/brainf-interpret/Interpreter.cpp | 90 |
diff --git a/homework/81270/brainf-interpret/Interpreter.cpp b/homework/81270/brainf-interpret/Interpreter.cpp new file mode 100644 index 0000000..ebca77b --- /dev/null +++ b/homework/81270/brainf-interpret/Interpreter.cpp @@ -0,0 +1,90 @@ +// +// Created by bmestanov on 15.11.18. +// + +#define TAPE_SIZE 65536 +#define STACK_SIZE 8192 + +#include <fstream> +#include <iostream> + +void failIf(bool condition, const char *message) { + if (condition) { + std::cerr << message; + exit(1); + } +} + +int main(int argc, char **argv) { + argc--; + argv++; + char memory[TAPE_SIZE] = {0}; + char *pp = memory; // program pointer + long stack[STACK_SIZE]; + int sp = 0; // stack pointer + + failIf(!argv[0], "No file provided"); + + std::ifstream file; + file.open(argv[0]); + + failIf(!file, "Error opening file"); + + while (!file.eof()) { + auto symbol = static_cast<char>(file.get()); + switch (symbol) { + case '>': { + // Allow memory wrap + pp = memory + (pp - memory + 1) % TAPE_SIZE; + break; + } + case '<': { + pp = memory + (pp - memory - 1) % TAPE_SIZE; + break; + } + case '+': { + (*pp)++; + break; + } + case '-': { + (*pp)--; + break; + } + case '.': { + std::putchar(*pp); + break; + } + case ',': { + *pp = static_cast<char>(std::getchar()); + break; + } + case '[': { + if (*pp) { + failIf(sp == STACK_SIZE, "Stack overflow"); + stack[sp++] = file.tellg(); + } else { + long move = 1; + while (move > 0) { + auto next = static_cast<char>(file.get()); + if (next == '[') move++; + if (next == ']') move--; + if (file.eof()) failIf(true, "Invalid syntax"); + } + } + break; + } + case ']': { + failIf(sp == 0, "Invalid syntax"); + if (*pp) { + long top = stack[sp - 1]; + file.seekg(top); + } else { + sp--; + } + } + default:; + } + } + + return 0; +}
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