Merge branch 'master' into rust-rewrite

Author: ararslan

Makefile

@@ -31,4 +31,4 @@ rust: setup
 	rustc rust/main.rs -o $(EXE)
 
 clean:
-	-rm $(EXECUTABLE)
+	-rm $(EXECUTABLE)

bin/.gitkeep

@@ -0,0 +1,257 @@
+//
+//  qqq.cpp
+//  ??? (Programming Language)
+//
+//  Created by Alex A. and BrainSteel
+//  Based heavily on https://gist.github.com/migimunz/964338
+//
+
+#include <iostream>
+#include <fstream>
+#include <sstream>
+#include <stdexcept>
+#include <vector>
+
+
+typedef char CELL;
+typedef std::vector<CELL> instruction_t;
+typedef instruction_t::iterator instruction_pointer;
+
+typedef std::vector<CELL> memory_t;
+typedef memory_t::iterator memory_pointer;
+
+
+struct environment {
+    memory_t memory;
+    instruction_t instructions;
+
+    instruction_pointer ip;
+    memory_pointer mp;
+
+    environment() : memory(3000) {
+        clear();
+        mp = memory.begin();
+    }
+
+    void clear() {
+        instructions.clear();
+        ip = instructions.begin();
+    }
+};
+
+
+void interpret(environment &env);
+int from_line(environment &env, std::string &line, int open_quotes = 0);
+int from_stream(environment &env, std::istream &stream, int open_quotes = 0);
+void interactive_mode(environment &env);
+void print_cell(CELL cell);
+
+
+int main(int argc, const char* argv[]) {
+
+    std::string filename;
+
+    if (argc < 2) {
+        std::cout << "Enter a file:\n";
+        std::cin >> filename;
+    } else {
+        filename = argv[1];
+    }
+
+    std::ifstream infile(filename.c_str());
+
+    if (infile.is_open()) {
+
+        environment env;
+
+        int unmatched_quotes = from_stream(env, infile);
+
+        if (unmatched_quotes == 0) {
+            interpret(env);
+        } else {
+            std::cerr << "Um, match up your quotes and try again.\n";
+            return 1;
+        }
+
+        infile.close();
+
+    } else {
+        std::cerr << "Input file does not exist!\n";
+        return 1;
+    }
+
+    return 0;
+}
+
+
+/*
+ * Prints a memory cell, or hex representation if unprintable
+ */
+void print_cell(CELL cell) {
+
+    if (isprint(cell))
+        std::cout << cell;
+    else
+        std::cout << "0x" << std::hex << (int)cell << std::dec;
+}
+
+
+/*
+ * Reads code from a line, returns number of unmatched quotes
+ */
+int from_line(environment &env, std::string &line, int open_quotes) {
+
+    std::istringstream stream(line);
+
+    return from_stream(env, stream, open_quotes);
+}
+
+
+/*
+ * Reads code from a stream into env.instructions
+ */
+int from_stream(environment &env, std::istream &stream, int open_quotes) {
+
+    if (open_quotes == 0)
+        env.instructions.push_back('\0');
+
+    CELL cell;
+
+    bool is_open = true;
+
+    while (true) {
+        stream >> cell;
+
+        if (!stream)
+            break;
+
+        switch (cell) {
+            case '!':
+            case '?':
+            case '.':
+            case ',':
+            case '-':
+            case ';':
+                env.instructions.push_back(cell);
+                break;
+
+            case '\'':
+                is_open = !is_open;
+                break;
+
+            case '"':
+                if (is_open) {
+                    open_quotes++;
+                    env.instructions.push_back('[');
+                } else {
+                    open_quotes--;
+                    env.instructions.push_back(']');
+                }
+                break;
+
+            default:
+                break;
+        }
+
+        if (open_quotes < 0)
+            break;
+    }
+
+    if (open_quotes == 0)
+        env.instructions.push_back('\0');
+
+    return open_quotes;
+}
+
+
+/*
+ * Finds the closing bracket, moves the ip to it
+ */
+void find_closing(environment &env) {
+    int balance = 1;
+    do {
+        env.ip++;
+        if (*env.ip == '[')
+            balance++;
+        else if (*env.ip == ']')
+            balance--;
+    } while (balance != 0);
+}
+
+
+/*
+ * Finds the opening bracket, moves the ip to one cell before it
+ */
+void find_opening(environment &env) {
+    int balance = 0;
+    do {
+        if (*env.ip == '[')
+            balance++;
+        else if (*env.ip == ']')
+            balance--;
+        env.ip--;
+    } while (balance != 0);
+}
+
+
+/*
+ * Interprets code
+ */
+void interpret(environment &env) {
+
+    env.ip = env.instructions.begin();
+
+    while (env.ip != env.instructions.end()) {
+
+        switch (*env.ip) {
+            case '.':
+                (*env.mp)++;
+                env.ip++;
+                break;
+
+            case ',':
+                (*env.mp)--;
+                env.ip++;
+                break;
+
+            case ';':
+                if (env.mp != (env.memory.end()--))
+                    env.mp++;
+                env.ip++;
+                break;
+
+            case '-':
+                if (env.mp != env.memory.begin())
+                    env.mp--;
+                env.ip++;
+                break;
+
+            case '!':
+                print_cell(*env.mp);
+                env.ip++;
+                break;
+
+            case '?':
+                CELL cell;
+                std::cin >> cell;
+                (*env.mp) = cell;
+                env.ip++;
+                break;
+
+            case '[':
+                if (!(*env.mp))
+                    find_closing(env);
+                env.ip++;
+                break;
+
+            case ']':
+                find_opening(env);
+                env.ip++;
+                break;
+
+            case '\0':
+                env.ip++;
+                break;
+        }
+    }
+}