Initial Commit

src/file.c

@@ -0,0 +1,28 @@
+#include "file.h"
+
+char* read_file(char* filename) {
+    FILE* fptr = fopen(filename, "r");
+    if (fptr == NULL) {
+        return NULL;
+    }
+    
+    // Get length
+    fseek(fptr, 0L, SEEK_END);
+    long file_size = ftell(fptr);
+    rewind(fptr);
+    
+    // Allocate buffer
+    char* buffer = malloc(file_size+1);
+    if (buffer == NULL) {
+        return NULL;
+    }
+    
+    // Read file
+    size_t read = fread(buffer, sizeof(char), file_size, fptr);
+    if (read != file_size) return NULL;
+    
+    buffer[file_size] = '\0';
+    fclose(fptr);
+    
+    return buffer;    
+}

src/file.h

@@ -0,0 +1,4 @@
+#include <stdlib.h>
+#include <stdio.h>
+
+char* read_file(char* filename);

src/main.c

@@ -0,0 +1,99 @@
+#include "struct.h"
+#include "file.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+int main(int argc, char* argv[]) {
+    if (argc != 3) {
+        fprintf(stderr, "Usage: %s <filename> <input>\n", argv[0]);
+        return 1;
+    }
+    
+    char* code = read_file(argv[1]);
+    if (code == NULL) {
+        fprintf(stderr, "Cannot open file \"%s\"\n", argv[1]);
+        return 2;
+    }
+    
+    char* input = argv[2];
+    int inputidx = 0;
+    
+    Celltape cells = {
+        .cells = calloc(30000, sizeof(bitarr)),
+        .ptr = 0
+    };
+    
+    int scope = 0;
+    int max_scope = 0; // Highest ever reached scope
+    int* loop_start = malloc(0);
+    
+    PartialByte to_print = {
+        .data = 0,
+        .idx = 0
+    };
+    
+    bool ignore = false;
+    
+    for (int idx = 0; code[idx] != '\0'; idx++) {
+        if (ignore) {
+            if (code[idx] == ']') {
+                ignore = false;
+            }
+            continue;
+        }
+        switch (code[idx]) {
+            case '+':
+            case '-':
+                flip_bit(&(cells.cells), cells.ptr);
+                break;
+            
+            case '>':
+                cells.ptr += 1;
+                break;
+                
+            case '<':
+                cells.ptr -= 1;
+                break;
+                
+            case '[':
+                if (!get_bit(cells.cells, cells.ptr)) {
+                    ignore = true;
+                    break;
+                }
+                scope += 1;
+                if (scope > max_scope) {
+                    max_scope += scope;
+                    loop_start = realloc(loop_start, scope);
+                }
+                loop_start[scope-1] = idx;
+                break;
+                
+            case ']':
+                if (get_bit(cells.cells, cells.ptr)) {
+                    idx = loop_start[scope-1];
+                } else {
+                    scope -= 1;
+                }
+                break;
+
+            case '.':
+            case ';':
+                append_bit(&to_print, get_bit(cells.cells, cells.ptr));
+                if (to_print.idx == 8) {
+                    to_print.idx = 0;
+                    printf("%c", to_print.data);
+                }
+                break;
+                
+            case ',':
+                if ((input[inputidx/8] & (1 << (inputidx % 8))) >> (inputidx % 8)) {
+                    one_bit(&cells.cells, cells.ptr);
+                } else {
+                    zero_bit(&cells.cells, cells.ptr);
+                }
+                inputidx += 1;
+                break;
+        }
+    }
+}

src/struct.c

@@ -0,0 +1,22 @@
+#include "struct.h"
+
+void flip_bit(bitarr** cells, int idx) {
+    (*cells)[idx / 8] ^= (bitarr)(0x80 >> (idx % 8));
+}
+
+int get_bit(bitarr* cells, int ptr) {
+    return ((cells[ptr/8]) & (128 >> (ptr % 8))) >> 7;
+}
+
+void append_bit(PartialByte* byte, int bit) {
+    (*byte).data |= bit << ((*byte).idx);
+    (*byte).idx += 1;
+}
+
+void zero_bit(bitarr** cells, int idx) {
+    (*cells)[idx / 8] &= 255 ^ (128 >> idx);
+}
+
+void one_bit(bitarr** cells, int idx) {
+    (*cells)[idx / 8] |= (128 >> idx);
+}

src/struct.h

@@ -0,0 +1,19 @@
+#define bitarr unsigned char
+#define u64 uint64_t
+#include <stdint.h>
+
+typedef struct {
+    bitarr data;
+    bitarr idx;
+} PartialByte;
+
+typedef struct {
+    bitarr* cells;
+    int ptr;
+} Celltape;
+
+void flip_bit(bitarr** cells, int idx);
+int get_bit(bitarr* cells, int ptr);
+void append_bit(PartialByte* byte, int bit);
+void zero_bit(bitarr** cells, int idx);
+void one_bit(bitarr** cells, int idx);

tests/aaaaaa.bf

@@ -0,0 +1 @@
++>+>+>+>+>+>+>+<<<<<<<,;,;,;,;,;,;,;,;