feat: Import project state of 2011-11-13

bf_interpreter.c

@@ -0,0 +1,96 @@
+#include <stdio.h>
+#include <error.h>
+#include <stdlib.h>
+
+static unsigned char *data_start;
+static unsigned char *data_ptr;
+
+void process_command(char command, FILE *file) {
+    
+    switch(command) {
+    case '>':
+        /* increment the data pointer (to point to the next cell to the right). */
+        ++data_ptr;
+        /* TODO : Check if over allocated memory */
+        break;
+    case '<':
+        /* decrement the data pointer (to point to the next cell to the left). */
+        --data_ptr;
+        /* TODO : Check if under allocated memory */
+        break;
+    case '+':
+        /* increment (increase by one) the byte at the data pointer. */
+        ++*data_ptr;
+        break;
+    case '-':
+        /* decrement (decrease by one) the byte at the data pointer. */
+        --*data_ptr;
+        break;
+    case '.':
+        /* output a character, the ASCII value of which being the byte at the
+         * data pointer. */
+        putchar(*data_ptr);
+        break;
+    case ',':
+        /* accept one byte of input, storing its value in the byte at the data
+         * pointer. */
+        *data_ptr = getchar();
+        break;
+    case '[':
+        /* [ : if the byte at the data pointer is zero, then instead of moving the
+         * instruction pointer forward to the next command, jump it forward to
+         * the command after the matching ] command. 
+         * ] : if the byte at the data pointer is nonzero, then instead of moving
+         * the instruction pointer forward to the next command, jump it back to
+         * the command after the matching [ command. */
+        {
+            fpos_t position;
+            fgetpos(file, &position);
+            while(*data_ptr != 0) {
+                fsetpos(file, &position);
+                char c = getc(file);
+                while( c!= ']' && c != EOF) {
+                    process_command(c, file);
+                    c = getc(file);
+                }
+            }
+        }
+        break;
+    case ']':
+        /* if we encounter one here, it means there are not balanced */
+        fprintf(stderr, "Error in the source file, unbalanced ']'\n");
+        exit(2);
+        break;
+    default:
+        /* Brainfuck ignores all characters except the eight commands +-<>[],. */
+        break;
+    }
+
+}
+
+int main(int argc, char **argv)
+{
+    data_start = calloc(30000, sizeof(char));
+    data_ptr = data_start;
+
+    if (argc > 1) {
+        char command;
+        FILE *file = fopen(argv[1], "r");
+
+        if (!file) {
+            fprintf(stderr, "Error: No such file %s\n", argv[1]);
+            return 2;
+        }
+
+        while((command = getc(file)) != EOF) {
+            process_command(command, file);
+        }
+        
+        fclose(file);
+        return 0;
+    } else {
+        fprintf(stderr, "Usage: %s source_file\n", argv[0]);
+        return 1;
+    }
+    return 0;
+}

bf_threaded.c

@@ -0,0 +1,127 @@
+#include <stdio.h>
+#include <error.h>
+#include <stdlib.h>
+
+static unsigned char *data_start;
+static unsigned char *data_ptr;
+
+#define MEM_SIZE 30000
+#define GOTO_NEXT goto *labels[op_char]
+
+void engine_run(FILE* file) {
+    void** labels[127]; /* We will address each char */
+    unsigned char op_char = 0;
+    fpos_t* loop_start_position = calloc(3000,sizeof(fpos_t));
+    
+    for (int i = 0; i <= 127; i++) labels[i] = &&unknown_char;
+    
+    labels['>'] = &&ptr_increment;
+    labels['<'] = &&ptr_decrement;
+    
+    labels['+'] = &&value_increment;
+    labels['-'] = &&value_decrement;
+    
+    labels['.'] = &&value_output;
+    labels[','] = &&value_input;
+    
+    labels['['] = &&loop_start;
+    labels[']'] = &&loop_end;
+    
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+    
+ptr_increment: {
+    if (data_ptr + 1 > data_start + MEM_SIZE) data_ptr = data_start;
+    ++data_ptr;
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+}
+
+ptr_decrement: {
+    if (data_ptr - 1 < data_start) data_ptr = data_start + MEM_SIZE;
+    --data_ptr;
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+}
+
+value_increment: {
+    ++*data_ptr;
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+}
+
+value_decrement: {
+    --*data_ptr;
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+}
+
+value_output: {
+    putchar(*data_ptr);
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+}
+
+value_input: {
+    *data_ptr = getchar();
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+}
+
+loop_start: {
+    fgetpos(file, loop_start_position);
+    loop_start_position++;
+    
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+}
+
+loop_end: {
+    if (*data_ptr != 0) {
+        fsetpos(file, loop_start_position-1);
+    } else {
+        loop_start_position--;
+    }
+    
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+}
+
+unknown_char: {
+    op_char = getc(file);
+    if (op_char > 127) return;
+    GOTO_NEXT;
+}
+}
+
+int main(int argc, char **argv)
+{
+    data_start = calloc(MEM_SIZE, sizeof(char));
+    data_ptr = data_start;
+
+    if (argc <= 1) {
+        fprintf(stderr, "Usage: %s source_file\n", argv[0]);
+        return 1;
+    }
+    
+    FILE *file = fopen(argv[1], "r");
+
+    if (!file) {
+        fprintf(stderr, "Error: No such file %s\n", argv[1]);
+        return 2;
+    }
+
+    engine_run(file);
+    
+    fclose(file);
+    return 0;
+}

examples/cat.bf

@@ -0,0 +1 @@
+,[.,]

examples/helloworld.bf

@@ -0,0 +1 @@
+ ++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.

examples/helloworld_comments.bf

@@ -0,0 +1,21 @@
++++++ +++++             initialize counter (cell #0) to 10
+[                       use loop to set the next four cells to 70/100/30/10
+    > +++++ ++              add  7 to cell #1
+    > +++++ +++++           add 10 to cell #2 
+    > +++                   add  3 to cell #3
+    > +                     add  1 to cell #4
+    <<<< -                  decrement counter (cell #0)
+]                   
+> ++ .                  print 'H'
+> + .                   print 'e'
++++++ ++ .              print 'l'
+.                       print 'l'
++++ .                   print 'o'
+> ++ .                  print ' '
+<< +++++ +++++ +++++ .  print 'W'
+> .                     print 'o'
++++ .                   print 'r'
+----- - .               print 'l'
+----- --- .             print 'd'
+> + .                   print '!'
+> .                     print '\n'

examples/uppercase.bf

@@ -0,0 +1 @@
+ ,----------[----------------------.,----------]