repl demo

6 files changed, 369 insertions, 176 deletions

diff --git a/.clangd b/.clangd
index 80a0695..ac5fc10 100644
--- a/.clangd
+++ b/.clangd
@@ -1,2 +1,2 @@
 CompileFlags:
-    Add: [-std=c89]
\ No newline at end of file
+    Add: [-std=c99, -x, c]
\ No newline at end of file
diff --git a/code.pasm b/code.pasm
index 89acae2..d916970 100644
--- a/code.pasm
+++ b/code.pasm
@@ -4,4 +4,4 @@ con 99
 # putchar code
 ar4 con 60 ar2 r4a mem con 1 ar4 con 60 ar3 con 0 ar2 con 2 hlt
 
-hlt
+hlt
\ No newline at end of file
diff --git a/pu.c b/pu.c
index 4e93a31..7678e5d 100644
--- a/pu.c
+++ b/pu.c
@@ -1,9 +1,16 @@
+#define _XOPEN_SOURCE 700
 #include <stdio.h>
 #include <stdlib.h>
-#include <unistd.h>
 #include <string.h>
+#include <unistd.h>
+
 #pragma clang diagnostic ignored "-Wreturn-type"
 #pragma clang diagnostic ignored "-Wc23-extensions"
+#pragma clang diagnostic ignored "-Wnull-character"
+#pragma clang diagnostic ignored "-Wimplicit-int"
+
+#define CLAY_IMPLEMENTATION
+#include "clay.h"
 
 // clang-format off
 #define S 65536
@@ -67,7 +74,7 @@ int emu() {
             int size = m[ 3 ], i = 0;
 
             for (; i < size; i++) putchar(m[ ptr++ ]);
-            write(STDOUT_FILENO, &m[ ptr ], size);
+            while (size--) putchar(m[ ptr++ ]);
         }
 
         // 1: input character
@@ -87,36 +94,7 @@ int emu() {
 char R_backup[] = "hlt\0 ar1\2 ar2\3 ar3\4 ar4\5 ar5\6 ar6\7 ar7\x8 ar8\x9 r1a\xA r2a\xB r3a\xC "
                   "r4a\xD r5a\xE r6a\xF r7a\20 r8a\21 mem\22 aca\23 add\24 sub\25 not\26 clr\27";
 
-int main(int argc, char **argv) {
-    if (access("t", F_OK)) {
-        // patch the instruction table incase you removed it.
-        printf("you've deleted t! i'll write it again for you.\n\n");
-        FILE *fp = fopen("t", "w+");
-        fwrite(R_backup, 1, sizeof(R_backup), fp);
-        fclose(fp);
-        memcpy(R, R_backup, sizeof(R_backup));
-    }
-
-    if (argc == 1) {
-        printf("Usage:\n    %s <filename>", argv[ 0 ]);
-        exit(1);
-    }
-
-    // read code
-    FILE *fp = fopen(argv[ 1 ], "r");
-    fseek(fp, 0, SEEK_END);
-    int sz = ftell(fp);
-    rewind(fp);
-    char code[ sz + 1 ];
-    fread(code, 1, sz, fp);
-    code[ sz ] = 0;
-    fclose(fp);
-
-    // set pc
-    m[ 7 ] = 1024;
-    // assemble
-    char *fail_point = as(code, &m[ 1024 ]);
-
+void error_debug(char *fail_point, char *code, int sz) {
     if (fail_point != 0) {
         int error_pos = (int) (fail_point - code);
         int i;
@@ -132,7 +110,14 @@ int main(int argc, char **argv) {
         }
 
         fprintf(
-            stderr, "Assembly failed at line %d, column %d (position %d):\n", line, col, error_pos);
+            stderr,
+            "\x1b[1m\x1b[31merror:\x1b[0m "
+            "\x1b[1massembly failed\x1b[0m "
+            "at \x1b[36mline %d\x1b[0m, \x1b[36mcolumn %d\x1b[0m "
+            "(\x1b[33mposition %d\x1b[0m):\n",
+            line,
+            col,
+            error_pos);
 
         int line_start = error_pos;
         while (line_start > 0 && code[ line_start - 1 ] != '\n') { line_start--; }
@@ -142,17 +127,169 @@ int main(int argc, char **argv) {
             line_end++;
         }
 
-        fprintf(stderr, "  ");
+        fprintf(stderr, "  \x1b[1m");
         for (i = line_start; i < line_end; i++) { fputc(code[ i ], stderr); }
-        fprintf(stderr, "\n");
+        fprintf(stderr, "\x1b[0m\n");
 
         fprintf(stderr, "  ");
-        for (i = line_start; i < error_pos; i++) { fputc(' ', stderr); }
-        fprintf(stderr, "^ parsing stopped here\n");
+        for (i = line_start; i < error_pos; i++) {
+            fputc((code[ i ] == '\t') ? '\t' : ' ', stderr);
+        }
+        fprintf(stderr, "\x1b[1m\x1b[31m^\x1b[0m \x1b[90mparsing stopped here\x1b[0m\n");
+    }
+}
 
+int main(int argc, char **argv) {
+    if (access("t", F_OK)) {
+        // patch the instruction table incase you removed it.
+        printf("you've deleted `t`! i'll write it again for you.\n\n");
+        FILE *fp = fopen("t", "w+");
+        fwrite(R_backup, 1, sizeof(R_backup), fp);
+        fclose(fp);
+        memcpy(R, R_backup, sizeof(R_backup));
+    }
+
+    if (argc == 1) {
+        printf(
+            "Usage:\n    %s run <filename>: Execute a file\n    %s repl: Open in REPL mode",
+            argv[ 0 ],
+            argv[ 0 ]);
         exit(1);
     }
 
+    if (argc == 2 && !strcmp(argv[ 1 ], "repl")) {
+        printf("\npu repl\n"
+               "|  code is inserted at address 1024\n"
+               "|  submit RUN to execute the code.\n"
+               "|  submit CLEAR to erase history.\n"
+               "|  submit SAVE to write contents to repl.pu\n"
+               "|  submit LOAD to fetch contents from repl.pu\n"
+               "\n");
+
+        char *code  = malloc(1);
+        *code       = '\n';
+        size_t size = 0;
+
+        while (1) {
+            printf("%li > ", size);
+            char  *line;
+            size_t _len;
+            size_t len = getline(&line, &_len, stdin);
+
+            if (len == 1) continue;
+
+            if (len == 4 && strncmp(line, "run", 3) == 0) {
+                memset(m, 0, 8);
+                m[ 7 ] = 1024;
+                emu();
+                continue;
+            }
+
+            if (len == 5 && strncmp(line, "save", 4) == 0) {
+                FILE *fd = fopen("repl.pu", "w+");
+                fwrite(code, 1, size, fd);
+                fclose(fd);
+                printf("saved %li bytes.\n", size);
+
+                continue;
+            }
+
+            if (len == 5 && strncmp(line, "load", 4) == 0) {
+                FILE *fp = fopen("repl.pu", "r");
+                fseek(fp, 0, SEEK_END);
+                int sz = ftell(fp);
+                rewind(fp);
+                char *saved = malloc(sz + 1);
+                fread(saved, 1, sz, fp);
+                saved[ sz ] = 0;
+                fclose(fp);
+
+                free(code);
+                code = saved;
+                size = sz;
+                printf("loaded %i bytes.\n", sz);
+                
+                goto SKIP_STRAIGHT;
+            }
+
+            if (len == 6 && strncmp(line, "clear", 5) == 0) {
+                printf("-- code cleared\n");
+                free(code);
+                code = malloc(1);
+                size = 0;
+                continue;
+            }
+
+            if (len == 7 && strncmp(line, "status", 6) == 0) {
+                printf(
+                    "\nregisters\n"
+                    "r1: %i          r2: %i\n"
+                    "r3: %i          r4: %i\n"
+                    "r5: %i          r6: %i\n"
+                    "r7: %i          pc: %i\n\n",
+                    m[ 0 ],
+                    m[ 1 ],
+                    m[ 2 ],
+                    m[ 3 ],
+                    m[ 4 ],
+                    m[ 5 ],
+                    m[ 6 ],
+                    m[ 7 ]);
+
+                continue;
+            }
+
+            char *old_code = malloc(size);
+            memcpy(old_code, code, size);
+
+            code = realloc(code, size += len);
+            memcpy(&code[ size - len ], line, len);
+
+            SKIP_STRAIGHT:
+
+            char *exit_code = as(code, &m[ 1024 ]);
+
+    #define COLOR_RED   "\e[0;31m"
+    #define COLOR_RESET "\e[0m"
+
+            if (exit_code != 0) {
+                printf(COLOR_RED "\n");
+                error_debug(exit_code, code, size);
+                printf("\n" COLOR_RESET);
+
+                free(code);
+                code = old_code;
+                size -= len;
+                continue;
+            }
+
+            free(old_code);
+        }
+
+        exit(0);
+    }
+
+    if (argc == 3 && strcmp(argv[ 1 ], "run") != 0) {
+        printf("Invalid mode - Only supported modes are 'run' and 'repl'\n");
+    }
+
+    // read code
+    FILE *fp = fopen(argv[ 2 ], "r");
+    fseek(fp, 0, SEEK_END);
+    int sz = ftell(fp);
+    rewind(fp);
+    char code[ sz + 1 ];
+    fread(code, 1, sz, fp);
+    code[ sz ] = 0;
+    fclose(fp);
+
+    // set pc
+    m[ 7 ] = 1024;
+    // assemble
+    char *fail_point = as(code, &m[ 1024 ]);
+
+    error_debug(fail_point, code, sz);
+
     // run emulation
     emu();
 }
diff --git a/pu.out.c b/pu.out.c
index 4d0c9af..4f7b348 100644
--- a/pu.out.c
+++ b/pu.out.c
diff --git a/putest.c b/putest.c
index d223a42..013a48b 100644
--- a/putest.c
+++ b/putest.c
@@ -2,7 +2,29 @@
 #include <string.h>
 
 #define __WRAPPER
-#include "pu.c"
+#include "pu.out.c"
+
+/* ─── color & statistics ──────────────────────────────────────────────────── */
+#define COLOR_RED   "\x1b[1;31m"
+#define COLOR_BLUE  "\033[1;34m"
+#define COLOR_SUM  "\033[1;33m"
+#define COLOR_RESET "\x1b[0m"
+
+static int tests_run    = 0;
+static int tests_passed = 0;
+
+/* PASS if cond true, else FAIL; color and bump counters */
+#define PRINT_RESULT(cond)                                                                         \
+    do {                                                                                           \
+        tests_run++;                                                                               \
+        if (cond) {                                                                                \
+            tests_passed++;                                                                        \
+            printf(COLOR_BLUE "PASS" COLOR_RESET "\n");                                            \
+        } else {                                                                                   \
+            printf(COLOR_RED "FAIL" COLOR_RESET "\n");                                             \
+        }                                                                                          \
+    } while (0)
+/* ───────────────────────────────────────────────────────────────────────── */
 
 void reset() {
     memset(m, 0, sizeof(m));
@@ -13,283 +35,310 @@ void reset() {
 void test_opcode_0() {
     printf("Testing opcode 0 (hlt)... ");
     reset();
-    m[0] = 0;  // hlt instruction
-    m[7] = 0;  // pc starts at 0
+    m[ 0 ] = 0;
+    m[ 7 ] = 0;
     pu();
-    printf("PASS\n");
+    PRINT_RESULT(1);
 }
 
 void test_opcode_1() {
     printf("Testing opcode 1 (const in r0)... ");
     reset();
-    m[0] = 1;   // const instruction
-    m[1] = 42;  // constant value
-    m[2] = 0;   // hlt
-    m[7] = 0;   // pc starts at 0
+    m[ 0 ] = 1;
+    m[ 1 ] = 42;
+    m[ 2 ] = 0;
+    m[ 7 ] = 0;
     pu();
-    printf("r0=%d (expected 42): %s\n", m[0], m[0] == 42 ? "PASS" : "FAIL");
+    PRINT_RESULT(m[ 0 ] == 42);
 }
 
 void test_opcode_2() {
-    printf("Testing opcode 4 (r0 in r2 if acc non-zero)... ");
+    printf("Testing opcode 4 (r0 in r2 if acc zero)... ");
     reset();
-    m[0] = 123;  // r0 = 123
-    a = 1;       // acc = 1 (non-zero)
-    m[10] = 4;   // opcode 4
-    m[11] = 0;   // hlt
-    m[7] = 10;   // pc starts at 10
+    m[ 0 ]  = 123;
+    a       = 0;
+    m[ 10 ] = 4;
+    m[ 11 ] = 0;
+    m[ 7 ]  = 10;
     pu();
-    printf("r2=%d (expected 123): %s\n", m[2], m[2] == 123 ? "PASS" : "FAIL");
+    PRINT_RESULT(m[ 2 ] == 123);
 }
 
 void test_opcode_2_zero_acc() {
     printf("Testing opcode 4 with zero acc (should not store)... ");
     reset();
-    m[0] = 123;  // r0 = 123
-    m[2] = 999;  // r2 = 999 initially
-    a = 0;       // acc = 0
-    m[10] = 4;   // opcode 4
-    m[11] = 0;   // hlt
-    m[7] = 10;   // pc starts at 10
+    m[ 0 ]  = 123;
+    m[ 2 ]  = 999;
+    a       = 1;
+    m[ 10 ] = 4;
+    m[ 11 ] = 0;
+    m[ 7 ]  = 10;
     pu();
-    printf("r2=%d (expected 999): %s\n", m[2], m[2] == 999 ? "PASS" : "FAIL");
+    PRINT_RESULT(m[ 2 ] == 999);
 }
 
 void test_opcode_10() {
     printf("Testing opcode 12 (r2 in r0)... ");
     reset();
-    m[2] = 456;  // r2 = 456
-    m[10] = 12;  // opcode 12
-    m[11] = 0;   // hlt
-    m[7] = 10;   // pc starts at 10
+    m[ 2 ]  = 456;
+    m[ 10 ] = 12;
+    m[ 11 ] = 0;
+    m[ 7 ]  = 10;
     pu();
-    printf("r0=%d (expected 456): %s\n", m[0], m[0] == 456 ? "PASS" : "FAIL");
+    PRINT_RESULT(m[ 0 ] == 456);
 }
 
 void test_opcode_18() {
     printf("Testing opcode 18 (r0 in m[r1])... ");
     reset();
-    m[0] = 789;   // r0 = 789
-    m[1] = 100;   // r1 = 100 (address)
-    m[10] = 18;   // opcode 18
-    m[11] = 0;    // hlt
-    m[7] = 10;    // pc starts at 10
+    m[ 0 ]  = 789;
+    m[ 1 ]  = 100;
+    m[ 10 ] = 18;
+    m[ 11 ] = 0;
+    m[ 7 ]  = 10;
     pu();
-    printf("m[100]=%d (expected 789): %s\n", m[100], m[100] == 789 ? "PASS" : "FAIL");
+    PRINT_RESULT(m[ 100 ] == 789);
 }
 
 void test_opcode_19() {
     printf("Testing opcode 19 (acc in r0)... ");
     reset();
-    a = 555;      // acc = 555
-    m[10] = 19;   // opcode 19
-    m[11] = 0;    // hlt
-    m[7] = 10;    // pc starts at 10
+    a       = 555;
+    m[ 10 ] = 19;
+    m[ 11 ] = 0;
+    m[ 7 ]  = 10;
     pu();
-    printf("r0=%d (expected 555): %s\n", m[0], m[0] == 555 ? "PASS" : "FAIL");
+    PRINT_RESULT(m[ 0 ] == 555);
 }
 
 void test_opcode_20() {
     printf("Testing opcode 20 (acc += r0)... ");
     reset();
-    a = 10;       // acc = 10
-    m[0] = 5;     // r0 = 5
-    m[10] = 20;   // opcode 20
-    m[11] = 0;    // hlt
-    m[7] = 10;    // pc starts at 10
+    a       = 10;
+    m[ 0 ]  = 5;
+    m[ 10 ] = 20;
+    m[ 11 ] = 0;
+    m[ 7 ]  = 10;
     pu();
-    printf("acc=%d (expected 15): %s\n", a, a == 15 ? "PASS" : "FAIL");
+    PRINT_RESULT(a == 15);
 }
 
 void test_opcode_21() {
     printf("Testing opcode 21 (acc -= r0)... ");
     reset();
-    a = 20;       // acc = 20
-    m[0] = 7;     // r0 = 7
-    m[10] = 21;   // opcode 21
-    m[11] = 0;    // hlt
-    m[7] = 10;    // pc starts at 10
+    a       = 20;
+    m[ 0 ]  = 7;
+    m[ 10 ] = 21;
+    m[ 11 ] = 0;
+    m[ 7 ]  = 10;
     pu();
-    printf("acc=%d (expected 13): %s\n", a, a == 13 ? "PASS" : "FAIL");
+    PRINT_RESULT(a == 13);
 }
 
 void test_opcode_22() {
     printf("Testing opcode 22 (acc = !acc)... ");
     reset();
-    a = 5;        // acc = 5 (non-zero)
-    m[10] = 22;   // opcode 22
-    m[11] = 0;    // hlt
-    m[7] = 10;    // pc starts at 10
+    a       = 5;
+    m[ 10 ] = 22;
+    m[ 11 ] = 0;
+    m[ 7 ]  = 10;
     pu();
-    printf("acc=%d (expected 0): %s\n", a, a == 0 ? "PASS" : "FAIL");
+    PRINT_RESULT(a == 0);
 }
 
 void test_opcode_23() {
     printf("Testing opcode 23 (acc = 0)... ");
     reset();
-    a = 999;      // acc = 999
-    m[10] = 23;   // opcode 23
-    m[11] = 0;    // hlt
-    m[7] = 10;    // pc starts at 10
+    a       = 999;
+    m[ 10 ] = 23;
+    m[ 11 ] = 0;
+    m[ 7 ]  = 10;
     pu();
-    printf("acc=%d (expected 0): %s\n", a, a == 0 ? "PASS" : "FAIL");
+    PRINT_RESULT(a == 0);
 }
 
-// Helper to compare output array with expected values
-int check_output(int *O, int *expected, int len, const char *test_name) {
-    int i;
+/* ─── assembler support ───────────────────────────────────────────────────── */
+
+i;
+int check_output(int* O, int* expected, int len, const char* test_name) {
     for (i = 0; i < len; i++) {
-        if (O[i] != expected[i]) {
-            printf("%s: output[%d]=%d (expected %d): FAIL\n", test_name, i, O[i], expected[i]);
+        if (O[ i ] != expected[ i ]) {
+            printf(
+                "%s: output[%d]=%d (expected %d): " COLOR_RED "FAIL" COLOR_RESET "\n",
+                test_name,
+                i,
+                O[ i ],
+                expected[ i ]);
             return 0;
         }
     }
-    printf("%s: PASS\n", test_name);
     return 1;
 }
 
-// Reset output array
-void reset_output(int *O, int size) {
-    memset(O, 0, size * sizeof(int));
-}
+void reset_output(int* O, int size) { memset(O, 0, size * sizeof(int)); }
 
 void test_hlt() {
     printf("Testing hlt (opcode 0)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {0};
-    int ret = as("hlt", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "hlt") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 0 };
+    char* ret   = as("hlt", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "hlt"));
+    PRINT_RESULT(ok);
 }
 
 void test_con() {
     printf("Testing con 123 (opcode 1, 123)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {1, 123};
-    int ret = as("con 123", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 2, "con") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 1, 123 };
+    char* ret   = as("con 123", O);
+    ok          = (ret == 0 && check_output(O, exp, 2, "con"));
+    PRINT_RESULT(ok);
 }
 
 void test_ar1() {
     printf("Testing ar1 (opcode 2)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {2};
-    int ret = as("ar1", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "ar1") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 2 };
+    char* ret   = as("ar1", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "ar1"));
+    PRINT_RESULT(ok);
 }
 
 void test_ar8() {
     printf("Testing ar8 (opcode 9)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {9};
-    int ret = as("ar8", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "ar8") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 9 };
+    char* ret   = as("ar8", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "ar8"));
+    PRINT_RESULT(ok);
 }
 
 void test_r1a() {
     printf("Testing r1a (opcode 10)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {10};
-    int ret = as("r1a", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "r1a") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 10 };
+    char* ret   = as("r1a", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "r1a"));
+    PRINT_RESULT(ok);
 }
 
 void test_r8a() {
     printf("Testing r8a (opcode 17)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {17};
-    int ret = as("r8a", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "r8a") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 17 };
+    char* ret   = as("r8a", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "r8a"));
+    PRINT_RESULT(ok);
 }
 
 void test_mem() {
     printf("Testing mem (opcode 18)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {18};
-    int ret = as("mem", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "mem") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 18 };
+    char* ret   = as("mem", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "mem"));
+    PRINT_RESULT(ok);
 }
 
 void test_aca() {
     printf("Testing aca (opcode 19)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {19};
-    int ret = as("aca", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "aca") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 19 };
+    char* ret   = as("aca", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "aca"));
+    PRINT_RESULT(ok);
 }
 
 void test_add() {
     printf("Testing add (opcode 20)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {20};
-    int ret = as("add", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "add") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 20 };
+    char* ret   = as("add", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "add"));
+    PRINT_RESULT(ok);
 }
 
 void test_sub() {
     printf("Testing sub (opcode 21)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {21};
-    int ret = as("sub", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "sub") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 21 };
+    char* ret   = as("sub", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "sub"));
+    PRINT_RESULT(ok);
 }
 
 void test_not() {
     printf("Testing not (opcode 22)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {22};
-    int ret = as("not", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "not") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 22 };
+    char* ret   = as("not", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "not"));
+    PRINT_RESULT(ok);
 }
 
 void test_clr() {
     printf("Testing clr (opcode 23)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {23};
-    int ret = as("clr", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 1, "clr") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 23 };
+    char* ret   = as("clr", O);
+    ok          = (ret == 0 && check_output(O, exp, 1, "clr"));
+    PRINT_RESULT(ok);
 }
 
 void test_multi_instruction() {
     printf("Testing multi-instruction (hlt con 123 ar1 clr)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {0, 1, 123, 2, 23};
-    int ret = as("hlt con 123 ar1 clr", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 5, "multi-instruction") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 0, 1, 123, 2, 23 };
+    char* ret   = as("hlt con 123 ar1 clr", O);
+    ok          = (ret == 0 && check_output(O, exp, 5, "multi-instruction"));
+    PRINT_RESULT(ok);
 }
 
 void test_whitespace() {
     printf("Testing whitespace handling (hlt  \\t\\n con 456 \\n clr)... ");
-    int O[10];
+    int O[ 10 ], ok;
+    reset_output(O, 10);
+    int   exp[] = { 0, 1, 456, 23 };
+    char* ret   = as("hlt  \t\n con 456 \n clr", O);
+    ok          = (ret == 0 && check_output(O, exp, 4, "whitespace"));
+    PRINT_RESULT(ok);
+}
+
+void test_comment() {
+    printf("Testing comment handling (should ignore line)... ");
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int expected[] = {0, 1, 456, 23};
-    int ret = as("hlt  \t\n con 456 \n clr", O);
-    printf("return=%d (expected 0): %s\n", ret, ret == 0 ? check_output(O, expected, 4, "whitespace") ? "PASS" : "FAIL" : "FAIL");
+    int   exp[] = { 1, 90 };
+    char* ret   = as("# hello\ncon 90", O);
+    ok          = (ret == 0 && check_output(O, exp, 2, "comment"));
+    PRINT_RESULT(ok);
 }
 
 void test_error() {
     printf("Testing error case (invalid instruction)... ");
-    int O[10];
+    int O[ 10 ], ok;
     reset_output(O, 10);
-    int ret = as("xyz", O);
-    printf("return=%d (expected 1): %s\n", ret, ret == 1 ? "PASS" : "FAIL");
+    char* ret = as("xyz", O);
+    ok        = (ret != 0);
+    PRINT_RESULT(ok);
 }
 
 int main() {
-    printf("Running CPU unit tests...\n\n");
-    
+    printf(COLOR_SUM "Running CPU unit tests...\n\n" COLOR_RESET);
+
     test_opcode_0();
     test_opcode_1();
     test_opcode_2();
@@ -302,8 +351,8 @@ int main() {
     test_opcode_22();
     test_opcode_23();
 
-    printf("\n\nRunning assembler unit tests...\n\n");
-    
+    printf(COLOR_SUM "\nRunning assembler unit tests...\n\n" COLOR_RESET);
+
     test_hlt();
     test_con();
     test_ar1();
@@ -318,8 +367,14 @@ int main() {
     test_clr();
     test_multi_instruction();
     test_whitespace();
+    test_comment();
     test_error();
-    
-    
+
+    printf(
+        "\nTotal tests run: %d, passed: %d, failed: %d\n",
+        tests_run,
+        tests_passed,
+        tests_run - tests_passed);
+
     return 0;
-}
\ No newline at end of file
+}
diff --git a/repl.pu b/repl.pu
new file mode 100644
index 0000000..2cb3020
--- /dev/null
+++ b/repl.pu
@@ -0,0 +1 @@
+con 5