Basic computational life as a single file done!

lib/prick_sv.h

@@ -1,12 +1,12 @@
-/* prick_sv.h: String Views.
+/* sv.h: String Views.
  * Created: 2026-03-01
  * Author: Aryadev Chavali
  * License: See end of file
  * Commentary:
 
  To utilise this library, please put:
-    #define PRICK_SV_IMPL
+    #define SV_IMPL
-    #include "prick_sv.h"
+    #include "sv.h"
  in one of your code units.
 
  This is a simple read-only string view library.  It defines some extremely
@@ -14,8 +14,8 @@
  require allocation.
  */
 
-#ifndef PRICK_SV_H
+#ifndef SV_H
-#define PRICK_SV_H
+#define SV_H
 
 #include <stdint.h>
 
@@ -23,79 +23,78 @@ typedef struct
 {
   uint64_t size;
   const char *data;
-} prick_sv_t;
+} sv_t;
 
-#define PRICK_SV(DATA, SIZE) ((prick_sv_t){.data = (DATA), .size = (SIZE)})
+#define SV(DATA, SIZE) ((sv_t){.data = (DATA), .size = (SIZE)})
-#define PRICK_SV_AUTO(DATA) \
+#define SV_AUTO(DATA)  ((sv_t){.data = (void *)(DATA), .size = sizeof(DATA) - 1})
-  ((prick_sv_t){.data = (void *)(DATA), .size = sizeof(DATA) - 1})
 
 // Pretty printers
-#define PRICK_SV_FMT(SV) (int)(SV).size, (SV).data
+#define SV_FMT(SV) (int)(SV).size, (SV).data
-#define PR_PRICK_SV      "%.*s"
+#define PR_SV      "%.*s"
 
-prick_sv_t prick_sv_chop_left(prick_sv_t, uint64_t size);
+sv_t sv_chop_left(sv_t, uint64_t size);
-prick_sv_t prick_sv_chop_right(prick_sv_t, uint64_t size);
+sv_t sv_chop_right(sv_t, uint64_t size);
-prick_sv_t prick_sv_truncate(prick_sv_t, uint64_t newsize);
+sv_t sv_truncate(sv_t, uint64_t newsize);
-prick_sv_t prick_sv_substr(prick_sv_t, uint64_t position, uint64_t size);
+sv_t sv_substr(sv_t, uint64_t position, uint64_t size);
 
-prick_sv_t prick_sv_till(prick_sv_t, const char *reject);
+sv_t sv_till(sv_t, const char *reject);
-prick_sv_t prick_sv_while(prick_sv_t, const char *accept);
+sv_t sv_while(sv_t, const char *accept);
 
-#ifdef PRICK_SV_IMPL
+#ifdef SV_IMPL
 #include <stddef.h>
 #include <string.h>
 
-prick_sv_t prick_sv_chop_left(prick_sv_t sv, uint64_t size)
+sv_t sv_chop_left(sv_t sv, uint64_t size)
 {
   if (sv.size <= size)
-    return PRICK_SV(NULL, 0);
+    return SV(NULL, 0);
-  return PRICK_SV(sv.data + size, sv.size - size);
+  return SV(sv.data + size, sv.size - size);
 }
 
-prick_sv_t prick_sv_chop_right(prick_sv_t sv, uint64_t size)
+sv_t sv_chop_right(sv_t sv, uint64_t size)
 {
   if (sv.size <= size)
-    return PRICK_SV(NULL, 0);
+    return SV(NULL, 0);
-  return PRICK_SV(sv.data, sv.size - size);
+  return SV(sv.data, sv.size - size);
 }
 
-prick_sv_t prick_sv_truncate(prick_sv_t sv, uint64_t newsize)
+sv_t sv_truncate(sv_t sv, uint64_t newsize)
 {
   if (newsize > sv.size)
-    return PRICK_SV(NULL, 0);
+    return SV(NULL, 0);
-  return PRICK_SV(sv.data, newsize);
+  return SV(sv.data, newsize);
 }
 
-prick_sv_t prick_sv_substr(prick_sv_t sv, uint64_t position, uint64_t size)
+sv_t sv_substr(sv_t sv, uint64_t position, uint64_t size)
 {
-  prick_sv_t result = prick_sv_truncate(prick_sv_chop_left(sv, position), size);
+  sv_t result = sv_truncate(sv_chop_left(sv, position), size);
   return result;
 }
 
-prick_sv_t prick_sv_till(prick_sv_t sv, const char *reject)
+sv_t sv_till(sv_t sv, const char *reject)
 {
   if (sv.size == 0 || !sv.data)
-    return PRICK_SV(NULL, 0);
+    return SV(NULL, 0);
 
   uint64_t offset;
   for (offset = 0; offset < sv.size && strchr(reject, sv.data[offset]) == NULL;
        ++offset)
     continue;
 
-  return prick_sv_truncate(sv, offset);
+  return sv_truncate(sv, offset);
 }
 
-prick_sv_t prick_sv_while(prick_sv_t sv, const char *accept)
+sv_t sv_while(sv_t sv, const char *accept)
 {
   if (sv.size == 0 || !sv.data)
-    return PRICK_SV(NULL, 0);
+    return SV(NULL, 0);
 
   uint64_t offset;
   for (offset = 0; offset < sv.size && strchr(accept, sv.data[offset]) != NULL;
        ++offset)
     continue;
 
-  return prick_sv_truncate(sv, offset);
+  return sv_truncate(sv, offset);
 }
 
 #endif

lib/prick_vec.h

@@ -30,8 +30,8 @@
 #include <stddef.h>
 #include <stdint.h>
 
-#define PRICK_VEC_INLINE_CAPACITY 32
+#define VEC_INLINE_CAPACITY 32
-#define PRICK_VEC_MULT            2
+#define VEC_MULT            2
 
 typedef struct
 {
@@ -40,48 +40,47 @@ typedef struct
   union
   {
     void *ptr;
-    alignas(max_align_t) uint8_t inlined[PRICK_VEC_INLINE_CAPACITY];
+    alignas(max_align_t) uint8_t inlined[VEC_INLINE_CAPACITY];
   };
-} prick_vec_t;
+} vec_t;
 
-static_assert(sizeof(prick_vec_t) == 64,
+static_assert(sizeof(vec_t) == 64, "Expected sizeof(vec_t) to be 64");
-              "Expected sizeof(prick_vec_t) to be 64");
 
-void prick_vec_append(prick_vec_t *vec, const void *const ptr, uint64_t size);
+void vec_append(vec_t *vec, const void *const ptr, uint64_t size);
-void prick_vec_append_byte(prick_vec_t *vec, uint8_t byte);
+void vec_append_byte(vec_t *vec, uint8_t byte);
-void *prick_vec_data(prick_vec_t *vec);
+void *vec_data(vec_t *vec);
-void prick_vec_ensure_capacity(prick_vec_t *vec, uint64_t capacity);
+void vec_ensure_capacity(vec_t *vec, uint64_t capacity);
-void prick_vec_ensure_free(prick_vec_t *vec, uint64_t size);
+void vec_ensure_free(vec_t *vec, uint64_t size);
-void prick_vec_free(prick_vec_t *vec);
+void vec_free(vec_t *vec);
-void prick_vec_clone(prick_vec_t *v2, prick_vec_t *v1);
+void vec_clone(vec_t *v2, vec_t *v1);
 
-#define PRICK_VEC_GET(VEC, INDEX, TYPE) (((TYPE *)prick_vec_data(VEC))[INDEX])
+#define VEC_GET(VEC, INDEX, TYPE) (((TYPE *)vec_data(VEC))[INDEX])
 
-#ifdef PRICK_VEC_IMPL
+#ifdef VEC_IMPL
 #define MAX(A, B) ((A) > (B) ? (A) : (B))
 
 #include <stdlib.h>
 #include <string.h>
 
-void prick_vec_append(prick_vec_t *vec, const void *const ptr, uint64_t size)
+void vec_append(vec_t *vec, const void *const ptr, uint64_t size)
 {
   if (!vec || !ptr || !size)
     return;
-  prick_vec_ensure_free(vec, size);
+  vec_ensure_free(vec, size);
-  memcpy(&PRICK_VEC_GET(vec, vec->size, uint8_t), ptr, size);
+  memcpy(&VEC_GET(vec, vec->size, uint8_t), ptr, size);
   vec->size += size;
 }
 
-void prick_vec_append_byte(prick_vec_t *vec, uint8_t byte)
+void vec_append_byte(vec_t *vec, uint8_t byte)
 {
   if (!vec)
     return;
-  prick_vec_ensure_free(vec, 1);
+  vec_ensure_free(vec, 1);
-  PRICK_VEC_GET(vec, vec->size, uint8_t) = byte;
+  VEC_GET(vec, vec->size, uint8_t) = byte;
   ++vec->size;
 }
 
-void *prick_vec_data(prick_vec_t *vec)
+void *vec_data(vec_t *vec)
 {
   if (!vec)
     return NULL;
@@ -96,15 +95,15 @@ void *prick_vec_data(prick_vec_t *vec)
   }
 }
 
-void prick_vec_ensure_capacity(prick_vec_t *vec, uint64_t capacity)
+void vec_ensure_capacity(vec_t *vec, uint64_t capacity)
 {
   if (!vec)
     return;
   if (vec->capacity == 0)
-    vec->capacity = PRICK_VEC_INLINE_CAPACITY;
+    vec->capacity = VEC_INLINE_CAPACITY;
   if (vec->capacity < capacity)
   {
-    vec->capacity = MAX(vec->capacity * PRICK_VEC_MULT, capacity);
+    vec->capacity = MAX(vec->capacity * VEC_MULT, capacity);
     if (!vec->not_inlined)
     {
       // We were a small buffer, and now we cannot be i.e. we need to allocate
@@ -123,14 +122,14 @@ void prick_vec_ensure_capacity(prick_vec_t *vec, uint64_t capacity)
   }
 }
 
-void prick_vec_ensure_free(prick_vec_t *vec, uint64_t size)
+void vec_ensure_free(vec_t *vec, uint64_t size)
 {
   if (!vec)
     return;
-  prick_vec_ensure_capacity(vec, vec->size + size);
+  vec_ensure_capacity(vec, vec->size + size);
 }
 
-void prick_vec_free(prick_vec_t *vec)
+void vec_free(vec_t *vec)
 {
   if (!vec)
     return;
@@ -139,11 +138,11 @@ void prick_vec_free(prick_vec_t *vec)
   memset(vec, 1, sizeof(*vec));
 }
 
-void prick_vec_clone(prick_vec_t *v2, prick_vec_t *v1)
+void vec_clone(vec_t *v2, vec_t *v1)
 {
   if (!v1 || !v2)
     return;
-  prick_vec_append(v2, prick_vec_data(v1), v1->size);
+  vec_append(v2, vec_data(v1), v1->size);
 }
 
 #undef MAX

main.c

@@ -6,19 +6,319 @@
 
 #include <raylib.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+#include "./lib/prick_aliases.h"
+
+#define SV_IMPL
+#include "./lib/prick_sv.h"
+
+#define VEC_IMPL
+#include "./lib/prick_vec.h"
+
+#define SAFE_SUB(A, B) ((A) < (B) ? 0 : (A) - (B))
+
+#define SIZEOF_PROGRAM (1LU << 6)
+struct ProgramConcat
+{
+  sv_t A, B;
+  u8 tape[SIZEOF_PROGRAM * 2];
+};
+
+void program_concat(struct ProgramConcat *ret, sv_t a, sv_t b)
+{
+  assert(a.size == SIZEOF_PROGRAM && b.size == SIZEOF_PROGRAM);
+  memset(ret, 0, sizeof(*ret));
+  ret->A = a;
+  ret->B = b;
+  memcpy(ret->tape, a.data, SIZEOF_PROGRAM);
+  memcpy(ret->tape + SIZEOF_PROGRAM, b.data, SIZEOF_PROGRAM);
+}
+
+u64 vec_pop(vec_t *vec)
+{
+  u64 ret = 0;
+  if (vec->size < sizeof(ret))
+    return ret;
+  vec->size -= sizeof(ret);
+  memcpy(&ret, (typeof(ret) *)(((u8 *)vec_data(vec)) + vec->size), sizeof(ret));
+  return ret;
+}
+
+bool vec_in(vec_t *vec, u64 n)
+{
+  for (u64 i = 0; i < vec->size / sizeof(n); ++i)
+  {
+    if (VEC_GET(vec, i, typeof(n)) == n)
+    {
+      return true;
+    }
+  }
+  return false;
+}
+
+void program_execute(struct ProgramConcat *prg)
+{
+  vec_t cond_stack = {0};
+  vec_ensure_capacity(&cond_stack, sizeof(prg->tape) * sizeof(u64));
+
+  for (u64 ip = 0, head0 = 0, head1 = 0, total_iters = 0;
+       ip < sizeof(prg->tape) && total_iters < (1LU << 13); ++total_iters)
+  {
+    u8 opcode = prg->tape[ip];
+    switch (opcode)
+    {
+    case '<':
+      head0 = SAFE_SUB(head0, 1);
+      ++ip;
+      break;
+    case '>':
+      head0++;
+      ++ip;
+      break;
+    case '{':
+      head1 = SAFE_SUB(head1, 1);
+      ++ip;
+      break;
+    case '}':
+      head1++;
+      ++ip;
+      break;
+    case '-':
+      prg->tape[head0]--;
+      ++ip;
+      break;
+    case '+':
+      prg->tape[head0]++;
+      ++ip;
+      break;
+    case '.':
+      prg->tape[head1] = prg->tape[head0];
+      ++ip;
+      break;
+    case ',':
+      prg->tape[head0] = prg->tape[head1];
+      ++ip;
+      break;
+    case '[':
+    {
+      if (!vec_in(&cond_stack, ip))
+      {
+        vec_append(&cond_stack, &ip, sizeof(ip));
+      }
+      if (!prg->tape[head0])
+      {
+        // Iterate forward, trying to find a matching closed bracket
+        u64 square_brackets = 0;
+        u64 close_ip;
+        for (close_ip = ip + 1; close_ip < sizeof(prg->tape); ++close_ip)
+        {
+          if (prg->tape[close_ip] == '[')
+          {
+            ++square_brackets;
+          }
+          else if (prg->tape[close_ip] == ']')
+          {
+            if (square_brackets == 0)
+            {
+              break;
+            }
+            --square_brackets;
+          }
+        }
+        if (square_brackets != 0)
+        {
+          // NOTE: as per paper, terminate.
+          ip = sizeof(prg->tape);
+        }
+        else
+        {
+          ip = close_ip;
+        }
+      }
+      break;
+    }
+    case ']':
+    {
+      if (prg->tape[head0])
+      {
+        if (cond_stack.size < sizeof(u64))
+        {
+          // NOTE: as per paper, terminate.
+          ip = sizeof(prg->tape);
+        }
+        else
+        {
+          ip = vec_pop(&cond_stack);
+        }
+      }
+      else
+      {
+        ++ip;
+      }
+      break;
+    }
+    default:
+      ++ip;
+      break;
+    }
+  }
+
+  vec_free(&cond_stack);
+}
+
+void program_split(struct ProgramConcat *prg)
+{
+  assert(prg->A.data && prg->B.data);
+  memcpy((char *)prg->A.data, prg->tape, SIZEOF_PROGRAM);
+  memcpy((char *)prg->B.data, prg->tape + SIZEOF_PROGRAM, SIZEOF_PROGRAM);
+}
 
 #define WIDTH  800
 #define HEIGHT 600
 
+#define NUM_PROGRAMS_POW_2 10
+#define NUM_PROGRAMS       (1LU << NUM_PROGRAMS_POW_2)
+#define SIMULATION_SIZE    (SIZEOF_PROGRAM * NUM_PROGRAMS)
+struct Simulation
+{
+  char buffer[SIMULATION_SIZE];
+  u64 p1, p2;
+};
+
+void simulation_init(struct Simulation *sim)
+{
+  for (u64 i = 0; i < SIMULATION_SIZE / sizeof(u16); ++i)
+  {
+    ((u16 *)(sim->buffer))[i] = rand() % UINT16_MAX;
+  }
+}
+
+void simulation_pick(struct Simulation *sim)
+{
+  sim->p1 = rand() % (SIMULATION_SIZE / SIZEOF_PROGRAM);
+  sim->p2 = rand() % (SIMULATION_SIZE / SIZEOF_PROGRAM);
+  while (sim->p1 * 8 <= ((sim->p2 * 8) + SIZEOF_PROGRAM) &&
+         sim->p2 * 8 <= ((sim->p1 * 8) + SIZEOF_PROGRAM))
+  {
+    sim->p2 = rand() % (SIMULATION_SIZE / SIZEOF_PROGRAM);
+  }
+}
+
+void simulation_update(struct Simulation *sim)
+{
+  sv_t a = SV(sim->buffer + (sim->p1 * SIZEOF_PROGRAM), 64);
+  sv_t b = SV(sim->buffer + (sim->p2 * SIZEOF_PROGRAM), 64);
+
+  struct ProgramConcat prog_concat = {0};
+  program_concat(&prog_concat, a, b);
+  program_execute(&prog_concat);
+  program_split(&prog_concat);
+}
+
+Color simulation_cell_color(const u8 *program)
+{
+  // How do we compute a "colour" for a program?  I say we count all the valid
+  // opcodes in the program.  These counts are used as weights for 10 distinct
+  // colours.
+  const Vector4 bases[] = {
+      ['<'] = ColorNormalize(ColorFromHSV(0.121, 0.467, 0.706)),
+      ['>'] = ColorNormalize(ColorFromHSV(1.000, 0.498, 0.055)),
+      ['{'] = ColorNormalize(ColorFromHSV(0.173, 0.627, 0.173)),
+      ['}'] = ColorNormalize(ColorFromHSV(0.839, 0.153, 0.157)),
+      ['-'] = ColorNormalize(ColorFromHSV(0.580, 0.404, 0.741)),
+      ['+'] = ColorNormalize(ColorFromHSV(0.549, 0.337, 0.294)),
+      ['.'] = ColorNormalize(ColorFromHSV(0.890, 0.467, 0.761)),
+      [','] = ColorNormalize(ColorFromHSV(0.498, 0.498, 0.498)),
+      ['['] = ColorNormalize(ColorFromHSV(0.737, 0.741, 0.133)),
+      [']'] = ColorNormalize(ColorFromHSV(0.090, 0.745, 0.812)),
+  };
+
+  static const char *VALID_OPS = "<>{}-+.,[]";
+
+  u64 counter[] = {
+      ['<'] = 0, ['>'] = 0, ['{'] = 0, ['}'] = 0, ['-'] = 0,
+      ['+'] = 0, ['.'] = 0, [','] = 0, ['['] = 0, [']'] = 0,
+  };
+
+  u64 total_valid = 0;
+  for (u64 i = 0; i < SIZEOF_PROGRAM; ++i)
+  {
+    if (strchr(VALID_OPS, program[i]))
+    {
+      counter[(u64)program[i]]++;
+      ++total_valid;
+    }
+  }
+
+  if (total_valid == 0)
+    return BLACK;
+
+  f64 colour_cells[3];
+  for (const char *ptr = VALID_OPS; *ptr; ++ptr)
+  {
+    colour_cells[0] += bases[(u64)*ptr].x;
+    colour_cells[1] += bases[(u64)*ptr].y;
+    colour_cells[2] += bases[(u64)*ptr].z;
+  }
+  colour_cells[0] /= total_valid;
+  colour_cells[1] /= total_valid;
+  colour_cells[2] /= total_valid;
+
+  return (Color){.r = 255 * colour_cells[0],
+                 .g = 255 * colour_cells[1],
+                 .b = 255 * colour_cells[2],
+                 .a = 255};
+}
+
+void simulation_draw(struct Simulation *sim)
+{
+  // Our grid will be of lengths sqrt(NUM_PROGRAMS) == 1 <<
+  // (NUM_PROGRAMS_POW_2/2).
+  const size_t GRID_WIDTH = 1LU << (NUM_PROGRAMS_POW_2 / 2);
+  const size_t CELL_WIDTH = WIDTH / GRID_WIDTH;
+
+  sv_t sv = SV(sim->buffer, SIMULATION_SIZE);
+
+  for (u64 i = 0; i < SIMULATION_SIZE / SIZEOF_PROGRAM; ++i)
+  {
+    sv_t program = sv_truncate(sv, SIZEOF_PROGRAM);
+
+    Color color = simulation_cell_color((const u8 *)program.data);
+
+    u64 x = i / GRID_WIDTH;
+    u64 y = i % GRID_WIDTH;
+    DrawRectangle(x * CELL_WIDTH, y * CELL_WIDTH, CELL_WIDTH, CELL_WIDTH,
+                  color);
+
+    if (i == sim->p1 || i == sim->p2)
+    {
+      DrawRectangleLines(x * CELL_WIDTH, y * CELL_WIDTH, CELL_WIDTH, CELL_WIDTH,
+                         BLUE);
+    }
+
+    sv = sv_chop_left(sv, 64);
+  }
+}
+
 int main(void)
 {
+  srand(time(NULL));
+
+  struct Simulation sim = {0};
+  simulation_init(&sim);
+
   InitWindow(WIDTH, HEIGHT, "CompLife");
   SetTargetFPS(60);
-  while (!WindowShouldClose())
+  for (size_t ticks = 0; !WindowShouldClose(); ++ticks)
   {
+    simulation_pick(&sim);
+    simulation_update(&sim);
     BeginDrawing();
     ClearBackground(BLACK);
-    DrawFPS(0, 0);
+    simulation_draw(&sim);
     EndDrawing();
   }
   CloseWindow();