🐐 Escape sequences

🐐 Web server
🐐 SVBSTITVE
2026-04-22 11:27:19 +02:00 · 2026-04-22 11:11:58 +02:00 · 2026-04-22 09:30:58 +02:00 · 2026-04-22 09:08:36 +02:00
19 changed files with 866 additions and 318 deletions
--- a/README.md
+++ b/README.md
@@ -349,6 +349,16 @@ Returns the type of `value` as a string: `NVMERVS` (integer), `LITTERA` (string)

 Sleeps for `n` seconds, where `n` is an integer, fraction, or NVLLVS (treated as 0). Returns nothing meaningful.

+### QVAERE
+`QVAERE(pattern, string)`
+
+Returns an array of all non-overlapping matches of the regex `pattern` in `string`. Both arguments must be strings. Patterns use extended regular expression syntax. Returns an empty array if there are no matches. Raises an error if the pattern is invalid.
+
+### SVBSTITVE
+`SVBSTITVE(pattern, replacement, string)`
+
+Replaces all non-overlapping matches of the regex `pattern` in `string` with `replacement`. All three arguments must be strings. The replacement string supports backreferences (`\1`, `\2`, etc.) to captured groups. Returns the resulting string. Raises an error if the pattern is invalid.
+
 ## Modules
 Modules are additions to the base `CENTVRION` syntax. They add or change certain features. Modules are included in your code by having

@@ -361,15 +371,15 @@ Vnlike many other programming languages with modules, the modules in `CENTVRION`
 ### FORS
 ![CVM FORS](snippets/fors.png)

-The `FORS` module allows you to add randomness to your `CENTVRION` program. It adds 4 new built-in functions: `FORTVITVS_NVMERVS int int`, `FORTVITA_ELECTIO ['a]`, `DECIMATIO ['a]`, and `SEMEN int`.
+The `FORS` module allows you to add randomness to your `CENTVRION` program. It adds 4 new built-in functions: `FORTVITVS_NVMERVS(int, int)`, `FORTVITA_ELECTIO(['a])`, `DECIMATIO(['a])`, and `SEMEN(int)`.

-`FORTVITVS_NVMERVS int int` picks a random int in the (inclusive) range of the two given ints.
+`FORTVITVS_NVMERVS(int, int)` picks a random int in the (inclusive) range of the two given ints.

-`FORTVITA_ELECTIO ['a]` picks a random element from the given array. `FORTVITA_ELECTIO array` is identical to ```array[FORTVITVS_NVMERVS NVLLVS ((LONGITVDO array)-I)]```.
+`FORTVITA_ELECTIO(['a])` picks a random element from the given array. `FORTVITA_ELECTIO(array)` is identical to ```array[FORTVITVS_NVMERVS(I, LONGITVDO(array))]```.

-`DECIMATIO ['a]` returns a copy of the given array with a random tenth of its elements removed. Arrays with fewer than 10 elements are returned unchanged.
+`DECIMATIO(['a])` returns a copy of the given array with a random tenth of its elements removed. Arrays with fewer than 10 elements are returned unchanged.

-`SEMEN int` seeds the random number generator for reproducibility.
+`SEMEN(int)` seeds the random number generator for reproducibility.

 ### FRACTIO
 ![CVM FRACTIO](snippets/fractio.png)
@@ -394,14 +404,26 @@ When `_` is added _after_ a numeric symbol, the symbol becomes 1.000 times large
 All integer symbols except `I` may be given a `_`.

 ### SCRIPTA
+![CVM SCRIPTA](snippets/scripta.png)

-The `SCRIPTA` module adds file I/O to your `CENTVRION` program. It adds 3 new built-in functions: `LEGE string`, `SCRIBE string string`, and `ADIVNGE string string`.
+The `SCRIPTA` module adds file I/O to your `CENTVRION` program. It adds 3 new built-in functions: `LEGE`, `SCRIBE`, and `ADIVNGE`.

-`LEGE string` reads the contents of the file at the given path and returns them as a string.
+`LEGE(string)` reads the contents of the file at the given path and returns them as a string.

-`SCRIBE string string` writes the second argument to the file at the path given by the first argument, overwriting any existing content.
+`SCRIBE(string, string)` writes the second argument to the file at the path given by the first argument, overwriting any existing content.

-`ADIVNGE string string` appends the second argument to the file at the path given by the first argument.
+`ADIVNGE(string, string)` appends the second argument to the file at the path given by the first argument.
+
+### RETE
+![CVM RETE](snippets/rete.png)
+
+The `RETE` module adds networking to your `CENTVRION` program.
+
+`PETE(string)` performs an HTTP GET request to the given URL and returns the response body as a string.
+
+`PETITVR(string, function)` registers a GET handler for the given path. The handler function receives a single argument: a dictionary with keys `"via"` (the request path), `"quaestio"` (query string), and `"methodus"` (HTTP method). The handler's return value becomes the response body (200 OK). Unmatched paths return a 404.
+
+`AVSCVLTA(integer)` starts an HTTP server on the given port. This call blocks indefinitely, serving registered routes. Routes must be registered with `PETITVR` before calling `AVSCVLTA`. Ports above 3999 require the `MAGNVM` module.

 ### SVBNVLLA
 ![CVM SVBNVLLA](snippets/svbnvlla.png)
--- a/4
+++ b/4
@@ -61,7 +61,7 @@ def main():
        with open(tmp_path, "w") as f:
          f.write(c_source)
        subprocess.run(
-          ["gcc", "-O2", tmp_path, runtime_c, "-o", out_path],
+          ["gcc", "-O2", tmp_path, runtime_c, "-o", out_path, "-lcurl", "-lmicrohttpd"],
          check=True,
        )
      else:
@@ -70,7 +70,7 @@ def main():
          tmp_path = tmp.name
        try:
          subprocess.run(
-            ["gcc", "-O2", tmp_path, runtime_c, "-o", out_path],
+            ["gcc", "-O2", tmp_path, runtime_c, "-o", out_path, "-lcurl", "-lmicrohttpd"],
            check=True,
          )
        finally:
--- a/centvrion/ast_nodes.py
+++ b/centvrion/ast_nodes.py
@@ -1,6 +1,8 @@
+import http.server
 import re
-import random
 import time
+import urllib.parse
+import urllib.request
 from fractions import Fraction

 from rply.token import BaseBox
@@ -8,6 +10,26 @@ from rply.token import BaseBox
 from centvrion.errors import CentvrionError
 from centvrion.values import Val, ValInt, ValStr, ValBool, ValList, ValDict, ValNul, ValFunc, ValFrac

+class _CentRng:
+  """Xorshift32 RNG — identical algorithm in Python and C runtime."""
+  def __init__(self, seed=None):
+    if seed is None:
+      seed = int(time.time())
+    self.state = seed & 0xFFFFFFFF or 1
+  def seed(self, s):
+    self.state = s & 0xFFFFFFFF or 1
+  def next(self):
+    x = self.state
+    x ^= (x << 13) & 0xFFFFFFFF
+    x ^= x >> 17
+    x ^= (x << 5) & 0xFFFFFFFF
+    self.state = x
+    return x
+  def randint(self, a, b):
+    return a + self.next() % (b - a + 1)
+
+_cent_rng = _CentRng()
+
 NUMERALS = {
  "I": 1,
  "IV": 4,
@@ -321,10 +343,15 @@ class String(Node):
    return f"String({self.value})"

  def print(self):
+    v = (self.value
+      .replace('\\', '\\\\')
+      .replace('\n', '\\n')
+      .replace('\t', '\\t')
+      .replace('\r', '\\r'))
    if self.quote == "'":
-      return f"'{self.value}'"
-    escaped = self.value.replace('{', '{{').replace('}', '}}')
-    return f'"{escaped}"'
+      return f"'{v}'"
+    v = v.replace('"', '\\"').replace('{', '{{').replace('}', '}}')
+    return f'"{v}"'

  def _eval(self, vtable):
    return vtable, ValStr(self.value)
@@ -1175,7 +1202,7 @@ class BuiltIn(Node):
          raise CentvrionError("FORTVITVS_NVMERVS requires two numbers")
        if a > b:
          raise CentvrionError(f"FORTVITVS_NVMERVS: first argument ({a}) must be ≤ second ({b})")
-        return vtable, ValInt(random.randint(a, b))
+        return vtable, ValInt(_cent_rng.randint(a, b))
      case "FORTVITA_ELECTIO":
        if "FORS" not in vtable["#modules"]:
          raise CentvrionError("Cannot use 'FORTVITA_ELECTIO' without module 'FORS'")
@@ -1184,14 +1211,14 @@ class BuiltIn(Node):
        lst = params[0].value()
        if len(lst) == 0:
          raise CentvrionError("FORTVITA_ELECTIO: cannot select from an empty array")
-        return vtable, lst[random.randint(0, len(lst) - 1)]
+        return vtable, lst[_cent_rng.randint(0, len(lst) - 1)]
      case "SEMEN":
        if "FORS" not in vtable["#modules"]:
          raise CentvrionError("Cannot use 'SEMEN' without module 'FORS'")
        seed = params[0].value()
        if not isinstance(seed, int):
          raise CentvrionError("SEMEN requires an integer seed")
-        random.seed(seed)
+        _cent_rng.seed(seed)
        return vtable, ValNul()
      case "DECIMATIO":
        if "FORS" not in vtable["#modules"]:
@@ -1201,7 +1228,7 @@ class BuiltIn(Node):
        arr = list(params[0].value())
        to_remove = len(arr) // 10
        for _ in range(to_remove):
-          arr.pop(random.randint(0, len(arr) - 1))
+          arr.pop(_cent_rng.randint(0, len(arr) - 1))
        return vtable, ValList(arr)
      case "SENATVS":
        if len(params) == 1 and isinstance(params[0], ValList):
@@ -1277,6 +1304,99 @@ class BuiltIn(Node):
        with open(path, "a") as f:
          f.write(content)
        return vtable, ValNul()
+      case "QVAERE":
+        pattern = params[0]
+        text = params[1]
+        if not isinstance(pattern, ValStr) or not isinstance(text, ValStr):
+          raise CentvrionError("QVAERE requires two strings")
+        try:
+          matches = [
+            ValStr(m.group(0))
+            for m in re.finditer(pattern.value(), text.value())
+          ]
+        except re.error as e:
+          raise CentvrionError(f"Invalid regex: {e}")
+        return vtable, ValList(matches)
+      case "SVBSTITVE":
+        pattern = params[0]
+        replacement = params[1]
+        text = params[2]
+        if not isinstance(pattern, ValStr) or not isinstance(replacement, ValStr) or not isinstance(text, ValStr):
+          raise CentvrionError("SVBSTITVE requires three strings")
+        try:
+          result = re.sub(pattern.value(), replacement.value(), text.value())
+        except re.error as e:
+          raise CentvrionError(f"Invalid regex: {e}")
+        return vtable, ValStr(result)
+      case "PETE":
+        if "RETE" not in vtable["#modules"]:
+          raise CentvrionError("Cannot use 'PETE' without module 'RETE'")
+        url = params[0]
+        if not isinstance(url, ValStr):
+          raise CentvrionError("PETE requires a string URL")
+        try:
+          with urllib.request.urlopen(url.value()) as resp:
+            return vtable, ValStr(resp.read().decode("utf-8"))
+        except Exception as e:
+          raise CentvrionError(f"PETE: {e}")
+      case "PETITVR":
+        if "RETE" not in vtable["#modules"]:
+          raise CentvrionError("Cannot use 'PETITVR' without module 'RETE'")
+        path, handler = params[0], params[1]
+        if not isinstance(path, ValStr):
+          raise CentvrionError("PETITVR requires a string path")
+        if not isinstance(handler, ValFunc):
+          raise CentvrionError("PETITVR requires a function handler")
+        vtable["#routes"].append((path.value(), handler))
+        return vtable, ValNul()
+      case "AVSCVLTA":
+        if "RETE" not in vtable["#modules"]:
+          raise CentvrionError("Cannot use 'AVSCVLTA' without module 'RETE'")
+        port = params[0]
+        if not isinstance(port, ValInt):
+          raise CentvrionError("AVSCVLTA requires an integer port")
+        routes = vtable["#routes"]
+        if not routes:
+          raise CentvrionError("AVSCVLTA: no routes registered")
+        captured_vtable = vtable.copy()
+        route_map = {p: h for p, h in routes}
+        class _CentHandler(http.server.BaseHTTPRequestHandler):
+          def do_GET(self):
+            parsed = urllib.parse.urlparse(self.path)
+            handler = route_map.get(parsed.path)
+            if handler is None:
+              self.send_response(404)
+              self.end_headers()
+              return
+            request_dict = ValDict({
+              "via": ValStr(parsed.path),
+              "quaestio": ValStr(parsed.query),
+              "methodus": ValStr("GET"),
+            })
+            func_vtable = captured_vtable.copy()
+            if len(handler.params) == 1:
+              func_vtable[handler.params[0].name] = request_dict
+            func_vtable["#return"] = None
+            for statement in handler.body:
+              func_vtable, _ = statement.eval(func_vtable)
+              if func_vtable["#return"] is not None:
+                break
+            result = func_vtable["#return"]
+            if isinstance(result, ValStr):
+              body = result.value().encode("utf-8")
+            elif result is not None:
+              body = make_string(result, magnvm, svbnvlla).encode("utf-8")
+            else:
+              body = b""
+            self.send_response(200)
+            self.send_header("Content-Type", "text/plain")
+            self.end_headers()
+            self.wfile.write(body)
+          def log_message(self, *args):
+            pass
+        server = http.server.HTTPServer(("0.0.0.0", port.value()), _CentHandler)
+        server.serve_forever()
+        return vtable, ValNul()
      case _:
        raise NotImplementedError(self.builtin)

@@ -1307,6 +1427,7 @@ class Program(BaseBox):
      "#continue": False,
      "#return": None,
      "#modules": [m.module_name for m in self.modules],
+      "#routes": [],
    }
    last_val = ValNul()
    for statement in self.statements:
--- a/centvrion/compiler/emit_expr.py
+++ b/centvrion/compiler/emit_expr.py
@@ -297,6 +297,35 @@ def _emit_builtin(node, ctx):
        lines.append(f"cent_adivnge({param_vars[0]}, {param_vars[1]});")
        lines.append(f"CentValue {tmp} = cent_null();")

+    case "QVAERE":
+      lines.append(f"CentValue {tmp} = cent_qvaere({param_vars[0]}, {param_vars[1]});")
+
+    case "SVBSTITVE":
+      lines.append(f"CentValue {tmp} = cent_svbstitve({param_vars[0]}, {param_vars[1]}, {param_vars[2]});")
+
+    case "PETE":
+      if not ctx.has_module("RETE"):
+        lines.append('cent_runtime_error("RETE module required for PETE");')
+        lines.append(f"CentValue {tmp} = cent_null();")
+      else:
+        lines.append(f"CentValue {tmp} = cent_pete({param_vars[0]});")
+
+    case "PETITVR":
+      if not ctx.has_module("RETE"):
+        lines.append('cent_runtime_error("RETE module required for PETITVR");')
+        lines.append(f"CentValue {tmp} = cent_null();")
+      else:
+        lines.append(f"cent_petitvr({param_vars[0]}, {param_vars[1]}, _scope);")
+        lines.append(f"CentValue {tmp} = cent_null();")
+
+    case "AVSCVLTA":
+      if not ctx.has_module("RETE"):
+        lines.append('cent_runtime_error("RETE module required for AVSCVLTA");')
+        lines.append(f"CentValue {tmp} = cent_null();")
+      else:
+        lines.append(f"cent_avscvlta({param_vars[0]});")
+        lines.append(f"CentValue {tmp} = cent_null();")
+
    case _:
      raise NotImplementedError(node.builtin)

--- a/centvrion/compiler/runtime/cent_runtime.c
+++ b/centvrion/compiler/runtime/cent_runtime.c
@@ -2,7 +2,12 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <stdint.h>
 #include <time.h>
+#include <unistd.h>
+#include <regex.h>
+#include <curl/curl.h>
+#include <microhttpd.h>

 /* ------------------------------------------------------------------ */
 /* Global arena                                                         */
@@ -11,6 +16,21 @@
 CentArena *cent_arena;
 int cent_magnvm = 0;

+/* ------------------------------------------------------------------ */
+/* Portable xorshift32 RNG (matches Python _CentRng)                   */
+/* ------------------------------------------------------------------ */
+
+static uint32_t cent_rng_state = 1;
+
+static uint32_t cent_rng_next(void) {
+  uint32_t x = cent_rng_state;
+  x ^= x << 13;
+  x ^= x >> 17;
+  x ^= x << 5;
+  cent_rng_state = x;
+  return x;
+}
+
 jmp_buf _cent_try_stack[CENT_TRY_STACK_MAX];
 int     _cent_try_depth = 0;
 const char *_cent_error_msg = NULL;
@@ -628,7 +648,7 @@ CentValue cent_fortuitus_numerus(CentValue lo, CentValue hi) {
  long range = hi.ival - lo.ival + 1;
  if (range <= 0)
    cent_runtime_error("'FORTVITVS_NVMERVS' requires lo <= hi");
-  return cent_int(lo.ival + rand() % range);
+  return cent_int(lo.ival + cent_rng_next() % range);
 }

 CentValue cent_fortuita_electionis(CentValue lst) {
@@ -636,7 +656,7 @@ CentValue cent_fortuita_electionis(CentValue lst) {
    cent_type_error("'FORTVITA_ELECTIO' requires a list");
  if (lst.lval.len == 0)
    cent_runtime_error("'FORTVITA_ELECTIO' requires a non-empty list");
-  return lst.lval.items[rand() % lst.lval.len];
+  return lst.lval.items[cent_rng_next() % lst.lval.len];
 }

 CentValue cent_senatus(CentValue *args, int n) {
@@ -664,7 +684,7 @@ CentValue cent_decimatio(CentValue lst) {
    cent_list_push(&result, lst.lval.items[i]);
  int to_remove = result.lval.len / 10;
  for (int i = 0; i < to_remove; i++) {
-    int idx = rand() % result.lval.len;
+    int idx = cent_rng_next() % result.lval.len;
    /* Shift remaining elements left */
    for (int j = idx; j < result.lval.len - 1; j++)
      result.lval.items[j] = result.lval.items[j + 1];
@@ -676,7 +696,8 @@ CentValue cent_decimatio(CentValue lst) {
 void cent_semen(CentValue seed) {
  if (seed.type != CENT_INT)
    cent_type_error("'SEMEN' requires an integer seed");
-  srand((unsigned)seed.ival);
+  cent_rng_state = (uint32_t)seed.ival;
+  if (cent_rng_state == 0) cent_rng_state = 1;
 }

 static int _ordina_comparator(const void *a, const void *b) {
@@ -870,11 +891,299 @@ CentValue cent_dict_keys(CentValue dict) {
  return result;
 }

+/* ------------------------------------------------------------------ */
+/* Regex                                                                */
+/* ------------------------------------------------------------------ */
+
+CentValue cent_qvaere(CentValue pattern, CentValue text) {
+  if (pattern.type != CENT_STR || text.type != CENT_STR)
+    cent_type_error("'QVAERE' requires two strings");
+  regex_t re;
+  int rc = regcomp(&re, pattern.sval, REG_EXTENDED);
+  if (rc != 0) {
+    char errbuf[256];
+    regerror(rc, &re, errbuf, sizeof(errbuf));
+    regfree(&re);
+    cent_runtime_error(errbuf);
+  }
+  CentValue result = cent_list_new(8);
+  const char *cursor = text.sval;
+  regmatch_t match;
+  while (*cursor && regexec(&re, cursor, 1, &match, 0) == 0) {
+    int len = match.rm_eo - match.rm_so;
+    char *buf = cent_arena_alloc(cent_arena, len + 1);
+    memcpy(buf, cursor + match.rm_so, len);
+    buf[len] = '\0';
+    cent_list_push(&result, cent_str(buf));
+    cursor += match.rm_eo;
+    if (len == 0) cursor++;  // avoid infinite loop on zero-length match
+  }
+  regfree(&re);
+  return result;
+}
+
+/* Expand replacement string, substituting \1..\9 with captured groups */
+static void _expand_replacement(const char *repl, const char *subject,
+                                regmatch_t *matches, int ngroups,
+                                char **out, size_t *opos, size_t *ocap) {
+  for (const char *r = repl; *r; r++) {
+    if (*r == '\\' && r[1] >= '1' && r[1] <= '9') {
+      int g = r[1] - '0';
+      r++;
+      if (g < ngroups && matches[g].rm_so != -1) {
+        size_t glen = matches[g].rm_eo - matches[g].rm_so;
+        while (*opos + glen + 1 > *ocap) {
+          *ocap *= 2;
+          char *newbuf = cent_arena_alloc(cent_arena, *ocap);
+          memcpy(newbuf, *out, *opos);
+          *out = newbuf;
+        }
+        memcpy(*out + *opos, subject + matches[g].rm_so, glen);
+        *opos += glen;
+      }
+    } else if (*r == '\\' && r[1] == '\\') {
+      /* escaped backslash → literal \ */
+      if (*opos + 2 > *ocap) {
+        *ocap *= 2;
+        char *newbuf = cent_arena_alloc(cent_arena, *ocap);
+        memcpy(newbuf, *out, *opos);
+        *out = newbuf;
+      }
+      (*out)[(*opos)++] = '\\';
+      r++;
+    } else {
+      if (*opos + 2 > *ocap) {
+        *ocap *= 2;
+        char *newbuf = cent_arena_alloc(cent_arena, *ocap);
+        memcpy(newbuf, *out, *opos);
+        *out = newbuf;
+      }
+      (*out)[(*opos)++] = *r;
+    }
+  }
+}
+
+CentValue cent_svbstitve(CentValue pattern, CentValue replacement, CentValue text) {
+  if (pattern.type != CENT_STR || replacement.type != CENT_STR || text.type != CENT_STR)
+    cent_type_error("'SVBSTITVE' requires three strings");
+  regex_t re;
+  int rc = regcomp(&re, pattern.sval, REG_EXTENDED);
+  if (rc != 0) {
+    char errbuf[256];
+    regerror(rc, &re, errbuf, sizeof(errbuf));
+    regfree(&re);
+    cent_runtime_error(errbuf);
+  }
+  size_t text_len = strlen(text.sval);
+  size_t repl_len = strlen(replacement.sval);
+  size_t cap = text_len + repl_len * 4 + 1;
+  char *result = cent_arena_alloc(cent_arena, cap);
+  size_t rpos = 0;
+  const char *cursor = text.sval;
+  int ngroups = (int)re.re_nsub + 1;
+  if (ngroups > 10) ngroups = 10;
+  regmatch_t matches[10];
+  while (*cursor && regexec(&re, cursor, ngroups, matches, 0) == 0) {
+    /* copy text before match */
+    size_t prefix_len = matches[0].rm_so;
+    while (rpos + prefix_len + 1 > cap) {
+      cap *= 2;
+      char *newbuf = cent_arena_alloc(cent_arena, cap);
+      memcpy(newbuf, result, rpos);
+      result = newbuf;
+    }
+    memcpy(result + rpos, cursor, prefix_len);
+    rpos += prefix_len;
+    /* expand replacement with backreferences */
+    _expand_replacement(replacement.sval, cursor, matches, ngroups,
+                        &result, &rpos, &cap);
+    cursor += matches[0].rm_eo;
+    if (matches[0].rm_eo == 0) cursor++;
+  }
+  /* copy remaining text */
+  size_t tail_len = strlen(cursor);
+  while (rpos + tail_len + 1 > cap) {
+    cap *= 2;
+    char *newbuf = cent_arena_alloc(cent_arena, cap);
+    memcpy(newbuf, result, rpos);
+    result = newbuf;
+  }
+  memcpy(result + rpos, cursor, tail_len);
+  rpos += tail_len;
+  result[rpos] = '\0';
+  regfree(&re);
+  return cent_str(result);
+}
+
+/* ------------------------------------------------------------------ */
+/* Networking (RETE)                                                    */
+/* ------------------------------------------------------------------ */
+
+typedef struct {
+  char  *buf;
+  size_t len;
+  size_t cap;
+} CurlBuf;
+
+static size_t _curl_write_cb(void *data, size_t size, size_t nmemb, void *userp) {
+  size_t bytes = size * nmemb;
+  CurlBuf *cb = (CurlBuf *)userp;
+  while (cb->len + bytes + 1 > cb->cap) {
+    cb->cap = cb->cap ? cb->cap * 2 : 4096;
+    cb->buf = realloc(cb->buf, cb->cap);
+    if (!cb->buf) cent_runtime_error("PETE: out of memory");
+  }
+  memcpy(cb->buf + cb->len, data, bytes);
+  cb->len += bytes;
+  cb->buf[cb->len] = '\0';
+  return bytes;
+}
+
+CentValue cent_pete(CentValue url) {
+  if (url.type != CENT_STR)
+    cent_type_error("'PETE' requires a string URL");
+  CURL *curl = curl_easy_init();
+  if (!curl) cent_runtime_error("PETE: failed to init curl");
+  CurlBuf cb = {0};
+  curl_easy_setopt(curl, CURLOPT_URL, url.sval);
+  curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, _curl_write_cb);
+  curl_easy_setopt(curl, CURLOPT_WRITEDATA, &cb);
+  curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
+  CURLcode res = curl_easy_perform(curl);
+  curl_easy_cleanup(curl);
+  if (res != CURLE_OK) {
+    free(cb.buf);
+    cent_runtime_error(curl_easy_strerror(res));
+  }
+  char *arena_buf = cent_arena_alloc(cent_arena, cb.len + 1);
+  memcpy(arena_buf, cb.buf, cb.len + 1);
+  free(cb.buf);
+  return cent_str(arena_buf);
+}
+
+/* ------------------------------------------------------------------ */
+/* Server (RETE)                                                        */
+/* ------------------------------------------------------------------ */
+
+#define CENT_MAX_ROUTES 64
+
+typedef struct {
+  const char   *path;
+  CentFuncInfo  handler;
+  CentScope     scope;
+} CentRoute;
+
+static CentRoute _cent_routes[CENT_MAX_ROUTES];
+static int       _cent_route_count = 0;
+
+void cent_petitvr(CentValue path, CentValue handler, CentScope scope) {
+  if (path.type != CENT_STR)
+    cent_type_error("PETITVR requires a string path");
+  if (handler.type != CENT_FUNC)
+    cent_type_error("PETITVR requires a function handler");
+  if (_cent_route_count >= CENT_MAX_ROUTES)
+    cent_runtime_error("PETITVR: too many routes");
+  _cent_routes[_cent_route_count].path = path.sval;
+  _cent_routes[_cent_route_count].handler = handler.fnval;
+  _cent_routes[_cent_route_count].scope = cent_scope_copy(&scope);
+  _cent_route_count++;
+}
+
+static enum MHD_Result
+_cent_request_handler(void *cls, struct MHD_Connection *conn,
+                      const char *url, const char *method,
+                      const char *version, const char *upload_data,
+                      size_t *upload_data_size, void **con_cls) {
+  (void)cls; (void)version; (void)upload_data;
+  (void)upload_data_size; (void)con_cls;
+
+  /* Find matching route */
+  CentFuncInfo *fi = NULL;
+  CentScope *captured_scope = NULL;
+  /* Split url at '?' to match path only */
+  const char *qmark = strchr(url, '?');
+  size_t path_len = qmark ? (size_t)(qmark - url) : strlen(url);
+  for (int i = 0; i < _cent_route_count; i++) {
+    if (strlen(_cent_routes[i].path) == path_len
+        && strncmp(_cent_routes[i].path, url, path_len) == 0) {
+      fi = &_cent_routes[i].handler;
+      captured_scope = &_cent_routes[i].scope;
+      break;
+    }
+  }
+
+  if (!fi) {
+    const char *msg = "CDIV — not found\n";
+    struct MHD_Response *resp = MHD_create_response_from_buffer(
+      strlen(msg), (void *)msg, MHD_RESPMEM_PERSISTENT);
+    enum MHD_Result ret = MHD_queue_response(conn, MHD_HTTP_NOT_FOUND, resp);
+    MHD_destroy_response(resp);
+    return ret;
+  }
+
+  /* Build request dict: via, quaestio, methodus */
+  char *via_buf = cent_arena_alloc(cent_arena, path_len + 1);
+  memcpy(via_buf, url, path_len);
+  via_buf[path_len] = '\0';
+
+  const char *qs = qmark ? qmark + 1 : "";
+  size_t qs_len = strlen(qs);
+  char *qs_buf = cent_arena_alloc(cent_arena, qs_len + 1);
+  memcpy(qs_buf, qs, qs_len + 1);
+
+  CentValue dict = cent_dict_new(4);
+  cent_dict_set(&dict, cent_str("via"), cent_str(via_buf));
+  cent_dict_set(&dict, cent_str("quaestio"), cent_str(qs_buf));
+  cent_dict_set(&dict, cent_str("methodus"), cent_str(method));
+
+  /* Call handler — start from the scope captured at registration time */
+  CentScope call_scope = cent_scope_copy(captured_scope);
+  if (fi->param_count == 1) {
+    cent_scope_set(&call_scope, fi->param_names[0], dict);
+  }
+  CentValue result = fi->fn(call_scope);
+
+  /* Build response */
+  const char *body = "";
+  size_t body_len = 0;
+  if (result.type == CENT_STR) {
+    body = result.sval;
+    body_len = strlen(body);
+  } else if (result.type != CENT_NULL) {
+    char *s = cent_make_string(result);
+    body = s;
+    body_len = strlen(s);
+  }
+
+  struct MHD_Response *resp = MHD_create_response_from_buffer(
+    body_len, (void *)body, MHD_RESPMEM_PERSISTENT);
+  MHD_add_response_header(resp, "Content-Type", "text/plain");
+  enum MHD_Result ret = MHD_queue_response(conn, MHD_HTTP_OK, resp);
+  MHD_destroy_response(resp);
+  return ret;
+}
+
+void cent_avscvlta(CentValue port) {
+  if (port.type != CENT_INT)
+    cent_type_error("AVSCVLTA requires an integer port");
+  if (_cent_route_count == 0)
+    cent_runtime_error("AVSCVLTA: no routes registered");
+  struct MHD_Daemon *d = MHD_start_daemon(
+    MHD_USE_INTERNAL_POLLING_THREAD,
+    (uint16_t)port.ival, NULL, NULL,
+    _cent_request_handler, NULL,
+    MHD_OPTION_END);
+  if (!d) cent_runtime_error("AVSCVLTA: failed to start server");
+  /* Block forever */
+  while (1) pause();
+}
+
 /* ------------------------------------------------------------------ */
 /* Initialisation                                                       */
 /* ------------------------------------------------------------------ */

 void cent_init(void) {
  cent_arena = cent_arena_new(1024 * 1024);  /* 1 MiB initial arena */
-  srand((unsigned)time(NULL));
+  cent_rng_state = (uint32_t)time(NULL);
+  if (cent_rng_state == 0) cent_rng_state = 1;
 }
--- a/centvrion/compiler/runtime/cent_runtime.h
+++ b/centvrion/compiler/runtime/cent_runtime.h
@@ -232,6 +232,11 @@ CentValue cent_ordina(CentValue lst);                           /* ORDINA */
 CentValue cent_lege(CentValue path);                            /* LEGE */
 void      cent_scribe(CentValue path, CentValue content);       /* SCRIBE */
 void      cent_adivnge(CentValue path, CentValue content);      /* ADIVNGE */
+CentValue cent_qvaere(CentValue pattern, CentValue text);       /* QVAERE */
+CentValue cent_svbstitve(CentValue pattern, CentValue replacement, CentValue text); /* SVBSTITVE */
+CentValue cent_pete(CentValue url);                             /* PETE */
+void      cent_petitvr(CentValue path, CentValue handler, CentScope scope); /* PETITVR */
+void      cent_avscvlta(CentValue port);                        /* AVSCVLTA */

 /* ------------------------------------------------------------------ */
 /* Array helpers                                                        */
--- a/centvrion/lexer.py
+++ b/centvrion/lexer.py
@@ -57,11 +57,16 @@ builtin_tokens = [("BUILTIN", i) for i in [
  "TYPVS",
  "LEGE",
  "SCRIBE",
-  "ADIVNGE"
+  "ADIVNGE",
+  "QVAERE",
+  "SVBSTITVE",
+  "PETE",
+  "PETITVR",
+  "AVSCVLTA"
 ]]

 data_tokens = [
-  ("DATA_STRING", r"(\".*?\"|'.*?')"),
+  ("DATA_STRING", r'("(?:[^"\\]|\\.)*"|' + r"'(?:[^'\\]|\\.)*')"),
  ("DATA_FRACTION", r"([IVXLCDM][IVXLCDM_]*)?([S][S:.|]*|:[S:.|]+|\.[S:.|]*)"),
  ("DATA_NUMERAL", r"[IVXLCDM][IVXLCDM_]*")
 ]
@@ -71,7 +76,8 @@ module_tokens = [("MODULE", i) for i in [
  "FRACTIO",
  "MAGNVM",
  "SCRIPTA",
-  "SVBNVLLA"
+  "SVBNVLLA",
+  "RETE"
 ]]

 symbol_tokens = [
--- a/centvrion/parser.py
+++ b/centvrion/parser.py
@@ -7,19 +7,61 @@ from . import ast_nodes
 ALL_TOKENS = list(set([i[0] for i in all_tokens]))


+_ESCAPE_MAP = {
+  'n': '\n',
+  't': '\t',
+  'r': '\r',
+  '\\': '\\',
+  '"': '"',
+  "'": "'",
+}
+
+
+def _read_escape(s, i):
+  """Read a backslash escape at position i (the backslash). Returns (char, new_i)."""
+  if i + 1 >= len(s):
+    raise CentvrionError("Trailing backslash in string")
+  nxt = s[i + 1]
+  if nxt in _ESCAPE_MAP:
+    return _ESCAPE_MAP[nxt], i + 2
+  # unknown escapes pass through literally (e.g. \1 for regex backrefs)
+  return '\\' + nxt, i + 2
+
+
+def _unescape(s):
+  """Process escape sequences in a string with no interpolation."""
+  out = []
+  i = 0
+  while i < len(s):
+    if s[i] == '\\':
+      ch, i = _read_escape(s, i)
+      out.append(ch)
+    else:
+      out.append(s[i])
+      i += 1
+  return ''.join(out)
+
+
 def _parse_interpolated(raw_value):
  quote_char = raw_value[0]
  inner = raw_value[1:-1]

-  if quote_char == "'" or len(inner) == 0:
+  if len(inner) == 0:
    return ast_nodes.String(inner)

+  if quote_char == "'":
+    return ast_nodes.String(_unescape(inner))
+
  parts = []
  i = 0
  current = []

  while i < len(inner):
    ch = inner[i]
+    if ch == '\\':
+      c, i = _read_escape(inner, i)
+      current.append(c)
+      continue
    if ch == '{':
      if i + 1 < len(inner) and inner[i + 1] == '{':
        current.append('{')
--- a/examples/web_server.cent
+++ b/examples/web_server.cent
@@ -0,0 +1,19 @@
+// A simple web server with dynamic content
+// Run: ./cent -i examples/web_server.cent
+// Then visit http://localhost:80/ in your browser
+CVM RETE
+CVM FORS
+
+DESIGNA salve VT ["SALVE", "AVE", "HAVETE", "SALVETE"]
+DESIGNA sententiae VT ["Alea iacta est.", "Veni, vidi, vici.", "Carpe diem.", "Cogito, ergo svm."]
+
+PETITVR("/", FVNCTIO (petitio) VT {
+  DESIGNA verbvm VT FORTVITA_ELECTIO(salve)
+  DESIGNA sententia VT FORTVITA_ELECTIO(sententiae)
+  DESIGNA a VT FORTVITVS_NVMERVS(I, VI)
+  DESIGNA b VT FORTVITVS_NVMERVS(I, VI)
+  REDI("{verbvm} MVNDE!\n\n{sententia}\n\nAlea: {a} + {b} = {a + b}")
+})
+
+DIC("Avscvlta in port MLXXX...")
+AVSCVLTA(MLXXX)
--- a/language/main.aux
+++ b/language/main.aux
@@ -1,2 +0,0 @@
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-\gdef \@abspage@last{2}
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+++ b/language/main.log
@@ -1,269 +0,0 @@
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-LaTeX Warning: Float too large for page by 44.293pt on input line 93.
-
-[1
-
-] [2] (./main.aux)
- ***********
-LaTeX2e <2025-11-01>
-L3 programming layer <2026-01-19>
- ***********
- ) 
-Here is how much of TeX's memory you used:
- 3526 strings out of 470191
- 106539 string characters out of 5479698
- 562689 words of memory out of 5000000
- 32135 multiletter control sequences out of 15000+600000
- 627857 words of font info for 57 fonts, out of 8000000 for 9000
- 14 hyphenation exceptions out of 8191
- 73i,9n,93p,432b,328s stack positions out of 10000i,1000n,20000p,200000b,200000s
-
-Output written on main.pdf (2 pages).
--- a/language/main.pdf
+++ b/language/main.pdf
--- a/language/main.tex
+++ b/language/main.tex
@@ -98,7 +98,7 @@
 \newpage
 \begin{itemize}
  \item \textbf{newline}: \\ Newlines are combined, so a single newline is the same as multiple.
-  \item \textbf{module-name}: \\ Modules are flags given to the interpreter/compiler, to let it know you want to be using certain rules, functions, or features. Available modules: \texttt{FORS} (randomness), \texttt{FRACTIO} (fractions), \texttt{MAGNVM} (large integers), \texttt{SCRIPTA} (file I/O: \texttt{LEGE}, \texttt{SCRIBE}, \texttt{ADIVNGE}), \texttt{SVBNVLLA} (negative literals).
+  \item \textbf{module-name}: \\ Modules are flags given to the interpreter/compiler, to let it know you want to be using certain rules, functions, or features. Available modules: \texttt{FORS} (randomness), \texttt{FRACTIO} (fractions), \texttt{MAGNVM} (large integers), \texttt{SCRIPTA} (file I/O: \texttt{LEGE}, \texttt{SCRIBE}, \texttt{ADIVNGE}), \texttt{SVBNVLLA} (negative literals), \texttt{RETE} (networking: \texttt{PETE}, \texttt{PETITVR}, \texttt{AVSCVLTA}).
  \item \textbf{id}: \\ Variable. Can only consist of lowercase characters and underscores, but not the letters j, u, or w.
  \item \textbf{builtin}: \\ Builtin functions are uppercase latin words.
  \item \textbf{string}: \\ Any text encased in \texttt{"} or \texttt{'} characters. Single-quoted strings are always literal. Strings support 1-based indexing (\texttt{string[I]}) and inclusive slicing (\texttt{string[I VSQVE III]}), returning single-character strings and substrings respectively.
--- a/snippets/rete.cent
+++ b/snippets/rete.cent
@@ -0,0 +1 @@
+CVM RETE
--- a/snippets/rete.png
+++ b/snippets/rete.png
--- a/snippets/scripta.cent
+++ b/snippets/scripta.cent
@@ -0,0 +1 @@
+CVM SCRIPTA
--- a/snippets/scripta.png
+++ b/snippets/scripta.png
--- a/snippets/syntaxes/centvrion.sublime-syntax
+++ b/snippets/syntaxes/centvrion.sublime-syntax
@@ -70,11 +70,11 @@ contexts:
      scope: constant.language.centvrion

  builtins:
-    - match: '\b(ADIVNGE|AVDI_NVMERVS|AVDI|CLAVES|DECIMATIO|DIC|EVERRE|FORTVITVS_NVMERVS|FORTVITA_ELECTIO|LEGE|LONGITVDO|ORDINA|SCRIBE|SEMEN|SENATVS)\b'
+    - match: '\b(ADIVNGE|AVDI_NVMERVS|AVDI|CLAVES|DECIMATIO|DIC|EVERRE|FORTVITVS_NVMERVS|FORTVITA_ELECTIO|LEGE|LONGITVDO|ORDINA|PETE|QVAERE|SCRIBE|SEMEN|SENATVS|SVBSTITVE)\b'
      scope: support.function.builtin.centvrion

  modules:
-    - match: '\b(FORS|FRACTIO|MAGNVM|SCRIPTA|SVBNVLLA)\b'
+    - match: '\b(FORS|FRACTIO|MAGNVM|RETE|SCRIPTA|SVBNVLLA)\b'
      scope: support.class.module.centvrion

  keywords:
--- a/tests.py
+++ b/tests.py
@@ -1,5 +1,4 @@
 import os
-import random
 import subprocess
 import tempfile
 import time
@@ -17,6 +16,7 @@ from centvrion.ast_nodes import (
  ModuleCall, Nullus, Numeral, PerStatement, Program, Redi, SiStatement,
  String, TemptaStatement, UnaryMinus, UnaryNot, Fractio, frac_to_fraction,
  fraction_to_frac, num_to_int, int_to_num, make_string,
+  _cent_rng,
 )
 from centvrion.compiler.emitter import compile_program
 from centvrion.errors import CentvrionError
@@ -30,7 +30,7 @@ _RUNTIME_C = os.path.join(
 )

 def run_test(self, source, target_nodes, target_value, target_output="", input_lines=[]):
-  random.seed(1)
+  _cent_rng.seed(1)

  lexer = Lexer().get_lexer()
  tokens = lexer.lex(source + "\n")
@@ -83,6 +83,8 @@ def run_test(self, source, target_nodes, target_value, target_output="", input_l
  ###### Compiler Test #####
  ##########################
  c_source = compile_program(program)
+  # Force deterministic RNG seed=1 for test reproducibility
+  c_source = c_source.replace("cent_init();", "cent_init(); cent_semen((CentValue){.type=CENT_INT, .ival=1});", 1)
  with tempfile.NamedTemporaryFile(suffix=".c", delete=False, mode="w") as tmp_c:
    tmp_c.write(c_source)
    tmp_c_path = tmp_c.name
@@ -90,7 +92,7 @@ def run_test(self, source, target_nodes, target_value, target_output="", input_l
    tmp_bin_path = tmp_bin.name
  try:
    subprocess.run(
-      ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path],
+      ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path, "-lcurl", "-lmicrohttpd"],
      check=True, capture_output=True,
    )
    stdin_data = "".join(f"{l}\n" for l in input_lines)
@@ -530,22 +532,22 @@ class TestFunctions(unittest.TestCase):
 builtin_tests = [
  ("AVDI_NVMERVS()", Program([], [ExpressionStatement(BuiltIn("AVDI_NVMERVS", []))]), ValInt(3), "", ["III"]),
  ("AVDI_NVMERVS()", Program([], [ExpressionStatement(BuiltIn("AVDI_NVMERVS", []))]), ValInt(10), "", ["X"]),
-  ("CVM FORS\nFORTVITVS_NVMERVS(I, X)", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("FORTVITVS_NVMERVS", [Numeral("I"), Numeral("X")]))]), ValInt(3)),
+  ("CVM FORS\nDESIGNA a VT [I, II, III]\nDIC(a[FORTVITVS_NVMERVS(I, LONGITVDO(a))])", Program([ModuleCall("FORS")], [Designa(ID("a"), DataArray([Numeral("I"), Numeral("II"), Numeral("III")])), ExpressionStatement(BuiltIn("DIC", [ArrayIndex(ID("a"), BuiltIn("FORTVITVS_NVMERVS", [Numeral("I"), BuiltIn("LONGITVDO", [ID("a")])]))]))]), ValStr("I"), "I\n"),
  ("AVDI()", Program([], [ExpressionStatement(BuiltIn("AVDI", []))]), ValStr("hello"), "", ["hello"]),
  ("LONGITVDO([I, II, III])", Program([], [ExpressionStatement(BuiltIn("LONGITVDO", [DataArray([Numeral("I"), Numeral("II"), Numeral("III")])]))]), ValInt(3)),
  ("LONGITVDO([])", Program([], [ExpressionStatement(BuiltIn("LONGITVDO", [DataArray([])]))]), ValInt(0)),
  ('LONGITVDO("salve")', Program([], [ExpressionStatement(BuiltIn("LONGITVDO", [String("salve")]))]), ValInt(5)),
  ('LONGITVDO("")', Program([], [ExpressionStatement(BuiltIn("LONGITVDO", [String("")]))]), ValInt(0)),
-  ("CVM FORS\nFORTVITA_ELECTIO([I, II, III])", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("FORTVITA_ELECTIO", [DataArray([Numeral("I"), Numeral("II"), Numeral("III")])]))]), ValInt(1)),
-  ("CVM FORS\nSEMEN(XLII)\nFORTVITVS_NVMERVS(I, C)", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("SEMEN", [Numeral("XLII")])), ExpressionStatement(BuiltIn("FORTVITVS_NVMERVS", [Numeral("I"), Numeral("C")]))]), ValInt(82)),
-  # DECIMATIO: seed 42, 10 elements → removes 1 (element II)
-  ("CVM FORS\nSEMEN(XLII)\nDECIMATIO([I, II, III, IV, V, VI, VII, VIII, IX, X])", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("SEMEN", [Numeral("XLII")])), ExpressionStatement(BuiltIn("DECIMATIO", [DataArray([Numeral("I"), Numeral("II"), Numeral("III"), Numeral("IV"), Numeral("V"), Numeral("VI"), Numeral("VII"), Numeral("VIII"), Numeral("IX"), Numeral("X")])]))]), ValList([ValInt(1), ValInt(3), ValInt(4), ValInt(5), ValInt(6), ValInt(7), ValInt(8), ValInt(9), ValInt(10)])),
+  ("CVM FORS\nDIC(FORTVITA_ELECTIO([I, II, III]))", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("DIC", [BuiltIn("FORTVITA_ELECTIO", [DataArray([Numeral("I"), Numeral("II"), Numeral("III")])])]))]), ValStr("I"), "I\n"),
+  ("CVM FORS\nSEMEN(XLII)\nDIC(FORTVITVS_NVMERVS(I, C))", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("SEMEN", [Numeral("XLII")])), ExpressionStatement(BuiltIn("DIC", [BuiltIn("FORTVITVS_NVMERVS", [Numeral("I"), Numeral("C")])]))]), ValStr("XXXIII"), "XXXIII\n"),
+  # DECIMATIO: seed 42, 10 elements → removes 1 (element III)
+  ("CVM FORS\nSEMEN(XLII)\nDIC(DECIMATIO([I, II, III, IV, V, VI, VII, VIII, IX, X]))", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("SEMEN", [Numeral("XLII")])), ExpressionStatement(BuiltIn("DIC", [BuiltIn("DECIMATIO", [DataArray([Numeral("I"), Numeral("II"), Numeral("III"), Numeral("IV"), Numeral("V"), Numeral("VI"), Numeral("VII"), Numeral("VIII"), Numeral("IX"), Numeral("X")])])]))]), ValStr("[I II IV V VI VII VIII IX X]"), "[I II IV V VI VII VIII IX X]\n"),
  # DECIMATIO: seed 1, 3 elements → 3//10=0, nothing removed
-  ("CVM FORS\nSEMEN(I)\nDECIMATIO([I, II, III])", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("SEMEN", [Numeral("I")])), ExpressionStatement(BuiltIn("DECIMATIO", [DataArray([Numeral("I"), Numeral("II"), Numeral("III")])]))]), ValList([ValInt(1), ValInt(2), ValInt(3)])),
+  ("CVM FORS\nSEMEN(I)\nDIC(DECIMATIO([I, II, III]))", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("SEMEN", [Numeral("I")])), ExpressionStatement(BuiltIn("DIC", [BuiltIn("DECIMATIO", [DataArray([Numeral("I"), Numeral("II"), Numeral("III")])])]))]), ValStr("[I II III]"), "[I II III]\n"),
  # DECIMATIO: empty array → empty array
-  ("CVM FORS\nDECIMATIO([])", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("DECIMATIO", [DataArray([])]))]), ValList([])),
-  # DECIMATIO: seed 42, 20 elements → removes 2 (elements I and IV)
-  ("CVM FORS\nSEMEN(XLII)\nDECIMATIO([I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVII, XVIII, XIX, XX])", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("SEMEN", [Numeral("XLII")])), ExpressionStatement(BuiltIn("DECIMATIO", [DataArray([Numeral("I"), Numeral("II"), Numeral("III"), Numeral("IV"), Numeral("V"), Numeral("VI"), Numeral("VII"), Numeral("VIII"), Numeral("IX"), Numeral("X"), Numeral("XI"), Numeral("XII"), Numeral("XIII"), Numeral("XIV"), Numeral("XV"), Numeral("XVI"), Numeral("XVII"), Numeral("XVIII"), Numeral("XIX"), Numeral("XX")])]))]), ValList([ValInt(2), ValInt(3), ValInt(5), ValInt(6), ValInt(7), ValInt(8), ValInt(9), ValInt(10), ValInt(11), ValInt(12), ValInt(13), ValInt(14), ValInt(15), ValInt(16), ValInt(17), ValInt(18), ValInt(19), ValInt(20)])),
+  ("CVM FORS\nDIC(DECIMATIO([]))", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("DIC", [BuiltIn("DECIMATIO", [DataArray([])])]))]), ValStr("[]"), "[]\n"),
+  # DECIMATIO: seed 42, 20 elements → removes 2 (elements XIII and XII)
+  ("CVM FORS\nSEMEN(XLII)\nDIC(DECIMATIO([I, II, III, IV, V, VI, VII, VIII, IX, X, XI, XII, XIII, XIV, XV, XVI, XVII, XVIII, XIX, XX]))", Program([ModuleCall("FORS")], [ExpressionStatement(BuiltIn("SEMEN", [Numeral("XLII")])), ExpressionStatement(BuiltIn("DIC", [BuiltIn("DECIMATIO", [DataArray([Numeral("I"), Numeral("II"), Numeral("III"), Numeral("IV"), Numeral("V"), Numeral("VI"), Numeral("VII"), Numeral("VIII"), Numeral("IX"), Numeral("X"), Numeral("XI"), Numeral("XII"), Numeral("XIII"), Numeral("XIV"), Numeral("XV"), Numeral("XVI"), Numeral("XVII"), Numeral("XVIII"), Numeral("XIX"), Numeral("XX")])])]))]), ValStr("[I II III IV V VI VII VIII IX X XI XIV XV XVI XVII XVIII XIX XX]"), "[I II III IV V VI VII VIII IX X XI XIV XV XVI XVII XVIII XIX XX]\n"),
  # SENATVS: majority true → VERITAS
  ("SENATVS(VERITAS, VERITAS, FALSITAS)", Program([], [ExpressionStatement(BuiltIn("SENATVS", [Bool(True), Bool(True), Bool(False)]))]), ValBool(True)),
  # SENATVS: majority false → FALSITAS
@@ -606,6 +608,36 @@ builtin_tests = [
  ("TYPVS(FVNCTIO () VT { REDI(I) })", Program([], [ExpressionStatement(BuiltIn("TYPVS", [Fvnctio([], [Redi([Numeral("I")])])]))]), ValStr("FVNCTIO")),
  # TYPVS: null
  ("TYPVS(NVLLVS)", Program([], [ExpressionStatement(BuiltIn("TYPVS", [Nullus()]))]), ValStr("NVLLVS")),
+  # QVAERE: basic literal match
+  ('QVAERE("ab", "abcabc")', Program([], [ExpressionStatement(BuiltIn("QVAERE", [String("ab"), String("abcabc")]))]), ValList([ValStr("ab"), ValStr("ab")])),
+  # QVAERE: no match → empty list
+  ('QVAERE("xyz", "abc")', Program([], [ExpressionStatement(BuiltIn("QVAERE", [String("xyz"), String("abc")]))]), ValList([])),
+  # QVAERE: regex character class
+  ('QVAERE("[a-z]+", "abc123def")', Program([], [ExpressionStatement(BuiltIn("QVAERE", [String("[a-z]+"), String("abc123def")]))]), ValList([ValStr("abc"), ValStr("def")])),
+  # QVAERE: empty text → empty list
+  ('QVAERE("a", "")', Program([], [ExpressionStatement(BuiltIn("QVAERE", [String("a"), String("")]))]), ValList([])),
+  # QVAERE: capture groups still return full match
+  ('QVAERE("(a)(b)", "ab")', Program([], [ExpressionStatement(BuiltIn("QVAERE", [String("(a)(b)"), String("ab")]))]), ValList([ValStr("ab")])),
+  # QVAERE: empty pattern matches between every character
+  ('QVAERE("", "ab")', Program([], [ExpressionStatement(BuiltIn("QVAERE", [String(""), String("ab")]))]), ValList([ValStr(""), ValStr(""), ValStr("")])),
+  # QVAERE: dot matches any character
+  ('QVAERE(".", "ab")', Program([], [ExpressionStatement(BuiltIn("QVAERE", [String("."), String("ab")]))]), ValList([ValStr("a"), ValStr("b")])),
+  # SVBSTITVE: basic literal replacement
+  ('SVBSTITVE("a", "b", "aaa")', Program([], [ExpressionStatement(BuiltIn("SVBSTITVE", [String("a"), String("b"), String("aaa")]))]), ValStr("bbb")),
+  # SVBSTITVE: regex character class
+  ('SVBSTITVE("[0-9]+", "N", "abc123def456")', Program([], [ExpressionStatement(BuiltIn("SVBSTITVE", [String("[0-9]+"), String("N"), String("abc123def456")]))]), ValStr("abcNdefN")),
+  # SVBSTITVE: no match → string unchanged
+  ('SVBSTITVE("x", "y", "abc")', Program([], [ExpressionStatement(BuiltIn("SVBSTITVE", [String("x"), String("y"), String("abc")]))]), ValStr("abc")),
+  # SVBSTITVE: empty replacement (deletion)
+  ('SVBSTITVE("a", "", "banana")', Program([], [ExpressionStatement(BuiltIn("SVBSTITVE", [String("a"), String(""), String("banana")]))]), ValStr("bnn")),
+  # SVBSTITVE: empty text → empty string
+  ('SVBSTITVE("a", "b", "")', Program([], [ExpressionStatement(BuiltIn("SVBSTITVE", [String("a"), String("b"), String("")]))]), ValStr("")),
+  # SVBSTITVE: dot matches any character
+  ('SVBSTITVE(".", "x", "ab")', Program([], [ExpressionStatement(BuiltIn("SVBSTITVE", [String("."), String("x"), String("ab")]))]), ValStr("xx")),
+  # SVBSTITVE: backreference swaps two groups
+  ('SVBSTITVE("(a)(b)", "\\2\\1", "ab")', Program([], [ExpressionStatement(BuiltIn("SVBSTITVE", [String("(a)(b)"), String("\\2\\1"), String("ab")]))]), ValStr("ba")),
+  # SVBSTITVE: backreference with unmatched group (ignored)
+  ('SVBSTITVE("(a)(b)?", "\\1\\2", "a")', Program([], [ExpressionStatement(BuiltIn("SVBSTITVE", [String("(a)(b)?"), String("\\1\\2"), String("a")]))]), ValStr("a")),
 ]

 class TestBuiltins(unittest.TestCase):
@@ -687,6 +719,21 @@ error_tests = [
  ("CVM FRACTIO\n[I, II, III][I VSQVE IIIS]", CentvrionError),            # slice with fractional upper bound
  ("CVM FRACTIO\n[I, II, III][I / II VSQVE III]", CentvrionError),        # slice with division-fraction lower bound
  ("TEMPTA {\nDESIGNA x VT I / NVLLVS\n} CAPE e {\nDESIGNA y VT I / NVLLVS\n}", CentvrionError),  # uncaught error in catch block propagates
+  ('QVAERE(I, "abc")', CentvrionError),                                     # QVAERE requires strings, not int
+  ('QVAERE("abc", I)', CentvrionError),                                     # QVAERE requires strings, not int
+  ('QVAERE("[", "abc")', CentvrionError),                                   # QVAERE invalid regex
+  ('SVBSTITVE(I, "b", "c")', CentvrionError),                                # SVBSTITVE requires strings, not int pattern
+  ('SVBSTITVE("a", I, "c")', CentvrionError),                                # SVBSTITVE requires strings, not int replacement
+  ('SVBSTITVE("a", "b", I)', CentvrionError),                                # SVBSTITVE requires strings, not int text
+  ('SVBSTITVE("[", "b", "c")', CentvrionError),                              # SVBSTITVE invalid regex
+  ('PETE("http://example.com")', CentvrionError),                             # RETE required for PETE
+  ('CVM RETE\nPETE(I)', CentvrionError),                                      # PETE requires a string URL
+  ('PETITVR("/", FVNCTIO (r) VT {\nREDI("hi")\n})', CentvrionError),           # RETE required for PETITVR
+  ('CVM RETE\nPETITVR(I, FVNCTIO (r) VT {\nREDI("hi")\n})', CentvrionError), # PETITVR path must be string
+  ('CVM RETE\nPETITVR("/", "not a func")', CentvrionError),                   # PETITVR handler must be function
+  ('CVM RETE\nAVSCVLTA(LXXX)', CentvrionError),                               # AVSCVLTA: no routes registered
+  ('AVSCVLTA(LXXX)', CentvrionError),                                         # RETE required for AVSCVLTA
+  ('CVM RETE\nPETITVR("/", FVNCTIO (r) VT {\nREDI("hi")\n})\nAVSCVLTA("text")', CentvrionError),  # AVSCVLTA port must be integer
 ]

 class TestErrors(unittest.TestCase):
@@ -711,7 +758,7 @@ def run_compiler_error_test(self, source):
    tmp_bin_path = tmp_bin.name
  try:
    subprocess.run(
-      ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path],
+      ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path, "-lcurl", "-lmicrohttpd"],
      check=True, capture_output=True,
    )
    proc = subprocess.run([tmp_bin_path], capture_output=True, text=True)
@@ -1033,6 +1080,63 @@ class TestInterpolation(unittest.TestCase):
    run_test(self, source, nodes, value, output)


+# --- Escape sequences ---
+
+escape_tests = [
+  # \n → newline
+  ('"hello\\nworld"',
+    Program([], [ExpressionStatement(String("hello\nworld"))]),
+    ValStr("hello\nworld")),
+  # \t → tab
+  ('"col\\tcol"',
+    Program([], [ExpressionStatement(String("col\tcol"))]),
+    ValStr("col\tcol")),
+  # \r → carriage return
+  ('"line\\rover"',
+    Program([], [ExpressionStatement(String("line\rover"))]),
+    ValStr("line\rover")),
+  # \\ → literal backslash
+  ('"back\\\\slash"',
+    Program([], [ExpressionStatement(String("back\\slash"))]),
+    ValStr("back\\slash")),
+  # \" → literal double quote
+  ('"say \\"salve\\""',
+    Program([], [ExpressionStatement(String('say "salve"'))]),
+    ValStr('say "salve"')),
+  # \' → literal single quote in single-quoted string
+  ("'it\\'s'",
+    Program([], [ExpressionStatement(String("it's"))]),
+    ValStr("it's")),
+  # \n in single-quoted string
+  ("'hello\\nworld'",
+    Program([], [ExpressionStatement(String("hello\nworld"))]),
+    ValStr("hello\nworld")),
+  # escape inside interpolated string
+  ('DESIGNA name VT "Roma"\n"salve\\n{name}"',
+    Program([], [
+      Designa(ID("name"), String("Roma")),
+      ExpressionStatement(InterpolatedString([String("salve\n"), ID("name")]))
+    ]), ValStr("salve\nRoma")),
+  # DIC with newline escape
+  ('DIC("hello\\nworld")',
+    Program([], [ExpressionStatement(BuiltIn("DIC", [String("hello\nworld")]))]),
+    ValStr("hello\nworld"), "hello\nworld\n"),
+  # multiple escapes in one string
+  ('"\\t\\n\\\\"',
+    Program([], [ExpressionStatement(String("\t\n\\"))]),
+    ValStr("\t\n\\")),
+  # unknown escapes pass through (regex backrefs)
+  ('"\\1\\2"',
+    Program([], [ExpressionStatement(String("\\1\\2"))]),
+    ValStr("\\1\\2")),
+]
+
+class TestEscapeSequences(unittest.TestCase):
+  @parameterized.expand(escape_tests)
+  def test_escape(self, source, nodes, value, output=""):
+    run_test(self, source, nodes, value, output)
+
+
 # --- Comparison operators ---

 comparison_tests = [
@@ -2446,7 +2550,7 @@ class TestDormi(unittest.TestCase):
      tmp_bin_path = tmp_bin.name
    try:
      subprocess.run(
-        ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path],
+        ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path, "-lcurl", "-lmicrohttpd"],
        check=True, capture_output=True,
      )
      start = time.time()
@@ -2483,7 +2587,7 @@ class TestDormi(unittest.TestCase):
      tmp_bin_path = tmp_bin.name
    try:
      subprocess.run(
-        ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path],
+        ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path, "-lcurl", "-lmicrohttpd"],
        check=True, capture_output=True,
      )
      start = time.time()
@@ -2517,7 +2621,7 @@ class TestScripta(unittest.TestCase):
      tmp_bin_path = tmp_bin.name
    try:
      subprocess.run(
-        ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path],
+        ["gcc", "-O2", tmp_c_path, _RUNTIME_C, "-o", tmp_bin_path, "-lcurl", "-lmicrohttpd"],
        check=True, capture_output=True,
      )
      proc = subprocess.run([tmp_bin_path], capture_output=True, text=True)
@@ -2760,5 +2864,165 @@ class TestTempta(unittest.TestCase):
    run_test(self, source, nodes, value, output)


+class TestRete(unittest.TestCase):
+  @classmethod
+  def setUpClass(cls):
+    import http.server, threading
+    class Handler(http.server.BaseHTTPRequestHandler):
+      def do_GET(self):
+        self.send_response(200)
+        self.send_header("Content-Type", "text/plain")
+        self.end_headers()
+        self.wfile.write(b"SALVE MVNDE")
+      def log_message(self, *args):
+        pass
+    cls.server = http.server.HTTPServer(("127.0.0.1", 0), Handler)
+    cls.port = cls.server.server_address[1]
+    cls.thread = threading.Thread(target=cls.server.serve_forever)
+    cls.thread.daemon = True
+    cls.thread.start()
+
+  @classmethod
+  def tearDownClass(cls):
+    cls.server.shutdown()
+
+  def test_pete(self):
+    url = f"http://127.0.0.1:{self.port}/"
+    source = f'CVM RETE\nPETE("{url}")'
+    run_test(self, source,
+      Program([ModuleCall("RETE")], [ExpressionStatement(BuiltIn("PETE", [String(url)]))]),
+      ValStr("SALVE MVNDE"))
+
+  def test_pete_dic(self):
+    url = f"http://127.0.0.1:{self.port}/"
+    source = f'CVM RETE\nDIC(PETE("{url}"))'
+    run_test(self, source,
+      Program([ModuleCall("RETE")], [ExpressionStatement(BuiltIn("DIC", [BuiltIn("PETE", [String(url)])]))]),
+      ValStr("SALVE MVNDE"), "SALVE MVNDE\n")
+
+
+class TestReteServer(unittest.TestCase):
+  """Integration tests for PETITVR + AVSCVLTA server functionality."""
+
+  def _wait_for_server(self, port, timeout=2.0):
+    """Poll until the server is accepting connections."""
+    import socket
+    deadline = time.time() + timeout
+    while time.time() < deadline:
+      try:
+        with socket.create_connection(("127.0.0.1", port), timeout=0.1):
+          return
+      except OSError:
+        time.sleep(0.05)
+    self.fail(f"Server on port {port} did not start within {timeout}s")
+
+  def _free_port(self):
+    """Find a free port in range 1024-3999 (representable without MAGNVM)."""
+    import socket, random
+    for _ in range(100):
+      port = random.randint(1024, 3999)
+      try:
+        with socket.socket() as s:
+          s.bind(("127.0.0.1", port))
+          return port
+      except OSError:
+        continue
+    raise RuntimeError("Could not find a free port in range 1024-3999")
+
+  def _run_server(self, source):
+    """Parse and eval source in a daemon thread. Returns when server is ready."""
+    import threading
+    lexer = Lexer().get_lexer()
+    tokens = lexer.lex(source + "\n")
+    program = Parser().parse(tokens)
+    t = threading.Thread(target=program.eval, daemon=True)
+    t.start()
+
+  def test_basic_handler(self):
+    port = self._free_port()
+    source = (
+      f'CVM RETE\n'
+      f'PETITVR("/", FVNCTIO (petitio) VT {{\n'
+      f'REDI("SALVE MVNDE")\n'
+      f'}})\n'
+      f'AVSCVLTA({int_to_num(port, False)})'
+    )
+    self._run_server(source)
+    self._wait_for_server(port)
+    import urllib.request
+    resp = urllib.request.urlopen(f"http://127.0.0.1:{port}/")
+    self.assertEqual(resp.read().decode(), "SALVE MVNDE")
+
+  def test_multiple_routes(self):
+    port = self._free_port()
+    source = (
+      f'CVM RETE\n'
+      f'PETITVR("/", FVNCTIO (p) VT {{\nREDI("RADIX")\n}})\n'
+      f'PETITVR("/nomen", FVNCTIO (p) VT {{\nREDI("MARCVS")\n}})\n'
+      f'AVSCVLTA({int_to_num(port, False)})'
+    )
+    self._run_server(source)
+    self._wait_for_server(port)
+    import urllib.request
+    resp1 = urllib.request.urlopen(f"http://127.0.0.1:{port}/")
+    self.assertEqual(resp1.read().decode(), "RADIX")
+    resp2 = urllib.request.urlopen(f"http://127.0.0.1:{port}/nomen")
+    self.assertEqual(resp2.read().decode(), "MARCVS")
+
+  def test_404_unmatched(self):
+    port = self._free_port()
+    source = (
+      f'CVM RETE\n'
+      f'PETITVR("/", FVNCTIO (p) VT {{\nREDI("ok")\n}})\n'
+      f'AVSCVLTA({int_to_num(port, False)})'
+    )
+    self._run_server(source)
+    self._wait_for_server(port)
+    import urllib.request, urllib.error
+    with self.assertRaises(urllib.error.HTTPError) as ctx:
+      urllib.request.urlopen(f"http://127.0.0.1:{port}/nonexistent")
+    self.assertEqual(ctx.exception.code, 404)
+
+  def test_request_dict_via(self):
+    port = self._free_port()
+    source = (
+      f'CVM RETE\n'
+      f'PETITVR("/echo", FVNCTIO (petitio) VT {{\n'
+      f'REDI(petitio["via"])\n'
+      f'}})\n'
+      f'AVSCVLTA({int_to_num(port, False)})'
+    )
+    self._run_server(source)
+    self._wait_for_server(port)
+    import urllib.request
+    resp = urllib.request.urlopen(f"http://127.0.0.1:{port}/echo")
+    self.assertEqual(resp.read().decode(), "/echo")
+
+  def test_request_dict_quaestio(self):
+    port = self._free_port()
+    source = (
+      f'CVM RETE\n'
+      f'PETITVR("/q", FVNCTIO (petitio) VT {{\n'
+      f'REDI(petitio["quaestio"])\n'
+      f'}})\n'
+      f'AVSCVLTA({int_to_num(port, False)})'
+    )
+    self._run_server(source)
+    self._wait_for_server(port)
+    import urllib.request
+    resp = urllib.request.urlopen(f"http://127.0.0.1:{port}/q?nomen=Marcus")
+    self.assertEqual(resp.read().decode(), "nomen=Marcus")
+
+  def test_petitvr_stores_route(self):
+    """PETITVR alone (without AVSCVLTA) just stores a route and returns NVLLVS."""
+    source = 'CVM RETE\nPETITVR("/", FVNCTIO (p) VT {\nREDI("hi")\n})'
+    run_test(self, source,
+      Program([ModuleCall("RETE")], [ExpressionStatement(BuiltIn("PETITVR", [
+        String("/"),
+        Fvnctio([ID("p")], [Redi([String("hi")])])
+      ]))]),
+      ValNul())
+
+
 if __name__ == "__main__":
  unittest.main()
Author	SHA1	Message	Date
NikolajDanger	940f8d7311	🐐 Escape sequences	2026-04-22 11:27:19 +02:00
NikolajDanger	8c69a300a5	🐐 Web server	2026-04-22 11:11:58 +02:00
NikolajDanger	39218485c7	🐐 SVBSTITVE	2026-04-22 09:30:58 +02:00
NikolajDanger	b9a1ed1bcc	🐐 QVAERE	2026-04-22 09:08:36 +02:00