Remove old shuffle header

libc/mem/shuffle.internal.h

@@ -1,21 +0,0 @@
-#ifndef COSMOPOLITAN_LIBC_RAND_SHUFFLE_H_
-#define COSMOPOLITAN_LIBC_RAND_SHUFFLE_H_
-#include "libc/intrin/xchg.h"
-
-/**
- * Fisher-Yates shuffle.
- *
- * @param R is a function like rand() → ≥0
- * @param A is a typed array
- * @param n is the number of items in A
- * @see ARRAYLEN()
- */
-#define shuffle(R, A, n)                      \
-  do {                                        \
-    autotype(A) Array = (A);                  \
-    for (size_t i = (n) - 1; i >= 1; --i) {   \
-      xchg(&Array[i], &Array[R() % (i + 1)]); \
-    }                                         \
-  } while (0)
-
-#endif /* COSMOPOLITAN_LIBC_RAND_SHUFFLE_H_ */

libc/stdio/getdelim_unlocked.c

@@ -44,9 +44,8 @@ ssize_t getdelim_unlocked(char **s, size_t *n, int delim, FILE *f) {
     *n = 0;
   for (i = 0;; i += m) {
     m = f->end - f->beg;
-    if ((p = memchr(f->buf + f->beg, delim, m))) {
+    if ((p = memchr(f->buf + f->beg, delim, m)))
       m = p + 1 - (f->buf + f->beg);
-    }
     if (i + m + 1 > *n) {
       n2 = i + m + 1;
       s2 = realloc(*s, n2);
@@ -59,10 +58,9 @@ ssize_t getdelim_unlocked(char **s, size_t *n, int delim, FILE *f) {
       }
     }
     memcpy(*s + i, f->buf + f->beg, m);
-    (*s)[i + m] = '\0';
+    (*s)[i + m] = 0;
-    if ((f->beg += m) == f->end) {
+    if ((f->beg += m) == f->end)
       f->beg = f->end = 0;
-    }
     if (p) {
       return i + m;
     } else if (f->fd == -1) {
@@ -71,7 +69,7 @@ ssize_t getdelim_unlocked(char **s, size_t *n, int delim, FILE *f) {
       if (!rc)
         break;
       f->end = rc;
-    } else if (errno != EINTR) {
+    } else {
       f->state = errno;
       return -1;
     }

libc/stdio/strfry.c

@@ -16,14 +16,23 @@
 │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
 │ PERFORMANCE OF THIS SOFTWARE.                                                │
 ╚─────────────────────────────────────────────────────────────────────────────*/
-#include "libc/mem/shuffle.internal.h"
 #include "libc/stdio/rand.h"
 #include "libc/str/str.h"
 
 /**
- * Jumbles up string.
+ * Performs Fisher-Yates shuffle on string in-place to create anagram.
+ *
+ * This implementation uses rand() so `srand(time(0))` may be desired.
  */
 char *strfry(char *s) {
-  shuffle(rand, s, strlen(s));
+  size_t i = strlen(s);
+  while (i > 1) {
+    size_t x = rand();
+    size_t y = rand();
+    size_t j = ((x << 31) ^ y) % i--;
+    char t = s[j];
+    s[j] = s[i];
+    s[i] = t;
+  }
   return s;
 }

test/libc/stdio/strfry_test.c

@@ -0,0 +1,38 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8                               :vi │
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2024 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/stdio/rand.h"
+#include "libc/testlib/testlib.h"
+
+TEST(strfry, empty) {
+  char s[1] = "";
+  EXPECT_EQ(s, strfry(s));
+  EXPECT_STREQ("", s);
+}
+
+TEST(strfry, one) {
+  char s[2] = "a";
+  EXPECT_EQ(s, strfry(s));
+  EXPECT_STREQ("a", s);
+}
+
+TEST(strfry, test) {
+  char s[5] = "abcd";
+  EXPECT_EQ(s, strfry(s));
+  EXPECT_STREQ("cbda", s);
+}

test/libc/x/utf8to32_test.c

@@ -18,7 +18,6 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
-#include "libc/mem/shuffle.internal.h"
 #include "libc/stdio/rand.h"
 #include "libc/testlib/ezbench.h"
 #include "libc/testlib/hyperion.h"
@@ -82,11 +81,20 @@ TEST(utf32to8, testLargeThompsonPikeEncoded) {
           -1, 0)));
 }
 
+void shuffle(wchar_t *a, int n) {
+  for (int i = n - 1; i >= 1; --i) {
+    int r = rand() % (i + 1);
+    wchar_t t = a[r];
+    a[r] = a[i];
+    a[i] = t;
+  }
+}
+
 char *GenerateBranchyUtf8Text(size_t *out_n) {
   char *p;
   size_t n;
   wchar_t *q = gc(utf8to32(kViewables, kViewablesSize, &n));
-  shuffle(lemur64, q, n);
+  shuffle(q, n);
   p = utf32to8(q, n, &n);
   if (out_n)
     *out_n = n;