Add numerical sort for files

Signed-off-by: Andrew Opalach <andrew@akon.city>

1 files changed, 61 insertions, 0 deletions

diff --git a/src/util/sort.c b/src/util/sort.c
new file mode 100644
index 0000000..8d306a8
--- /dev/null
+++ b/src/util/sort.c
@@ -0,0 +1,61 @@
+#include <al/str.h>
+
+static inline u32 find_number(str *s)
+{
+    u32 i = 0;
+    while (i < s->length && !al_isnumber(al_str_at(s, i))) { i++; }
+    return (i == s->length) ? AL_STR_NO_POS : i;
+}
+
+static inline u32 find_non_number(str *s)
+{
+    u32 i = 0;
+    while (i < s->length && al_isnumber(al_str_at(s, i))) { i++; }
+    return i;
+}
+
+s32 nn_numerical_compare(const void *a, const void *b)
+{
+    str s1 = *(str *)a, s2 = *(str *)b;
+    s32 ret;
+    str sub1, sub2;
+    bool error;
+    s64 n1, n2;
+    u32 nn1 = find_number(&s1);
+    u32 nn2 = find_number(&s2);
+    if (nn1 != nn2) {
+        goto compare_remainder;
+    }
+    s1 = al_str_substr(&s1, nn1, s1.length);
+    s2 = al_str_substr(&s2, nn2, s2.length);
+    do {
+        nn1 = find_non_number(&s1);
+        nn2 = find_non_number(&s2);
+        sub1 = al_str_substr(&s1, 0, nn1);
+        sub2 = al_str_substr(&s2, 0, nn2);
+        n1 = al_str_to_long(&sub1, 10, &error);
+        al_assert(!error);
+        n2 = al_str_to_long(&sub2, 10, &error);
+        al_assert(!error);
+        if (n1 > n2) return 1;
+        else if (n1 < n2) return -1;
+        s1 = al_str_substr(&s1, nn1, s1.length);
+        s2 = al_str_substr(&s2, nn2, s2.length);
+        nn1 = find_number(&s1);
+        nn2 = find_number(&s2);
+        if (nn1 == AL_STR_NO_POS || nn2 == AL_STR_NO_POS) {
+            goto compare_remainder;
+        }
+        sub1 = al_str_substr(&s1, 0, nn1);
+        sub2 = al_str_substr(&s2, 0, nn2);
+        if (!al_str_eq(&sub1, &sub2)) {
+            goto compare_remainder;
+        }
+        s1 = al_str_substr(&s1, nn1, s1.length);
+        s2 = al_str_substr(&s2, nn2, s2.length);
+    } while (1);
+compare_remainder:
+    ret = al_str_cmp(&s1, &s2, 0, MIN(s1.length, s2.length));
+    if (ret == 0) return s1.length - s2.length;
+    return ret;
+}