refactor for clarity

1 files changed, 24 insertions, 23 deletions

diff --git a/booki.c b/booki.c
index 6840849..a199701 100644
--- a/booki.c
+++ b/booki.c
@@ -14,6 +14,30 @@
 #define MAX_SEARCH_OPTS 5
 
 /*** helpers ***/
+char* characters_from_end(char* str, int len_in_bytes, int number_of_chars) {
+    assert(len_in_bytes >= number_of_chars);
+
+    // let's not zoom past the beginning of the string
+    if (number_of_chars == 0 || len_in_bytes == 0)
+        return str;
+
+    // start at the end of the string, locate all code points
+    char* newptr = str + len_in_bytes; // will update to last character in do..while
+    unsigned char ch;
+    do {
+        // update the pointer, get the character
+        newptr--;
+        len_in_bytes--;
+        ch = (unsigned char) *newptr;
+
+        // if we're at the first byte of a unicode point, we've found a whole character
+        if (ch < 0x80 || ch >= 0xC3)
+            number_of_chars--;
+    } while (number_of_chars > 0 && len_in_bytes > 0);
+
+    return newptr;
+}
+
 bool comparable(const char* pattern, const char* candidate, int len) {
     unsigned char p = *pattern;
     unsigned char c = *candidate;
@@ -632,29 +656,6 @@ char* next_book(char* current_pos) {
     return current_pos;
 }
 
-char* characters_from_end(char* str, int len, int number_of_chars) {
-    assert(len >= number_of_chars);
-
-    // let's not zoom past the beginning of the string
-    if (number_of_chars == 0)
-        return str;
-
-    // start at the end of the string, locate all code points
-    char* newptr = str + len; // will update to last character in do..while
-    unsigned char ch;
-    do {
-        // update the pointer, get the character
-        newptr--;
-        len--;
-        ch = (unsigned char) *newptr;
-
-        // if we're at the first byte of a unicode point, we've found a whole character
-        if (ch < 0x80 || ch >= 0xC3)
-            number_of_chars--;
-    } while (number_of_chars > 0 && len > 0);
-
-    return newptr;
-}
 
 /*** search ***/
 bool match_string(const char* pattern, const struct es text) {