src/colors.c cleanup

diff -r e77b384a9d4d src/colors.c
--- a/src/colors.c	Sat May 26 13:58:42 2012 +0200
+++ b/src/colors.c	Sat May 26 17:36:54 2012 +0400
@@ -9,24 +9,24 @@
  * (at your option) any later version.
  */
 
+#include <ctype.h>
+#include <stdlib.h>
 #include <string.h>
-#include <stdlib.h>
-#include <ctype.h>
+
 #include "colors.h"
-
 #include "msg.h"
 
 /*
  * If EXTENDED_COLOR is defined, the extended set of named colors is supported.
  * These colors're not standard but they're supported in most browsers.
- * NOTE: The colors MUST be in alphabetical order and lower case because the
- *       code uses a binary search.
+ * NOTE: The colors MUST be in alphabetical order because the code uses a
+ * binary search.
  */
 
 #define EXTENDED_COLOR
 
 static const struct key {
-   char *key;
+   const char *key;
    int32_t val;
 } color_keyword [] = {
 #ifdef EXTENDED_COLOR
@@ -44,7 +44,7 @@
 #ifdef EXTENDED_COLOR
    { "blanchedalmond", 0xffebcd},
 #endif
-   {"blue", 0x0000ff},
+   { "blue", 0x0000ff},
 #ifdef EXTENDED_COLOR
    { "blueviolet", 0x8a2be2},
    { "brown", 0xa52a2a},
@@ -201,7 +201,12 @@
 #endif
 };
 
-#define NCOLORS   (sizeof(color_keyword) / sizeof(color_keyword[0]))
+#define LEN(x) (sizeof(x)/sizeof((x)[0]))
+
+/* Helper function for bsearch. */
+static int Color_cmp(const void *a, const void *b) {
+   return dStrAsciiCasecmp(((struct key *)a)->key, ((struct key *)b)->key);
+}
 
 /*
  * Parse a color in hex (RRGGBB) or (RGB)
@@ -212,22 +217,22 @@
  */
 static int32_t Color_parse_hex (const char *s, int32_t default_color, int *err)
 {
-  int32_t ret_color;
-  char *tail;
+   int32_t ret_color;
+   char *tail;
 
-  *err = 1;
-  ret_color = strtol(s, &tail, 16);
-  if (tail - s == 6)
-     *err = 0;
-  else if (tail - s == 3) {       /* #RGB as allowed by CSS */
-     *err = 0;
-         ret_color = ((ret_color & 0xf00) << 12) | ((ret_color & 0xf00) << 8) |
-                     ((ret_color & 0x0f0) << 8)  | ((ret_color & 0x0f0) << 4) |
-                     ((ret_color & 0x00f) << 4)  | ((ret_color & 0x00f) << 0);
-  } else
-     ret_color = default_color;
+   *err = 1;
+   ret_color = strtol(s, &tail, 16);
+   if (tail - s == 6)
+      *err = 0;
+   else if (tail - s == 3) { /* #RGB as allowed by CSS */
+      *err = 0;
+      ret_color = ((ret_color & 0xf00) << 12) | ((ret_color & 0xf00) << 8) |
+                  ((ret_color & 0x0f0) << 8)  | ((ret_color & 0x0f0) << 4) |
+                  ((ret_color & 0x00f) << 4)  | ((ret_color & 0x00f) << 0);
+   } else
+      ret_color = default_color;
 
-  return ret_color;
+   return ret_color;
 }
 
 /*
@@ -243,37 +248,27 @@
 {
    const char *cp;
    int32_t ret_color;
-   int ret, low, mid, high, st = 1;
+   int st = 1;
+   struct key key;
+   const struct key *color;
 
    /* skip leading spaces */
    for (cp = subtag; dIsspace(*cp); cp++);
 
    ret_color = default_color;
-   if (*cp == '#') {
+   if (*cp == '#')
       ret_color = Color_parse_hex(cp + 1, default_color, &st);
-
-   } else if (*cp == '0' && (cp[1] == 'x' || cp[1] == 'X') ) {
+   else if (*cp == '0' && (cp[1] == 'x' || cp[1] == 'X')) {
       ret_color = Color_parse_hex(cp + 2, default_color, &st);
       st = 2;
-
    } else {
-      /* Binary search */
-      low = 0;
-      high = NCOLORS - 1;
-      while (low <= high) {
-         mid = (low + high) / 2;
-         if ((ret = dStrAsciiCasecmp(cp, color_keyword[mid].key)) < 0)
-            high = mid - 1;
-         else if (ret > 0)
-            low = mid + 1;
-         else {
-            ret_color = color_keyword[mid].val;
-            st = 0;
-            break;
-         }
-      }
-
-      if (low > high) {
+      key.key = cp;
+      color = bsearch(&key, color_keyword, LEN(color_keyword),
+                      sizeof color_keyword[0], Color_cmp);
+      if (color) {
+         st = 0;
+         ret_color = color->val;
+      } else {
          /* try for RRGGBB lacking the leading '#' */
          ret_color = Color_parse_hex(cp, default_color, &st);
          st = 1;
@@ -325,46 +320,44 @@
  *   if candidate has good contrast with C_txt, C_lnk and C_bg  -> candidate
  *   else another color (from the internal list)
  */
-int32_t a_Color_vc(int32_t candidate,
-                   int32_t C_txt, int32_t C_lnk, int32_t C_bg)
+int32_t a_Color_vc(int32_t candidate, int32_t C_txt, int32_t C_lnk,
+                   int32_t C_bg)
 {
-                    /* candidate purple    darkcyan  darkmagenta olive   */
-  static int32_t v[] = {0x000000, 0x800080, 0x008b8b, 0x8b008b, 0x808000,
-                    /* darkred   coral     black                        */
-                       0x8b0000, 0xff7f50, 0x000000};
-  int v_size = sizeof(v) / sizeof(v[0]);
-  int i, max_i, score, max_score, d_bg, d_txt, d_lnk;
+                      /* candidate purple    darkcyan  darkmagenta olive */
+   static int32_t v[] = {0x000000, 0x800080, 0x008b8b, 0x8b008b, 0x808000,
+                      /* darkred   coral     black                       */
+                         0x8b0000, 0xff7f50, 0x000000};
+   int i, max_i, score, max_score, d_bg, d_txt, d_lnk, vsize = LEN(v);
 
+   /* set candidate in the list */
+   v[0] = candidate;
 
-  /* set candidate in the list */
-  v[0] = candidate;
-
-  /* Try to get good overall and individual contrast */
-  max_i = max_score = 0;
-  for (i = 0; i < v_size; ++i) {
-     _MSG("a_Color_vc: [%d]%.6x: %d %d %d\n", i, v[i],
+   /* Try to get good overall and individual contrast */
+   max_i = max_score = 0;
+   for (i = 0; i < vsize; ++i) {
+      _MSG("a_Color_vc: [%d]%.6x: %d %d %d\n", i, v[i],
          Color_distance2(C_txt, v[i]),
          Color_distance2(C_lnk, v[i]),
          Color_distance2(C_bg, v[i]));
 
-     /* Tuned with: slashdot.org, paulgraham.com, newsforge.com,
-      *             linuxjournal.com
-      */
-     d_txt = Color_distance2(C_txt, v[i]);
-     d_lnk = Color_distance2(C_lnk, v[i]);
-     d_bg  = Color_distance2(C_bg, v[i]);
-     score = (d_bg >= 2 ? 4 : 2 * d_bg) +
-             (d_txt + d_lnk >= 2 ? 2 : d_txt + d_lnk) +
-             (Color_distance3(C_lnk, v[i]) >= 1 ? 1 : 0);
-     if (score >= 7) {
-        /* enough distance, use this color */
-        max_i = i;
-        break;
-     } else if (score > max_score) {
-        /* keep track of the best candidate so far */
-        max_score = score;
-        max_i = i;
-     }
-  }
-  return v[max_i];
+      /* Tuned with: slashdot.org, paulgraham.com, newsforge.com,
+       * linuxjournal.com
+       */
+      d_txt = Color_distance2(C_txt, v[i]);
+      d_lnk = Color_distance2(C_lnk, v[i]);
+      d_bg  = Color_distance2(C_bg, v[i]);
+      score = (d_bg >= 2 ? 4 : 2 * d_bg) +
+              (d_txt + d_lnk >= 2 ? 2 : d_txt + d_lnk) +
+              (Color_distance3(C_lnk, v[i]) >= 1 ? 1 : 0);
+      if (score >= 7) {
+         /* enough distance, use this color */
+         max_i = i;
+         break;
+      } else if (score > max_score) {
+         /* keep track of the best candidate so far */
+         max_score = score;
+         max_i = i;
+      }
+   }
+   return v[max_i];
 }