Add an iswblank compatibility API.

CHANGELOG.md

 # Change Log
 
+## 9.0.0.1 - (In Progress)
+
+*  Add `iswblank` compatibility.
+
 ## 9.0.0 - 2016-12-28
 
 *  Update to Unicode Character Data 9.0.0.

README.md

 |---------------|----------------|
 | `ucd_isalnum` | `ucd::isalnum` |
 | `ucd_isalpha` | `ucd::isalpha` |
+| `ucd_isblank` | `ucd::isblank` |
 | `ucd_iscntrl` | `ucd::iscntrl` |
 | `ucd_isdigit` | `ucd::isdigit` |
 | `ucd_isgraph` | `ucd::isgraph` |
 | `ucd_isspace` | `ucd::isspace` |
 | `ucd_isupper` | `ucd::isupper` |
 
-__NOTE:__ Equivalents for `isblank` and `isxdigit` are not provided.
+__NOTE:__ An equivalent for `isxdigit` is not provided.
 
 ## Build Dependencies
 

src/ctype.c

 	}
 }
 
+int ucd_isblank(codepoint_t c)
+{
+	switch (ucd_lookup_category(c))
+	{
+	case UCD_CATEGORY_Zs:
+		return 1;
+	case UCD_CATEGORY_Cc:
+		return c == 0x09; // U+0009 : CHARACTER TABULATION
+	default:
+		return 0;
+	}
+}
+
 int ucd_iscntrl(codepoint_t c)
 {
 	return ucd_lookup_category(c) == UCD_CATEGORY_Cc;

src/include/ucd/ucd.h

   */
 int ucd_isalpha(codepoint_t c);
 
+/** @brief Is the codepoint a tab or Unicode whitespace character?
+  *
+  * @param c The Unicode codepoint to check.
+  * @return  Non-zero if the codepoint is a whitespace character, zero otherwise.
+  */
+int ucd_isblank(codepoint_t c);
+
 /** @brief Is the codepoint a control character?
   *
   * @param c The Unicode codepoint to check.
 		return ucd_isalpha(c);
 	}
 
+	/** @brief Is the codepoint a tab or Unicode whitespace character?
+	  *
+	  * @param c The Unicode codepoint to check.
+	  * @return  Non-zero if the codepoint is a whitespace character, zero otherwise.
+	  */
+	inline int isblank(codepoint_t c)
+	{
+		return ucd_isblank(c);
+	}
+
 	/** @brief Is the codepoint a control character?
 	  *
 	  * @param c The Unicode codepoint to check.

tests/printcdata.c

 	case 'a': // alpha
 		fputc(iswalpha(c) ? '1' : '0', out);
 		break;
+	case 'b': // blank
+		fputc(iswblank(c) ? '1' : '0', out);
+		break;
 	case 'c': // control
 		fputc(iswcntrl(c) ? '1' : '0', out);
 		break;

tests/printucddata.c

 	case 'a': // alpha
 		fputc(ucd_isalpha(c) ? '1' : '0', out);
 		break;
+	case 'b': // blank
+		fputc(ucd_isblank(c) ? '1' : '0', out);
+		break;
 	case 'c': // control
 		fputc(ucd_iscntrl(c) ? '1' : '0', out);
 		break;

tests/printucddata_cpp.cpp

 	case 'a': // alpha
 		fputc(ucd::isalpha(c) ? '1' : '0', out);
 		break;
+	case 'b': // blank
+		fputc(ucd::isblank(c) ? '1' : '0', out);
+		break;
 	case 'c': // control
 		fputc(ucd::iscntrl(c) ? '1' : '0', out);
 		break;