exception: use natural explanatory style

src/Dibi/exceptions.php

@@ -11,7 +11,7 @@
 
 
 /**
- * Dibi common exception.
+ * A database operation failed.
  */
 class Exception extends \Exception
 {
@@ -44,15 +44,15 @@ public function __toString(): string
 
 
 /**
- * database server exception.
+ * The database server reported an error.
  */
 class DriverException extends Exception
 {
 }
 
 
 /**
- * PCRE exception.
+ * Regular expression pattern or execution failed.
  */
 class PcreException extends Exception
 {
@@ -63,18 +63,24 @@ public function __construct()
 }
 
 
+/**
+ * The requested feature is not implemented.
+ */
 class NotImplementedException extends Exception
 {
 }
 
 
+/**
+ * The requested operation is not supported.
+ */
 class NotSupportedException extends Exception
 {
 }
 
 
 /**
- * Database procedure exception.
+ * A database stored procedure failed.
  */
 class ProcedureException extends Exception
 {
@@ -102,31 +108,31 @@ public function getSeverity(): string
 
 
 /**
- * Base class for all constraint violation related exceptions.
+ * A database constraint was violated.
  */
 class ConstraintViolationException extends DriverException
 {
 }
 
 
 /**
- * Exception for a foreign key constraint violation.
+ * The foreign key constraint check failed.
  */
 class ForeignKeyConstraintViolationException extends ConstraintViolationException
 {
 }
 
 
 /**
- * Exception for a NOT NULL constraint violation.
+ * The NOT NULL constraint check failed.
  */
 class NotNullConstraintViolationException extends ConstraintViolationException
 {
 }
 
 
 /**
- * Exception for a unique constraint violation.
+ * The unique constraint check failed.
  */
 class UniqueConstraintViolationException extends ConstraintViolationException
 {