--- a/src/Pure/Thy/text_edit.scala Mon Jan 11 18:23:06 2010 +0100
+++ b/src/Pure/Thy/text_edit.scala Mon Jan 11 18:24:22 2010 +0100
@@ -8,72 +8,40 @@
package isabelle
-sealed abstract class Text_Edit
-{
- val start: Int
- def text: String
- def after(offset: Int): Int
- def before(offset: Int): Int
- def can_edit(string_length: Int, shift: Int): Boolean
- def edit(string: String, shift: Int): (Option[Text_Edit], String)
-}
-
-
-object Text_Edit
+class Text_Edit(val is_insert: Boolean, val start: Int, val text: String)
{
/* transform offsets */
- private def after_insert(start: Int, text: String, offset: Int): Int =
- if (start <= offset) offset + text.length
- else offset
+ private def transform(do_insert: Boolean, offset: Int): Int =
+ if (offset < start) offset
+ else if (is_insert == do_insert) offset + text.length
+ else (offset - text.length) max start
- private def after_remove(start: Int, text: String, offset: Int): Int =
- if (start > offset) offset
- else (offset - text.length) max start
+ def after(offset: Int): Int = transform(true, offset)
+ def before(offset: Int): Int = transform(false, offset)
/* edit strings */
- private def insert(index: Int, text: String, string: String): String =
+ private def insert(index: Int, string: String): String =
string.substring(0, index) + text + string.substring(index)
private def remove(index: Int, count: Int, string: String): String =
string.substring(0, index) + string.substring(index + count)
-
- /* explicit edits */
-
- case class Insert(start: Int, text: String) extends Text_Edit
- {
- def after(offset: Int): Int = after_insert(start, text, offset)
- def before(offset: Int): Int = after_remove(start, text, offset)
-
- def can_edit(string_length: Int, shift: Int): Boolean =
- shift <= start && start <= shift + string_length
-
- def edit(string: String, shift: Int): (Option[Insert], String) =
- if (can_edit(string.length, shift)) (None, insert(start - shift, text, string))
- else (Some(this), string)
- }
+ def can_edit(string: String, shift: Int): Boolean =
+ shift <= start && start < shift + string.length
- case class Remove(start: Int, text: String) extends Text_Edit
- {
- def after(offset: Int): Int = after_remove(start, text, offset)
- def before(offset: Int): Int = after_insert(start, text, offset)
-
- def can_edit(string_length: Int, shift: Int): Boolean =
- shift <= start && start < shift + string_length
-
- def edit(string: String, shift: Int): (Option[Remove], String) =
- if (can_edit(string.length, shift)) {
- val index = start - shift
- val count = text.length min (string.length - index)
- val rest =
- if (count == text.length) None
- else Some(Remove(start, text.substring(count)))
- (rest, remove(index, count, string))
- }
- else (Some(this), string)
- }
+ def edit(string: String, shift: Int): (Option[Text_Edit], String) =
+ if (!can_edit(string, shift)) (Some(this), string)
+ else if (is_insert) (None, insert(start - shift, string))
+ else {
+ val index = start - shift
+ val count = text.length min (string.length - index)
+ val rest =
+ if (count == text.length) None
+ else Some(new Text_Edit(false, start, text.substring(count)))
+ (rest, remove(index, count, string))
+ }
}