9387dfa · helix · git.iko.soy

122 /// Returns the changes since the given revision composed into a transaction.

123 /// Returns None if there are no changes between the current and given revisions.

124 pub fn changes_since(&self, revision: usize) -> Option<Transaction> {

125− use std::cmp::Ordering::*;

125+ let lca = self.lowest_common_ancestor(revision, self.current);

126+ let up = self.path_up(revision, lca);

127+ let down = self.path_up(self.current, lca);

128+ let up_txns = up

129+ .iter()

130+ .rev()

131+ .map(|&n| self.revisions[n].inversion.clone());

132+ let down_txns = down.iter().map(|&n| self.revisions[n].transaction.clone());

126

133

127− match revision.cmp(&self.current) {

134+ up_txns.chain(down_txns).reduce(|acc, tx| tx.compose(acc))

128− Equal => None,

129− Less => {

130− let mut child = self.revisions[revision].last_child?.get();

131− let mut transaction = self.revisions[child].transaction.clone();

132− while child != self.current {

133− child = self.revisions[child].last_child?.get();

134− transaction = transaction.compose(self.revisions[child].transaction.clone());

135− }

136− Some(transaction)

137− }

138− Greater => {

139− let mut inversion = self.revisions[revision].inversion.clone();

140− let mut parent = self.revisions[revision].parent;

141− while parent != self.current {

142− parent = self.revisions[parent].parent;

143− if parent == 0 {

144− return None;

145− }

146− inversion = inversion.compose(self.revisions[parent].inversion.clone());

147− }

148− Some(inversion)

149− }

150− }

151 }

135 }

152

136

153 /// Undo the last edit.

137 /// Undo the last edit.