DIRECTORY
Tioga USING [CapChange, ChangeTextCaps, ChangeTextLooks, CopyProp, CopyText, DeleteText, LastSibling, LastWithin, Level, Location, Looks, MapProps, maxLen, MoveText, MoveTextOnto, NewNode, Next, Node, NodeBody, nodeItself, nullLocation, nullSpan, Order, Parent, Place, Previous, ReplaceText, Root, Size, Span, StepBackward, StepForward, Text, TransposeText],
TiogaPrivate USING [Change, EditNotify, Is, NoteEvent, PutProp, World, WorldRep];
Slice support routines
Invariant:
PROC [predicate:
BOOL] ~
INLINE { true:
BOOL[
TRUE..
TRUE] ~ predicate; };
MakeSlices:
PROC [node: Node]
RETURNS [before, after: Slice ←
NIL] = {
before[0]=root; before[i]=Parent[before[i+1]]; before[before.length-1]=node
after[i]=Next[before[i]]
if node.child # NIL then after[before.length]=node.child
IF node#
NIL
THEN {
Slicer:
PROC [node: Node, height:
NAT]
RETURNS [before, after: Slice, level:
NAT] ~ {
IF node=
NIL
THEN {
-- have gone beyond root
RETURN[GetSlice[height], GetSlice[height+1], 0];
}
ELSE {
[before, after, level] ← Slicer[Parent[node], height+1];
before[level] ← node; after[level] ← Next[node];
RETURN[before, after, level+1];
};
};
[before, after, ] ← Slicer[node, 0];
Invariant[before.length=after.length+1];
after[before.length] ← node.child;
FOR i:
NAT
DECREASING
IN [0..after.length)
DO
-- delete trailing NILs from after
IF after[i]=NIL THEN after.length ← i ELSE EXIT;
ENDLOOP
};
};
MakeParentSlice:
PROC [node: Node]
RETURNS [slice: Slice ←
NIL] = {
result is same as MakeSlices[node].before
Slicer:
PROC [node: Node, height:
NAT]
RETURNS [slice: Slice, level:
NAT] ~ {
IF node=
NIL
THEN {
-- have gone beyond root
RETURN[GetSlice[height], 0];
}
ELSE {
[slice, level] ← Slicer[Parent[node], height+1];
slice[level] ← node;
RETURN[slice, level+1];
};
};
IF node#NIL THEN [slice, ] ← Slicer[node, 0];
};
InsertPrefix:
PROC [first, last: Slice, firstLen:
NAT]
RETURNS [new: Slice] = {
new[i]=first[i] for i in [0..firstLen)
new[i+firstLen]=last[i] for i in [0..last.length)
new.length=firstLen+last.length
Invariant[KindOfSlice[first]=before AND KindOfSlice[last]=before];
Invariant[firstLen>first.length];
new ← GetSlice[firstLen+last.length];
FOR i: NAT IN [0..firstLen) DO new[i] ← first[i]; ENDLOOP;
FOR i: NAT IN [0..last.length) DO new[firstLen+i] ← last[i]; ENDLOOP
};
DeletePrefix:
PROC [slice: Slice, depth:
NAT] = {
remove entries from start of slice
newLen: NAT ~ slice.length-depth;
FOR i: NAT IN [0..newLen) DO slice[i] ← slice[depth+i]; ENDLOOP;
FOR i: NAT IN [newLen..slice.length) DO slice[i] ← NIL; ENDLOOP;
slice.length ← newLen;
};
NeededNestingChange:
TYPE = { needNest, needUnNest, ok };
NeedNestingChange:
PROC [before, after, top, bottom: Slice, nesting:
INTEGER, depth:
NAT]
RETURNS [NeededNestingChange] = {
bandStart, afterOver: INTEGER;
topLen, botLen: NAT;
nesting ← MIN[1,nesting];
topLen ← top.length; botLen ← bottom.length;
bandStart ← before.length+nesting-(topLen-depth);
IF bandStart <= 0 THEN RETURN [needNest]; -- must be at least 1
afterOver ← after.length-(botLen-depth+bandStart);
IF afterOver > 1 THEN RETURN [needUnNest];
RETURN [ok]
};
Splice:
PROC [before, after: Slice, beforeStart, afterStart:
NAT ← 0] = {
join slices
make after[afterStart+i] be successor of before[beforeStart+i]
if more after's than before's, adopt as children of last before
beforeLen: NAT ~ before.length-beforeStart;
afterLen: NAT ~ after.length-afterStart;
Invariant[KindOfSlice[before]=before AND KindOfSlice[after]=after];
Invariant[afterLen<=beforeLen+1];
FOR i:
NAT
DECREASING
IN [0..beforeLen]
DO
bi: NAT ~ i+beforeStart;
ai: NAT ~ i+afterStart;
b: Node ~ IF bi<before.length THEN before[bi] ELSE NIL;
p: Node ~ IF bi>0 THEN before[bi-1] ELSE NIL; -- b's parent
a: Node ~
IF ai<after.length
THEN after[ai]
ELSE
NIL;
-- b's successor
IF b=
NIL
THEN {
-- adopt children
IF p=
NIL
THEN {
IF a#NIL THEN ERROR; -- orphans!
}
ELSE {
p.child ← a;
IF a#NIL THEN LastSibling[a].next ← p;
};
}
ELSE {
-- link successor
IF a=
NIL
THEN {
-- no successor
b.next ← p; b.last ← TRUE;
}
ELSE {
-- has successor
IF a=b THEN RETURN;
b.next ← a; b.last ← FALSE;
LastSibling[a].next ← p;
};
};
ENDLOOP;
};
ReplaceBand:
PROC [before, after, top, bottom: Slice, nesting:
INTEGER] = {
do Splices to insert (top..bottom) between (before..after)
nesting tells how to offset last of before vs. last of top
before[before.length-1+nesting] will be predecessor of top[top.length-1]
depth: NAT ~ MAX[1, before.length+MIN[nesting, 1]-top.length];
fullBottom: Slice ~ InsertPrefix[before, bottom, depth];
Splice[fullBottom, after];
Splice[before, top, depth];
FreeSlice[fullBottom]
};
DescribeBand:
PROC [first, last: Node]
RETURNS [before, after, top, bottom: Slice ←
NIL, nesting:
INTEGER, depth:
NAT] = {
ENABLE UNWIND => { FreeSlice[before]; FreeSlice[after]; FreeSlice[top]; FreeSlice[bottom] };
top[top.length-1] = first
before[before.length-1+nesting] = predecessor of first
bottom[bottom.length-1] = last
raises BadBand error if last doesn't follow first in tree structure
or if first or last is root node
pred: Node ← StepBackward[first];
minDepth: NAT;
IF pred=NIL THEN ERROR BadBand; -- first is root node
IF pred=last THEN ERROR BadBand; -- this actually happened during testing!
[before, top] ← MakeSlices[pred];
nesting ← top.length-before.length; -- nesting of LastOfSlice[top] wrt LastOfSlice[before]
[bottom, after] ← MakeSlices[last];
minDepth ← MIN[before.length, bottom.length];
FOR depth ← 0, depth+1
UNTIL depth >= minDepth
DO
IF before[depth] # bottom[depth]
THEN {
-- check for legality
bot: Node ← bottom[depth];
FOR node: Node ← before[depth], Next[node]
DO
IF node=bot THEN EXIT;
IF node=NIL THEN ERROR BadBand; -- last must come before first
ENDLOOP;
EXIT;
};
ENDLOOP;
IF depth=0 THEN ERROR BadBand; -- different root nodes for first and last
check assertions
Invariant[LastOfSlice[top]=first AND LastOfSlice[bottom]=last];
Invariant[before[before.length+nesting-2]=Parent[first]];
};
DestSlices:
PROC [dest: Node, where: Place]
RETURNS [before, after: Slice, nesting:
INTEGER] = {
where = after means insert starting as sibling after dest
where = child means insert starting as child of dest
where = before means insert starting as sibling before dest
SELECT where
FROM
after => { [before, after] ← MakeSlices[dest]; nesting ← 0 };
child => { [before, after] ← MakeSlices[dest]; nesting ← 1 };
before => {
pred: Node ← StepBackward[dest];
[before, after] ← MakeSlices[pred];
nesting ← after.length-before.length;
};
ENDCASE => ERROR;
};
CreateDest:
PROC [depth:
NAT]
RETURNS [dest: Location] = {
create tree of parents
node: Node ← NIL;
THROUGH [0..depth)
DO
child: Node ~ NewNode[];
IF node#NIL THEN { node.child ← child; child.next ← node; child.last ← TRUE; };
node ← child;
ENDLOOP;
RETURN [[node, nodeItself]];
};
CopySpan:
PROC [span: Span]
RETURNS [result: Span] = {
node, prev, parent, first: Node ← NIL;
IF (node ← span.start.node)=NIL THEN RETURN [nullSpan];
parent ← NewNode[]; -- parent for the span
DO
-- create new node each time through the loop
new: Node ~ NEW[NodeBody];
new.new ← TRUE;
new.rope ← node.rope;
new.runs ← node.runs;
Inherit[n: new, from: node, allprops: TRUE]; -- inherit properties from node
IF prev=NIL THEN parent.child ← new
ELSE { prev.last ← FALSE; prev.next ← new }; -- insert new
new.last ← TRUE; new.next ← parent;
IF node=span.start.node THEN first ← new;
IF node=span.end.node THEN RETURN [[[first, span.start.where], [new, span.end.where]]];
go to next node
prev ← new;
IF node.child#
NIL
THEN {
-- descend in the tree
node ← node.child; parent ← new; prev ← NIL;
}
ELSE
DO
-- move to next node, sibling or up* then sibling
IF node.last
THEN {
-- move up to node's parent
node ← node.next; -- node ← node.parent
IF node=NIL THEN RETURN [nullSpan]; -- bad arg span
Invariant[parent.last];
prev ← parent; -- next new node will be parent's sibling
parent ← parent.next; -- parent ← parent.parent
IF parent=
NIL
THEN {
-- need a new parent
parent ← NewNode[];
parent.child ← prev;
prev.next ← parent;
};
}
ELSE { node ← node.next; EXIT }; -- move to next sibling
ENDLOOP;
ENDLOOP;
};
CompareSliceOrder:
PROC [s1, s2: Slice]
RETURNS [order: Order] = {
determines relative order in tree of last nodes in the slices
returns "same" if slices are identical
returns "before" if last node of s1 comes before last node of s2
returns "after" if last node of s1 comes after last node of s2
returns "disjoint" if slices are not from the same tree
IF s1=NIL OR s2=NIL OR s1.length=0 OR s2.length=0 THEN RETURN [disjoint];
Invariant[KindOfSlice[s1]=before AND KindOfSlice[s2]=before]; -- only valid for parent slices
IF s1[0]#s2[0] THEN RETURN [disjoint]; -- different roots
FOR i:
NAT
IN[1..
MIN[s1.length, s2.length])
DO
n1: Node ~ s1[i];
n2: Node ~ s2[i];
IF n1#n2
THEN {
-- they are siblings, so can check order by Next's
FOR n: Node ← Next[n1], Next[n]
DO
-- search from s1 to s2
IF n=n2 THEN RETURN [before]; -- n1 comes before n2
IF n=NIL THEN RETURN [after]; -- n2 not found, so n1 must be after n2
ENDLOOP;
};
ENDLOOP;
SELECT s1.length
FROM
<s2.length => RETURN [before]; -- s1Last is a parent of s2Last
=s2.length => RETURN [same]; -- s1Last=s2Last
>s2.length => RETURN [after]; -- s2Last is a parent of s1Last
ENDCASE => ERROR;
};
CompareNodeOrder:
PUBLIC
PROC [node1, node2: Node]
RETURNS [Order] = {
IF node1=NIL OR node2=NIL THEN RETURN [disjoint];
IF node1=node2 THEN RETURN [same]
ELSE {
s1: Slice ~ MakeParentSlice[node1];
s2: Slice ~ MakeParentSlice[node2];
order: Order ~ CompareSliceOrder[s1, s2];
FreeSlice[s1];
FreeSlice[s2];
RETURN[order];
};
};
DoSplits:
PROC [world: World, alpha, beta: Span]
RETURNS [Span, Span] = {
split off head or tail sections of text
MakeSplit:
PROC [split: Location] ~ {
IF split.node#
NIL
AND split.where#nodeItself
THEN {
new: Node ~ Split[world, Root[split.node], split];
FixLoc:
PROC [old: Location]
RETURNS [Location] ~ {
IF old.node=split.node
THEN {
Invariant[old.where#nodeItself];
IF old.where>=split.where THEN RETURN [[new, old.where-split.where]];
};
RETURN[old];
};
alpha.start ← FixLoc[alpha.start];
alpha.end ← FixLoc[alpha.end];
beta.start ← FixLoc[beta.start];
beta.end ← FixLoc[beta.end]
};
};
IF alpha.start.where#nodeItself THEN MakeSplit[alpha.start];
IF beta.start.where#nodeItself THEN MakeSplit[beta.start];
IF alpha.end.where#nodeItself THEN MakeSplit[alpha.end];
IF beta.end.where#nodeItself THEN MakeSplit[beta.end];
RETURN [alpha, beta]
};
DoSplits2:
PROC [world: World, dest: Location, source: Span, where: Place, nesting:
INTEGER]
RETURNS [Location, Span, Place,
INTEGER] = {
destLoc: Location;
destSpan: Span ← [dest, nullLocation];
[destSpan, source] ← DoSplits[world, destSpan, source];
destLoc ← destSpan.start;
IF dest.where # nodeItself
THEN {
-- did a split
destLoc ← BackLoc[destLoc]; where ← after; nesting ← 0;
};
RETURN [destLoc, source, where, nesting]
};
ReMerge:
PROC [world: World, alpha, beta: Span, merge: Node, tail:
BOOL ←
FALSE]
RETURNS [Span, Span] = {
IF tail THEN merge ← StepForward[merge];
IF merge#
NIL
THEN {
loc: Location ~ Merge[world, Root[merge], merge];
FixLoc:
PROC [old: Location]
RETURNS [Location] = {
IF old.node=merge
THEN {
Invariant[old.where#nodeItself];
RETURN [[loc.node, loc.where+old.where]];
};
RETURN[old];
};
alpha.start ← FixLoc[alpha.start];
alpha.end ← FixLoc[alpha.end];
beta.start ← FixLoc[beta.start];
beta.end ← FixLoc[beta.end];
};
RETURN [alpha, beta]
};
UndoSplits:
PROC [world: World, alpha, beta: Span]
RETURNS [Span, Span] = {
IF alpha.start.where#nodeItself
THEN
[alpha, beta] ← ReMerge[world, alpha, beta, alpha.start.node];
IF beta.start.where#nodeItself
THEN
[alpha, beta] ← ReMerge[world, alpha, beta, beta.start.node];
IF alpha.end.where#nodeItself
THEN
[alpha, beta] ← ReMerge[world, alpha, beta, alpha.end.node, TRUE];
IF beta.end.where#nodeItself
THEN
[alpha, beta] ← ReMerge[world, alpha, beta, beta.end.node, TRUE];
RETURN [alpha, beta];
};
UndoSplits2:
PROC [world: World, dest: Location, source: Span]
RETURNS [Location, Span] = {
destSpan: Span ← [dest, nullLocation];
[destSpan, source] ← UndoSplits[world, destSpan, source];
RETURN [destSpan.end, source];
};
SliceOrder:
PROC [alpha, beta: Span, aBefore, aBottom, bBefore, bBottom: Slice]
RETURNS [overlap:
BOOL, head, tail: Span, startOrder, endOrder: Order] = {
IF CompareSliceOrder[aBottom, bBefore]#after -- alphaend before betastart
OR CompareSliceOrder[aBefore, bBottom]#before -- alphastart after betaend
THEN { overlap ← FALSE; RETURN };
startOrder ← CompareSliceOrder[aBefore, bBefore];
endOrder ← CompareSliceOrder[aBottom, bBottom];
head ←
SELECT startOrder
FROM
before => [alpha.start, BackLoc[beta.start]],
same => nullSpan,
after => [beta.start, BackLoc[alpha.start]],
ENDCASE => ERROR;
tail ←
SELECT endOrder
FROM
before => [ForwardLoc[alpha.end], beta.end],
same => nullSpan,
after => [ForwardLoc[beta.end], alpha.end],
ENDCASE => ERROR;
overlap ← TRUE;
};
Editing operations on spans
CannotDoEdit: PUBLIC ERROR ~ CODE;
Replace:
PUBLIC
PROC [world: World, destRoot, sourceRoot: Node, dest, source: Span, saveForPaste:
BOOL ←
TRUE]
RETURNS [Span] = {
replace dest span by copy of source span
result is the new copy of source
IF TextSpan[dest]
AND TextSpan[source]
THEN {
-- pure text replace
destText: Text ~ TextFromSpan[dest];
sourceText: Text ~ TextFromSpan[source];
IF saveForPaste THEN SaveTextForPaste[world, destText];
RETURN [SpanFromText[ReplaceText[world, destRoot, sourceRoot, destText, sourceText]]];
}
ELSE {
result, newDest: Span;
source ← CopySpan[source];
sourceRoot ← Root[source.start.node];
sourceRoot.deleted ← TRUE;
[result, newDest] ← Transpose[world, sourceRoot, destRoot, source, dest];
IF saveForPaste THEN SaveSpanForPaste[world, newDest];
RETURN[result];
};
};
Delete:
PUBLIC
PROC [world: World, root: Node, del: Span, saveForPaste:
BOOL ←
TRUE] = {
IF CheckForNil[del] THEN RETURN;
IF TextSpan[del]
THEN {
-- pure text
delText: Text ~ TextFromSpan[del];
IF saveForPaste THEN SaveTextForPaste[world, delText];
DeleteText[world, root, delText];
}
ELSE {
d: Span ~ MoveToLimbo[world, root, del];
IF saveForPaste THEN SaveSpanForPaste[world, d]
};
};
MoveToLimbo:
PROC [world: World, root: Node, span: Span]
RETURNS [result: Span] = {
RETURN [Move[world, NIL, root, nullLocation, span, after, 1]]
};
Copy:
PUBLIC
PROC [world: World, destRoot, sourceRoot: Node, dest: Location, source: Span, where: Place ← after, nesting:
INT ← 0]
RETURNS [result: Span] = {
result is the new copy of source
IF CheckForNil[source] OR dest.node=NIL THEN RETURN [nullSpan];
IF TextLoc[dest]
AND TextSpan[source]
THEN {
-- pure text copy
sourceText: Text ~ TextFromSpan[source];
RETURN[SpanFromText[CopyText[world, destRoot, sourceRoot, dest, sourceText]]];
}
ELSE {
source ← CopySpan[source];
sourceRoot ← Root[source.start.node];
sourceRoot.deleted ← TRUE;
result ← Move[world, destRoot, sourceRoot, dest, source, where, nesting];
};
};
Move:
PUBLIC
PROC [world: World, destRoot, sourceRoot: Node, dest: Location, source: Span, where: Place ← after, nesting:
INT ← 0]
RETURNS [result: Span] = {
dest cannot be within source
result is moved span
sBefore, sAfter, sTop, sBottom, dBefore, dAfter: Slice;
sNesting, dNesting: INT;
sDepth: NAT;
beforeSource, afterSource: Node; -- nodes adjacent to source after do splits
afterLoc: Location;
FreeSlices:
PROC = {
FreeSlice[sBefore]; FreeSlice[sAfter]; FreeSlice[sTop]; FreeSlice[sBottom];
FreeSlice[dBefore]; FreeSlice[dAfter];
sBefore ← sAfter ← sTop ← sBottom ← dBefore ← dAfter ← NIL
};
ForcedUnNest:
PROC [afterNode: Node] = {
span: Span = NodeSpan[afterNode, LastWithin[afterNode]];
FreeSlices[];
[] ← UnNest[world, Root[afterNode], span]
};
ForcedNest:
PROC = {
span: Span ← NodeSpan[sTop[sDepth], LastWithin[sBottom[sDepth]]];
IF SliceLength[sTop] = sDepth+1
THEN {
-- can't do it by calling Nest
IF nesting >= 1 THEN ERROR;
nesting ← nesting+1; -- move to a deeper position
FreeSlices[];
RETURN
};
FreeSlices[];
[] ← Nest[world, Root[span.start.node], span]
};
IF CheckForNil[source] THEN RETURN [nullSpan];
IF TextLoc[dest]
AND TextSpan[source]
THEN {
-- pure text move
sourceText: Text ~ TextFromSpan[source];
RETURN[SpanFromText[MoveText[world, destRoot, sourceRoot, dest, sourceText]]];
};
IF where=child THEN { where ← after; nesting ← nesting+1 }
ELSE
IF where=sibling
THEN {
newDest: Node = LastWithin[dest.node];
where ← after;
nesting ← nesting + Level[dest.node] - Level[newDest];
dest ← [newDest, nodeItself];
};
split source and dest, if necessary, so can deal with entire nodes
[dest, source, where, nesting] ← DoSplits2[world, dest, source, where, nesting];
beforeSource ← StepBackward[source.start.node];
afterSource ← StepForward[source.end.node];
afterLoc ← [afterSource, 0];
{
-- for exits
check for dest already in correct position
IF dest # nullLocation AND
((where = after
AND (dest.node = beforeSource
OR dest.node = source.end.node))
OR (where = before AND (dest.node = afterSource OR dest.node = source.start.node)))
THEN {
-- not going anywhere, but might be changing nesting
IF nesting > 0 THEN
FOR i:
INT
IN [0..nesting)
DO
[] ← Nest[world, sourceRoot, WholeNodeSpan[source]];
ENDLOOP
ELSE IF nesting < 0 THEN
FOR i:
INT
IN [nesting..0)
DO
[] ← UnNest[world, sourceRoot, WholeNodeSpan[source]];
ENDLOOP
}
ELSE
DO
-- repeat this loop only if have forced nest or unnest or source and dest in same tree
check for dest inside source
[sBefore, sAfter, sTop, sBottom, sNesting, sDepth] ←
DescribeBand[source.start.node, source.end.node ! BadBand =>
{ source ← nullSpan; GOTO ErrorReturn } ];
IF dest = nullLocation
THEN {
-- moving to limbo
dest ← CreateDest[SliceLength[sTop]-sDepth];
destRoot ← Root[dest.node];
destRoot.deleted ← TRUE; -- so will free this when it falls off the edit history list
where ← after; nesting ← 1
};
[dBefore, dAfter, dNesting] ← DestSlices[dest.node, where];
IF CompareSliceOrder[dBefore, sBefore]=after AND
CompareSliceOrder[dBefore, sBottom]=before THEN GOTO ErrorReturn;
dest inside source
IF dBefore[0] = sBefore[0]
THEN {
-- source and dest in same tree
span: Span = NodeSpan[source.start.node, source.end.node];
FreeSlices[];
[] ← MoveToLimbo[world, sourceRoot, span];
LOOP
};
dNesting ← dNesting + nesting;
SELECT NeedNestingChange[dBefore, dAfter, sTop, sBottom, dNesting, sDepth]
FROM
needUnNest => { ForcedUnNest[LastOfSlice[dAfter]]; LOOP };
needNest => { ForcedNest[]; LOOP };
ENDCASE;
IF SliceLength[sAfter] > SliceLength[sBefore]+1
THEN {
ForcedUnNest[LastOfSlice[sAfter]]; LOOP
}
ELSE {
-- do it
notify: REF MovingNodes Change;
notify ←
NEW[MovingNodes Change ← [MovingNodes[
destRoot, sourceRoot, dest.node, source.start.node, source.end.node,
LastOfSlice[sBefore], sNesting, (where # before)]]];
EditNotify[world, notify, before];
DeletePrefix[sTop, sDepth]; DeletePrefix[sBottom, sDepth];
ReplaceBand[dBefore, dAfter, sTop, sBottom, dNesting];
Splice[sBefore, sAfter];
FreeSlices[];
EditNotify[world, notify, after];
NoteEvent[world, UndoMoveNodes, notify];
};
EXIT;
ENDLOOP;
IF TextLoc[dest]
THEN {
-- undo prior splits
start, end: BOOL ← FALSE;
IF TextLoc[source.start]
THEN {
-- merge start of source with front of dest
start ← TRUE;
[source, ] ← ReMerge[world, source, nullSpan, source.start.node]
};
IF TextLoc[source.end]
THEN {
-- merge end of source with tail of dest
end ← TRUE;
[source, ] ← ReMerge[world, source, nullSpan, source.end.node, TRUE]
};
IF start
AND end
THEN {
-- merge before source with after source
afterLoc ← Merge[world, Root[afterSource], afterSource]
}
}
ELSE
IF TextLoc[source.start]
AND TextLoc[source.end]
THEN {
afterLoc ← Merge[world, Root[afterSource], afterSource]
};
world.afterMoved2 ← world.afterMoved1; -- save previous hint
world.afterMoved1 ← IF afterSource=NIL THEN [beforeSource, 0] ELSE afterLoc; -- hint for repaint
RETURN [source];
EXITS ErrorReturn => {
FreeSlices[];
[, source] ← UndoSplits2[world, dest, source];
ERROR CannotDoEdit
}
}
};
UndoMoveNodes:
PROC [world: World, undoRef:
REF Change] = {
WITH undoRef
SELECT
FROM
x: REF Change.MovingNodes => [] ← Move[world, x.sourceRoot, x.destRoot, NodeLoc[x.pred], NodeSpan[x.first, x.last], after, x.nesting];
ENDCASE => ERROR
};
Transpose:
PUBLIC
PROC [world: World, alphaRoot, betaRoot: Node, alpha, beta: Span]
RETURNS [newAlpha, newBeta: Span] = {
newAlpha is new location of alpha span; ditto for newBeta
aBefore, aAfter, aTop, aBottom, bBefore, bAfter, bTop, bBottom: Slice;
aNesting, bNesting: INT;
aDepth, bDepth: NAT;
beforeAlpha, afterAlpha, beforeBeta, afterBeta: Node; -- nodes adjacent after do splits
afterAlphaLoc, afterBetaLoc: Location;
FreeSlices:
PROC = {
FreeSlice[aBefore]; FreeSlice[aAfter]; FreeSlice[aTop]; FreeSlice[aBottom];
FreeSlice[bBefore]; FreeSlice[bAfter]; FreeSlice[bTop]; FreeSlice[bBottom];
aBefore ← aAfter ← aTop ← aBottom ← bBefore ← bAfter ← bTop ← bBottom ← NIL
};
{
-- for exit
IF CheckForNil[alpha] OR CheckForNil[beta] THEN RETURN [nullSpan, nullSpan];
IF TextSpan[alpha]
AND TextSpan[beta]
THEN {
-- pure text transpose
alphaText: Text ~ TextFromSpan[alpha];
betaText: Text ~ TextFromSpan[beta];
alphaResultText, betaResultText: Text;
[alphaResultText, betaResultText] ← TransposeText[world, alphaRoot, betaRoot, alphaText, betaText];
newAlpha ← SpanFromText[alphaResultText];
newBeta ← SpanFromText[betaResultText];
RETURN;
};
[alpha, beta] ← DoSplits[world, alpha, beta]; -- so can deal with entire nodes
beforeAlpha ← StepBackward[alpha.start.node];
afterAlpha ← StepForward[alpha.end.node];
afterAlphaLoc ← [afterAlpha, 0];
beforeBeta ← StepBackward[beta.start.node];
afterBeta ← StepForward[beta.end.node];
afterBetaLoc ← [afterBeta, 0];
now check for alpha beta adjacent or overlapping as special cases
IF afterAlpha = beta.start.node
THEN {
-- alpha just before beta
move beta nodes to before alpha nodes
[] ← Move[world, alphaRoot, betaRoot, WholeNodeLoc[alpha.start], WholeNodeSpan[beta], before, 0]
}
ELSE
IF afterBeta = alpha.start.node
THEN {
-- beta just before alpha
move alpha nodes to before beta nodes
[] ← Move[world, betaRoot, alphaRoot, WholeNodeLoc[beta.start], WholeNodeSpan[alpha], before, 0]
}
ELSE {
-- get slices describing the bands of nodes to be transposed
overlap: BOOL;
head, tail: Span; -- sections of alpha or beta before and after the overlap
startOrder, endOrder: Order;
[aBefore, aAfter, aTop, aBottom, aNesting, aDepth] ←
DescribeBand[alpha.start.node, alpha.end.node ! BadBand =>
{ alpha ← beta ← nullSpan; GOTO ErrorReturn }];
[bBefore, bAfter, bTop, bBottom, bNesting, bDepth] ←
DescribeBand[beta.start.node, beta.end.node ! BadBand =>
{ alpha ← beta ← nullSpan; GOTO ErrorReturn }];
check for overlap
[overlap, head, tail, startOrder, endOrder] ←
SliceOrder[alpha, beta, aBefore, aBottom, bBefore, bBottom];
IF overlap
THEN {
-- bands overlap
FreeSlices[];
IF head = nullSpan AND tail = nullSpan THEN NULL
ELSE
IF head = nullSpan
THEN {
--move tail to before alphastart
[] ← Move[world, alphaRoot, betaRoot, WholeNodeLoc[alpha.start], WholeNodeSpan[tail], before, 0];
IF endOrder=before
THEN {
-- alpha end before beta end
beta.start ← tail.start; beta.end ← alpha.end
}
ELSE {
-- beta end before alpha end
alpha.start ← tail.start; alpha.end ← beta.end
}
}
ELSE
IF tail = nullSpan
THEN {
--move head to after alphaend
[] ← Move[world, alphaRoot, betaRoot, WholeNodeLoc[alpha.end], WholeNodeSpan[head], after, 0];
IF startOrder=before
THEN {
-- alpha start before beta start
alpha.start ← beta.start; alpha.end ← head.end
}
ELSE {
-- beta start before alpha start
beta.start ← alpha.start; beta.end ← head.end
}
}
ELSE IF startOrder # endOrder THEN NULL -- one contained in the other
ELSE {
--transpose head and tail
[] ← Transpose[world, alphaRoot, betaRoot, WholeNodeSpan[head], WholeNodeSpan[tail]];
IF startOrder=before
THEN {
-- alpha start before beta start
alpha.start ← beta.start; alpha.end ← head.end;
beta.start ← tail.start; beta.end ← alpha.end
}
ELSE {
-- beta start before alpha start
beta.start ← alpha.start; beta.end ← head.end;
alpha.start ← tail.start; alpha.end ← beta.end
}
}
}
ELSE {
-- do transpose as two moves
aSpan, bSpan: Span;
after1, after2: Location;
bLoc: Location ← NodeLoc[LastOfSlice[bBefore]];
aLoc: Location ← NodeLoc[LastOfSlice[aBefore]];
FreeSlices[];
aSpan ← NodeSpan[alpha.start.node, alpha.end.node];
bSpan ← NodeSpan[beta.start.node, beta.end.node];
[] ← MoveToLimbo[world, alphaRoot, aSpan]; after1 ← world.afterMoved1;
[] ← MoveToLimbo[world, betaRoot, bSpan]; after2 ← world.afterMoved1;
[] ← Move[world, betaRoot, Root[aSpan.start.node], bLoc, aSpan, after, bNesting];
[] ← Move[world, alphaRoot, Root[bSpan.start.node], aLoc, bSpan, after, aNesting];
world.afterMoved1 ← after1; world.afterMoved2 ← after2
}
};
IF TextLoc[alpha.start]
AND TextLoc[beta.start]
THEN {
-- remerge starts
[alpha, beta] ← ReMerge[world, alpha, beta, alpha.start.node];
[alpha, beta] ← ReMerge[world, alpha, beta, beta.start.node]
};
IF TextLoc[alpha.end]
AND TextLoc[beta.end]
THEN {
-- remerge ends
[alpha, beta] ← ReMerge[world, alpha, beta, alpha.end.node, TRUE];
[alpha, beta] ← ReMerge[world, alpha, beta, beta.end.node, TRUE];
afterAlphaLoc ← beta.end; afterBetaLoc ← alpha.end
};
world.afterMoved1 ← IF afterAlphaLoc.node=NIL THEN [beforeAlpha, 0] ELSE afterAlphaLoc; -- hint for repaint
world.afterMoved2 ← IF afterBetaLoc.node=NIL THEN [beforeBeta, 0] ELSE afterBetaLoc;
RETURN [alpha, beta];
EXITS ErrorReturn => {
FreeSlices[]; [alpha, beta] ← UndoSplits[world, alpha, beta];
ERROR CannotDoEdit
}
}
};
MoveOnto:
PUBLIC
PROC [world: World, destRoot, sourceRoot: Node, dest, source: Span, saveForPaste:
BOOL ←
TRUE]
RETURNS [result: Span] = {
like Replace, but moves source instead of copying it
result is moved span
overlap: BOOL;
head, tail, newDest: Span; -- sections of alpha or beta before and after the overlap
startOrder, endOrder: Order;
aBefore, aAfter, aTop, aBottom, bBefore, bAfter, bTop, bBottom: Slice;
aNesting, bNesting: INT;
aDepth, bDepth: NAT;
FreeSlices:
PROC = {
FreeSlice[aBefore]; FreeSlice[aAfter]; FreeSlice[aTop]; FreeSlice[aBottom];
FreeSlice[bBefore]; FreeSlice[bAfter]; FreeSlice[bTop]; FreeSlice[bBottom];
aBefore ← aAfter ← aTop ← aBottom ← bBefore ← bAfter ← bTop ← bBottom ← NIL
};
{
-- for exit
IF CheckForNil[source] OR CheckForNil[dest] THEN RETURN [nullSpan];
IF TextSpan[dest]
AND TextSpan[source]
THEN {
-- pure text move
destText: Text ~ TextFromSpan[dest];
sourceText: Text ~ TextFromSpan[source];
IF saveForPaste THEN SaveTextForPaste[world, destText];
RETURN [SpanFromText[MoveTextOnto[world, destRoot, sourceRoot, destText, sourceText]]];
};
[dest, source] ← DoSplits[world, dest, source];
[aBefore, aAfter, aTop, aBottom, aNesting, aDepth] ←
DescribeBand[dest.start.node, dest.end.node ! BadBand =>
{ dest ← source ← nullSpan; GOTO ErrorReturn }];
[bBefore, bAfter, bTop, bBottom, bNesting, bDepth] ←
DescribeBand[source.start.node, source.end.node ! BadBand =>
{ dest ← source ← nullSpan; GOTO ErrorReturn }];
get slices for dest and source
[overlap, head, tail, startOrder, endOrder] ←
SliceOrder[dest, source, aBefore, aBottom, bBefore, bBottom];
FreeSlices[];
check for overlap
IF overlap
THEN {
-- bands overlap. modify dest so doesn't overlap
IF head = nullSpan AND tail = nullSpan THEN GOTO ErrorReturn;
IF head = nullSpan
THEN {
-- source start = dest start
IF endOrder=before THEN GOTO ErrorReturn -- dest end before source end
ELSE dest.start ← tail.start
}
ELSE
IF tail = nullSpan
THEN {
--source end = dest end
IF startOrder=before THEN
dest.end ← head.end
-- dest start before source start
ELSE GOTO ErrorReturn
} -- source start before dest start
ELSE {
-- have both head and tail
IF startOrder=before
AND endOrder=after
THEN {
[] ← Delete[world, destRoot, tail]; dest.end ← head.end
}
ELSE
IF startOrder=before
THEN dest.end ← head.end
ELSE IF endOrder=after THEN dest.start ← tail.start
ELSE GOTO ErrorReturn
}
};
[dest, source] ← UndoSplits[world, dest, source];
source ← MoveToLimbo[world, sourceRoot, source];
sourceRoot ← Root[source.start.node];
[result, newDest] ← Transpose[world, sourceRoot, destRoot, source, dest];
IF saveForPaste THEN SaveSpanForPaste[world, newDest];
RETURN;
EXITS ErrorReturn => {
[dest, source] ← UndoSplits[world, dest, source]; ERROR CannotDoEdit
}
}
};
New nodes; split & merge
Insert:
PUBLIC
PROC [world: World, root, old: Node, where: Place ← after, inherit:
BOOL ←
TRUE]
RETURNS [new: Node] = {
empty copy of old node is inserted in tree in position determined by "where"
IF old=NIL THEN RETURN [NIL];
new ← NewNode[];
IF inherit THEN Inherit[old, new];
DoInsertNode[world, root, old, new, where]
};
Inherit:
PROC [n: Node, from: Node, allprops:
BOOL ←
FALSE] = {
Copy:
PROC [name:
ATOM, value:
REF]
RETURNS [
BOOL] = {
IF allprops
OR Is[name, $Inheritable]
THEN {
newvalue: REF ~ CopyProp[name, value];
IF newvalue # NIL THEN PutProp[n, name, newvalue];
};
RETURN [FALSE];
};
n.formatName ← from.formatName;
n.comment ← from.comment;
IF allprops
OR from.hasprefix
OR from.haspostfix
OR from.hasstyledef
THEN
[] ← MapProps[from, Copy, FALSE, FALSE];
};
DoInsertNode:
PROC [world: World, root, old, new: Node, where: Place] = {
dest, parent: Node;
child: BOOL;
notify: REF InsertingNode Change;
IF new = NIL OR old = NIL THEN RETURN;
parent ← IF where = child THEN old ELSE Parent[old];
IF where = sibling THEN { dest ← LastWithin[old]; child ← FALSE }
ELSE IF where = after THEN { dest ← old; child ← FALSE }
ELSE IF where = child THEN { dest ← old; child ← TRUE }
ELSE {
IF parent.child = old THEN { dest ← parent; child ← TRUE }
ELSE { dest ← LastWithin[Previous[old, parent]]; child ← FALSE }
};
notify ← NEW[InsertingNode Change ← [InsertingNode[root, new, dest]]];
EditNotify[world, notify, before];
IF child
THEN {
-- insert as first child of dest
IF dest.child # NIL THEN { new.next ← dest.child; new.last ← FALSE }
ELSE { new.next ← dest; new.last ← TRUE };
dest.child ← new
}
ELSE
IF where = sibling
THEN {
-- insert as next sibling of old; don't adopt children
new.next ← old.next; new.last ← old.last;
old.last ← FALSE; old.next ← new
}
ELSE {
-- insert as next sibling of dest
new.next ← dest.next; new.last ← dest.last;
dest.last ← FALSE; dest.next ← new;
IF where = after
AND (new.child ← dest.child) #
NIL
THEN {
-- adopt dest's children
LastSibling[new.child].next ← new;
dest.child ← NIL
}
};
EditNotify[world, notify, after];
NoteEvent[world, UndoInsertNode, notify]
};
UndoInsertNode:
PROC [world: World, undoRef:
REF Change] = {
WITH undoRef
SELECT
FROM
x: REF Change.InsertingNode => [] ← Delete[world, x.root, NodeSpan[x.new, x.new]];
ENDCASE => ERROR
};
Split:
PUBLIC
PROC [world: World, root: Node, loc: Location]
RETURNS [new: Node] = {
inserts copy of loc.node directly after loc.node (as sibling)
new adopts children of old (if any)
if loc.where # nodeItself and loc.node is a text node, then
text after loc.where moves to new node
text before loc.where stays in old node
returns the new node
IF loc.node=NIL THEN RETURN [NIL];
new ← Insert[world, root, loc.node, after];
IF TextLoc[loc]
THEN {
[] ← MoveText[world, root, root, [new, 0], [loc.node, loc.where, maxLen]];
}
};
Merge:
PUBLIC
PROC [world: World, root, node: Node]
RETURNS [loc: Location] = {
copies text of node to end of previous node
then deletes node
returns location of join in the merged node
pred: Node ~ StepBackward[node];
IF pred=NIL OR Parent[pred]=NIL OR node=NIL THEN ERROR CannotDoEdit
ELSE {
result: Text ~ CopyText[world, root, root, [pred, maxLen], [node, 0, maxLen]];
[] ← Delete[world, root, NodeSpan[node, node]];
RETURN [[result.node, result.start]];
};
};