TextLooksImpl.mesa
Copyright © 1985, 1986 by Xerox Corporation. All rights reserved.
written by Bill Paxton, February 1981
Bill Paxton, December 13, 1982 1:17 pm
Maxwell, January 5, 1983 3:54 pm
Russ Atkinson, July 25, 1983 3:36 pm
Michael Plass, March 29, 1985 5:24:46 pm PST
Doug Wyatt, September 22, 1986 3:48:40 pm PDT
DIRECTORY
AMBridge USING [IsRemote, TVForReferent],
AMTypes USING [Apply, Domain, First, Next, TV, TVEqual],
Basics USING [DoubleAnd, DoubleNot, DoubleOr, NonNegative],
IO USING [PutChar, PutRope],
PrincOpsUtils USING [LongCopy],
PrintTV USING [RegisterTVPrintProc, TVPrintProc],
Rope USING [Cat, Fetch, FromChar, ROPE, Size],
RunReader USING [FreeRunReader, Get, GetRunReader, Ref, SetPosition],
SafeStorage USING [Type],
TextLooks USING [allLooks, BaseRuns, FlatMax, Look, Looks, MaxLen, noLooks, Run, Runs, RunsBody, Tchange, Tconcat, Treplace, Tsubstr],
TextLooksSupport USING [];
TextLooksBasicImpl
CheckLongSub:
PROC [x, y:
INT]
RETURNS [
INT] ~
INLINE {
RETURN[Basics.NonNegative[x-y]];
};
ReplaceByRun:
PUBLIC
PROC [dest: Runs, start, len, runLen, destSize:
INT, inherit:
BOOL, looks: Looks]
RETURNS [Runs] = {
merge: BOOL ← FALSE;
mergeLooks: Looks;
split, numruns: NAT;
flat: BaseRuns;
c, numRuns, oldPos, size: INT;
Count:
PROC [start, len:
INT]
RETURNS [
INT] = {
IF len=0 THEN RETURN[numRuns];
[c, merge, mergeLooks] ←
CountRuns[dest, start, len, FlatMax-numRuns, merge, mergeLooks];
RETURN [numRuns←numRuns+c];
};
AddIt:
PROC
RETURNS [
INT] = {
c ← IF merge AND mergeLooks=looks THEN 0 ELSE 1;
merge ← TRUE; mergeLooks ← looks;
RETURN [numRuns←numRuns+c];
};
Extract:
PROC [start, len:
INT] = {
IF len > 0 THEN split ← ExtractRuns[flat, dest, start, len, split];
};
TryFlatAppendRun:
PROC [base: Runs]
RETURNS [Runs] = {
flat: BaseRuns;
size: INT;
[numRuns, merge, mergeLooks] ← CountRuns[base, 0, size←Size[base], FlatMax];
IF numRuns > FlatMax OR AddIt[] > FlatMax THEN RETURN [NIL];
flat ← NewBase[numruns←numRuns];
split ← ExtractRuns[flat, base, 0, size, 0];
split ← InsertRun[flat, runLen, looks, split];
IF split # numruns THEN ERROR;
IF flat[numruns-1].after # size+runLen THEN ERROR;
RETURN [flat];
};
IF runLen=0 THEN RETURN [Replace[base: dest, start: start, len: len, replace: NIL, baseSize: destSize, repSize: 0, tryFlat: TRUE]];
IF inherit
THEN {
-- get looks from destination
IF destSize = 0 THEN NULL -- take from arg list
ELSE looks ← FetchLooks[dest,
IF start > 0 THEN start-1 -- take from before replacement
ELSE IF len=destSize THEN 0 -- replacing everything
ELSE len]; -- take from after replacement
};
IF dest=NIL AND looks=noLooks THEN RETURN[NIL];
numRuns ← 0; oldPos ← start+len; size ← destSize-len+runLen;
IF Count[0, start] > FlatMax
OR AddIt[] > FlatMax
OR Count[oldPos, destSize-oldPos] > FlatMax
THEN {
newPos: INT ← start+runLen;
replace, new: Runs;
WHILE dest #
NIL
DO
WITH dest
SELECT
FROM
x:
REF RunsBody.node.replace => {
xnewPos: INT ← x.newPos;
xstart: INT ← x.start;
IF start <= xstart
AND oldPos >= xnewPos
THEN {
replacing the replacement
oldPos ← x.oldPos+(oldPos-xnewPos); dest ← x.base; len ← oldPos-start; LOOP;
}
ELSE IF start = xnewPos -- appending to the replacement
AND (new ← TryFlatAppendRun[x.replace])#
NIL
THEN {
start ← xstart; oldPos ← x.oldPos+len;
dest ← x.base; replace ← new;
Exit the loop from here; len and runLen are not needed anymore, so don't upate the values.
}
};
x:
REF RunsBody.node.concat => {
-- try to append to first part of the concat
xpos: INT ← x.pos;
IF start=xpos AND len=0 AND
(new ← TryFlatAppendRun[x.base])#
NIL
THEN
RETURN [
NEW[Tconcat ← [node[concat
[size, new, x.rest, xpos+runLen]]]]];
};
ENDCASE;
EXIT;
ENDLOOP;
IF replace=NIL AND (replace ← CreateRun[runLen, looks])=NIL THEN
replace ← MakeRun[runLen];
IF dest=NIL THEN dest ← MakeRun[destSize];
RETURN [NEW[Treplace ← [node[replace[size, dest, replace, start, oldPos, newPos]]]]]
};
IF numRuns=0 THEN RETURN[NIL];
flat ← NewBase[numruns←numRuns]; split ← 0;
Extract[0, start];
split ← InsertRun[flat, runLen, looks, split];
Extract[oldPos, destSize-oldPos];
IF split # numruns THEN ERROR;
IF flat[numruns-1].after # size THEN ERROR;
RETURN [flat]
};
CountRuns:
PUBLIC
PROC [runs: Runs, start, len:
INT, limit:
INT ← MaxLen, merge:
BOOL ←
FALSE, firstLooks: Looks ← noLooks]
RETURNS [count:
INT, nonempty:
BOOL, lastLooks: Looks] = {
stops counting when exceeds limit
if merge is true, then doesn't count first run if its looks=firstLooks
c: INT;
count ← 0;
DO nonempty ← merge;
IF len=0 THEN { lastLooks ← firstLooks; RETURN };
IF runs=
NIL
THEN {
c ← IF merge AND firstLooks=noLooks THEN 0 ELSE 1;
RETURN [count+c, TRUE, noLooks]
};
WITH runs
SELECT
FROM
x:
REF RunsBody.base => {
first, last: NAT;
len ← MIN[len, CheckLongSub[TbaseSize[x], start]];
[first, last] ← FindBaseRuns[x, start, len];
c ← last-first+1;
IF merge AND firstLooks=x[first].looks THEN c ← c-1;
RETURN [count+c, TRUE, x[last].looks]
};
x:
REF RunsBody.node.substr => {
len ← MIN[len, CheckLongSub[x.size, start]];
start ← start + x.start; runs ← x.base; LOOP
};
x:
REF RunsBody.node.concat => {
xpos: INT ← x.pos;
len ← MIN[len, CheckLongSub[x.size, start]];
IF start < xpos
THEN {
subLen: INT ← xpos - start;
IF len <= subLen THEN { runs ← x.base; LOOP };
[c, merge, firstLooks] ← CountRuns[
x.base, start, subLen, limit, merge, firstLooks];
count ← count+c; IF c > limit THEN RETURN;
limit ← limit-c; start ← xpos; len ← len-subLen;
};
start ← start-xpos; runs ← x.rest; LOOP
};
x:
REF RunsBody.node.replace => {
xstart: INT ← x.start;
xnew: INT ← x.newPos;
len ← MIN[len, CheckLongSub[x.size, start]];
IF start < xstart
THEN {
subLen: INT ← xstart - start;
IF len <= subLen THEN {runs ← x.base; LOOP};
[c, merge, firstLooks] ← CountRuns[
x.base, start, subLen, limit, merge, firstLooks];
count ← count+c; IF c > limit THEN RETURN;
limit ← limit-c;
start ← xstart; len ← len-subLen;
};
IF start < xnew
THEN {
st: INT ← start - xstart;
subLen: INT ← xnew - start;
IF len <= subLen
THEN {
start ← st; runs ← x.replace; LOOP
};
[c, merge, firstLooks] ← CountRuns[
x.replace, st, subLen, limit, merge, firstLooks];
count ← count+c; IF c > limit THEN RETURN;
limit ← limit-c; start ← xnew; len ← len-subLen
};
start ← start - xnew + x.oldPos; runs ← x.base; LOOP
};
x:
REF RunsBody.node.change => {
xstart: INT ← x.start;
xend, subLen: INT;
len ← MIN[len, CheckLongSub[x.size, start]];
IF start < xstart
THEN {
IF len <= (subLen ← xstart-start) THEN {runs ← x.base; LOOP};
[c, merge, firstLooks] ← CountRuns[
x.base, start, subLen, limit, merge, firstLooks];
count ← count+c; IF c > limit THEN RETURN;
limit ← limit-c;
start ← xstart; len ← len-subLen;
};
IF start < (xend ← xstart+x.len)
THEN {
subLen ← MIN[xend-start, len];
[c, merge, firstLooks] ← CountRunsAfterChanges[
x.base, start, subLen, limit,
x.remove, x.add, merge, firstLooks];
count ← count+c; IF c > limit THEN RETURN;
limit ← limit-c; start ← xend; len ← len-subLen;
};
runs ← x.base; LOOP
};
ENDCASE => ERROR;
ENDLOOP;
};
ExtractRuns:
PUBLIC
PROC [base: BaseRuns, ref: Runs, start, len:
INT, index:
NAT ← 0]
RETURNS [
NAT] =
TRUSTED {
-- value is next index
DO
IF len=0 THEN RETURN [index];
IF ref=NIL THEN -- treat as noLooks
RETURN [InsertRun[base, len, noLooks, index]];
WITH ref
SELECT
FROM
x:
REF RunsBody.base => {
firstLen, lastLen, xloc, next, loc: INT;
first, last: NAT;
len ← MIN[len, CheckLongSub[TbaseSize[x], start]];
[first, last] ← FindBaseRuns[x, start, len];
[firstLen, lastLen] ← BaseRunLengths[x, start, len, first, last];
now extract the runs
IF index=0
THEN {
-- this is the first run to be extracted
loc ← firstLen; base[0] ← [loc, x[first].looks]; index ← 1;
}
ELSE {
loc ← base[index-1].after + firstLen;
IF base[index-1].looks=x[first].looks -- merge runs
THEN base[index-1].after ← loc
ELSE { base[index] ← [loc, x[first].looks]; index ← index+1 }
};
IF first=last THEN RETURN [index];
IF (xloc ← x[first].after) = loc
THEN {
-- can simply copy runs
numRuns: NAT;
IF (numRuns ← last-first-1) > 0
THEN {
CopyRuns[to:base, toLoc:index,
from:x, fromLoc:first+1, nRuns: numRuns];
index ← index+numRuns; loc ← base[index-1].after
}
}
ELSE
FOR i:
NAT
IN (first..last)
DO
loc ← loc + (next ← x[i].after) - xloc; xloc ← next;
base[index] ← [loc, x[i].looks];
index ← index+1; ENDLOOP;
base[index] ← [loc+lastLen, x[last].looks];
RETURN [index+1]
};
x:
REF RunsBody.node.substr => {
len ← MIN[len, CheckLongSub[x.size, start]];
start ← start + x.start; ref ← x.base; LOOP
};
x:
REF RunsBody.node.concat => {
xpos: INT ← x.pos;
len ← MIN[len, CheckLongSub[x.size, start]];
IF start < xpos
THEN {
subLen: INT ← xpos - start;
IF len <= subLen THEN { ref ← x.base; LOOP };
index ← ExtractRuns[base, x.base, start, subLen, index];
start ← xpos; len ← len-subLen
};
start ← start-xpos; ref ← x.rest; LOOP
};
x:
REF RunsBody.node.replace => {
xstart: INT ← x.start;
xnew: INT ← x.newPos;
len ← MIN[len, CheckLongSub[x.size, start]];
IF start < xstart
THEN {
subLen: INT ← xstart - start;
IF len <= subLen THEN {ref ← x.base; LOOP};
index ← ExtractRuns[base, x.base, start, subLen, index];
start ← xstart; len ← len-subLen
};
IF start < xnew
THEN {
st: INT ← start - xstart;
subLen: INT ← xnew - start;
IF len <= subLen
THEN {
start ← st; ref ← x.replace; LOOP
};
index ← ExtractRuns[base, x.replace, st, subLen, index];
start ← xnew; len ← len-subLen
};
start ← start - xnew + x.oldPos; ref ← x.base; LOOP
};
x:
REF RunsBody.node.change => {
xstart: INT ← x.start;
xend, subLen: INT;
len ← MIN[len, CheckLongSub[x.size, start]];
IF start < xstart
THEN {
IF len <= (subLen ← xstart-start) THEN {ref ← x.base; LOOP};
index ← ExtractRuns[base, x.base, start, subLen, index];
start ← xstart; len ← len-subLen
};
IF start < (xend ← xstart+x.len)
THEN {
subLen ← MIN[xend-start, len];
index ← ExtractRunsAfterChanges[
base, x.base, x.remove, x.add, start, subLen, index];
start ← xend; len ← len-subLen
};
ref ← x.base; LOOP
};
ENDCASE => ERROR;
ENDLOOP
};
NewBase:
PUBLIC
PROC [runs:
NAT]
RETURNS [BaseRuns] = {
RETURN [NEW[base RunsBody[runs]]];
};
BaseRun:
PUBLIC
PROC [x: BaseRuns, index:
INT, lower:
NAT ← 0, upper:
NAT ←
LAST[
NAT]]
RETURNS [
NAT] = {
len: NAT;
size: INT;
IF index = 0 THEN RETURN [0];
IF (len←x.length) <= 1 THEN RETURN [0];
IF index+1 >= (size←TbaseSize[x]) THEN RETURN[len-1];
IF upper >= len THEN upper ← len-1;
IF lower > 0 AND x[lower-1].after > index THEN lower ← 0;
DO
-- always know index is in run between lower and upper inclusive
run: NAT ← (upper+lower)/2;
IF index < x[run].after THEN upper ← run ELSE lower ← run+1;
IF upper=lower THEN RETURN[upper];
ENDLOOP
};
CopyRuns:
PUBLIC
PROC [to, from: BaseRuns, toLoc, fromLoc, nRuns:
NAT] =
TRUSTED {
RunsOffset: NAT = SIZE[base RunsBody[0]];
nLeft: NAT;
IF nRuns=0 THEN RETURN;
IF fromLoc >= from.length OR toLoc >= to.length THEN ERROR;
nLeft ← nRuns-1;
to[toLoc+nLeft] ← from[fromLoc+nLeft]; -- bounds check
PrincOpsUtils.LongCopy[
from: LOOPHOLE[from, LONG POINTER]+fromLoc*SIZE[Run]+RunsOffset,
to: LOOPHOLE[to, LONG POINTER]+toLoc*SIZE[Run]+RunsOffset,
nwords: nLeft*SIZE[Run]]
};
InsertRun:
PUBLIC
PROC [base: BaseRuns, len:
INT, looks: Looks, index:
NAT]
RETURNS [
NAT] = {
-- value is next index
IF index=0 THEN { base[0] ← [len, looks]; index ← 1 }
ELSE {
loc: INT ← base[index-1].after + len;
IF base[index-1].looks=looks -- merge runs
THEN base[index-1].after ← loc
ELSE { base[index] ← [loc, looks]; index ← index+1 }
};
RETURN [index]
};
FindBaseRuns:
PUBLIC
PROC [x: BaseRuns, start, len:
INT]
RETURNS [first, last:
NAT] = {
first ← BaseRun[x, start];
last ←
IF len>1
THEN BaseRun[x, start+len-1, first]
ELSE first
};
BaseRunLengths:
PUBLIC
PROC [x: BaseRuns, start, len:
INT, first, last:
NAT]
RETURNS [firstLen, lastLen:
INT] = {
IF first=last THEN RETURN[len, len];
RETURN[x[first].after-start, start+len-x[last-1].after]
};
And:
PROC [a, b: Looks]
RETURNS [Looks] ~
INLINE {
RETURN[LOOPHOLE[Basics.DoubleAnd[LOOPHOLE[a], LOOPHOLE[b]]]];
};
Or:
PROC [a, b: Looks]
RETURNS [Looks] ~
INLINE {
RETURN[LOOPHOLE[Basics.DoubleOr[LOOPHOLE[a], LOOPHOLE[b]]]];
};
Not:
PROC [a: Looks]
RETURNS [Looks] ~
INLINE {
RETURN[LOOPHOLE[Basics.DoubleNot[LOOPHOLE[a]]]];
};
LooksAND:
PUBLIC
PROC [looks1, looks2: Looks]
RETURNS [Looks] ~ {
RETURN[And[looks1, looks2]];
};
LooksOR:
PUBLIC
PROC [looks1, looks2: Looks]
RETURNS [Looks] ~ {
RETURN[Or[looks1, looks2]];
};
LooksNOT:
PUBLIC
PROC [looks: Looks]
RETURNS [Looks] ~ {
RETURN[Not[looks]];
};
ModifyLooks:
PUBLIC
PROC [old, remove, add: Looks]
RETURNS [Looks] = {
modified looks are == (old & ~remove) v add
RETURN[Or[And[old, Not[remove]], add]];
};
MergeChanges:
PUBLIC
PROC [oldrem, oldadd, rem, add: Looks]
RETURNS [newrem, newadd: Looks] = {
((lks & ~oldrem) v oldadd) & ~rem) v add ==
lks & ~(oldrem v rem)) v ((oldadd & ~rem) v add
thus, newrem ← oldrem v rem, newadd ← (oldadd & ~rem) v add
RETURN[newrem: Or[oldrem, rem], newadd: Or[And[oldadd, Not[rem]], add]];
};
Edit operations
Size:
PUBLIC
PROC [base: Runs]
RETURNS [size:
INT] = {
RETURN [
IF base =
NIL
THEN 0
ELSE
WITH base
SELECT
FROM
x: REF RunsBody.base => IF x.length=0 THEN 0 ELSE x[x.length-1].after,
x: REF RunsBody.node.substr => x.size,
x: REF RunsBody.node.concat => x.size,
x: REF RunsBody.node.replace => x.size,
x: REF RunsBody.node.change => x.size,
ENDCASE => ERROR
]
};
Substr:
PUBLIC
PROC [base: Runs, start:
INT, len:
INT]
RETURNS [new: Runs] = {
DO
IF base=NIL OR len=0 THEN RETURN[NIL];
WITH base
SELECT
FROM
x:
REF RunsBody.base => {
rem: INT;
IF (rem ← TbaseSize[x]-start) <= len THEN
IF start = 0 THEN RETURN [base] ELSE len ← rem;
};
x:
REF RunsBody.node.substr => {
rem: INT;
IF (rem ← CheckLongSub[x.size, start]) <= len THEN
IF start = 0 THEN RETURN [base] ELSE len ← rem;
start ← start + x.start; base ← x.base; LOOP;
};
x:
REF RunsBody.node.concat => {
xpos, rem: INT;
IF (rem ← CheckLongSub[x.size, start]) <= len THEN
IF start = 0 THEN RETURN [base] ELSE len ← rem;
IF start >= (xpos ← x.pos)
THEN {
start ← start - xpos; base ← x.rest; LOOP
};
IF xpos >= start+len THEN {base ← x.base; LOOP};
};
x:
REF RunsBody.node.replace => {
xstart, xnew, rem: INT;
IF (rem ← CheckLongSub[x.size, start]) <= len THEN
IF start = 0 THEN RETURN [base] ELSE len ← rem;
IF start >= (xnew ← x.newPos)
THEN {
start ← start - xnew + x.oldPos; base ← x.base; LOOP
};
IF (rem ← start+len) <= (xstart ← x.start)
THEN {
base ← x.base; LOOP
};
IF start >= xstart
AND rem <= xnew
THEN {
start ← start - xstart; base ← x.replace; LOOP
};
};
x:
REF RunsBody.node.change => {
xstart: INT ← x.start;
xend: INT ← xstart+x.len;
IF start >= xend
OR start+len <= xstart
THEN {
base ← x.base; LOOP
};
};
ENDCASE => ERROR;
IF (new ← TryFlatSubstr[base, start, len]) # NIL THEN RETURN;
EXIT;
ENDLOOP;
IF base=NIL THEN ERROR;
RETURN [NEW[Tsubstr ← [node[substr[len, base, start]]]]];
};
TryFlatSubstr:
PUBLIC
PROC [base: Runs, start, len:
INT, limit:
INT ← FlatMax]
RETURNS [BaseRuns] = {
-- return NIL if couldn't flatten
count: INT;
numruns: NAT;
flat: BaseRuns;
[count, , ] ← CountRuns[base, start, len, limit];
IF count > limit THEN RETURN [NIL];
flat ← NewBase[numruns𡤌ount];
IF ExtractRuns[flat, base, start, len] # numruns THEN ERROR;
IF flat[numruns-1].after # len THEN ERROR;
RETURN [flat];
};
Flatten:
PUBLIC
PROC [base: Runs]
RETURNS [new: Runs] = {
size, half: INT;
IF base=NIL THEN RETURN [NIL];
WITH base
SELECT
FROM
x: REF RunsBody.base => RETURN [x]; -- already flat
ENDCASE => NULL;
new ← TryFlatSubstr[base, 0, Size[base], 8000];
IF new#NIL THEN RETURN; -- else was too big to flatten in one piece
half ← (size ← Size[base])/2; -- flatten the halves
RETURN [Concat[
Flatten[Substr[base, 0, half]],
Flatten[Substr[base, half, size]],
half,
size-half]];
};
Concat:
PUBLIC
PROC [base, rest: Runs, baseLen, restLen:
INT]
RETURNS [new: Runs] =
TRUSTED {
c, numRuns, size, flatLen: INT;
split: NAT;
merge: BOOL;
looks: Looks;
IF base=NIL AND rest=NIL THEN RETURN[NIL];
IF restLen=0 THEN RETURN [base];
IF baseLen=0 THEN RETURN [rest];
size ← baseLen+restLen;
[numRuns, merge, looks] ← CountRuns[base, 0, baseLen, FlatMax];
IF numRuns <= FlatMax
THEN {
-- try flattening base
IF (new ← TryFlatConcatRest[base, rest, baseLen, restLen,
numRuns, merge, looks]) # NIL THEN RETURN;
otherwise try to break up rest
IF rest #
NIL
THEN
WITH rest
SELECT
FROM
x:
REF RunsBody.node.concat => {
-- try to combine base & rest.base
[c, , ] ← CountRuns[x.base, 0, x.pos, FlatMax-numRuns, merge, looks];
IF (numRuns ← numRuns+c) <= FlatMax
THEN {
-- flatten
numruns: NAT;
flat: BaseRuns ← NewBase[numruns←numRuns];
split ← ExtractRuns[flat, base, 0, baseLen];
IF ExtractRuns[flat, x.base, 0, x.pos, split] # numruns
THEN ERROR;
flatLen ← baseLen+x.pos;
IF flat[numruns-1].after # flatLen THEN ERROR;
RETURN[
NEW[Tconcat ← [node[concat
[size, flat, x.rest, flatLen]]]]]
}
};
ENDCASE => NULL;
};
IF base #
NIL
THEN
WITH base
SELECT
FROM
x:
REF RunsBody.node.concat => {
-- try to combine base.rest & rest
baseRestLen: INT ← baseLen-x.pos;
[numRuns, merge, looks] ← CountRuns[x.rest, 0, baseRestLen, FlatMax];
IF numRuns <= FlatMax
THEN {
[c, , ] ← CountRuns[rest, 0, restLen, FlatMax-numRuns, merge, looks];
IF (numRuns ← numRuns+c) <= FlatMax
THEN {
-- flatten
numruns: NAT;
flat: BaseRuns ← NewBase[numruns←numRuns];
split ← ExtractRuns[flat, x.rest, 0, baseRestLen];
IF ExtractRuns[flat, rest, 0, restLen, split] # numruns
THEN ERROR;
IF flat[numruns-1].after # baseRestLen+restLen THEN ERROR;
RETURN[
NEW[Tconcat ← [node[concat
[size, x.base, flat, x.pos]]]]]
}
}
};
x:
REF RunsBody.node.substr => {
see if doing concat of adjacent substr's
WITH rest
SELECT
FROM
y:
REF RunsBody.node.substr => {
see if adjacent to x
IF x.base = y.base AND x.start+x.size = y.start THEN -- join them
RETURN[
NEW[Tsubstr ←
[node[substr[size, x.base, x.start]]]]];
};
ENDCASE => NULL;
};
ENDCASE => NULL;
IF base=NIL THEN base ← MakeRun[baseLen];
IF rest=NIL THEN rest ← MakeRun[restLen];
RETURN[NEW[Tconcat ← [node[concat[size, base, rest, baseLen]]]]];
};
TryFlatConcat:
PUBLIC
PROC [base, rest: Runs, baseLen, restLen:
INT]
RETURNS [new: BaseRuns] = {
-- returns NIL if too big to flatten
numRuns: INT;
merge: BOOL;
looks: Looks;
[numRuns, merge, looks] ← CountRuns[base, 0, baseLen, FlatMax];
IF numRuns > FlatMax THEN RETURN [NIL];
RETURN [TryFlatConcatRest[base, rest, baseLen, restLen, numRuns, merge, looks]];
};
TryFlatConcatRest:
PUBLIC
PROC [base, rest: Runs, baseLen, restLen, numRuns:
INT, merge:
BOOL, looks: Looks]
RETURNS [BaseRuns] = {
-- returns NIL if too big to flatten
c: INT;
split, numruns: NAT;
flat: BaseRuns;
[c, , ] ← CountRuns[rest, 0, restLen, FlatMax-numRuns, merge, looks];
IF (numRuns ← numRuns+c) > FlatMax THEN RETURN [NIL];
flat ← NewBase[numruns←numRuns];
split ← ExtractRuns[flat, base, 0, baseLen];
IF ExtractRuns[flat, rest, 0, restLen, split] # numruns THEN
ERROR;
IF flat[numruns-1].after # baseLen+restLen THEN ERROR;
RETURN [flat];
};
Replace:
PUBLIC
PROC [base: Runs, start, len:
INT, replace: Runs, baseSize, repSize:
INT, tryFlat:
BOOL ←
TRUE]
RETURNS [new: Runs] = {
oldPos, newPos, size: INT;
IF base=NIL AND replace=NIL THEN RETURN [NIL];
oldPos ← start+len;
newPos ← start+repSize;
size ← baseSize-len+repSize;
IF repSize=0 THEN -- deleting
IF base=NIL OR (start=0 AND len=baseSize) THEN RETURN[NIL]
ELSE IF len=0 THEN RETURN[base];
IF tryFlat
THEN {
merge: BOOL ← FALSE;
flat: BaseRuns;
looks: Looks;
c, numRuns: INT;
split, numruns: NAT;
Count:
PROC [r: Runs, start, len:
INT]
RETURNS [
INT] =
TRUSTED {
IF len=0 THEN RETURN[numRuns];
[c, merge, looks] ← CountRuns[r, start, len, FlatMax-numRuns, merge, looks];
RETURN [numRuns←numRuns+c]
};
Extract:
PROC [r: Runs, start, len:
INT] =
TRUSTED {
IF len > 0 THEN split ← ExtractRuns[flat, r, start, len, split]
};
numRuns ← 0;
IF Count[base, 0, start] <= FlatMax AND
Count[replace, 0, repSize] <= FlatMax AND
Count[base, oldPos, baseSize-oldPos] <= FlatMax
THEN {
flat ← NewBase[numruns←numRuns]; split ← 0;
Extract[base, 0, start]; Extract[replace, 0, repSize];
Extract[base, oldPos, baseSize-oldPos];
IF split # numruns THEN ERROR;
IF flat[numruns-1].after # size THEN ERROR;
RETURN [flat]
}
};
WHILE base #
NIL
DO
WITH base
SELECT
FROM
x:
REF RunsBody.node.replace => {
xnewPos: INT ← x.newPos;
xstart: INT ← x.start;
xsize: INT;
IF start <= xstart
AND oldPos >= xnewPos
THEN {
replacing the replacement
oldPos ← x.oldPos+(oldPos-xnewPos); len ← oldPos-start;
base ← x.base; LOOP
}
ELSE IF repSize = 0 AND start > xstart AND
oldPos = xnewPos AND -- deleting end of prior replacement
(new ← TryFlatSubstr[x.replace, 0, start-xstart])#
NIL
THEN {
newPos ← start; oldPos ← x.oldPos; start ← xstart;
replace ← new; base ← x.base
}
ELSE IF repSize = 0 AND start = xstart AND
oldPos < xnewPos AND -- deleting start of prior replacement
(new ← TryFlatSubstr[x.replace, len, xnewPos-oldPos])#
NIL
THEN {
newPos ← start+xnewPos-oldPos; oldPos ← x.oldPos;
replace ← new; base ← x.base
}
ELSE IF start = xnewPos AND -- replacing just after prior replacement
(new ← TryFlatConcat[x.replace, replace, xsize←xnewPos-xstart, repSize])#
NIL
len ← len+x.oldPos-xstart; oldPos ← start+len;
repSize ← xsize+repSize; newPos ← start+repSize;
replace ← new; base ← x.base; LOOP
}
ELSE IF start+len = xstart AND -- replacing just before prior replacement
(new ← TryFlatConcat[replace, x.replace, repSize, xsize←xnewPos-xstart])#
NIL
THEN {
len ← len+x.oldPos-xstart; oldPos ← start+len;
repSize ← xsize+repSize; newPos ← start+repSize;
replace ← new; base ← x.base; LOOP
}
};
x:
REF RunsBody.node.concat => {
xpos: INT ← x.pos;
IF start=xpos
AND len=0
THEN {
-- insert between base&rest
first try concat of x.base&replacement
IF (new ← TryFlatConcat[x.base, replace, xpos, repSize])#
NIL
THEN
RETURN [
NEW[Tconcat ←
[node[concat[size, new, x.rest, xpos+repSize]]]]];
otherwise try concat of replacement&x.rest
IF (new ← TryFlatConcat[replace, x.rest, repSize, x.size-xpos])#
NIL
THEN
RETURN [
NEW[Tconcat ←
[node[concat[size, x.base, new, x.pos]]]]]
}
};
ENDCASE => NULL;
EXIT;
ENDLOOP;
IF base=NIL THEN base ← MakeRun[baseSize];
IF replace=NIL THEN replace ← MakeRun[repSize];
RETURN [NEW[Treplace ← [node[replace[size, base, replace, start, oldPos, newPos]]]]];
};
Copy:
PUBLIC
PROC [dest: Runs, destLoc:
INT, source: Runs, start, len, destSize:
INT]
RETURNS [Runs] = {
merge: BOOL ← FALSE;
flat: BaseRuns;
looks: Looks;
c, numRuns: INT;
split, numruns: NAT;
Count:
PROC [base: Runs, start, len:
INT]
RETURNS [
INT] = {
IF len=0 THEN RETURN[numRuns];
[c, merge, looks] ← CountRuns[base, start, len, FlatMax-numRuns, merge, looks];
RETURN [numRuns←numRuns+c]
};
Extract:
PROC [base: Runs, start, len:
INT] = {
IF len > 0 THEN split ← ExtractRuns[flat, base, start, len, split]
};
IF dest=NIL AND source=NIL THEN RETURN[NIL];
numRuns ← 0;
IF Count[dest, 0, destLoc] > FlatMax OR
Count[source, start, len] > FlatMax OR
Count[dest, destLoc, destSize-destLoc] > FlatMax
THEN
RETURN [
Replace[dest, destLoc, 0, Substr[source, start, len], destSize, len, FALSE]];
IF numRuns=0 THEN RETURN [NIL];
flat ← NewBase[numruns←numRuns]; split ← 0;
Extract[dest, 0, destLoc]; Extract[source, start, len];
Extract[dest, destLoc, destSize-destLoc];
IF split # numruns THEN ERROR;
IF flat[numruns-1].after # destSize+len THEN ERROR;
RETURN [flat];
};