relations
ancestry: of commits, a partial order
C > D C is a descendant of D
inclusion: commit includes change made in another
a partial order, consistent with ancestry but more partial
C has D <=> D isin C
C has D => C > D
define convenience function
cont(C) := { Cx | Cx isin C }
patches
patch P is two sets Px of commits, Ptip and Pbase
each subset has a single ur-ancestor C0_Ptip resp C0_Pbase
all these subsets Ptip,Qbase,Rtip,Sbase mutually exclusive
P(C) is either Ptip, Pbase, or nil (recorded in commit)
commits fall into three categories wrt P
inpatch(P,C) = included
P included in C
\forall D \elem Ptip, C has D <=> C > D
inpatch(P,C) = absent
P absent from C
\forall D \elem Ptip, !(C has D)
inpatch(P,C) = removed
P removed from C
cont(C) \intersection Ptip = { }
but maybe \exists Cx \elem Ptip s.t. Cx < C
the ends E(C,Px) of Px = Pbase or Ptip are
every maximal Ce < C in Px
ie every Ce for which
C > Ce and !\exists C s.t. C > Ce
existence of corresponding base B for every tip commit C
\forall C s.t. P(C) = Ptip
\exists B s.t. E(C,Pbase) = { B }
resulting function B(C)
contents of tip commits
\forall C s.t. P(c) = Ptip
cont(C) = cont(B(C)) \union { Cp s.t. P(Cp) = Ptip and Cp < C }
non-circularity
\forall B s.t. P(c) = Pbase
cont(B) \notintersect Ptip
normal commits
make C from D
result
C < { D }
P(C) = P(D)
Cx isin C <=> Cx = D v Cx isin D
inpatch(P,C) = inpatch(P,D)
anticommit for removing a patch P from D to make C
make C from D, A-
where
P(C) = Qbase
P(A-) = Ptip
inpatch(P,C) = included
E(D,Ptip) = { A- }
then let
A+ = B(A-)
hence
A+ < A- < D
E(D,Pbase) = { A+ }
result
C >1 { D }
P(C) = P(D)
inpatch(P,C) = removed
single patch dependency application
make C from D, A+
where
P(C) = Qbase
P(A+) = Ptip
inpatch(P,C) != included
then let
A- = B(A+)
hence
A- < A+
result
C >1 { D, A+ } => C > D, C > A+ > A-
P(C) = P(D)
inpatch(P,C) = included
simple merge
make C from L, R, M
where
M < L < C
M < R < C
result
C >1 { L, R }
P(C) = P(L)
if Cx isin L = Cx isin R,
Cx isin C = Cx isin L
otherwise
Cx isin C = ! Cx isin M
cases of inpatch(P,L) and ,R
or Cx isin