Merge provides functions to build custom 3-way merge operators for various user-defined contents.
An 'a promise is a function which, when called, will eventually return a value type of 'a. A promise is an optional, lazy and non-blocking value.
val promise : 'a -> 'a promisepromise a is the promise containing a.
promise_map f a is the promise containing f applied to what is promised by a.
promise_bind a f is the promise returned by f applied to what is promised by a.
Signature of a merge function. old is the value of the least-common ancestor.
/----> t1 ----\
----> old |--> result
\----> t2 ----/Call the merge functions in sequence. Stop as soon as one is not returning a conflict.
The apply combinator is useful to untie recursive loops when building a complex merge function.
Use the merge function defined in another domain. If the converting functions raise any exception the merge is a conflict.
Same as biject but with blocking domain converting functions.
Create a default merge function. This is a simple merge function which supports changes in one branch at a time:
t1=t2 then the result of the merge is `OK t1;t1=old then the result of the merge is `OK t2;t2=old then return `OK t1;`Conflict.val string : string tThe default string merge function. Do not do anything clever, just compare the strings using the default merge function.
Lift a merge function to optional values of the same type. If all the provided values are inhabited, then call the provided merge function, otherwise use the same behavior as default.
Lift merge functions to pair of elements.
Lift merge functions to triple of elements.
The type for counter values. It is expected that the only valid operations on counters are increment and decrement. The following merge functions ensure that the counter semantics are preserved: i.e. it ensures that the number of increments and decrements is preserved.
val counter : int tThe merge function for mergeable counters.
We consider the only valid operations for maps and association lists to be:
We thus assume that no operation on maps is modifying the key names. So the following merge functions ensures that (i) new bindings are preserved (ii) removed bindings stay removed and (iii) modified bindings are merged using the merge function of values.
Note: We only consider sets of bindings, instead of multisets. Application developers should take care of concurrent addition and removal of similar bindings themselves, by using the appropriate multi-sets.
Lift the merge functions to association lists.
Lift the merge functions to maps.
module OP : sig ... endUseful merge operators.