package monolith

Changes

2021/05/25

• Fix a bug where the exception PleaseBackOff was unintendedly caught by the combinator ^!> and therefore did not work as intended. (Reported and fixed by Nicolas Osborne.)

2020/10/26

• The functions declare_concrete_type, &&& and &&@ disappear. They are replaced with two new combinators, constructible and deconstructible. The combinator ifpol (described further on) can be used to construct a specification that is both constructible and deconstructible. The idiom int &&& range is replaced with int_within range.

• The function declare_abstract_type no longer requires the type's name as an argument; it takes a unit argument instead.

• The arrow combinator ^^> is renamed ^>. The dependent arrow combinator ^&> is renamed ^>>.

• New specification combinator ^!>. This combinator describes a function that can raise an exception, and requires the reference implementation and the candidate implementation to raise exactly the same exception.

• New specification combinator ^?>. This combinator describes a nondeterministic function. spec1 ^?> spec2 is a short-hand for spec1 ^> nondet spec2.

• New specification combinator ^!?>. This combinator describes a function that can raise an exception, and can decide in a nondeterministic way whether it wishes to raise an exception and what exception it wishes to raise. The reference implementation is allowed to observe this behavior and to react accordingly.

• New specification combinators ^!>>, ^?>>, and ^!?>>. These are the dependent variants of the previous three combinators.

• New specification combinators option, result, and list. These combinators make it easy to describe an operation that expects or returns an option, a result, or a list.

• New specification combinator declare_seq. This (effectful) combinator makes it relatively easy to describe an operation that expects or returns a sequence.

• New specification combinator map_into. This combinator is typically used to wrap an operation or to transform the result of an operation.

• New specification combinator map_outof. This combinator is typically used to construct an argument to an operation via a transformation.

• Removed the combinator map, whose type was fishy.

• New specification combinators rot2 and rot3. (rot2 is also known as flip.) These combinators move a distant argument to the front. This is useful when a dependency between arguments runs contrary to the order of the arguments. These combinators can be used only in a positive position.

• New specification combinators curry and uncurry. These combinators transform a function that expects a pair into a function that expects two separate arguments, and vice-versa. These combinators can be used only in a positive position.

• New specification combinator ignored. This combinator is used to describe the output (or part of the output) of an operation, and indicates that this output should be ignored.

• Changed the type of the specification combinator nondet. Removed the limitation that this combinator can be applied only to a concrete type.

• New specification constant exn. The new function override_exn_eq allows overriding the notion of equality that is associated with the concrete type exn. This is useful when the reference implementation and candidate implementation raise different exceptions.

• New specification combinator ifpol, which allows distinguishing between negative and positive occurrences in a specification. This low-level combinator can be useful in the definition of higher-level abstractions.

• New specification combinator fix, which allows building recursive specifications.

• New specification combinator abstract, which declares an abstract type on the fly, together with a conversion operation out of this abstract type to its concrete definition. This can be used to deal with functions that return functions.

• New exception PleaseBackOff, which the reference implementation is allowed to raise when an operation (or some particular case of an operation) is illegal or is not implemented. This causes the Monolith engine to silently ignore this scenario. No side effects must be performed by the reference implementation before raising this exception.

• New exception Unimplemented, which the candidate implementation is allowed to raise when an operation (or some particular case of an operation) is not implemented. This causes the Monolith engine to silently ignore this scenario.

• New definition of the type 'a code as a synonym for 'a * appearance. New constructors for the type appearance, including constant, document, and infix.

• The functions interval and interval_ are renamed semi_open_interval and closed_interval.

• Significant internal changes, leading to simpler and possibly faster code.

• The file Makefile.monolith is now installed with the library, so it need no longer be copied into one's project, unless one wishes to adapt it.

• In Makefile.monolith, new entries make multicore and make tmux, both of which implement parallel fuzzing with multiple afl-fuzz processes.

• In Makefile.monolith, new entry make random, which implements random testing.

• On 64-bit machines, the function bits did not generate the full range of 63-bit integers; it was inadvertently limited to 32-bit integers. A number of other functions that depend on it, such as interval, were also wrong. Fixed (hopefully).

2020/06/09

• Initial release.