GenSourceValues of type 'a Gen.t represent a possibly infinite sequence of values of type 'a. One can only iterate once on the sequence, as it is consumed by iteration/deconstruction/access. None is returned when the generator is exhausted.
The submodule Restart provides utilities to work with restartable generators, that is, functions unit -> 'a Gen.t that allow to build as many generators from the same source as needed.
A generator may be called several times, yielding the next value each time. It returns None when no elements remain
Call the same function an infinite number of times (useful for instance if the function is a random generator).
Operations on transient generators
include S with type 'a t := 'a genDual of fold, with a deconstructing operation. It keeps on unfolding the 'b value into a new 'b, and a 'a which is yielded, until None is returned.
Calls the function, starting from 0, on increasing indices. If limit is provided and is a positive int, iteration will stop at the limit (excluded). For instance init ~limit:4 id will yield 0, 1, 2, and 3.
Note: those combinators, applied to generators (not restartable generators) consume their argument. Sometimes they consume it lazily, sometimes eagerly, but in any case once f gen has been called (with f a combinator), gen shouldn't be used anymore.
Fold on the generator, tail-recursively. Consumes the generator.
Fold on non-empty sequences. Consumes the generator.
Like fold, but keeping successive values of the accumulator. Consumes the generator.
Iterate on elements with their index in the gen, from 0, consuming it.
Lazy map. No iteration is performed now, the function will be called when the result is traversed.
Lazy map with indexing starting from 0. No iteration is performed now, the function will be called when the result is traversed.
Lazy fold and map. No iteration is performed now, the function will be called when the result is traversed. The result is an iterator over the successive states of the fold.
Append the two gens; the result contains the elements of the first, then the elements of the second gen.
Flatten the generator of generators
Monadic bind; each element is transformed to a sub-gen which is then iterated on, before the next element is processed, and so on.
Is the given element, member of the gen?
take_nth n g returns every element of g whose index is a multiple of n. For instance take_nth 2 (1--10) |> to_list will return 1;3;5;7;9
Filter out elements that do not satisfy the predicate.
Take elements while they satisfy the predicate. The initial generator itself is not to be used anymore after this.
Fold elements until ('a, `Stop) is indicated by the accumulator.
Drop elements while they satisfy the predicate. The initial generator itself should not be used anymore, only the result of drop_while.
Maps some elements to 'b, drop the other ones
partition p l returns the elements that satisfy p, and the elements that do not satisfy p
Minimum element, according to the given comparison function.
Lexicographic comparison of generators. If a generator is a prefix of the other one, it is considered smaller.
find p e returns the first element of e to satisfy p, or None.
Map on the two sequences. Stops once one of them is exhausted.
Iterate on the two sequences. Stops once one of them is exhausted.
Fold the common prefix of the two iterators
Succeeds if all pairs of elements satisfy the predicate. Ignores elements of an iterator if the other runs dry.
Succeeds if some pair of elements satisfy the predicate. Ignores elements of an iterator if the other runs dry.
Combine common part of the gens (stops when one is exhausted)
Pick elements fairly in each sub-generator. The merge of gens e1, e2, ... picks elements in e1, e2, in e3, e1, e2 .... Once a generator is empty, it is skipped; when they are all empty, and none remains in the input, their merge is also empty. For instance, merge [1;3;5] [2;4;6] will be, in disorder, 1;2;3;4;5;6.
Intersection of two sorted sequences. Only elements that occur in both inputs appear in the output
Merge two sorted sequences into a sorted sequence
Sorted merge of multiple sorted sequences
Duplicate the gen into n generators (default 2). The generators share the same underlying instance of the gen, so the optimal case is when they are consumed evenly
Split the gen into n generators in a fair way. Elements with index = k mod n with go to the k-th gen. n default value is 2.
interleave a b yields an element of a, then an element of b, and so on. When a generator is exhausted, this behaves like the other generator.
Put the separator element between all elements of the given gen
Cartesian product, in no predictable order. Works even if some of the arguments are infinite.
Group equal consecutive elements together.
Remove consecutive duplicate elements. Basically this is like fun e -> map List.hd (group e).
Sort according to the given comparison function. The gen must be finite.
Sort and remove duplicates. The gen must be finite.
chunks n e returns a generator of arrays of length n, composed of successive elements of e. The last array may be smaller than n
Permutations of the gen, using Heap's algorithm.
Combinations of given length. The ordering of the elements within each combination is unspecified. Example (ignoring ordering): combinations 2 (1--3) |> to_list = [[1;2]; [1;3]; [2;3]]
Tail call conversion to list, in reverse order (more efficient)
Iterate on (a slice of) the given array
int_range ~step a b generates integers between a and b, included, with steps of length step (1 if omitted). a is assumed to be smaller than b, otherwise the result will be empty.
Explode lines into their chars, adding a '\n' after each one
Monadic bind operator
val pp :
?start:string ->
?stop:string ->
?sep:string ->
?horizontal:bool ->
(Format.formatter -> 'a -> unit) ->
Format.formatter ->
'a gen ->
unitPretty print the content of the generator on a formatter.
A restartable generator is a function that produces copies of the same generator, on demand. It has the type unit -> 'a gen and it is assumed that every generated returned by the function behaves the same (that is, that it traverses the same sequence of elements).
Store content of the transient generator in memory, to be able to iterate on it several times later. If possible, consider using combinators from Restart directly instead.
Same as persistent, but consumes the generator on demand (by chunks). This allows to make a restartable generator out of an ephemeral one, without paying a big cost upfront (nor even consuming it fully). Optional parameters: see GenMList.of_gen_lazy.
Same as persistent, but returns a standard Seq.
Same as persistent_lazy, but returns a standard Seq.
peek g transforms the generator g into a generator of x, Some next if x was followed by next in g, or x, None if x was the last element of g
peek_n n g iterates on g, returning along with each element the array of the (at most) n elements that follow it immediately
Very basic interface to manipulate files as sequence of chunks/lines.