Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

QCheck2.Gen: enforce naming consistency #223

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
+323 −124
Open

QCheck2.Gen: enforce naming consistency #223

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
91 changes: 56 additions & 35 deletions src/core/QCheck2.ml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -266,12 +266,14 @@ module Gen = struct
else if origin > high then invalid_arg Format.(asprintf "%s: origin value %a is greater than high value %a" loc pp origin pp high)
else origin

let small_nat : int t = fun st ->
let nat_small : int t = fun st ->
let p = RS.float st 1. in
let x = if p < 0.75 then RS.int st 10 else RS.int st 100 in
let shrink a = fun () -> Shrink.int_towards 0 a () in
Tree.make_primitive shrink x

let small_nat = nat_small

(** Natural number generator *)
let nat : int t = fun st ->
let p = RS.float st 1. in
Expand All @@ -284,14 +286,16 @@ module Gen = struct
let shrink a = fun () -> Shrink.int_towards 0 a () in
Tree.make_primitive shrink x

let big_nat : int t = fun st ->
let nat_big : int t = fun st ->
let p = RS.float st 1. in
if p < 0.75
then nat st
else
let shrink a = fun () -> Shrink.int_towards 0 a () in
Tree.make_primitive shrink (RS.int st 1_000_000)

let big_nat = nat_big

let unit : unit t = fun _st -> Tree.pure ()

let bool : bool t = fun st ->
Expand All @@ -307,9 +311,13 @@ module Gen = struct
let shrink a = fun () -> Shrink.float_towards 0. a () in
Tree.make_primitive shrink x

let pfloat : float t = float >|= abs_float
let float_pos : float t = float >|= abs_float

let pfloat = float_pos

let float_neg : float t = float_pos >|= Float.neg

let nfloat : float t = pfloat >|= Float.neg
let nfloat = float_neg

let float_bound_inclusive ?(origin : float = 0.) (bound : float) : float t = fun st ->
let (low, high) = Float.min_max_num 0. bound in
Expand Down Expand Up @@ -353,15 +361,20 @@ module Gen = struct

let (--.) low high = float_range ?origin:None low high

let neg_int : int t = nat >|= Int.neg
let int_neg : int t = nat >|= Int.neg

(** [opt gen] shrinks towards [None] then towards shrinks of [gen]. *)
let opt ?(ratio : float = 0.85) (gen : 'a t) : 'a option t = fun st ->
let neg_int = int_neg

let option_ratio ~ratio (gen : 'a t) : 'a option t = fun st ->
jmid marked this conversation as resolved.
Show resolved Hide resolved
let p = RS.float st 1. in
if p < (1. -. ratio)
then Tree.pure None
else Tree.opt (gen st)

let option gen = option_ratio ~ratio:0.85 gen

let opt ?(ratio = 0.85) = option_ratio ~ratio
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Does this compile without the dreaded "this-optional-argument-is-not-so-option" warning/error?
(I realize it is curried, so that option_ratio will expect a later gen argument)

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I did not have the warning but I will double check. But I think the gen argument should prevent the warning yes.


(* Uniform positive random int generator.
We can't use {!RS.int} because the upper bound must be positive and is excluded,
Expand Down Expand Up @@ -399,14 +412,16 @@ module Gen = struct
let right = RS.bits st in
left lor middle lor right

let pint ?(origin : int = 0) : int t = fun st ->
let nat_origin origin : int t = fun st ->
let x = pint_raw st in
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I suggest renaming pint_raw to nat_pos_raw while we are at it.
I know it isn't visible from the outside, however using the naming principles internally should make reading the implementation easier for ourselves and others going forward.

let shrink a = fun () ->
let origin = parse_origin "Gen.pint" Format.pp_print_int ~origin ~low:0 ~high:max_int in
let origin = parse_origin "Gen.nat_origin" Format.pp_print_int ~origin ~low:0 ~high:max_int in
Shrink.int_towards origin a ()
in
Tree.make_primitive shrink x

let pint ?(origin = 0) = nat_origin origin

let number_towards = Shrink.number_towards

let int_towards = Shrink.int_towards
Expand All @@ -420,15 +435,15 @@ module Gen = struct
let int : int t =
bool >>= fun b ->
if b
then pint ~origin:0 >|= (fun n -> - n - 1)
else pint ~origin:0
then nat_origin 0 >|= (fun n -> - n - 1)
else nat_origin 0

let int_bound (n : int) : int t =
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

For consistency, should this really be called nat_bound? 😬

if n < 0 then invalid_arg "Gen.int_bound";
fun st ->
if n <= (1 lsl 30) - 2
then Tree.make_primitive (fun a () -> Shrink.int_towards 0 a ()) (RS.int st (n + 1))
else Tree.map (fun r -> r mod (n + 1)) (pint st)
else Tree.map (fun r -> r mod (n + 1)) (nat st)
Copy link
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think suspect this renaming introduces a bug: the else branch handles n bigger than 30-bit,
which will then need the old pint (now: nat_origin) to stitch together 3 calls.
Using plain nat outputs max 10.000 though. A statistics test should reveal the change in distribution!
This would be a good opportunity to add it 😀


(** To support ranges wider than [Int.max_int], the general idea is to find the center,
and generate a random half-difference number as well as whether we add or
Expand Down Expand Up @@ -467,20 +482,20 @@ module Gen = struct
let oneof (l : 'a t list) : 'a t =
int_range 0 (List.length l - 1) >>= List.nth l

let oneofl (l : 'a list) : 'a t =
let oneof_l (l : 'a list) : 'a t =
int_range 0 (List.length l - 1) >|= List.nth l
let oneofl = oneof_l

let oneofa (a : 'a array) : 'a t =
let oneof_a (a : 'a array) : 'a t =
int_range 0 (Array.length a - 1) >|= Array.get a
let oneofa = oneof_a

(* NOTE: we keep this alias to not break code that uses [small_int]
for sizes of strings, arrays, etc. *)
let small_int = small_nat

let small_signed_int : int t = fun st ->
let int_small : int t = fun st ->
if RS.bool st
then small_nat st
else (small_nat >|= Int.neg) st
then nat_small st
else (nat_small >|= Int.neg) st

let small_signed_int = int_small

(** Shrink towards the first element of the list *)
let frequency (l : (int * 'a t) list) : 'a t =
Expand All @@ -495,11 +510,13 @@ module Gen = struct
in
aux 0 l

let frequencyl (l : (int * 'a) list) : 'a t =
let frequency_l (l : (int * 'a) list) : 'a t =
List.map (fun (weight, value) -> (weight, pure value)) l
|> frequency
let frequencyl = frequency_l

let frequencya a = frequencyl (Array.to_list a)
let frequency_a a = frequencyl (Array.to_list a)
let frequencya = frequency_a

let char_range ?(origin : char option) (a : char) (b : char) : char t =
(int_range ~origin:(Char.code (Option.value ~default:a origin)) (Char.code a) (Char.code b)) >|= Char.chr
Expand All @@ -519,15 +536,11 @@ module Gen = struct
let shrink a = fun () -> Shrink.int32_towards 0l a () in
Tree.make_primitive shrink x

let ui32 : int32 t = map Int32.abs int32

let int64 : int64 t = fun st ->
let x = random_binary_string 64 st |> Int64.of_string in
let shrink a = fun () -> Shrink.int64_towards 0L a () in
Tree.make_primitive shrink x

let ui64 : int64 t = map Int64.abs int64

(* A tail-recursive implementation over Tree.t *)
let list_size (size : int t) (gen : 'a t) : 'a list t =
fun st ->
Expand Down Expand Up @@ -561,7 +574,7 @@ module Gen = struct
let flatten_opt (o : 'a t option) : 'a option t =
match o with
| None -> pure None
| Some gen -> opt gen
| Some gen -> option gen

let flatten_res (res : ('a t, 'e) result) : ('a, 'e) result t =
match res with
Expand Down Expand Up @@ -644,15 +657,19 @@ module Gen = struct
(* Put alphabet first for shrinking *)
List.flatten [lower_alphabet; before_lower_alphabet; after_lower_alphabet; newline]

let printable : char t =
let char_printable : char t =
int_range ~origin:0 0 (List.length printable_chars - 1)
>|= List.nth printable_chars

let numeral : char t =
let printable = char_printable

let char_numeral : char t =
let zero = 48 in
let nine = 57 in
int_range ~origin:zero zero nine >|= char_of_int

let numeral = char_numeral

let bytes_size ?(gen = char) (size : int t) : bytes t = fun st ->
let open Tree in
size st >>= fun size ->
Expand Down Expand Up @@ -683,13 +700,16 @@ module Gen = struct

let string_of gen = string_size ~gen nat

let string_printable = string_size ~gen:printable nat
let string_printable = string_size ~gen:char_printable nat

let small_string ?gen st = string_size ?gen small_nat st
let string_small ?gen st = string_size ?gen nat_small st
let small_string = string_small

let small_list gen = list_size small_nat gen
let list_small gen = list_size nat_small gen
let small_list = list_small

let small_array gen = array_size small_nat gen
let array_small gen = array_size nat_small gen
let small_array = array_small

let join (gen : 'a t t) : 'a t = gen >>= Fun.id

Expand All @@ -704,7 +724,8 @@ module Gen = struct

let int_corners = int_pos_corners @ [min_int]

let small_int_corners () : int t = graft_corners nat int_pos_corners ()
let int_small_corners () : int t = graft_corners nat int_pos_corners ()
let small_int_corners = int_small_corners

(* sized, fix *)

Expand Down
Loading