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(* Title: Pure/General/alist.ML
Author: Florian Haftmann, TU Muenchen
Association lists -- lists of (key, value) pairs.
*)
signature ALIST =
sig
exception DUP
val lookup: ('a * 'b -> bool) -> ('b * 'c) list -> 'a -> 'c option
val defined: ('a * 'b -> bool) -> ('b * 'c) list -> 'a -> bool
val update: ('a * 'a -> bool) -> ('a * 'b)
-> ('a * 'b) list -> ('a * 'b) list
val default: ('a * 'a -> bool) -> ('a * 'b)
-> ('a * 'b) list -> ('a * 'b) list
val delete: ('a * 'b -> bool) -> 'a
-> ('b * 'c) list -> ('b * 'c) list
val map_entry: ('a * 'b -> bool) -> 'a -> ('c -> 'c)
-> ('b * 'c) list -> ('b * 'c) list
val map_entry_yield: ('a * 'b -> bool) -> 'a -> ('c -> 'd * 'c)
-> ('b * 'c) list -> 'd option * ('b * 'c) list
val map_default: ('a * 'a -> bool) -> 'a * 'b -> ('b -> 'b)
-> ('a * 'b) list -> ('a * 'b) list
val join: ('a * 'a -> bool) -> ('a -> 'b * 'b -> 'b) (*exception DUP*)
-> ('a * 'b) list * ('a * 'b) list -> ('a * 'b) list (*exception DUP*)
val merge: ('a * 'a -> bool) -> ('b * 'b -> bool)
-> ('a * 'b) list * ('a * 'b) list -> ('a * 'b) list (*exception DUP*)
val make: ('a -> 'b) -> 'a list -> ('a * 'b) list
val find: ('a * 'b -> bool) -> ('c * 'b) list -> 'a -> 'c list
val coalesce: ('a * 'a -> bool) -> ('a * 'b) list -> ('a * 'b list) list
(*coalesce ranges of equal neighbour keys*)
val group: ('a * 'a -> bool) -> ('a * 'b) list -> ('a * 'b list) list
end;
structure AList: ALIST =
struct
fun find_index eq xs key =
let
fun find [] _ = ~1
| find ((key', value)::xs) i =
if eq (key, key')
then i
else find xs (i+1);
in find xs 0 end;
fun map_index eq key f_none f_some xs =
let
val i = find_index eq xs key;
fun mapp 0 (x::xs) = f_some x xs
| mapp i (x::xs) = x :: mapp (i-1) xs;
in (if i = ~1 then f_none else mapp i) xs end;
fun lookup _ [] _ = NONE
| lookup eq ((key, value)::xs) key' =
if eq (key', key) then SOME value
else lookup eq xs key';
fun defined _ [] _ = false
| defined eq ((key, value)::xs) key' =
eq (key', key) orelse defined eq xs key';
fun update eq (x as (key, value)) =
map_index eq key (cons x) (fn _ => cons x);
fun default eq (key, value) xs =
if defined eq xs key then xs else (key, value) :: xs;
fun delete eq key =
map_index eq key I (K I);
fun map_entry eq key f =
map_index eq key I (fn (key, value) => cons (key, f value));
fun map_default eq (key, value) f =
map_index eq key (cons (key, f value)) (fn (key, value) => cons (key, f value));
fun map_entry_yield eq key f xs =
let
val i = find_index eq xs key;
fun mapp 0 ((x as (key, value))::xs) =
let val (r, value') = f value
in (SOME r, (key, value') :: xs) end
| mapp i (x::xs) =
let val (r, xs') = mapp (i-1) xs
in (r, x::xs') end;
in if i = ~1 then (NONE, xs) else mapp i xs end;
exception DUP;
fun join eq f (xs, ys) =
let
fun add (y as (key, value)) xs =
(case lookup eq xs key of
NONE => cons y xs
| SOME value' => update eq (key, f key (value', value)) xs);
in fold_rev add ys xs end;
fun merge eq_key eq_val =
join eq_key (K (fn (yx as (_, x)) => if eq_val yx then x else raise DUP));
fun make keyfun =
let fun keypair x = (x, keyfun x)
in map keypair end;
fun find eq [] _ = []
| find eq ((key, value) :: xs) value' =
let
val values = find eq xs value';
in if eq (value', value) then key :: values else values end;
fun coalesce eq =
let
fun vals _ [] = ([], [])
| vals x (lst as (y, b) :: ps) =
if eq (x, y) then vals x ps |>> cons b
else ([], lst);
fun coal [] = []
| coal ((x, a) :: ps) =
let val (bs, qs) = vals x ps
in (x, a :: bs) :: coal qs end;
in coal end;
fun group eq xs =
fold_rev (fn (k, v) => map_default eq (k, []) (cons v)) xs [];
end;
¤ Dauer der Verarbeitung: 0.21 Sekunden
(vorverarbeitet)
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