src/Pure/library.ML
author wenzelm
Tue Jul 10 23:29:41 2007 +0200 (2007-07-10)
changeset 23718 8ff68cb5860c
parent 23424 d0580634f128
child 23826 463903573934
permissions -rw-r--r--
simplified funpow, untabify;
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(*  Title:      Pure/library.ML
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    ID:         $Id$
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    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
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    Author:     Markus Wenzel, TU Muenchen
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Basic library: functions, options, pairs, booleans, lists, integers,
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strings, lists as sets, orders, current directory, misc.
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See also General/basics.ML for the most fundamental concepts.
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*)
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infix 1 |>>>
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infix 2 ?
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infix 3 o oo ooo oooo
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infix 4 ~~ upto downto
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infix orf andf \ \\ mem mem_int mem_string union union_int
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  union_string inter inter_int inter_string subset subset_int subset_string
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signature BASIC_LIBRARY =
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sig
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  (*functions*)
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  val I: 'a -> 'a
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  val K: 'a -> 'b -> 'a
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  val flip: ('a -> 'b -> 'c) -> 'b -> 'a -> 'c
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  val curry: ('a * 'b -> 'c) -> 'a -> 'b -> 'c
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  val uncurry: ('a -> 'b -> 'c) -> 'a * 'b -> 'c
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  val |>>> : ('a * 'c) * ('a -> 'b * 'd) -> 'b * ('c * 'd)
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  val ? : bool * ('a -> 'a) -> 'a -> 'a
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  val oo: ('a -> 'b) * ('c -> 'd -> 'a) -> 'c -> 'd -> 'b
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  val ooo: ('a -> 'b) * ('c -> 'd -> 'e -> 'a) -> 'c -> 'd -> 'e -> 'b
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  val oooo: ('a -> 'b) * ('c -> 'd -> 'e -> 'f -> 'a) -> 'c -> 'd -> 'e -> 'f -> 'b
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  val funpow: int -> ('a -> 'a) -> 'a -> 'a
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  (*exceptions*)
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  exception EXCEPTION of exn * string
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  val do_transform_failure: bool ref
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  val transform_failure: (exn -> exn) -> ('a -> 'b) -> 'a -> 'b
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  datatype 'a result = Result of 'a | Exn of exn
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  val capture: ('a -> 'b) -> 'a -> 'b result
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  val release: 'a result -> 'a
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  val get_result: 'a result -> 'a option
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  val get_exn: 'a result -> exn option
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  (*errors*)
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  exception SYS_ERROR of string
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  val sys_error: string -> 'a
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  exception ERROR of string
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  val error: string -> 'a
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  val cat_error: string -> string -> 'a
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  val assert_all: ('a -> bool) -> 'a list -> ('a -> string) -> unit
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  (*pairs*)
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  val pair: 'a -> 'b -> 'a * 'b
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  val rpair: 'a -> 'b -> 'b * 'a
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  val fst: 'a * 'b -> 'a
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  val snd: 'a * 'b -> 'b
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  val eq_fst: ('a * 'c -> bool) -> ('a * 'b) * ('c * 'd) -> bool
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  val eq_snd: ('b * 'd -> bool) -> ('a * 'b) * ('c * 'd) -> bool
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  val eq_pair: ('a * 'c -> bool) -> ('b * 'd -> bool) -> ('a * 'b) * ('c * 'd) -> bool
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  val swap: 'a * 'b -> 'b * 'a
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  val apfst: ('a -> 'b) -> 'a * 'c -> 'b * 'c
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  val apsnd: ('a -> 'b) -> 'c * 'a -> 'c * 'b
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  val pairself: ('a -> 'b) -> 'a * 'a -> 'b * 'b
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  (*booleans*)
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  val equal: ''a -> ''a -> bool
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  val not_equal: ''a -> ''a -> bool
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  val orf: ('a -> bool) * ('a -> bool) -> 'a -> bool
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  val andf: ('a -> bool) * ('a -> bool) -> 'a -> bool
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  val exists: ('a -> bool) -> 'a list -> bool
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  val forall: ('a -> bool) -> 'a list -> bool
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  val set: bool ref -> bool
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  val reset: bool ref -> bool
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  val toggle: bool ref -> bool
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  val change: 'a ref -> ('a -> 'a) -> unit
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  val setmp: 'a ref -> 'a -> ('b -> 'c) -> 'b -> 'c
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  (*lists*)
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  exception UnequalLengths
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  val single: 'a -> 'a list
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  val the_single: 'a list -> 'a
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  val singleton: ('a list -> 'b list) -> 'a -> 'b
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  val apply: ('a -> 'a) list -> 'a -> 'a
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  val foldr1: ('a * 'a -> 'a) -> 'a list -> 'a
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  val foldl_map: ('a * 'b -> 'a * 'c) -> 'a * 'b list -> 'a * 'c list
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  val flat: 'a list list -> 'a list
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  val unflat: 'a list list -> 'b list -> 'b list list
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  val burrow: ('a list -> 'b list) -> 'a list list -> 'b list list
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  val fold_burrow: ('a list -> 'c -> 'b list * 'd) -> 'a list list -> 'c -> 'b list list * 'd
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  val maps: ('a -> 'b list) -> 'a list -> 'b list
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  val chop: int -> 'a list -> 'a list * 'a list
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  val dropwhile: ('a -> bool) -> 'a list -> 'a list
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  val nth: 'a list -> int -> 'a
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  val nth_map: int -> ('a -> 'a) -> 'a list -> 'a list
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  val nth_list: 'a list list -> int -> 'a list
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  val map_index: (int * 'a -> 'b) -> 'a list -> 'b list
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  val fold_index: (int * 'a -> 'b -> 'b) -> 'a list -> 'b -> 'b
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  val split_last: 'a list -> 'a list * 'a
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  val find_index: ('a -> bool) -> 'a list -> int
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  val find_index_eq: ''a -> ''a list -> int
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  val find_first: ('a -> bool) -> 'a list -> 'a option
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  val get_index: ('a -> 'b option) -> 'a list -> (int * 'b) option
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  val get_first: ('a -> 'b option) -> 'a list -> 'b option
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  val eq_list: ('a * 'b -> bool) -> 'a list * 'b list -> bool
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  val map2: ('a -> 'b -> 'c) -> 'a list -> 'b list -> 'c list
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  val fold2: ('a -> 'b -> 'c -> 'c) -> 'a list -> 'b list -> 'c -> 'c
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  val zip_options: 'a list -> 'b option list -> ('a * 'b) list
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  val ~~ : 'a list * 'b list -> ('a * 'b) list
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  val split_list: ('a * 'b) list -> 'a list * 'b list
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  val separate: 'a -> 'a list -> 'a list
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  val replicate: int -> 'a -> 'a list
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  val multiply: 'a list -> 'a list list -> 'a list list
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  val product: 'a list -> 'b list -> ('a * 'b) list
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  val filter: ('a -> bool) -> 'a list -> 'a list
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  val filter_out: ('a -> bool) -> 'a list -> 'a list
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  val map_filter: ('a -> 'b option) -> 'a list -> 'b list
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  val is_prefix: ('a * 'a -> bool) -> 'a list -> 'a list -> bool
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  val take_prefix: ('a -> bool) -> 'a list -> 'a list * 'a list
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  val chop_prefix: ('a * 'b -> bool) -> 'a list * 'b list -> 'a list * ('a list * 'b list)
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  val take_suffix: ('a -> bool) -> 'a list -> 'a list * 'a list
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  val prefixes1: 'a list -> 'a list list
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  val prefixes: 'a list -> 'a list list
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  val suffixes1: 'a list -> 'a list list
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  val suffixes: 'a list -> 'a list list
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  (*integers*)
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  val inc: int ref -> int
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  val dec: int ref -> int
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  val upto: int * int -> int list
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  val downto: int * int -> int list
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  val radixpand: int * int -> int list
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  val radixstring: int * string * int -> string
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  val string_of_int: int -> string
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  val signed_string_of_int: int -> string
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  val string_of_indexname: string * int -> string
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  val read_intinf: int -> string list -> IntInf.int * string list
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  val read_int: string list -> int * string list
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  val oct_char: string -> string
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  (*strings*)
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  val nth_string: string -> int -> string
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  val fold_string: (string -> 'a -> 'a) -> string -> 'a -> 'a
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  val exists_string: (string -> bool) -> string -> bool
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  val forall_string: (string -> bool) -> string -> bool
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  val enclose: string -> string -> string -> string
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  val unenclose: string -> string
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  val quote: string -> string
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  val space_implode: string -> string list -> string
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  val commas: string list -> string
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  val commas_quote: string list -> string
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  val cat_lines: string list -> string
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  val space_explode: string -> string -> string list
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  val split_lines: string -> string list
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  val prefix_lines: string -> string -> string
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  val untabify: string list -> string list
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  val prefix: string -> string -> string
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  val suffix: string -> string -> string
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  val unprefix: string -> string -> string
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  val unsuffix: string -> string -> string
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  val replicate_string: int -> string -> string
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  val translate_string: (string -> string) -> string -> string
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  (*lists as sets -- see also Pure/General/ord_list.ML*)
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  val member: ('b * 'a -> bool) -> 'a list -> 'b -> bool
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  val insert: ('a * 'a -> bool) -> 'a -> 'a list -> 'a list
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  val remove: ('b * 'a -> bool) -> 'b -> 'a list -> 'a list
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  val subtract: ('b * 'a -> bool) -> 'b list -> 'a list -> 'a list
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  val merge: ('a * 'a -> bool) -> 'a list * 'a list -> 'a list
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  val mem: ''a * ''a list -> bool
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  val mem_int: int * int list -> bool
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  val mem_string: string * string list -> bool
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  val union: ''a list * ''a list -> ''a list
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  val union_int: int list * int list -> int list
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  val union_string: string list * string list -> string list
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  val gen_union: ('a * 'a -> bool) -> 'a list * 'a list -> 'a list
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  val gen_inter: ('a * 'b -> bool) -> 'a list * 'b list -> 'a list
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  val inter: ''a list * ''a list -> ''a list
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  val inter_int: int list * int list -> int list
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  val inter_string: string list * string list -> string list
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  val subset: ''a list * ''a list -> bool
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  val subset_int: int list * int list -> bool
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  val subset_string: string list * string list -> bool
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  val eq_set: ''a list * ''a list -> bool
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  val eq_set_string: string list * string list -> bool
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  val gen_subset: ('a * 'b -> bool) -> 'a list * 'b list -> bool
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  val gen_eq_set: ('a * 'b -> bool) -> 'a list * 'b list -> bool
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  val \ : ''a list * ''a -> ''a list
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  val \\ : ''a list * ''a list -> ''a list
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  val distinct: ('a * 'a -> bool) -> 'a list -> 'a list
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  val duplicates: ('a * 'a -> bool) -> 'a list -> 'a list
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  val has_duplicates: ('a * 'a -> bool) -> 'a list -> bool
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  (*lists as multisets*)
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  val remove1: ('b * 'a -> bool) -> 'b -> 'a list -> 'a list
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  val submultiset: ('a * 'b -> bool) -> 'a list * 'b list -> bool
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  (*orders*)
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  val is_equal: order -> bool
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  val rev_order: order -> order
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  val make_ord: ('a * 'a -> bool) -> 'a * 'a -> order
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  val int_ord: int * int -> order
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  val string_ord: string * string -> order
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  val fast_string_ord: string * string -> order
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  val option_ord: ('a * 'b -> order) -> 'a option * 'b option -> order
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  val prod_ord: ('a * 'b -> order) -> ('c * 'd -> order) -> ('a * 'c) * ('b * 'd) -> order
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  val dict_ord: ('a * 'b -> order) -> 'a list * 'b list -> order
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  val list_ord: ('a * 'b -> order) -> 'a list * 'b list -> order
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  val sort: ('a * 'a -> order) -> 'a list -> 'a list
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  val sort_distinct: ('a * 'a -> order) -> 'a list -> 'a list
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  val sort_strings: string list -> string list
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  val sort_wrt: ('a -> string) -> 'a list -> 'a list
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  (*random numbers*)
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  exception RANDOM
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  val random: unit -> real
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  val random_range: int -> int -> int
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  val one_of: 'a list -> 'a
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  val frequency: (int * 'a) list -> 'a
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  (*current directory*)
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  val cd: string -> unit
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  val pwd: unit -> string
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  (*misc*)
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  val divide_and_conquer: ('a -> 'a list * ('b list -> 'b)) -> 'a -> 'b
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  val partition_eq: ('a * 'a -> bool) -> 'a list -> 'a list list
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  val partition_list: (int -> 'a -> bool) -> int -> int -> 'a list -> 'a list list
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  val gensym: string -> string
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  type stamp
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  val stamp: unit -> stamp
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  type serial
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  val serial: unit -> serial
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  val serial_string: unit -> string
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  structure Object: sig type T end
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end;
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signature LIBRARY =
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sig
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  include BASIC_LIBRARY
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  val foldl: ('a * 'b -> 'a) -> 'a * 'b list -> 'a
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  val foldr: ('a * 'b -> 'b) -> 'a list * 'b -> 'b
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  val take: int * 'a list -> 'a list
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  val drop: int * 'a list -> 'a list
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  val last_elem: 'a list -> 'a
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end;
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structure Library: LIBRARY =
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struct
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(* functions *)
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fun I x = x;
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fun K x = fn _ => x;
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fun flip f x y = f y x;
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fun curry f x y = f (x, y);
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fun uncurry f (x, y) = f x y;
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(*application and structured results -- old version*)
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fun (x, y) |>>> f = let val (x', z) = f x in (x', (y, z)) end;
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(*conditional application*)
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fun b ? f = fn x => if b then f x else x;
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(*composition with multiple args*)
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fun (f oo g) x y = f (g x y);
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fun (f ooo g) x y z = f (g x y z);
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fun (f oooo g) x y z w = f (g x y z w);
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(*function exponentiation: f(...(f x)...) with n applications of f*)
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fun funpow 0 _ x = x
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  | funpow n f x = funpow (n - 1) f (f x);
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(* exceptions *)
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val do_transform_failure = ref true;
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fun transform_failure exn f x =
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  if ! do_transform_failure then
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    f x handle Interrupt => raise Interrupt | e => raise exn e
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  else f x;
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exception EXCEPTION of exn * string;
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datatype 'a result =
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  Result of 'a |
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  Exn of exn;
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fun capture f x = Result (f x) handle e => Exn e;
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fun release (Result y) = y
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  | release (Exn e) = raise e;
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fun get_result (Result x) = SOME x
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  | get_result _ = NONE;
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fun get_exn (Exn exn) = SOME exn
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  | get_exn _ = NONE;
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(* errors *)
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exception SYS_ERROR of string;
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fun sys_error msg = raise SYS_ERROR msg;
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   305
wenzelm@18681
   306
exception ERROR of string;
wenzelm@18681
   307
fun error msg = raise ERROR msg;
wenzelm@18681
   308
wenzelm@18681
   309
fun cat_error "" msg = error msg
wenzelm@18681
   310
  | cat_error msg1 msg2 = error (msg1 ^ "\n" ^ msg2);
wenzelm@18681
   311
wenzelm@18681
   312
fun assert_all pred list msg =
wenzelm@18681
   313
  let
wenzelm@18681
   314
    fun ass [] = ()
wenzelm@18681
   315
      | ass (x :: xs) = if pred x then ass xs else error (msg x);
wenzelm@18681
   316
  in ass list end;
wenzelm@18681
   317
wenzelm@18681
   318
wenzelm@21395
   319
(* pairs *)
wenzelm@233
   320
wenzelm@233
   321
fun pair x y = (x, y);
wenzelm@233
   322
fun rpair x y = (y, x);
wenzelm@233
   323
wenzelm@233
   324
fun fst (x, y) = x;
wenzelm@233
   325
fun snd (x, y) = y;
wenzelm@233
   326
haftmann@17498
   327
fun eq_fst eq ((x1, _), (x2, _)) = eq (x1, x2);
haftmann@17498
   328
fun eq_snd eq ((_, y1), (_, y2)) = eq (y1, y2);
haftmann@19454
   329
fun eq_pair eqx eqy ((x1, y1), (x2, y2)) = eqx (x1, x2) andalso eqy (y1, y2);
wenzelm@233
   330
wenzelm@233
   331
fun swap (x, y) = (y, x);
wenzelm@233
   332
wenzelm@233
   333
fun apfst f (x, y) = (f x, y);
wenzelm@233
   334
fun apsnd f (x, y) = (x, f y);
wenzelm@4212
   335
fun pairself f (x, y) = (f x, f y);
wenzelm@233
   336
wenzelm@233
   337
wenzelm@21395
   338
(* booleans *)
wenzelm@233
   339
wenzelm@21395
   340
(*polymorphic equality*)
wenzelm@233
   341
fun equal x y = x = y;
wenzelm@233
   342
fun not_equal x y = x <> y;
wenzelm@233
   343
wenzelm@21395
   344
(*combining predicates*)
wenzelm@16721
   345
fun p orf q = fn x => p x orelse q x;
wenzelm@16721
   346
fun p andf q = fn x => p x andalso q x;
wenzelm@233
   347
wenzelm@233
   348
(*exists pred [x1, ..., xn] ===> pred x1 orelse ... orelse pred xn*)
wenzelm@233
   349
fun exists (pred: 'a -> bool) : 'a list -> bool =
wenzelm@233
   350
  let fun boolf [] = false
wenzelm@233
   351
        | boolf (x :: xs) = pred x orelse boolf xs
wenzelm@233
   352
  in boolf end;
wenzelm@233
   353
wenzelm@233
   354
(*forall pred [x1, ..., xn] ===> pred x1 andalso ... andalso pred xn*)
wenzelm@233
   355
fun forall (pred: 'a -> bool) : 'a list -> bool =
wenzelm@233
   356
  let fun boolf [] = true
wenzelm@233
   357
        | boolf (x :: xs) = pred x andalso boolf xs
wenzelm@233
   358
  in boolf end;
clasohm@0
   359
wenzelm@19644
   360
wenzelm@380
   361
(* flags *)
wenzelm@380
   362
wenzelm@380
   363
fun set flag = (flag := true; true);
wenzelm@380
   364
fun reset flag = (flag := false; false);
wenzelm@380
   365
fun toggle flag = (flag := not (! flag); ! flag);
wenzelm@380
   366
wenzelm@9118
   367
fun change r f = r := f (! r);
wenzelm@9118
   368
wenzelm@18712
   369
(*temporarily set flag during execution*)
wenzelm@2978
   370
fun setmp flag value f x =
wenzelm@2958
   371
  let
wenzelm@2958
   372
    val orig_value = ! flag;
wenzelm@18712
   373
    val _ = flag := value;
wenzelm@18712
   374
    val result = capture f x;
wenzelm@18712
   375
    val _ = flag := orig_value;
wenzelm@18712
   376
  in release result end;
wenzelm@2958
   377
wenzelm@19644
   378
wenzelm@21395
   379
wenzelm@233
   380
(** lists **)
wenzelm@233
   381
skalberg@15570
   382
exception UnequalLengths;
wenzelm@233
   383
wenzelm@5285
   384
fun single x = [x];
wenzelm@233
   385
wenzelm@20882
   386
fun the_single [x] = x
wenzelm@20882
   387
  | the_single _ = raise Empty;
wenzelm@20882
   388
wenzelm@20882
   389
fun singleton f x = the_single (f [x]);
wenzelm@19273
   390
wenzelm@5904
   391
fun apply [] x = x
wenzelm@5904
   392
  | apply (f :: fs) x = apply fs (f x);
wenzelm@5904
   393
wenzelm@233
   394
wenzelm@21395
   395
(* fold -- old versions *)
haftmann@16691
   396
wenzelm@233
   397
(*the following versions of fold are designed to fit nicely with infixes*)
clasohm@0
   398
wenzelm@233
   399
(*  (op @) (e, [x1, ..., xn])  ===>  ((e @ x1) @ x2) ... @ xn
wenzelm@233
   400
    for operators that associate to the left (TAIL RECURSIVE)*)
wenzelm@233
   401
fun foldl (f: 'a * 'b -> 'a) : 'a * 'b list -> 'a =
wenzelm@233
   402
  let fun itl (e, [])  = e
wenzelm@233
   403
        | itl (e, a::l) = itl (f(e, a), l)
wenzelm@233
   404
  in  itl end;
wenzelm@233
   405
wenzelm@233
   406
(*  (op @) ([x1, ..., xn], e)  ===>   x1 @ (x2 ... @ (xn @ e))
wenzelm@233
   407
    for operators that associate to the right (not tail recursive)*)
wenzelm@233
   408
fun foldr f (l, e) =
wenzelm@233
   409
  let fun itr [] = e
wenzelm@233
   410
        | itr (a::l) = f(a, itr l)
wenzelm@233
   411
  in  itr l  end;
wenzelm@233
   412
wenzelm@233
   413
(*  (op @) [x1, ..., xn]  ===>   x1 @ (x2 ... @ (x[n-1] @ xn))
wenzelm@233
   414
    for n > 0, operators that associate to the right (not tail recursive)*)
paulson@20443
   415
fun foldr1 f [] = raise Empty
wenzelm@20510
   416
  | foldr1 f l =
paulson@20443
   417
      let fun itr [x] = x
wenzelm@20510
   418
            | itr (x::l) = f(x, itr l)
paulson@20443
   419
      in  itr l  end;
wenzelm@233
   420
wenzelm@16705
   421
fun foldl_map f =
wenzelm@16705
   422
  let
wenzelm@16705
   423
    fun fold_aux (x, []) = (x, [])
wenzelm@16705
   424
      | fold_aux (x, y :: ys) =
wenzelm@16705
   425
          let
wenzelm@16705
   426
            val (x', y') = f (x, y);
wenzelm@16705
   427
            val (x'', ys') = fold_aux (x', ys);
wenzelm@16705
   428
          in (x'', y' :: ys') end;
wenzelm@16705
   429
  in fold_aux end;
wenzelm@16705
   430
wenzelm@233
   431
wenzelm@233
   432
(* basic list functions *)
wenzelm@233
   433
wenzelm@20510
   434
fun eq_list eq (list1, list2) =
haftmann@20348
   435
  let
wenzelm@20510
   436
    fun eq_lst (x :: xs, y :: ys) = eq (x, y) andalso eq_lst (xs, ys)
wenzelm@20510
   437
      | eq_lst _ = true;
wenzelm@20510
   438
  in length list1 = length list2 andalso eq_lst (list1, list2) end;
haftmann@20348
   439
wenzelm@19483
   440
fun maps f [] = []
wenzelm@19483
   441
  | maps f (x :: xs) = f x @ maps f xs;
wenzelm@19483
   442
wenzelm@23220
   443
fun chop 0 xs = ([], xs)
wenzelm@23220
   444
  | chop _ [] = ([], [])
wenzelm@23220
   445
  | chop n (x :: xs) = chop (n - 1) xs |>> cons x;
wenzelm@19011
   446
wenzelm@233
   447
(*take the first n elements from a list*)
wenzelm@233
   448
fun take (n, []) = []
wenzelm@233
   449
  | take (n, x :: xs) =
wenzelm@233
   450
      if n > 0 then x :: take (n - 1, xs) else [];
wenzelm@233
   451
wenzelm@233
   452
(*drop the first n elements from a list*)
wenzelm@233
   453
fun drop (n, []) = []
wenzelm@233
   454
  | drop (n, x :: xs) =
wenzelm@233
   455
      if n > 0 then drop (n - 1, xs) else x :: xs;
clasohm@0
   456
nipkow@4713
   457
fun dropwhile P [] = []
nipkow@4713
   458
  | dropwhile P (ys as x::xs) = if P x then dropwhile P xs else ys;
nipkow@4713
   459
wenzelm@233
   460
(*return nth element of a list, where 0 designates the first element;
wenzelm@18461
   461
  raise Subscript if list too short*)
haftmann@18011
   462
fun nth xs i = List.nth (xs, i);
wenzelm@233
   463
wenzelm@18461
   464
fun nth_list xss i = nth xss i handle Subscript => [];
wenzelm@18461
   465
haftmann@18011
   466
fun nth_map 0 f (x :: xs) = f x :: xs
haftmann@18011
   467
  | nth_map n f (x :: xs) = x :: nth_map (n - 1) f xs
haftmann@18011
   468
  | nth_map _ _ [] = raise Subscript;
wenzelm@11773
   469
haftmann@18514
   470
fun map_index f =
haftmann@18514
   471
  let
haftmann@18514
   472
    fun mapp _ [] = []
haftmann@18514
   473
      | mapp i (x :: xs) = f (i, x) :: mapp (i+1) xs
haftmann@18514
   474
  in mapp 0 end;
haftmann@18514
   475
haftmann@21118
   476
fun fold_index f =
haftmann@21118
   477
  let
haftmann@21118
   478
    fun fold_aux _ [] y = y
haftmann@21118
   479
      | fold_aux i (x :: xs) y = fold_aux (i+1) xs (f (i, x) y);
haftmann@21118
   480
  in fold_aux 0 end;
haftmann@21118
   481
skalberg@15570
   482
val last_elem = List.last;
wenzelm@233
   483
wenzelm@3762
   484
(*rear decomposition*)
skalberg@15570
   485
fun split_last [] = raise Empty
wenzelm@3762
   486
  | split_last [x] = ([], x)
wenzelm@3762
   487
  | split_last (x :: xs) = apfst (cons x) (split_last xs);
wenzelm@3762
   488
wenzelm@4212
   489
(*find the position of an element in a list*)
wenzelm@4212
   490
fun find_index pred =
wenzelm@4212
   491
  let fun find _ [] = ~1
wenzelm@4212
   492
        | find n (x :: xs) = if pred x then n else find (n + 1) xs;
wenzelm@4212
   493
  in find 0 end;
wenzelm@3762
   494
wenzelm@4224
   495
fun find_index_eq x = find_index (equal x);
wenzelm@4212
   496
wenzelm@4212
   497
(*find first element satisfying predicate*)
paulson@22593
   498
val find_first = List.find;
wenzelm@233
   499
wenzelm@4916
   500
(*get first element by lookup function*)
skalberg@15531
   501
fun get_first _ [] = NONE
wenzelm@4916
   502
  | get_first f (x :: xs) =
wenzelm@4916
   503
      (case f x of
skalberg@15531
   504
        NONE => get_first f xs
wenzelm@4916
   505
      | some => some);
wenzelm@4916
   506
haftmann@19233
   507
fun get_index f =
haftmann@19233
   508
  let
haftmann@19233
   509
    fun get _ [] = NONE
wenzelm@19461
   510
      | get i (x :: xs) =
haftmann@19233
   511
          case f x
wenzelm@19461
   512
           of NONE => get (i + 1) xs
haftmann@19233
   513
            | SOME y => SOME (i, y)
haftmann@19233
   514
  in get 0 end;
haftmann@19233
   515
skalberg@15531
   516
val flat = List.concat;
wenzelm@233
   517
wenzelm@12136
   518
fun unflat (xs :: xss) ys =
wenzelm@19424
   519
      let val (ps, qs) = chop (length xs) ys
nipkow@13629
   520
      in ps :: unflat xss qs end
wenzelm@12136
   521
  | unflat [] [] = []
skalberg@15570
   522
  | unflat _ _ = raise UnequalLengths;
wenzelm@12136
   523
wenzelm@21479
   524
fun burrow f xss = unflat xss (f (flat xss));
haftmann@18359
   525
haftmann@18549
   526
fun fold_burrow f xss s =
haftmann@18549
   527
  apfst (unflat xss) (f (flat xss) s);
haftmann@18359
   528
wenzelm@233
   529
(*separate s [x1, x2, ..., xn]  ===>  [x1, s, x2, s, ..., s, xn]*)
wenzelm@233
   530
fun separate s (x :: (xs as _ :: _)) = x :: s :: separate s xs
wenzelm@233
   531
  | separate _ xs = xs;
wenzelm@233
   532
wenzelm@233
   533
(*make the list [x, x, ..., x] of length n*)
wenzelm@233
   534
fun replicate n (x: 'a) : 'a list =
wenzelm@233
   535
  let fun rep (0, xs) = xs
wenzelm@233
   536
        | rep (n, xs) = rep (n - 1, x :: xs)
wenzelm@233
   537
  in
skalberg@15570
   538
    if n < 0 then raise Subscript
wenzelm@233
   539
    else rep (n, [])
wenzelm@233
   540
  end;
wenzelm@233
   541
wenzelm@14926
   542
fun translate_string f = String.translate (f o String.str);
wenzelm@14926
   543
wenzelm@4248
   544
(*multiply [a, b, c, ...] * [xs, ys, zs, ...]*)
wenzelm@18148
   545
fun multiply [] _ = []
wenzelm@18148
   546
  | multiply (x :: xs) yss = map (cons x) yss @ multiply xs yss;
wenzelm@4248
   547
wenzelm@14792
   548
(*direct product*)
wenzelm@14792
   549
fun product _ [] = []
wenzelm@14792
   550
  | product [] _ = []
wenzelm@14792
   551
  | product (x :: xs) ys = map (pair x) ys @ product xs ys;
wenzelm@14792
   552
wenzelm@233
   553
wenzelm@233
   554
(* filter *)
wenzelm@233
   555
wenzelm@233
   556
(*copy the list preserving elements that satisfy the predicate*)
skalberg@15531
   557
val filter = List.filter;
clasohm@0
   558
fun filter_out f = filter (not o f);
wenzelm@19483
   559
val map_filter = List.mapPartial;
wenzelm@233
   560
wenzelm@233
   561
wenzelm@233
   562
(* lists of pairs *)
wenzelm@233
   563
skalberg@15570
   564
exception UnequalLengths;
skalberg@15570
   565
haftmann@18330
   566
fun map2 _ [] [] = []
haftmann@18330
   567
  | map2 f (x :: xs) (y :: ys) = f x y :: map2 f xs ys
haftmann@18330
   568
  | map2 _ _ _ = raise UnequalLengths;
wenzelm@380
   569
wenzelm@23220
   570
fun fold2 f [] [] z = z
wenzelm@23220
   571
  | fold2 f (x :: xs) (y :: ys) z = fold2 f xs ys (f x y z)
wenzelm@23220
   572
  | fold2 f _ _ _ = raise UnequalLengths;
wenzelm@380
   573
wenzelm@19799
   574
fun zip_options (x :: xs) (SOME y :: ys) = (x, y) :: zip_options xs ys
wenzelm@19799
   575
  | zip_options (_ :: xs) (NONE :: ys) = zip_options xs ys
wenzelm@19799
   576
  | zip_options _ [] = []
wenzelm@19799
   577
  | zip_options [] _ = raise UnequalLengths;
wenzelm@4956
   578
wenzelm@233
   579
(*combine two lists forming a list of pairs:
wenzelm@233
   580
  [x1, ..., xn] ~~ [y1, ..., yn]  ===>  [(x1, y1), ..., (xn, yn)]*)
wenzelm@233
   581
fun [] ~~ [] = []
wenzelm@233
   582
  | (x :: xs) ~~ (y :: ys) = (x, y) :: (xs ~~ ys)
skalberg@15570
   583
  | _ ~~ _ = raise UnequalLengths;
wenzelm@233
   584
wenzelm@233
   585
(*inverse of ~~; the old 'split':
wenzelm@233
   586
  [(x1, y1), ..., (xn, yn)]  ===>  ([x1, ..., xn], [y1, ..., yn])*)
skalberg@15570
   587
val split_list = ListPair.unzip;
wenzelm@233
   588
wenzelm@233
   589
wenzelm@233
   590
(* prefixes, suffixes *)
wenzelm@233
   591
haftmann@18441
   592
fun is_prefix _ [] _ = true
haftmann@18441
   593
  | is_prefix eq (x :: xs) (y :: ys) = eq (x, y) andalso is_prefix eq xs ys
haftmann@18441
   594
  | is_prefix eq _ _ = false;
wenzelm@233
   595
wenzelm@233
   596
(* [x1, ..., xi, ..., xn]  --->  ([x1, ..., x(i-1)], [xi, ..., xn])
wenzelm@233
   597
   where xi is the first element that does not satisfy the predicate*)
wenzelm@233
   598
fun take_prefix (pred : 'a -> bool)  (xs: 'a list) : 'a list * 'a list =
wenzelm@233
   599
  let fun take (rxs, []) = (rev rxs, [])
wenzelm@255
   600
        | take (rxs, x :: xs) =
wenzelm@255
   601
            if  pred x  then  take(x :: rxs, xs)  else  (rev rxs, x :: xs)
wenzelm@233
   602
  in  take([], xs)  end;
wenzelm@233
   603
haftmann@20108
   604
fun chop_prefix eq ([], ys) = ([], ([], ys))
haftmann@20108
   605
  | chop_prefix eq (xs, []) = ([], (xs, []))
wenzelm@23220
   606
  | chop_prefix eq (xs as x :: xs', ys as y :: ys') =
haftmann@20108
   607
      if eq (x, y) then
haftmann@20108
   608
        let val (ps', xys'') = chop_prefix eq (xs', ys')
wenzelm@23220
   609
        in (x :: ps', xys'') end
haftmann@20108
   610
      else ([], (xs, ys));
haftmann@20108
   611
wenzelm@233
   612
(* [x1, ..., xi, ..., xn]  --->  ([x1, ..., xi], [x(i+1), ..., xn])
wenzelm@233
   613
   where xi is the last element that does not satisfy the predicate*)
wenzelm@233
   614
fun take_suffix _ [] = ([], [])
wenzelm@233
   615
  | take_suffix pred (x :: xs) =
wenzelm@233
   616
      (case take_suffix pred xs of
wenzelm@233
   617
        ([], sffx) => if pred x then ([], x :: sffx) else ([x], sffx)
wenzelm@233
   618
      | (prfx, sffx) => (x :: prfx, sffx));
wenzelm@233
   619
wenzelm@12249
   620
fun prefixes1 [] = []
wenzelm@12249
   621
  | prefixes1 (x :: xs) = map (cons x) ([] :: prefixes1 xs);
wenzelm@12249
   622
wenzelm@19011
   623
fun prefixes xs = [] :: prefixes1 xs;
wenzelm@19011
   624
wenzelm@12249
   625
fun suffixes1 xs = map rev (prefixes1 (rev xs));
wenzelm@19011
   626
fun suffixes xs = [] :: suffixes1 xs;
wenzelm@233
   627
wenzelm@23220
   628
wenzelm@23220
   629
wenzelm@233
   630
(** integers **)
wenzelm@233
   631
wenzelm@2958
   632
fun inc i = (i := ! i + 1; ! i);
wenzelm@2958
   633
fun dec i = (i := ! i - 1; ! i);
wenzelm@233
   634
wenzelm@233
   635
wenzelm@233
   636
(* lists of integers *)
wenzelm@233
   637
wenzelm@233
   638
(*make the list [from, from + 1, ..., to]*)
wenzelm@21859
   639
fun (i upto j) =
wenzelm@21859
   640
  if i > j then [] else i :: (i + 1 upto j);
wenzelm@233
   641
wenzelm@233
   642
(*make the list [from, from - 1, ..., to]*)
wenzelm@21859
   643
fun (i downto j) =
wenzelm@21859
   644
  if i < j then [] else i :: (i - 1 downto j);
wenzelm@233
   645
wenzelm@233
   646
wenzelm@233
   647
(* convert integers to strings *)
wenzelm@233
   648
wenzelm@233
   649
(*expand the number in the given base;
wenzelm@233
   650
  example: radixpand (2, 8) gives [1, 0, 0, 0]*)
wenzelm@233
   651
fun radixpand (base, num) : int list =
wenzelm@233
   652
  let
wenzelm@233
   653
    fun radix (n, tail) =
wenzelm@233
   654
      if n < base then n :: tail
wenzelm@233
   655
      else radix (n div base, (n mod base) :: tail)
wenzelm@233
   656
  in radix (num, []) end;
wenzelm@233
   657
wenzelm@233
   658
(*expands a number into a string of characters starting from "zerochar";
wenzelm@233
   659
  example: radixstring (2, "0", 8) gives "1000"*)
wenzelm@233
   660
fun radixstring (base, zerochar, num) =
wenzelm@233
   661
  let val offset = ord zerochar;
wenzelm@233
   662
      fun chrof n = chr (offset + n)
wenzelm@233
   663
  in implode (map chrof (radixpand (base, num))) end;
wenzelm@233
   664
wenzelm@233
   665
paulson@3407
   666
val string_of_int = Int.toString;
wenzelm@233
   667
wenzelm@21942
   668
fun signed_string_of_int i =
wenzelm@21942
   669
  if i < 0 then "-" ^ string_of_int (~ i) else string_of_int i;
wenzelm@21942
   670
wenzelm@23220
   671
fun string_of_indexname (a, 0) = a
wenzelm@23220
   672
  | string_of_indexname (a, i) = a ^ "_" ^ string_of_int i;
wenzelm@233
   673
wenzelm@233
   674
wenzelm@14826
   675
(* read integers *)
wenzelm@14826
   676
wenzelm@20095
   677
fun read_intinf radix cs =
wenzelm@20095
   678
  let
wenzelm@20095
   679
    val zero = ord "0";
wenzelm@20095
   680
    val limit = zero + radix;
wenzelm@20095
   681
    fun scan (num, []) = (num, [])
wenzelm@20095
   682
      | scan (num, c :: cs) =
wenzelm@20095
   683
        if zero <= ord c andalso ord c < limit then
wenzelm@20095
   684
          scan (IntInf.fromInt radix * num + IntInf.fromInt (ord c - zero), cs)
wenzelm@20095
   685
        else (num, c :: cs);
wenzelm@21859
   686
  in scan (IntInf.fromInt 0, cs) end;
wenzelm@14826
   687
wenzelm@20095
   688
fun read_int cs = apfst IntInf.toInt (read_intinf 10 cs);
wenzelm@14826
   689
wenzelm@20095
   690
fun oct_char s = chr (IntInf.toInt (#1 (read_intinf 8 (explode s))));
wenzelm@14826
   691
wenzelm@14826
   692
wenzelm@14826
   693
wenzelm@233
   694
(** strings **)
wenzelm@233
   695
wenzelm@16188
   696
(* functions tuned for strings, avoiding explode *)
wenzelm@6312
   697
haftmann@18011
   698
fun nth_string str i =
wenzelm@6959
   699
  (case try String.substring (str, i, 1) of
skalberg@15531
   700
    SOME s => s
skalberg@15570
   701
  | NONE => raise Subscript);
wenzelm@6312
   702
wenzelm@16188
   703
fun fold_string f str x0 =
wenzelm@6282
   704
  let
wenzelm@6282
   705
    val n = size str;
wenzelm@16188
   706
    fun iter (x, i) =
wenzelm@16188
   707
      if i < n then iter (f (String.substring (str, i, 1)) x, i + 1) else x;
wenzelm@16188
   708
  in iter (x0, 0) end;
wenzelm@6282
   709
wenzelm@14968
   710
fun exists_string pred str =
wenzelm@14968
   711
  let
wenzelm@14968
   712
    val n = size str;
wenzelm@14968
   713
    fun ex i = i < n andalso (pred (String.substring (str, i, 1)) orelse ex (i + 1));
wenzelm@14968
   714
  in ex 0 end;
wenzelm@6312
   715
wenzelm@16188
   716
fun forall_string pred = not o exists_string (not o pred);
wenzelm@16188
   717
lcp@512
   718
(*enclose in brackets*)
lcp@512
   719
fun enclose lpar rpar str = lpar ^ str ^ rpar;
wenzelm@6642
   720
fun unenclose str = String.substring (str, 1, size str - 2);
wenzelm@255
   721
wenzelm@233
   722
(*simple quoting (does not escape special chars)*)
lcp@512
   723
val quote = enclose "\"" "\"";
wenzelm@233
   724
wenzelm@4212
   725
(*space_implode "..." (explode "hello") = "h...e...l...l...o"*)
wenzelm@233
   726
fun space_implode a bs = implode (separate a bs);
wenzelm@233
   727
wenzelm@255
   728
val commas = space_implode ", ";
wenzelm@380
   729
val commas_quote = commas o map quote;
wenzelm@255
   730
wenzelm@233
   731
(*concatenate messages, one per line, into a string*)
wenzelm@255
   732
val cat_lines = space_implode "\n";
wenzelm@233
   733
wenzelm@4212
   734
(*space_explode "." "h.e..l.lo" = ["h", "e", "", "l", "lo"]*)
wenzelm@3832
   735
fun space_explode _ "" = []
paulson@21899
   736
  | space_explode sep s = String.fields (fn c => str c = sep) s;
wenzelm@3832
   737
wenzelm@3832
   738
val split_lines = space_explode "\n";
wenzelm@3832
   739
wenzelm@14826
   740
fun prefix_lines "" txt = txt
wenzelm@14826
   741
  | prefix_lines prfx txt = txt |> split_lines |> map (fn s => prfx ^ s) |> cat_lines;
wenzelm@14826
   742
wenzelm@7712
   743
fun untabify chs =
wenzelm@7712
   744
  let
wenzelm@7712
   745
    val tab_width = 8;
wenzelm@7712
   746
wenzelm@22582
   747
    fun untab pos [] ys = rev ys
berghofe@22256
   748
      | untab pos ("\n" :: xs) ys = untab 0 xs ("\n" :: ys)
berghofe@22256
   749
      | untab pos ("\t" :: xs) ys =
wenzelm@22582
   750
          let val d = tab_width - (pos mod tab_width)
wenzelm@23718
   751
          in untab (pos + d) xs (funpow d (cons " ") ys) end
berghofe@22256
   752
      | untab pos (c :: xs) ys = untab (pos + 1) xs (c :: ys);
wenzelm@7712
   753
  in
wenzelm@19301
   754
    if not (exists (fn c => c = "\t") chs) then chs
berghofe@22256
   755
    else untab 0 chs []
wenzelm@7712
   756
  end;
wenzelm@7712
   757
wenzelm@18681
   758
fun prefix prfx s = prfx ^ s;
wenzelm@16188
   759
fun suffix sffx s = s ^ sffx;
wenzelm@5285
   760
wenzelm@18681
   761
fun unprefix prfx s =
wenzelm@18681
   762
  if String.isPrefix prfx s then String.substring (s, size prfx, size s - size prfx)
wenzelm@18681
   763
  else raise Fail "unprefix";
wenzelm@18681
   764
wenzelm@16188
   765
fun unsuffix sffx s =
wenzelm@17061
   766
  if String.isSuffix sffx s then String.substring (s, 0, size s - size sffx)
wenzelm@17061
   767
  else raise Fail "unsuffix";
wenzelm@5285
   768
wenzelm@10951
   769
fun replicate_string 0 _ = ""
wenzelm@10951
   770
  | replicate_string 1 a = a
wenzelm@10951
   771
  | replicate_string k a =
wenzelm@10951
   772
      if k mod 2 = 0 then replicate_string (k div 2) (a ^ a)
wenzelm@10951
   773
      else replicate_string (k div 2) (a ^ a) ^ a;
wenzelm@10951
   774
wenzelm@233
   775
wenzelm@23220
   776
wenzelm@16492
   777
(** lists as sets -- see also Pure/General/ord_list.ML **)
wenzelm@233
   778
wenzelm@18923
   779
(*canonical member, insert, remove*)
wenzelm@18923
   780
fun member eq list x =
wenzelm@18923
   781
  let
wenzelm@18923
   782
    fun memb [] = false
wenzelm@18923
   783
      | memb (y :: ys) = eq (x, y) orelse memb ys;
wenzelm@18923
   784
  in memb list end;
berghofe@1576
   785
wenzelm@18923
   786
fun insert eq x xs = if member eq xs x then xs else x :: xs;
wenzelm@18923
   787
fun remove eq x xs = if member eq xs x then filter_out (fn y => eq (x, y)) xs else xs;
wenzelm@233
   788
wenzelm@19301
   789
fun subtract eq = fold (remove eq);
wenzelm@19301
   790
wenzelm@18923
   791
fun merge _ ([], ys) = ys
wenzelm@18923
   792
  | merge eq (xs, ys) = fold_rev (insert eq) ys xs;
clasohm@0
   793
wenzelm@18923
   794
(*old-style infixes*)
wenzelm@18923
   795
fun x mem xs = member (op =) xs x;
wenzelm@18923
   796
fun (x: int) mem_int xs = member (op =) xs x;
wenzelm@18923
   797
fun (x: string) mem_string xs = member (op =) xs x;
berghofe@1576
   798
wenzelm@233
   799
wenzelm@233
   800
(*union of sets represented as lists: no repetitions*)
wenzelm@233
   801
fun xs union [] = xs
wenzelm@233
   802
  | [] union ys = ys
haftmann@20854
   803
  | (x :: xs) union ys = xs union (insert (op =) x ys);
clasohm@0
   804
paulson@2175
   805
(*union of sets, optimized version for ints*)
berghofe@1576
   806
fun (xs:int list) union_int [] = xs
berghofe@1576
   807
  | [] union_int ys = ys
haftmann@20854
   808
  | (x :: xs) union_int ys = xs union_int (insert (op =) x ys);
berghofe@1576
   809
paulson@2175
   810
(*union of sets, optimized version for strings*)
berghofe@1576
   811
fun (xs:string list) union_string [] = xs
berghofe@1576
   812
  | [] union_string ys = ys
haftmann@20854
   813
  | (x :: xs) union_string ys = xs union_string (insert (op =) x ys);
berghofe@1576
   814
clasohm@0
   815
(*generalized union*)
wenzelm@233
   816
fun gen_union eq (xs, []) = xs
wenzelm@233
   817
  | gen_union eq ([], ys) = ys
wenzelm@18923
   818
  | gen_union eq (x :: xs, ys) = gen_union eq (xs, insert eq x ys);
wenzelm@233
   819
wenzelm@233
   820
wenzelm@233
   821
(*intersection*)
wenzelm@233
   822
fun [] inter ys = []
wenzelm@233
   823
  | (x :: xs) inter ys =
wenzelm@233
   824
      if x mem ys then x :: (xs inter ys) else xs inter ys;
wenzelm@233
   825
paulson@2175
   826
(*intersection, optimized version for ints*)
berghofe@1576
   827
fun ([]:int list) inter_int ys = []
berghofe@1576
   828
  | (x :: xs) inter_int ys =
berghofe@1576
   829
      if x mem_int ys then x :: (xs inter_int ys) else xs inter_int ys;
berghofe@1576
   830
paulson@2175
   831
(*intersection, optimized version for strings *)
berghofe@1576
   832
fun ([]:string list) inter_string ys = []
berghofe@1576
   833
  | (x :: xs) inter_string ys =
berghofe@1576
   834
      if x mem_string ys then x :: (xs inter_string ys) else xs inter_string ys;
berghofe@1576
   835
paulson@7090
   836
(*generalized intersection*)
paulson@7090
   837
fun gen_inter eq ([], ys) = []
wenzelm@12284
   838
  | gen_inter eq (x::xs, ys) =
wenzelm@18923
   839
      if member eq ys x then x :: gen_inter eq (xs, ys)
wenzelm@18923
   840
      else gen_inter eq (xs, ys);
paulson@7090
   841
wenzelm@233
   842
wenzelm@233
   843
(*subset*)
wenzelm@233
   844
fun [] subset ys = true
wenzelm@233
   845
  | (x :: xs) subset ys = x mem ys andalso xs subset ys;
wenzelm@233
   846
paulson@2175
   847
(*subset, optimized version for ints*)
wenzelm@16439
   848
fun ([]: int list) subset_int ys = true
berghofe@1576
   849
  | (x :: xs) subset_int ys = x mem_int ys andalso xs subset_int ys;
berghofe@1576
   850
paulson@2175
   851
(*subset, optimized version for strings*)
wenzelm@16439
   852
fun ([]: string list) subset_string ys = true
berghofe@1576
   853
  | (x :: xs) subset_string ys = x mem_string ys andalso xs subset_string ys;
berghofe@1576
   854
wenzelm@4363
   855
(*set equality*)
wenzelm@4363
   856
fun eq_set (xs, ys) =
wenzelm@4363
   857
  xs = ys orelse (xs subset ys andalso ys subset xs);
wenzelm@4363
   858
paulson@2182
   859
(*set equality for strings*)
wenzelm@16439
   860
fun eq_set_string ((xs: string list), ys) =
berghofe@1576
   861
  xs = ys orelse (xs subset_string ys andalso ys subset_string xs);
berghofe@1576
   862
wenzelm@18923
   863
fun gen_subset eq (xs, ys) = forall (member eq ys) xs;
paulson@2182
   864
wenzelm@19301
   865
fun gen_eq_set eq (xs, ys) =
haftmann@20348
   866
  eq_list eq (xs, ys) orelse
wenzelm@19301
   867
    (gen_subset eq (xs, ys) andalso gen_subset (eq o swap) (ys, xs));
wenzelm@19301
   868
wenzelm@265
   869
wenzelm@233
   870
(*removing an element from a list WITHOUT duplicates*)
wenzelm@233
   871
fun (y :: ys) \ x = if x = y then ys else y :: (ys \ x)
wenzelm@233
   872
  | [] \ x = [];
paulson@2243
   873
fun ys \\ xs = foldl (op \) (ys,xs);
clasohm@0
   874
wenzelm@233
   875
wenzelm@233
   876
(*makes a list of the distinct members of the input; preserves order, takes
wenzelm@233
   877
  first of equal elements*)
wenzelm@19046
   878
fun distinct eq lst =
wenzelm@233
   879
  let
wenzelm@233
   880
    fun dist (rev_seen, []) = rev rev_seen
wenzelm@233
   881
      | dist (rev_seen, x :: xs) =
wenzelm@18923
   882
          if member eq rev_seen x then dist (rev_seen, xs)
wenzelm@233
   883
          else dist (x :: rev_seen, xs);
wenzelm@19046
   884
  in dist ([], lst) end;
wenzelm@233
   885
wenzelm@255
   886
(*returns a list containing all repeated elements exactly once; preserves
wenzelm@255
   887
  order, takes first of equal elements*)
wenzelm@18966
   888
fun duplicates eq lst =
wenzelm@255
   889
  let
wenzelm@255
   890
    fun dups (rev_dups, []) = rev rev_dups
wenzelm@255
   891
      | dups (rev_dups, x :: xs) =
wenzelm@18923
   892
          if member eq rev_dups x orelse not (member eq xs x) then
wenzelm@255
   893
            dups (rev_dups, xs)
wenzelm@255
   894
          else dups (x :: rev_dups, xs);
wenzelm@18966
   895
  in dups ([], lst) end;
wenzelm@255
   896
wenzelm@16878
   897
fun has_duplicates eq =
wenzelm@16878
   898
  let
wenzelm@16878
   899
    fun dups [] = false
wenzelm@16878
   900
      | dups (x :: xs) = member eq xs x orelse dups xs;
wenzelm@16878
   901
  in dups end;
wenzelm@16878
   902
wenzelm@255
   903
wenzelm@23220
   904
nipkow@22142
   905
(** lists as multisets **)
nipkow@22142
   906
nipkow@22142
   907
fun remove1 _ _ [] = raise Empty
wenzelm@23220
   908
  | remove1 eq y (x::xs) = if eq (y, x) then xs else x :: remove1 eq y xs;
nipkow@22142
   909
wenzelm@23220
   910
fun submultiset _ ([], _)  = true
wenzelm@23220
   911
  | submultiset eq (x :: xs, ys) = member eq ys x andalso submultiset eq (xs, remove1 eq x ys);
wenzelm@233
   912
clasohm@0
   913
clasohm@0
   914
wenzelm@2506
   915
(** orders **)
wenzelm@2506
   916
wenzelm@18966
   917
fun is_equal EQUAL = true
wenzelm@18966
   918
  | is_equal _ = false;
wenzelm@18966
   919
wenzelm@4445
   920
fun rev_order LESS = GREATER
wenzelm@4445
   921
  | rev_order EQUAL = EQUAL
wenzelm@4445
   922
  | rev_order GREATER = LESS;
wenzelm@4445
   923
wenzelm@4479
   924
(*assume rel is a linear strict order*)
wenzelm@4445
   925
fun make_ord rel (x, y) =
wenzelm@4445
   926
  if rel (x, y) then LESS
wenzelm@4445
   927
  else if rel (y, x) then GREATER
wenzelm@4445
   928
  else EQUAL;
wenzelm@4445
   929
wenzelm@15051
   930
val int_ord = Int.compare;
wenzelm@15051
   931
val string_ord = String.compare;
wenzelm@2506
   932
wenzelm@16676
   933
fun fast_string_ord (s1, s2) =
wenzelm@16676
   934
  (case int_ord (size s1, size s2) of EQUAL => string_ord (s1, s2) | ord => ord);
wenzelm@16676
   935
wenzelm@16492
   936
fun option_ord ord (SOME x, SOME y) = ord (x, y)
wenzelm@16492
   937
  | option_ord _ (NONE, NONE) = EQUAL
wenzelm@16492
   938
  | option_ord _ (NONE, SOME _) = LESS
wenzelm@16492
   939
  | option_ord _ (SOME _, NONE) = GREATER;
wenzelm@16492
   940
wenzelm@4343
   941
(*lexicographic product*)
wenzelm@4343
   942
fun prod_ord a_ord b_ord ((x, y), (x', y')) =
wenzelm@4343
   943
  (case a_ord (x, x') of EQUAL => b_ord (y, y') | ord => ord);
wenzelm@4343
   944
wenzelm@4343
   945
(*dictionary order -- in general NOT well-founded!*)
wenzelm@16984
   946
fun dict_ord elem_ord (x :: xs, y :: ys) =
wenzelm@16984
   947
      (case elem_ord (x, y) of EQUAL => dict_ord elem_ord (xs, ys) | ord => ord)
wenzelm@16984
   948
  | dict_ord _ ([], []) = EQUAL
wenzelm@4343
   949
  | dict_ord _ ([], _ :: _) = LESS
wenzelm@16984
   950
  | dict_ord _ (_ :: _, []) = GREATER;
wenzelm@4343
   951
wenzelm@4343
   952
(*lexicographic product of lists*)
wenzelm@4343
   953
fun list_ord elem_ord (xs, ys) =
wenzelm@16676
   954
  (case int_ord (length xs, length ys) of EQUAL => dict_ord elem_ord (xs, ys) | ord => ord);
wenzelm@4343
   955
wenzelm@2506
   956
wenzelm@4621
   957
(* sorting *)
wenzelm@4621
   958
wenzelm@18427
   959
(*quicksort -- stable, i.e. does not reorder equal elements*)
wenzelm@18427
   960
fun quicksort unique ord =
wenzelm@4621
   961
  let
wenzelm@16878
   962
    fun qsort [] = []
wenzelm@16878
   963
      | qsort (xs as [_]) = xs
wenzelm@18427
   964
      | qsort (xs as [x, y]) =
wenzelm@18427
   965
          (case ord (x, y) of
wenzelm@18427
   966
            LESS => xs
wenzelm@18427
   967
          | EQUAL => if unique then [x] else xs
wenzelm@18427
   968
          | GREATER => [y, x])
wenzelm@16878
   969
      | qsort xs =
haftmann@18011
   970
          let val (lts, eqs, gts) = part (nth xs (length xs div 2)) xs
wenzelm@16878
   971
          in qsort lts @ eqs @ qsort gts end
wenzelm@4621
   972
    and part _ [] = ([], [], [])
wenzelm@4621
   973
      | part pivot (x :: xs) = add (ord (x, pivot)) x (part pivot xs)
wenzelm@4621
   974
    and add LESS x (lts, eqs, gts) = (x :: lts, eqs, gts)
wenzelm@18427
   975
      | add EQUAL x (lts, [], gts) = (lts, [x], gts)
wenzelm@18427
   976
      | add EQUAL x (res as (lts, eqs, gts)) = if unique then res else (lts, x :: eqs, gts)
wenzelm@4621
   977
      | add GREATER x (lts, eqs, gts) = (lts, eqs, x :: gts);
wenzelm@4621
   978
  in qsort end;
wenzelm@4621
   979
wenzelm@18427
   980
fun sort ord = quicksort false ord;
wenzelm@18427
   981
fun sort_distinct ord = quicksort true ord;
wenzelm@18427
   982
wenzelm@4621
   983
val sort_strings = sort string_ord;
wenzelm@4621
   984
fun sort_wrt sel xs = sort (string_ord o pairself sel) xs;
wenzelm@4621
   985
wenzelm@4621
   986
wenzelm@2506
   987
berghofe@14106
   988
(** random numbers **)
berghofe@14106
   989
berghofe@14106
   990
exception RANDOM;
berghofe@14106
   991
berghofe@14618
   992
fun rmod x y = x - y * Real.realFloor (x / y);
berghofe@14106
   993
berghofe@14106
   994
local
berghofe@14106
   995
  val a = 16807.0;
berghofe@14106
   996
  val m = 2147483647.0;
berghofe@14106
   997
  val random_seed = ref 1.0;
berghofe@14106
   998
in
berghofe@14106
   999
berghofe@14106
  1000
fun random () =
berghofe@14106
  1001
  let val r = rmod (a * !random_seed) m
berghofe@14106
  1002
  in (random_seed := r; r) end;
berghofe@14106
  1003
berghofe@14106
  1004
end;
berghofe@14106
  1005
berghofe@14106
  1006
fun random_range l h =
berghofe@14106
  1007
  if h < l orelse l < 0 then raise RANDOM
berghofe@14106
  1008
  else l + Real.floor (rmod (random ()) (real (h - l + 1)));
berghofe@14106
  1009
haftmann@18011
  1010
fun one_of xs = nth xs (random_range 0 (length xs - 1));
berghofe@14106
  1011
berghofe@14106
  1012
fun frequency xs =
berghofe@14106
  1013
  let
berghofe@14106
  1014
    val sum = foldl op + (0, map fst xs);
wenzelm@17756
  1015
    fun pick n ((k: int, x) :: xs) =
berghofe@14106
  1016
      if n <= k then x else pick (n - k) xs
berghofe@14106
  1017
  in pick (random_range 1 sum) xs end;
berghofe@14106
  1018
berghofe@14106
  1019
wenzelm@23220
  1020
wenzelm@14826
  1021
(** current directory **)
wenzelm@233
  1022
paulson@2243
  1023
val cd = OS.FileSys.chDir;
wenzelm@2317
  1024
val pwd = OS.FileSys.getDir;
paulson@2243
  1025
berghofe@3606
  1026
wenzelm@19644
  1027
wenzelm@4621
  1028
(** misc **)
wenzelm@233
  1029
wenzelm@19644
  1030
fun divide_and_conquer decomp x =
wenzelm@19644
  1031
  let val (ys, recomb) = decomp x
wenzelm@19644
  1032
  in recomb (map (divide_and_conquer decomp) ys) end;
wenzelm@19644
  1033
clasohm@0
  1034
wenzelm@233
  1035
(*Partition a list into buckets  [ bi, b(i+1), ..., bj ]
clasohm@0
  1036
   putting x in bk if p(k)(x) holds.  Preserve order of elements if possible.*)
clasohm@0
  1037
fun partition_list p i j =
wenzelm@233
  1038
  let fun part k xs =
wenzelm@233
  1039
            if k>j then
clasohm@0
  1040
              (case xs of [] => []
skalberg@15570
  1041
                         | _ => raise Fail "partition_list")
clasohm@0
  1042
            else
wenzelm@19691
  1043
            let val (ns, rest) = List.partition (p k) xs;
wenzelm@233
  1044
            in  ns :: part(k+1)rest  end
clasohm@0
  1045
  in  part i end;
clasohm@0
  1046
wenzelm@19691
  1047
fun partition_eq (eq:'a * 'a -> bool) =
wenzelm@19691
  1048
  let
wenzelm@19691
  1049
    fun part [] = []
wenzelm@19691
  1050
      | part (x :: ys) =
wenzelm@19691
  1051
          let val (xs, xs') = List.partition (fn y => eq (x, y)) ys
wenzelm@19691
  1052
          in (x::xs)::(part xs') end
wenzelm@19691
  1053
  in part end;
wenzelm@19691
  1054
wenzelm@19691
  1055
clasohm@0
  1056
wenzelm@233
  1057
(* generating identifiers *)
clasohm@0
  1058
paulson@4063
  1059
(** Freshly generated identifiers; supplied prefix MUST start with a letter **)
wenzelm@22369
  1060
local
wenzelm@22369
  1061
(*Maps 0-61 to A-Z, a-z, 0-9; exclude _ or ' to avoid clash with internal/unusual indentifiers*)
wenzelm@22582
  1062
fun gensym_char i =
paulson@22368
  1063
  if i<26 then chr (ord "A" + i)
paulson@22368
  1064
  else if i<52 then chr (ord "a" + i - 26)
wenzelm@22369
  1065
  else chr (ord "0" + i - 52);
paulson@4063
  1066
wenzelm@22369
  1067
val char_vec = Vector.tabulate (62, gensym_char);
wenzelm@22369
  1068
fun newid n = implode (map (fn i => Vector.sub (char_vec, i)) (radixpand (62, n)));
wenzelm@4284
  1069
paulson@22368
  1070
val gensym_seed = ref 0;
paulson@2003
  1071
wenzelm@22369
  1072
in
wenzelm@22369
  1073
  fun gensym pre = pre ^ newid (inc gensym_seed);
wenzelm@22369
  1074
end;
paulson@4063
  1075
paulson@4063
  1076
wenzelm@16439
  1077
(* stamps and serial numbers *)
wenzelm@16439
  1078
wenzelm@16439
  1079
type stamp = unit ref;
wenzelm@16439
  1080
val stamp: unit -> stamp = ref;
wenzelm@16439
  1081
wenzelm@16439
  1082
type serial = int;
wenzelm@16439
  1083
local val count = ref 0
wenzelm@16439
  1084
in fun serial () = inc count end;
wenzelm@16439
  1085
wenzelm@19512
  1086
val serial_string = string_of_int o serial;
wenzelm@19512
  1087
wenzelm@16535
  1088
wenzelm@16535
  1089
(* generic objects *)
wenzelm@16535
  1090
wenzelm@16535
  1091
(*note that the builtin exception datatype may be extended by new
wenzelm@16535
  1092
  constructors at any time*)
wenzelm@16535
  1093
structure Object = struct type T = exn end;
wenzelm@16535
  1094
clasohm@1364
  1095
end;
clasohm@1364
  1096
wenzelm@15745
  1097
structure BasicLibrary: BASIC_LIBRARY = Library;
wenzelm@15745
  1098
open BasicLibrary;