src/Pure/library.ML
author wenzelm
Sat May 20 23:37:02 2006 +0200 (2006-05-20)
changeset 19691 dd9ccb370f52
parent 19644 0b01436e1843
child 19799 666de5708ae8
permissions -rw-r--r--
removed obsolete partition (cf. List.partition);
tuned;
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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, balanced trees, orders, current directory, misc.
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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 \ \\ ins ins_string ins_int 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 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 * ('a -> 'b) -> 'b
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  val |-> : ('c * 'a) * ('c -> 'a -> 'b) -> 'b
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  val ||> : ('c * 'a) * ('a -> 'b) -> 'c * 'b
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  val ||>> : ('c * 'a) * ('a -> 'd * 'b) -> ('c * 'd) * 'b
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  val |>> : ('a * 'c) * ('a -> 'b) -> 'b * 'c
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  val |>>> : ('a * 'c) * ('a -> 'b * 'd) -> 'b * ('c * 'd)
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  val #> : ('a -> 'b) * ('b -> 'c) -> 'a -> 'c
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  val #-> : ('a -> 'c * 'b) * ('c -> 'b -> 'd) -> 'a -> 'd
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  val ? : ('a -> bool) * ('a -> 'a) -> 'a -> 'a
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  val ` : ('b -> 'a) -> 'b -> 'a * 'b
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  val tap: ('b -> 'a) -> 'b -> 'b
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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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  (*options*)
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  val the: 'a option -> 'a
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  val these: 'a list option -> 'a list
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  val the_default: 'a -> 'a option -> 'a
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  val the_list: 'a option -> 'a list
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  val is_some: 'a option -> bool
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  val is_none: 'a option -> bool
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  val perhaps: ('a -> 'a option) -> 'a -> 'a
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  val merge_opt: ('a * 'a -> bool) -> 'a option * 'a option -> 'a option
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  (*exceptions*)
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  val try: ('a -> 'b) -> 'a -> 'b option
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  val can: ('a -> 'b) -> 'a -> bool
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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: bool -> string -> unit
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  val deny: bool -> string -> unit
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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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  val string_of_pair: ('a -> string) -> ('b -> string) -> 'a * 'b -> string
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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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  val conditional: bool -> (unit -> unit) -> unit
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  (*lists*)
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  exception UnequalLengths
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  val cons: 'a -> 'a list -> 'a list
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  val single: 'a -> 'a list
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  val singleton: ('a list -> 'b list) -> 'a -> 'b
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  val append: 'a list -> 'a list -> 'a list
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  val apply: ('a -> 'a) list -> 'a -> 'a
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  val fold: ('a -> 'b -> 'b) -> 'a list -> 'b -> 'b
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  val fold_rev: ('a -> 'b -> 'b) -> 'a list -> 'b -> 'b
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  val fold_map: ('a -> 'b -> 'c * 'b) -> 'a list -> 'b -> 'c list * 'b
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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 maps: ('a -> 'b list) -> 'a list -> 'b 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 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_update: int * 'a -> 'a list -> 'a list
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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 ~~ : '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 equal_lists: ('a * 'b -> bool) -> 'a list * 'b list -> bool
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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 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 gcd: IntInf.int * IntInf.int -> IntInf.int
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  val lcm: IntInf.int * IntInf.int -> IntInf.int
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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 downto0: int list * int -> bool
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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 string_of_indexname: string * int -> string
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  val read_radixint: int * string list -> 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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  val string_of_list: ('a -> string) -> 'a list -> string
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  val string_of_option: ('a -> string) -> 'a option -> 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 ins: ''a * ''a list -> ''a list
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  val ins_int: int * int list -> int list
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  val ins_string: string * string list -> string list
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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 gen_rem: ('a * 'b -> bool) -> 'a list * 'b -> 'a list
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  val gen_rems: ('a * 'b -> bool) -> 'a list * 'b list -> 'a list
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  val findrep: ''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 tables -- see also Pure/General/alist.ML*)
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  val gen_merge_lists: ('a * 'a -> bool) -> 'a list -> 'a list -> 'a list
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  val merge_lists: ''a list -> ''a list -> ''a list
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  val merge_alists: (''a * 'b) list -> (''a * 'b) list -> (''a * 'b) list
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  (*balanced trees*)
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  exception Balance
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  val fold_bal: ('a * 'a -> 'a) -> 'a list -> 'a
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  val access_bal: ('a -> 'a) * ('a -> 'a) * 'a -> int -> int -> 'a
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  val accesses_bal: ('a -> 'a) * ('a -> 'a) * 'a -> int -> 'a list
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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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  val scanwords: (string -> bool) -> string list -> string list
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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;
wenzelm@4621
   281
wenzelm@15745
   282
signature LIBRARY =
skalberg@15570
   283
sig
wenzelm@15745
   284
  include BASIC_LIBRARY
skalberg@15570
   285
  val foldl: ('a * 'b -> 'a) -> 'a * 'b list -> 'a
skalberg@15570
   286
  val foldr: ('a * 'b -> 'b) -> 'a list * 'b -> 'b
skalberg@15570
   287
  val take: int * 'a list -> 'a list
skalberg@15570
   288
  val drop: int * 'a list -> 'a list
skalberg@15570
   289
  val last_elem: 'a list -> 'a
skalberg@15570
   290
  val seq: ('a -> unit) -> 'a list -> unit
skalberg@15570
   291
end;
skalberg@15570
   292
wenzelm@15745
   293
structure Library: LIBRARY =
clasohm@1364
   294
struct
clasohm@0
   295
wenzelm@4995
   296
wenzelm@233
   297
(** functions **)
clasohm@0
   298
wenzelm@16842
   299
fun I x = x;
wenzelm@16842
   300
fun K x = fn _ => x;
wenzelm@233
   301
fun curry f x y = f (x, y);
wenzelm@233
   302
fun uncurry f (x, y) = f x y;
clasohm@0
   303
wenzelm@16705
   304
(*reverse application and structured results*)
wenzelm@16705
   305
fun x |> f = f x;
wenzelm@16705
   306
fun (x, y) |-> f = f x y;
wenzelm@16705
   307
fun (x, y) |>> f = (f x, y);
wenzelm@16705
   308
fun (x, y) ||> f = (x, f y);
wenzelm@16705
   309
fun (x, y) |>>> f = let val (x', z) = f x in (x', (y, z)) end;
wenzelm@16705
   310
fun (x, y) ||>> f = let val (z, y') = f y in ((x, z), y') end;
wenzelm@16842
   311
wenzelm@16842
   312
(*reverse composition*)
haftmann@16780
   313
fun f #> g = g o f;
wenzelm@16842
   314
fun f #-> g = uncurry g o f;
wenzelm@16842
   315
haftmann@17141
   316
(*conditional application*)
wenzelm@17545
   317
fun b ? f = fn x => if b x then f x else x;
haftmann@17141
   318
wenzelm@16842
   319
(*view results*)
wenzelm@16842
   320
fun `f = fn x => (f x, x);
wenzelm@17545
   321
fun tap f = fn x => (f x; x);
wenzelm@380
   322
wenzelm@16721
   323
(*composition with multiple args*)
wenzelm@16721
   324
fun (f oo g) x y = f (g x y);
wenzelm@16721
   325
fun (f ooo g) x y z = f (g x y z);
wenzelm@16721
   326
fun (f oooo g) x y z w = f (g x y z w);
wenzelm@16721
   327
wenzelm@233
   328
(*function exponentiation: f(...(f x)...) with n applications of f*)
wenzelm@233
   329
fun funpow n f x =
wenzelm@233
   330
  let fun rep (0, x) = x
wenzelm@233
   331
        | rep (n, x) = rep (n - 1, f x)
wenzelm@233
   332
  in rep (n, x) end;
wenzelm@160
   333
wenzelm@160
   334
wenzelm@233
   335
(** options **)
clasohm@0
   336
wenzelm@15970
   337
val the = Option.valOf;
wenzelm@17341
   338
haftmann@17153
   339
fun these (SOME x) = x
haftmann@17313
   340
  | these _ = [];
wenzelm@17341
   341
haftmann@17313
   342
fun the_default x (SOME y) = y
haftmann@17313
   343
  | the_default x _ = x;
wenzelm@17341
   344
haftmann@17313
   345
fun the_list (SOME x) = [x]
haftmann@17313
   346
  | the_list _ = []
wenzelm@15970
   347
wenzelm@15970
   348
fun is_some (SOME _) = true
wenzelm@15970
   349
  | is_some NONE = false;
wenzelm@15970
   350
wenzelm@15970
   351
fun is_none (SOME _) = false
wenzelm@15970
   352
  | is_none NONE = true;
wenzelm@15970
   353
wenzelm@18376
   354
fun perhaps f x = the_default x (f x);
wenzelm@18376
   355
haftmann@19454
   356
fun merge_opt _ (NONE, y) = y
haftmann@19454
   357
  | merge_opt _ (x, NONE) = x
haftmann@19454
   358
  | merge_opt eq (SOME x, SOME y) = if eq (x, y) then SOME y else raise Option;
wenzelm@6959
   359
wenzelm@19474
   360
wenzelm@17341
   361
(* exceptions *)
wenzelm@17341
   362
wenzelm@18681
   363
val do_transform_failure = ref true;
wenzelm@18681
   364
wenzelm@18681
   365
fun transform_failure exn f x =
wenzelm@18681
   366
  if ! do_transform_failure then
wenzelm@18681
   367
    f x handle Interrupt => raise Interrupt | e => raise exn e
wenzelm@18681
   368
  else f x;
wenzelm@18681
   369
wenzelm@17341
   370
exception EXCEPTION of exn * string;
wenzelm@6959
   371
wenzelm@6959
   372
skalberg@15531
   373
fun try f x = SOME (f x)
wenzelm@18681
   374
  handle Interrupt => raise Interrupt | _ => NONE;
wenzelm@6959
   375
wenzelm@6959
   376
fun can f x = is_some (try f x);
wenzelm@4139
   377
wenzelm@4139
   378
wenzelm@14868
   379
datatype 'a result =
wenzelm@14868
   380
  Result of 'a |
wenzelm@14868
   381
  Exn of exn;
wenzelm@14868
   382
wenzelm@14868
   383
fun capture f x = Result (f x) handle e => Exn e;
wenzelm@14868
   384
wenzelm@14868
   385
fun release (Result y) = y
wenzelm@14868
   386
  | release (Exn e) = raise e;
wenzelm@14868
   387
skalberg@15531
   388
fun get_result (Result x) = SOME x
skalberg@15531
   389
  | get_result _ = NONE;
wenzelm@14868
   390
skalberg@15531
   391
fun get_exn (Exn exn) = SOME exn
skalberg@15531
   392
  | get_exn _ = NONE;
wenzelm@14868
   393
wenzelm@14868
   394
wenzelm@18681
   395
(* errors *)
wenzelm@18681
   396
wenzelm@19542
   397
exception SYS_ERROR of string;
wenzelm@19542
   398
fun sys_error msg = raise SYS_ERROR msg;
wenzelm@19542
   399
wenzelm@18681
   400
exception ERROR of string;
wenzelm@18681
   401
fun error msg = raise ERROR msg;
wenzelm@18681
   402
wenzelm@18681
   403
fun cat_error "" msg = error msg
wenzelm@18681
   404
  | cat_error msg1 msg2 = error (msg1 ^ "\n" ^ msg2);
wenzelm@18681
   405
wenzelm@18681
   406
fun assert p msg = if p then () else error msg;
wenzelm@18681
   407
fun deny p msg = if p then error msg else ();
wenzelm@18681
   408
wenzelm@18681
   409
fun assert_all pred list msg =
wenzelm@18681
   410
  let
wenzelm@18681
   411
    fun ass [] = ()
wenzelm@18681
   412
      | ass (x :: xs) = if pred x then ass xs else error (msg x);
wenzelm@18681
   413
  in ass list end;
wenzelm@18681
   414
wenzelm@18681
   415
wenzelm@233
   416
(** pairs **)
wenzelm@233
   417
wenzelm@233
   418
fun pair x y = (x, y);
wenzelm@233
   419
fun rpair x y = (y, x);
wenzelm@233
   420
wenzelm@233
   421
fun fst (x, y) = x;
wenzelm@233
   422
fun snd (x, y) = y;
wenzelm@233
   423
haftmann@17498
   424
fun eq_fst eq ((x1, _), (x2, _)) = eq (x1, x2);
haftmann@17498
   425
fun eq_snd eq ((_, y1), (_, y2)) = eq (y1, y2);
haftmann@19454
   426
fun eq_pair eqx eqy ((x1, y1), (x2, y2)) = eqx (x1, x2) andalso eqy (y1, y2);
wenzelm@233
   427
wenzelm@233
   428
fun swap (x, y) = (y, x);
wenzelm@233
   429
wenzelm@4212
   430
(*apply function to components*)
wenzelm@233
   431
fun apfst f (x, y) = (f x, y);
wenzelm@233
   432
fun apsnd f (x, y) = (x, f y);
wenzelm@4212
   433
fun pairself f (x, y) = (f x, f y);
wenzelm@233
   434
webertj@19567
   435
fun string_of_pair f1 f2 (x, y) = "(" ^ f1 x ^ ", " ^ f2 y ^ ")";
wenzelm@233
   436
wenzelm@233
   437
wenzelm@233
   438
(** booleans **)
wenzelm@233
   439
wenzelm@233
   440
(* equality *)
wenzelm@233
   441
wenzelm@233
   442
fun equal x y = x = y;
wenzelm@233
   443
fun not_equal x y = x <> y;
wenzelm@233
   444
wenzelm@233
   445
(* operators for combining predicates *)
wenzelm@233
   446
wenzelm@16721
   447
fun p orf q = fn x => p x orelse q x;
wenzelm@16721
   448
fun p andf q = fn x => p x andalso q x;
wenzelm@233
   449
wenzelm@233
   450
(* predicates on lists *)
wenzelm@233
   451
wenzelm@233
   452
(*exists pred [x1, ..., xn] ===> pred x1 orelse ... orelse pred xn*)
wenzelm@233
   453
fun exists (pred: 'a -> bool) : 'a list -> bool =
wenzelm@233
   454
  let fun boolf [] = false
wenzelm@233
   455
        | boolf (x :: xs) = pred x orelse boolf xs
wenzelm@233
   456
  in boolf end;
wenzelm@233
   457
wenzelm@233
   458
(*forall pred [x1, ..., xn] ===> pred x1 andalso ... andalso pred xn*)
wenzelm@233
   459
fun forall (pred: 'a -> bool) : 'a list -> bool =
wenzelm@233
   460
  let fun boolf [] = true
wenzelm@233
   461
        | boolf (x :: xs) = pred x andalso boolf xs
wenzelm@233
   462
  in boolf end;
clasohm@0
   463
wenzelm@19644
   464
wenzelm@380
   465
(* flags *)
wenzelm@380
   466
wenzelm@380
   467
fun set flag = (flag := true; true);
wenzelm@380
   468
fun reset flag = (flag := false; false);
wenzelm@380
   469
fun toggle flag = (flag := not (! flag); ! flag);
wenzelm@380
   470
wenzelm@9118
   471
fun change r f = r := f (! r);
wenzelm@9118
   472
wenzelm@18712
   473
(*temporarily set flag during execution*)
wenzelm@2978
   474
fun setmp flag value f x =
wenzelm@2958
   475
  let
wenzelm@2958
   476
    val orig_value = ! flag;
wenzelm@18712
   477
    val _ = flag := value;
wenzelm@18712
   478
    val result = capture f x;
wenzelm@18712
   479
    val _ = flag := orig_value;
wenzelm@18712
   480
  in release result end;
wenzelm@2958
   481
wenzelm@19644
   482
wenzelm@11853
   483
(* conditional execution *)
wenzelm@11853
   484
wenzelm@11853
   485
fun conditional b f = if b then f () else ();
wenzelm@11853
   486
wenzelm@233
   487
wenzelm@233
   488
(** lists **)
wenzelm@233
   489
skalberg@15570
   490
exception UnequalLengths;
wenzelm@233
   491
wenzelm@233
   492
fun cons x xs = x :: xs;
wenzelm@5285
   493
fun single x = [x];
wenzelm@233
   494
wenzelm@19273
   495
fun singleton f x = (case f [x] of [y] => y | _ => raise Empty);
wenzelm@19273
   496
wenzelm@4629
   497
fun append xs ys = xs @ ys;
wenzelm@4629
   498
wenzelm@5904
   499
fun apply [] x = x
wenzelm@5904
   500
  | apply (f :: fs) x = apply fs (f x);
wenzelm@5904
   501
wenzelm@233
   502
wenzelm@233
   503
(* fold *)
wenzelm@233
   504
wenzelm@16654
   505
fun fold f =
wenzelm@16654
   506
  let
wenzelm@16654
   507
    fun fold_aux [] y = y
wenzelm@16654
   508
      | fold_aux (x :: xs) y = fold_aux xs (f x y);
wenzelm@16654
   509
  in fold_aux end;
wenzelm@15760
   510
wenzelm@16654
   511
fun fold_rev f =
wenzelm@16654
   512
  let
wenzelm@16654
   513
    fun fold_aux [] y = y
wenzelm@16654
   514
      | fold_aux (x :: xs) y = f x (fold_aux xs y);
wenzelm@16654
   515
  in fold_aux end;
wenzelm@16654
   516
haftmann@16869
   517
fun fold_map f =
haftmann@16691
   518
  let
haftmann@16691
   519
    fun fold_aux [] y = ([], y)
haftmann@16691
   520
      | fold_aux (x :: xs) y =
haftmann@16691
   521
          let
wenzelm@16705
   522
            val (x', y') = f x y;
wenzelm@16705
   523
            val (xs', y'') = fold_aux xs y';
haftmann@16691
   524
          in (x' :: xs', y'') end;
haftmann@16691
   525
  in fold_aux end;
haftmann@16691
   526
wenzelm@233
   527
(*the following versions of fold are designed to fit nicely with infixes*)
clasohm@0
   528
wenzelm@233
   529
(*  (op @) (e, [x1, ..., xn])  ===>  ((e @ x1) @ x2) ... @ xn
wenzelm@233
   530
    for operators that associate to the left (TAIL RECURSIVE)*)
wenzelm@233
   531
fun foldl (f: 'a * 'b -> 'a) : 'a * 'b list -> 'a =
wenzelm@233
   532
  let fun itl (e, [])  = e
wenzelm@233
   533
        | itl (e, a::l) = itl (f(e, a), l)
wenzelm@233
   534
  in  itl end;
wenzelm@233
   535
wenzelm@233
   536
(*  (op @) ([x1, ..., xn], e)  ===>   x1 @ (x2 ... @ (xn @ e))
wenzelm@233
   537
    for operators that associate to the right (not tail recursive)*)
wenzelm@233
   538
fun foldr f (l, e) =
wenzelm@233
   539
  let fun itr [] = e
wenzelm@233
   540
        | itr (a::l) = f(a, itr l)
wenzelm@233
   541
  in  itr l  end;
wenzelm@233
   542
wenzelm@233
   543
(*  (op @) [x1, ..., xn]  ===>   x1 @ (x2 ... @ (x[n-1] @ xn))
wenzelm@233
   544
    for n > 0, operators that associate to the right (not tail recursive)*)
wenzelm@233
   545
fun foldr1 f l =
wenzelm@4181
   546
  let fun itr [x] = x
wenzelm@233
   547
        | itr (x::l) = f(x, itr l)
wenzelm@233
   548
  in  itr l  end;
wenzelm@233
   549
haftmann@18050
   550
fun fold_index f =
haftmann@18050
   551
  let
haftmann@18514
   552
    fun fold_aux _ [] y = y
haftmann@18050
   553
      | fold_aux i (x :: xs) y = fold_aux (i+1) xs (f (i, x) y);
haftmann@18050
   554
  in fold_aux 0 end;
wenzelm@14792
   555
wenzelm@16705
   556
fun foldl_map f =
wenzelm@16705
   557
  let
wenzelm@16705
   558
    fun fold_aux (x, []) = (x, [])
wenzelm@16705
   559
      | fold_aux (x, y :: ys) =
wenzelm@16705
   560
          let
wenzelm@16705
   561
            val (x', y') = f (x, y);
wenzelm@16705
   562
            val (x'', ys') = fold_aux (x', ys);
wenzelm@16705
   563
          in (x'', y' :: ys') end;
wenzelm@16705
   564
  in fold_aux end;
wenzelm@16705
   565
wenzelm@233
   566
wenzelm@233
   567
(* basic list functions *)
wenzelm@233
   568
wenzelm@19483
   569
fun maps f [] = []
wenzelm@19483
   570
  | maps f (x :: xs) = f x @ maps f xs;
wenzelm@19483
   571
wenzelm@19011
   572
fun chop 0 xs = ([], xs)
wenzelm@19011
   573
  | chop _ [] = ([], [])
wenzelm@19011
   574
  | chop n (x :: xs) = chop (n - 1) xs |>> cons x;
wenzelm@19011
   575
wenzelm@233
   576
(*take the first n elements from a list*)
wenzelm@233
   577
fun take (n, []) = []
wenzelm@233
   578
  | take (n, x :: xs) =
wenzelm@233
   579
      if n > 0 then x :: take (n - 1, xs) else [];
wenzelm@233
   580
wenzelm@233
   581
(*drop the first n elements from a list*)
wenzelm@233
   582
fun drop (n, []) = []
wenzelm@233
   583
  | drop (n, x :: xs) =
wenzelm@233
   584
      if n > 0 then drop (n - 1, xs) else x :: xs;
clasohm@0
   585
nipkow@4713
   586
fun dropwhile P [] = []
nipkow@4713
   587
  | dropwhile P (ys as x::xs) = if P x then dropwhile P xs else ys;
nipkow@4713
   588
wenzelm@233
   589
(*return nth element of a list, where 0 designates the first element;
wenzelm@18461
   590
  raise Subscript if list too short*)
haftmann@18011
   591
fun nth xs i = List.nth (xs, i);
wenzelm@233
   592
wenzelm@18461
   593
fun nth_list xss i = nth xss i handle Subscript => [];
wenzelm@18461
   594
haftmann@18011
   595
(*update nth element*)
haftmann@18011
   596
fun nth_update (n, x) xs =
wenzelm@19474
   597
  (case chop n xs of
wenzelm@19474
   598
    (_, []) => raise Subscript
wenzelm@19474
   599
  | (prfx, _ :: sffx') => prfx @ (x :: sffx'));
haftmann@18011
   600
haftmann@18011
   601
fun nth_map 0 f (x :: xs) = f x :: xs
haftmann@18011
   602
  | nth_map n f (x :: xs) = x :: nth_map (n - 1) f xs
haftmann@18011
   603
  | nth_map _ _ [] = raise Subscript;
wenzelm@11773
   604
haftmann@18514
   605
fun map_index f =
haftmann@18514
   606
  let
haftmann@18514
   607
    fun mapp _ [] = []
haftmann@18514
   608
      | mapp i (x :: xs) = f (i, x) :: mapp (i+1) xs
haftmann@18514
   609
  in mapp 0 end;
haftmann@18514
   610
skalberg@15570
   611
val last_elem = List.last;
wenzelm@233
   612
wenzelm@3762
   613
(*rear decomposition*)
skalberg@15570
   614
fun split_last [] = raise Empty
wenzelm@3762
   615
  | split_last [x] = ([], x)
wenzelm@3762
   616
  | split_last (x :: xs) = apfst (cons x) (split_last xs);
wenzelm@3762
   617
wenzelm@4212
   618
(*find the position of an element in a list*)
wenzelm@4212
   619
fun find_index pred =
wenzelm@4212
   620
  let fun find _ [] = ~1
wenzelm@4212
   621
        | find n (x :: xs) = if pred x then n else find (n + 1) xs;
wenzelm@4212
   622
  in find 0 end;
wenzelm@3762
   623
wenzelm@4224
   624
fun find_index_eq x = find_index (equal x);
wenzelm@4212
   625
wenzelm@4212
   626
(*find first element satisfying predicate*)
skalberg@15531
   627
fun find_first _ [] = NONE
wenzelm@4212
   628
  | find_first pred (x :: xs) =
skalberg@15531
   629
      if pred x then SOME x else find_first pred xs;
wenzelm@233
   630
wenzelm@4916
   631
(*get first element by lookup function*)
skalberg@15531
   632
fun get_first _ [] = NONE
wenzelm@4916
   633
  | get_first f (x :: xs) =
wenzelm@4916
   634
      (case f x of
skalberg@15531
   635
        NONE => get_first f xs
wenzelm@4916
   636
      | some => some);
wenzelm@4916
   637
haftmann@19233
   638
fun get_index f =
haftmann@19233
   639
  let
haftmann@19233
   640
    fun get _ [] = NONE
wenzelm@19461
   641
      | get i (x :: xs) =
haftmann@19233
   642
          case f x
wenzelm@19461
   643
           of NONE => get (i + 1) xs
haftmann@19233
   644
            | SOME y => SOME (i, y)
haftmann@19233
   645
  in get 0 end;
haftmann@19233
   646
haftmann@19454
   647
fun eq_list _ ([], []) = true
wenzelm@19461
   648
  | eq_list eq (x :: xs, y :: ys) = eq (x, y) andalso eq_list eq (xs, ys)
haftmann@19454
   649
  | eq_list _ _ = false;
haftmann@19454
   650
skalberg@15531
   651
val flat = List.concat;
wenzelm@233
   652
wenzelm@12136
   653
fun unflat (xs :: xss) ys =
wenzelm@19424
   654
      let val (ps, qs) = chop (length xs) ys
nipkow@13629
   655
      in ps :: unflat xss qs end
wenzelm@12136
   656
  | unflat [] [] = []
skalberg@15570
   657
  | unflat _ _ = raise UnequalLengths;
wenzelm@12136
   658
haftmann@18441
   659
fun burrow f xss =
haftmann@18359
   660
  unflat xss ((f o flat) xss);
haftmann@18359
   661
haftmann@18549
   662
fun fold_burrow f xss s =
haftmann@18549
   663
  apfst (unflat xss) (f (flat xss) s);
haftmann@18359
   664
wenzelm@233
   665
(*like Lisp's MAPC -- seq proc [x1, ..., xn] evaluates
wenzelm@233
   666
  (proc x1; ...; proc xn) for side effects*)
skalberg@15570
   667
val seq = List.app;
wenzelm@233
   668
wenzelm@233
   669
(*separate s [x1, x2, ..., xn]  ===>  [x1, s, x2, s, ..., s, xn]*)
wenzelm@233
   670
fun separate s (x :: (xs as _ :: _)) = x :: s :: separate s xs
wenzelm@233
   671
  | separate _ xs = xs;
wenzelm@233
   672
wenzelm@233
   673
(*make the list [x, x, ..., x] of length n*)
wenzelm@233
   674
fun replicate n (x: 'a) : 'a list =
wenzelm@233
   675
  let fun rep (0, xs) = xs
wenzelm@233
   676
        | rep (n, xs) = rep (n - 1, x :: xs)
wenzelm@233
   677
  in
skalberg@15570
   678
    if n < 0 then raise Subscript
wenzelm@233
   679
    else rep (n, [])
wenzelm@233
   680
  end;
wenzelm@233
   681
wenzelm@14926
   682
fun translate_string f = String.translate (f o String.str);
wenzelm@14926
   683
wenzelm@4248
   684
(*multiply [a, b, c, ...] * [xs, ys, zs, ...]*)
wenzelm@18148
   685
fun multiply [] _ = []
wenzelm@18148
   686
  | multiply (x :: xs) yss = map (cons x) yss @ multiply xs yss;
wenzelm@4248
   687
wenzelm@14792
   688
(*direct product*)
wenzelm@14792
   689
fun product _ [] = []
wenzelm@14792
   690
  | product [] _ = []
wenzelm@14792
   691
  | product (x :: xs) ys = map (pair x) ys @ product xs ys;
wenzelm@14792
   692
wenzelm@233
   693
wenzelm@233
   694
(* filter *)
wenzelm@233
   695
wenzelm@233
   696
(*copy the list preserving elements that satisfy the predicate*)
skalberg@15531
   697
val filter = List.filter;
clasohm@0
   698
fun filter_out f = filter (not o f);
wenzelm@19483
   699
val map_filter = List.mapPartial;
wenzelm@233
   700
wenzelm@233
   701
wenzelm@233
   702
(* lists of pairs *)
wenzelm@233
   703
skalberg@15570
   704
exception UnequalLengths;
skalberg@15570
   705
haftmann@18330
   706
fun map2 _ [] [] = []
haftmann@18330
   707
  | map2 f (x :: xs) (y :: ys) = f x y :: map2 f xs ys
haftmann@18330
   708
  | map2 _ _ _ = raise UnequalLengths;
wenzelm@380
   709
haftmann@18330
   710
fun fold2 f =
haftmann@18330
   711
  let
haftmann@18330
   712
    fun fold_aux [] [] z = z
haftmann@18330
   713
      | fold_aux (x :: xs) (y :: ys) z = fold_aux xs ys (f x y z)
haftmann@18330
   714
      | fold_aux _ _ _ = raise UnequalLengths;
haftmann@18330
   715
  in fold_aux end;
wenzelm@380
   716
wenzelm@4956
   717
wenzelm@233
   718
(*combine two lists forming a list of pairs:
wenzelm@233
   719
  [x1, ..., xn] ~~ [y1, ..., yn]  ===>  [(x1, y1), ..., (xn, yn)]*)
wenzelm@233
   720
fun [] ~~ [] = []
wenzelm@233
   721
  | (x :: xs) ~~ (y :: ys) = (x, y) :: (xs ~~ ys)
skalberg@15570
   722
  | _ ~~ _ = raise UnequalLengths;
wenzelm@233
   723
wenzelm@233
   724
(*inverse of ~~; the old 'split':
wenzelm@233
   725
  [(x1, y1), ..., (xn, yn)]  ===>  ([x1, ..., xn], [y1, ..., yn])*)
skalberg@15570
   726
val split_list = ListPair.unzip;
wenzelm@233
   727
haftmann@18330
   728
fun equal_lists eq (xs, ys) =
haftmann@18330
   729
  let
haftmann@18330
   730
    fun eq' [] [] = true
haftmann@18330
   731
      | eq' (x :: xs) (y :: ys) = eq (x, y) andalso eq' xs ys
haftmann@18330
   732
  in length xs = length ys andalso eq' xs ys end;
wenzelm@7468
   733
wenzelm@233
   734
wenzelm@233
   735
(* prefixes, suffixes *)
wenzelm@233
   736
haftmann@18441
   737
fun is_prefix _ [] _ = true
haftmann@18441
   738
  | is_prefix eq (x :: xs) (y :: ys) = eq (x, y) andalso is_prefix eq xs ys
haftmann@18441
   739
  | is_prefix eq _ _ = false;
wenzelm@233
   740
wenzelm@233
   741
(* [x1, ..., xi, ..., xn]  --->  ([x1, ..., x(i-1)], [xi, ..., xn])
wenzelm@233
   742
   where xi is the first element that does not satisfy the predicate*)
wenzelm@233
   743
fun take_prefix (pred : 'a -> bool)  (xs: 'a list) : 'a list * 'a list =
wenzelm@233
   744
  let fun take (rxs, []) = (rev rxs, [])
wenzelm@255
   745
        | take (rxs, x :: xs) =
wenzelm@255
   746
            if  pred x  then  take(x :: rxs, xs)  else  (rev rxs, x :: xs)
wenzelm@233
   747
  in  take([], xs)  end;
wenzelm@233
   748
wenzelm@233
   749
(* [x1, ..., xi, ..., xn]  --->  ([x1, ..., xi], [x(i+1), ..., xn])
wenzelm@233
   750
   where xi is the last element that does not satisfy the predicate*)
wenzelm@233
   751
fun take_suffix _ [] = ([], [])
wenzelm@233
   752
  | take_suffix pred (x :: xs) =
wenzelm@233
   753
      (case take_suffix pred xs of
wenzelm@233
   754
        ([], sffx) => if pred x then ([], x :: sffx) else ([x], sffx)
wenzelm@233
   755
      | (prfx, sffx) => (x :: prfx, sffx));
wenzelm@233
   756
wenzelm@12249
   757
fun prefixes1 [] = []
wenzelm@12249
   758
  | prefixes1 (x :: xs) = map (cons x) ([] :: prefixes1 xs);
wenzelm@12249
   759
wenzelm@19011
   760
fun prefixes xs = [] :: prefixes1 xs;
wenzelm@19011
   761
wenzelm@12249
   762
fun suffixes1 xs = map rev (prefixes1 (rev xs));
wenzelm@19011
   763
fun suffixes xs = [] :: suffixes1 xs;
wenzelm@233
   764
wenzelm@233
   765
wenzelm@233
   766
(** integers **)
wenzelm@233
   767
wenzelm@16439
   768
fun gcd (x, y) =
paulson@15965
   769
  let fun gxd x y : IntInf.int =
nipkow@10692
   770
    if y = 0 then x else gxd y (x mod y)
nipkow@10692
   771
  in if x < y then gxd y x else gxd x y end;
nipkow@10692
   772
wenzelm@16439
   773
fun lcm (x, y) = (x * y) div gcd (x, y);
nipkow@10692
   774
wenzelm@2958
   775
fun inc i = (i := ! i + 1; ! i);
wenzelm@2958
   776
fun dec i = (i := ! i - 1; ! i);
wenzelm@233
   777
wenzelm@233
   778
wenzelm@233
   779
(* lists of integers *)
wenzelm@233
   780
wenzelm@233
   781
(*make the list [from, from + 1, ..., to]*)
paulson@2175
   782
fun (from upto to) =
wenzelm@233
   783
  if from > to then [] else from :: ((from + 1) upto to);
wenzelm@233
   784
wenzelm@233
   785
(*make the list [from, from - 1, ..., to]*)
paulson@2175
   786
fun (from downto to) =
wenzelm@233
   787
  if from < to then [] else from :: ((from - 1) downto to);
wenzelm@233
   788
wenzelm@233
   789
(*predicate: downto0 (is, n) <=> is = [n, n - 1, ..., 0]*)
wenzelm@233
   790
fun downto0 (i :: is, n) = i = n andalso downto0 (is, n - 1)
wenzelm@233
   791
  | downto0 ([], n) = n = ~1;
wenzelm@233
   792
wenzelm@233
   793
wenzelm@233
   794
(* convert integers to strings *)
wenzelm@233
   795
wenzelm@233
   796
(*expand the number in the given base;
wenzelm@233
   797
  example: radixpand (2, 8) gives [1, 0, 0, 0]*)
wenzelm@233
   798
fun radixpand (base, num) : int list =
wenzelm@233
   799
  let
wenzelm@233
   800
    fun radix (n, tail) =
wenzelm@233
   801
      if n < base then n :: tail
wenzelm@233
   802
      else radix (n div base, (n mod base) :: tail)
wenzelm@233
   803
  in radix (num, []) end;
wenzelm@233
   804
wenzelm@233
   805
(*expands a number into a string of characters starting from "zerochar";
wenzelm@233
   806
  example: radixstring (2, "0", 8) gives "1000"*)
wenzelm@233
   807
fun radixstring (base, zerochar, num) =
wenzelm@233
   808
  let val offset = ord zerochar;
wenzelm@233
   809
      fun chrof n = chr (offset + n)
wenzelm@233
   810
  in implode (map chrof (radixpand (base, num))) end;
wenzelm@233
   811
wenzelm@233
   812
paulson@3407
   813
val string_of_int = Int.toString;
wenzelm@233
   814
paulson@3407
   815
fun string_of_indexname (a,0) = a
paulson@3407
   816
  | string_of_indexname (a,i) = a ^ "_" ^ Int.toString i;
wenzelm@233
   817
wenzelm@233
   818
wenzelm@14826
   819
(* read integers *)
wenzelm@14826
   820
wenzelm@14826
   821
fun read_radixint (radix: int, cs) : int * string list =
wenzelm@14826
   822
  let val zero = ord"0"
wenzelm@14826
   823
      val limit = zero+radix
wenzelm@14826
   824
      fun scan (num,[]) = (num,[])
wenzelm@14826
   825
        | scan (num, c::cs) =
wenzelm@14826
   826
              if  zero <= ord c  andalso  ord c < limit
wenzelm@14826
   827
              then scan(radix*num + ord c - zero, cs)
wenzelm@14826
   828
              else (num, c::cs)
wenzelm@14826
   829
  in  scan(0,cs)  end;
wenzelm@14826
   830
wenzelm@14826
   831
fun read_int cs = read_radixint (10, cs);
wenzelm@14826
   832
wenzelm@14826
   833
fun oct_char s = chr (#1 (read_radixint (8, explode s)));
wenzelm@14826
   834
wenzelm@14826
   835
wenzelm@14826
   836
wenzelm@233
   837
(** strings **)
wenzelm@233
   838
wenzelm@16188
   839
(* functions tuned for strings, avoiding explode *)
wenzelm@6312
   840
haftmann@18011
   841
fun nth_string str i =
wenzelm@6959
   842
  (case try String.substring (str, i, 1) of
skalberg@15531
   843
    SOME s => s
skalberg@15570
   844
  | NONE => raise Subscript);
wenzelm@6312
   845
wenzelm@16188
   846
fun fold_string f str x0 =
wenzelm@6282
   847
  let
wenzelm@6282
   848
    val n = size str;
wenzelm@16188
   849
    fun iter (x, i) =
wenzelm@16188
   850
      if i < n then iter (f (String.substring (str, i, 1)) x, i + 1) else x;
wenzelm@16188
   851
  in iter (x0, 0) end;
wenzelm@6282
   852
wenzelm@14968
   853
fun exists_string pred str =
wenzelm@14968
   854
  let
wenzelm@14968
   855
    val n = size str;
wenzelm@14968
   856
    fun ex i = i < n andalso (pred (String.substring (str, i, 1)) orelse ex (i + 1));
wenzelm@14968
   857
  in ex 0 end;
wenzelm@6312
   858
wenzelm@16188
   859
fun forall_string pred = not o exists_string (not o pred);
wenzelm@16188
   860
lcp@512
   861
(*enclose in brackets*)
lcp@512
   862
fun enclose lpar rpar str = lpar ^ str ^ rpar;
wenzelm@6642
   863
fun unenclose str = String.substring (str, 1, size str - 2);
wenzelm@255
   864
wenzelm@233
   865
(*simple quoting (does not escape special chars)*)
lcp@512
   866
val quote = enclose "\"" "\"";
wenzelm@233
   867
wenzelm@4212
   868
(*space_implode "..." (explode "hello") = "h...e...l...l...o"*)
wenzelm@233
   869
fun space_implode a bs = implode (separate a bs);
wenzelm@233
   870
wenzelm@255
   871
val commas = space_implode ", ";
wenzelm@380
   872
val commas_quote = commas o map quote;
wenzelm@255
   873
wenzelm@233
   874
(*concatenate messages, one per line, into a string*)
wenzelm@255
   875
val cat_lines = space_implode "\n";
wenzelm@233
   876
wenzelm@4212
   877
(*space_explode "." "h.e..l.lo" = ["h", "e", "", "l", "lo"]*)
wenzelm@3832
   878
fun space_explode _ "" = []
wenzelm@3832
   879
  | space_explode sep str =
wenzelm@3832
   880
      let
wenzelm@3832
   881
        fun expl chs =
wenzelm@19301
   882
          (case take_prefix (fn s => s <> sep) chs of
wenzelm@3832
   883
            (cs, []) => [implode cs]
wenzelm@3832
   884
          | (cs, _ :: cs') => implode cs :: expl cs');
wenzelm@3832
   885
      in expl (explode str) end;
wenzelm@3832
   886
wenzelm@3832
   887
val split_lines = space_explode "\n";
wenzelm@3832
   888
wenzelm@14826
   889
fun prefix_lines "" txt = txt
wenzelm@14826
   890
  | prefix_lines prfx txt = txt |> split_lines |> map (fn s => prfx ^ s) |> cat_lines;
wenzelm@14826
   891
wenzelm@7712
   892
fun untabify chs =
wenzelm@7712
   893
  let
wenzelm@7712
   894
    val tab_width = 8;
wenzelm@7712
   895
wenzelm@7712
   896
    fun untab (_, "\n") = (0, ["\n"])
wenzelm@9118
   897
      | untab (pos, "\t") =
wenzelm@9118
   898
          let val d = tab_width - (pos mod tab_width) in (pos + d, replicate d " ") end
wenzelm@7712
   899
      | untab (pos, c) = (pos + 1, [c]);
wenzelm@7712
   900
  in
wenzelm@19301
   901
    if not (exists (fn c => c = "\t") chs) then chs
wenzelm@7712
   902
    else flat (#2 (foldl_map untab (0, chs)))
wenzelm@7712
   903
  end;
wenzelm@7712
   904
wenzelm@18681
   905
fun prefix prfx s = prfx ^ s;
wenzelm@16188
   906
fun suffix sffx s = s ^ sffx;
wenzelm@5285
   907
wenzelm@18681
   908
fun unprefix prfx s =
wenzelm@18681
   909
  if String.isPrefix prfx s then String.substring (s, size prfx, size s - size prfx)
wenzelm@18681
   910
  else raise Fail "unprefix";
wenzelm@18681
   911
wenzelm@16188
   912
fun unsuffix sffx s =
wenzelm@17061
   913
  if String.isSuffix sffx s then String.substring (s, 0, size s - size sffx)
wenzelm@17061
   914
  else raise Fail "unsuffix";
wenzelm@5285
   915
wenzelm@10951
   916
fun replicate_string 0 _ = ""
wenzelm@10951
   917
  | replicate_string 1 a = a
wenzelm@10951
   918
  | replicate_string k a =
wenzelm@10951
   919
      if k mod 2 = 0 then replicate_string (k div 2) (a ^ a)
wenzelm@10951
   920
      else replicate_string (k div 2) (a ^ a) ^ a;
wenzelm@10951
   921
wenzelm@19644
   922
fun string_of_list f = enclose "[" "]" o commas o map f;
wenzelm@19644
   923
wenzelm@19644
   924
fun string_of_option f NONE = "NONE"
wenzelm@19644
   925
  | string_of_option f (SOME x) = "SOME (" ^ f x ^ ")";
wenzelm@19644
   926
wenzelm@3832
   927
wenzelm@233
   928
wenzelm@16492
   929
(** lists as sets -- see also Pure/General/ord_list.ML **)
wenzelm@233
   930
wenzelm@18923
   931
(*canonical member, insert, remove*)
wenzelm@18923
   932
fun member eq list x =
wenzelm@18923
   933
  let
wenzelm@18923
   934
    fun memb [] = false
wenzelm@18923
   935
      | memb (y :: ys) = eq (x, y) orelse memb ys;
wenzelm@18923
   936
  in memb list end;
berghofe@1576
   937
wenzelm@18923
   938
fun insert eq x xs = if member eq xs x then xs else x :: xs;
wenzelm@18923
   939
fun remove eq x xs = if member eq xs x then filter_out (fn y => eq (x, y)) xs else xs;
wenzelm@233
   940
wenzelm@19301
   941
fun subtract eq = fold (remove eq);
wenzelm@19301
   942
wenzelm@18923
   943
fun merge _ ([], ys) = ys
wenzelm@18923
   944
  | merge eq (xs, ys) = fold_rev (insert eq) ys xs;
clasohm@0
   945
wenzelm@18923
   946
(*old-style infixes*)
wenzelm@18923
   947
fun x mem xs = member (op =) xs x;
wenzelm@18923
   948
fun (x: int) mem_int xs = member (op =) xs x;
wenzelm@18923
   949
fun (x: string) mem_string xs = member (op =) xs x;
berghofe@1576
   950
wenzelm@18923
   951
fun x ins xs = insert (op =) x xs;
wenzelm@18989
   952
fun (x: int) ins_int xs = insert (op =) x xs;
wenzelm@18989
   953
fun (x: string) ins_string xs = insert (op =) x xs;
wenzelm@18989
   954
wenzelm@233
   955
wenzelm@233
   956
(*union of sets represented as lists: no repetitions*)
wenzelm@233
   957
fun xs union [] = xs
wenzelm@233
   958
  | [] union ys = ys
wenzelm@233
   959
  | (x :: xs) union ys = xs union (x ins ys);
clasohm@0
   960
paulson@2175
   961
(*union of sets, optimized version for ints*)
berghofe@1576
   962
fun (xs:int list) union_int [] = xs
berghofe@1576
   963
  | [] union_int ys = ys
berghofe@1576
   964
  | (x :: xs) union_int ys = xs union_int (x ins_int ys);
berghofe@1576
   965
paulson@2175
   966
(*union of sets, optimized version for strings*)
berghofe@1576
   967
fun (xs:string list) union_string [] = xs
berghofe@1576
   968
  | [] union_string ys = ys
berghofe@1576
   969
  | (x :: xs) union_string ys = xs union_string (x ins_string ys);
berghofe@1576
   970
clasohm@0
   971
(*generalized union*)
wenzelm@233
   972
fun gen_union eq (xs, []) = xs
wenzelm@233
   973
  | gen_union eq ([], ys) = ys
wenzelm@18923
   974
  | gen_union eq (x :: xs, ys) = gen_union eq (xs, insert eq x ys);
wenzelm@233
   975
wenzelm@233
   976
wenzelm@233
   977
(*intersection*)
wenzelm@233
   978
fun [] inter ys = []
wenzelm@233
   979
  | (x :: xs) inter ys =
wenzelm@233
   980
      if x mem ys then x :: (xs inter ys) else xs inter ys;
wenzelm@233
   981
paulson@2175
   982
(*intersection, optimized version for ints*)
berghofe@1576
   983
fun ([]:int list) inter_int ys = []
berghofe@1576
   984
  | (x :: xs) inter_int ys =
berghofe@1576
   985
      if x mem_int ys then x :: (xs inter_int ys) else xs inter_int ys;
berghofe@1576
   986
paulson@2175
   987
(*intersection, optimized version for strings *)
berghofe@1576
   988
fun ([]:string list) inter_string ys = []
berghofe@1576
   989
  | (x :: xs) inter_string ys =
berghofe@1576
   990
      if x mem_string ys then x :: (xs inter_string ys) else xs inter_string ys;
berghofe@1576
   991
paulson@7090
   992
(*generalized intersection*)
paulson@7090
   993
fun gen_inter eq ([], ys) = []
wenzelm@12284
   994
  | gen_inter eq (x::xs, ys) =
wenzelm@18923
   995
      if member eq ys x then x :: gen_inter eq (xs, ys)
wenzelm@18923
   996
      else gen_inter eq (xs, ys);
paulson@7090
   997
wenzelm@233
   998
wenzelm@233
   999
(*subset*)
wenzelm@233
  1000
fun [] subset ys = true
wenzelm@233
  1001
  | (x :: xs) subset ys = x mem ys andalso xs subset ys;
wenzelm@233
  1002
paulson@2175
  1003
(*subset, optimized version for ints*)
wenzelm@16439
  1004
fun ([]: int list) subset_int ys = true
berghofe@1576
  1005
  | (x :: xs) subset_int ys = x mem_int ys andalso xs subset_int ys;
berghofe@1576
  1006
paulson@2175
  1007
(*subset, optimized version for strings*)
wenzelm@16439
  1008
fun ([]: string list) subset_string ys = true
berghofe@1576
  1009
  | (x :: xs) subset_string ys = x mem_string ys andalso xs subset_string ys;
berghofe@1576
  1010
wenzelm@4363
  1011
(*set equality*)
wenzelm@4363
  1012
fun eq_set (xs, ys) =
wenzelm@4363
  1013
  xs = ys orelse (xs subset ys andalso ys subset xs);
wenzelm@4363
  1014
paulson@2182
  1015
(*set equality for strings*)
wenzelm@16439
  1016
fun eq_set_string ((xs: string list), ys) =
berghofe@1576
  1017
  xs = ys orelse (xs subset_string ys andalso ys subset_string xs);
berghofe@1576
  1018
wenzelm@18923
  1019
fun gen_subset eq (xs, ys) = forall (member eq ys) xs;
paulson@2182
  1020
wenzelm@19301
  1021
fun gen_eq_set eq (xs, ys) =
wenzelm@19301
  1022
  equal_lists eq (xs, ys) orelse
wenzelm@19301
  1023
    (gen_subset eq (xs, ys) andalso gen_subset (eq o swap) (ys, xs));
wenzelm@19301
  1024
wenzelm@265
  1025
wenzelm@233
  1026
(*removing an element from a list WITHOUT duplicates*)
wenzelm@233
  1027
fun (y :: ys) \ x = if x = y then ys else y :: (ys \ x)
wenzelm@233
  1028
  | [] \ x = [];
wenzelm@233
  1029
paulson@2243
  1030
fun ys \\ xs = foldl (op \) (ys,xs);
clasohm@0
  1031
wenzelm@233
  1032
(*removing an element from a list -- possibly WITH duplicates*)
wenzelm@233
  1033
fun gen_rem eq (xs, y) = filter_out (fn x => eq (x, y)) xs;
wenzelm@18923
  1034
fun gen_rems eq (xs, ys) = filter_out (member eq ys) xs;
wenzelm@233
  1035
wenzelm@19046
  1036
(*returns the tail beginning with the first repeated element, or []*)
wenzelm@19046
  1037
fun findrep [] = []
wenzelm@19046
  1038
  | findrep (x :: xs) = if x mem xs then x :: xs else findrep xs;
wenzelm@19046
  1039
wenzelm@19046
  1040
wenzelm@233
  1041
(*makes a list of the distinct members of the input; preserves order, takes
wenzelm@233
  1042
  first of equal elements*)
wenzelm@19046
  1043
fun distinct eq lst =
wenzelm@233
  1044
  let
wenzelm@233
  1045
    fun dist (rev_seen, []) = rev rev_seen
wenzelm@233
  1046
      | dist (rev_seen, x :: xs) =
wenzelm@18923
  1047
          if member eq rev_seen x then dist (rev_seen, xs)
wenzelm@233
  1048
          else dist (x :: rev_seen, xs);
wenzelm@19046
  1049
  in dist ([], lst) end;
wenzelm@233
  1050
wenzelm@255
  1051
(*returns a list containing all repeated elements exactly once; preserves
wenzelm@255
  1052
  order, takes first of equal elements*)
wenzelm@18966
  1053
fun duplicates eq lst =
wenzelm@255
  1054
  let
wenzelm@255
  1055
    fun dups (rev_dups, []) = rev rev_dups
wenzelm@255
  1056
      | dups (rev_dups, x :: xs) =
wenzelm@18923
  1057
          if member eq rev_dups x orelse not (member eq xs x) then
wenzelm@255
  1058
            dups (rev_dups, xs)
wenzelm@255
  1059
          else dups (x :: rev_dups, xs);
wenzelm@18966
  1060
  in dups ([], lst) end;
wenzelm@255
  1061
wenzelm@16878
  1062
fun has_duplicates eq =
wenzelm@16878
  1063
  let
wenzelm@16878
  1064
    fun dups [] = false
wenzelm@16878
  1065
      | dups (x :: xs) = member eq xs x orelse dups xs;
wenzelm@16878
  1066
  in dups end;
wenzelm@16878
  1067
wenzelm@255
  1068
haftmann@19119
  1069
(** association lists -- legacy operations **)
wenzelm@233
  1070
wenzelm@12284
  1071
fun gen_merge_lists _ xs [] = xs
wenzelm@12284
  1072
  | gen_merge_lists _ [] ys = ys
wenzelm@12284
  1073
  | gen_merge_lists eq xs ys = xs @ gen_rems eq (ys, xs);
clasohm@0
  1074
wenzelm@12284
  1075
fun merge_lists xs ys = gen_merge_lists (op =) xs ys;
haftmann@17498
  1076
fun merge_alists al = gen_merge_lists (eq_fst (op =)) al;
clasohm@0
  1077
clasohm@0
  1078
wenzelm@233
  1079
(** balanced trees **)
wenzelm@233
  1080
wenzelm@233
  1081
exception Balance;      (*indicates non-positive argument to balancing fun*)
wenzelm@233
  1082
wenzelm@233
  1083
(*balanced folding; avoids deep nesting*)
wenzelm@233
  1084
fun fold_bal f [x] = x
wenzelm@233
  1085
  | fold_bal f [] = raise Balance
wenzelm@233
  1086
  | fold_bal f xs =
wenzelm@19474
  1087
      let val (ps, qs) = chop (length xs div 2) xs
nipkow@13629
  1088
      in  f (fold_bal f ps, fold_bal f qs)  end;
wenzelm@233
  1089
wenzelm@233
  1090
(*construct something of the form f(...g(...(x)...)) for balanced access*)
wenzelm@233
  1091
fun access_bal (f, g, x) n i =
wenzelm@233
  1092
  let fun acc n i =     (*1<=i<=n*)
wenzelm@233
  1093
          if n=1 then x else
wenzelm@233
  1094
          let val n2 = n div 2
wenzelm@233
  1095
          in  if i<=n2 then f (acc n2 i)
wenzelm@233
  1096
                       else g (acc (n-n2) (i-n2))
wenzelm@233
  1097
          end
wenzelm@233
  1098
  in  if 1<=i andalso i<=n then acc n i else raise Balance  end;
wenzelm@233
  1099
wenzelm@233
  1100
(*construct ALL such accesses; could try harder to share recursive calls!*)
wenzelm@233
  1101
fun accesses_bal (f, g, x) n =
wenzelm@233
  1102
  let fun acc n =
wenzelm@233
  1103
          if n=1 then [x] else
wenzelm@233
  1104
          let val n2 = n div 2
wenzelm@233
  1105
              val acc2 = acc n2
wenzelm@233
  1106
          in  if n-n2=n2 then map f acc2 @ map g acc2
wenzelm@233
  1107
                         else map f acc2 @ map g (acc (n-n2)) end
wenzelm@233
  1108
  in  if 1<=n then acc n else raise Balance  end;
wenzelm@233
  1109
wenzelm@233
  1110
wenzelm@233
  1111
wenzelm@2506
  1112
(** orders **)
wenzelm@2506
  1113
wenzelm@18966
  1114
fun is_equal EQUAL = true
wenzelm@18966
  1115
  | is_equal _ = false;
wenzelm@18966
  1116
wenzelm@4445
  1117
fun rev_order LESS = GREATER
wenzelm@4445
  1118
  | rev_order EQUAL = EQUAL
wenzelm@4445
  1119
  | rev_order GREATER = LESS;
wenzelm@4445
  1120
wenzelm@4479
  1121
(*assume rel is a linear strict order*)
wenzelm@4445
  1122
fun make_ord rel (x, y) =
wenzelm@4445
  1123
  if rel (x, y) then LESS
wenzelm@4445
  1124
  else if rel (y, x) then GREATER
wenzelm@4445
  1125
  else EQUAL;
wenzelm@4445
  1126
wenzelm@15051
  1127
val int_ord = Int.compare;
wenzelm@15051
  1128
val string_ord = String.compare;
wenzelm@2506
  1129
wenzelm@16676
  1130
fun fast_string_ord (s1, s2) =
wenzelm@16676
  1131
  (case int_ord (size s1, size s2) of EQUAL => string_ord (s1, s2) | ord => ord);
wenzelm@16676
  1132
wenzelm@16492
  1133
fun option_ord ord (SOME x, SOME y) = ord (x, y)
wenzelm@16492
  1134
  | option_ord _ (NONE, NONE) = EQUAL
wenzelm@16492
  1135
  | option_ord _ (NONE, SOME _) = LESS
wenzelm@16492
  1136
  | option_ord _ (SOME _, NONE) = GREATER;
wenzelm@16492
  1137
wenzelm@4343
  1138
(*lexicographic product*)
wenzelm@4343
  1139
fun prod_ord a_ord b_ord ((x, y), (x', y')) =
wenzelm@4343
  1140
  (case a_ord (x, x') of EQUAL => b_ord (y, y') | ord => ord);
wenzelm@4343
  1141
wenzelm@4343
  1142
(*dictionary order -- in general NOT well-founded!*)
wenzelm@16984
  1143
fun dict_ord elem_ord (x :: xs, y :: ys) =
wenzelm@16984
  1144
      (case elem_ord (x, y) of EQUAL => dict_ord elem_ord (xs, ys) | ord => ord)
wenzelm@16984
  1145
  | dict_ord _ ([], []) = EQUAL
wenzelm@4343
  1146
  | dict_ord _ ([], _ :: _) = LESS
wenzelm@16984
  1147
  | dict_ord _ (_ :: _, []) = GREATER;
wenzelm@4343
  1148
wenzelm@4343
  1149
(*lexicographic product of lists*)
wenzelm@4343
  1150
fun list_ord elem_ord (xs, ys) =
wenzelm@16676
  1151
  (case int_ord (length xs, length ys) of EQUAL => dict_ord elem_ord (xs, ys) | ord => ord);
wenzelm@4343
  1152
wenzelm@2506
  1153
wenzelm@4621
  1154
(* sorting *)
wenzelm@4621
  1155
wenzelm@18427
  1156
(*quicksort -- stable, i.e. does not reorder equal elements*)
wenzelm@18427
  1157
fun quicksort unique ord =
wenzelm@4621
  1158
  let
wenzelm@16878
  1159
    fun qsort [] = []
wenzelm@16878
  1160
      | qsort (xs as [_]) = xs
wenzelm@18427
  1161
      | qsort (xs as [x, y]) =
wenzelm@18427
  1162
          (case ord (x, y) of
wenzelm@18427
  1163
            LESS => xs
wenzelm@18427
  1164
          | EQUAL => if unique then [x] else xs
wenzelm@18427
  1165
          | GREATER => [y, x])
wenzelm@16878
  1166
      | qsort xs =
haftmann@18011
  1167
          let val (lts, eqs, gts) = part (nth xs (length xs div 2)) xs
wenzelm@16878
  1168
          in qsort lts @ eqs @ qsort gts end
wenzelm@4621
  1169
    and part _ [] = ([], [], [])
wenzelm@4621
  1170
      | part pivot (x :: xs) = add (ord (x, pivot)) x (part pivot xs)
wenzelm@4621
  1171
    and add LESS x (lts, eqs, gts) = (x :: lts, eqs, gts)
wenzelm@18427
  1172
      | add EQUAL x (lts, [], gts) = (lts, [x], gts)
wenzelm@18427
  1173
      | add EQUAL x (res as (lts, eqs, gts)) = if unique then res else (lts, x :: eqs, gts)
wenzelm@4621
  1174
      | add GREATER x (lts, eqs, gts) = (lts, eqs, x :: gts);
wenzelm@4621
  1175
  in qsort end;
wenzelm@4621
  1176
wenzelm@18427
  1177
fun sort ord = quicksort false ord;
wenzelm@18427
  1178
fun sort_distinct ord = quicksort true ord;
wenzelm@18427
  1179
wenzelm@4621
  1180
val sort_strings = sort string_ord;
wenzelm@4621
  1181
fun sort_wrt sel xs = sort (string_ord o pairself sel) xs;
wenzelm@4621
  1182
wenzelm@4621
  1183
wenzelm@2506
  1184
berghofe@14106
  1185
(** random numbers **)
berghofe@14106
  1186
berghofe@14106
  1187
exception RANDOM;
berghofe@14106
  1188
berghofe@14618
  1189
fun rmod x y = x - y * Real.realFloor (x / y);
berghofe@14106
  1190
berghofe@14106
  1191
local
berghofe@14106
  1192
  val a = 16807.0;
berghofe@14106
  1193
  val m = 2147483647.0;
berghofe@14106
  1194
  val random_seed = ref 1.0;
berghofe@14106
  1195
in
berghofe@14106
  1196
berghofe@14106
  1197
fun random () =
berghofe@14106
  1198
  let val r = rmod (a * !random_seed) m
berghofe@14106
  1199
  in (random_seed := r; r) end;
berghofe@14106
  1200
berghofe@14106
  1201
end;
berghofe@14106
  1202
berghofe@14106
  1203
fun random_range l h =
berghofe@14106
  1204
  if h < l orelse l < 0 then raise RANDOM
berghofe@14106
  1205
  else l + Real.floor (rmod (random ()) (real (h - l + 1)));
berghofe@14106
  1206
haftmann@18011
  1207
fun one_of xs = nth xs (random_range 0 (length xs - 1));
berghofe@14106
  1208
berghofe@14106
  1209
fun frequency xs =
berghofe@14106
  1210
  let
berghofe@14106
  1211
    val sum = foldl op + (0, map fst xs);
wenzelm@17756
  1212
    fun pick n ((k: int, x) :: xs) =
berghofe@14106
  1213
      if n <= k then x else pick (n - k) xs
berghofe@14106
  1214
  in pick (random_range 1 sum) xs end;
berghofe@14106
  1215
berghofe@14106
  1216
wenzelm@14826
  1217
(** current directory **)
wenzelm@233
  1218
paulson@2243
  1219
val cd = OS.FileSys.chDir;
wenzelm@2317
  1220
val pwd = OS.FileSys.getDir;
paulson@2243
  1221
berghofe@3606
  1222
wenzelm@19644
  1223
wenzelm@4621
  1224
(** misc **)
wenzelm@233
  1225
wenzelm@19644
  1226
fun divide_and_conquer decomp x =
wenzelm@19644
  1227
  let val (ys, recomb) = decomp x
wenzelm@19644
  1228
  in recomb (map (divide_and_conquer decomp) ys) end;
wenzelm@19644
  1229
clasohm@0
  1230
wenzelm@233
  1231
(*Partition a list into buckets  [ bi, b(i+1), ..., bj ]
clasohm@0
  1232
   putting x in bk if p(k)(x) holds.  Preserve order of elements if possible.*)
clasohm@0
  1233
fun partition_list p i j =
wenzelm@233
  1234
  let fun part k xs =
wenzelm@233
  1235
            if k>j then
clasohm@0
  1236
              (case xs of [] => []
skalberg@15570
  1237
                         | _ => raise Fail "partition_list")
clasohm@0
  1238
            else
wenzelm@19691
  1239
            let val (ns, rest) = List.partition (p k) xs;
wenzelm@233
  1240
            in  ns :: part(k+1)rest  end
clasohm@0
  1241
  in  part i end;
clasohm@0
  1242
wenzelm@19691
  1243
fun partition_eq (eq:'a * 'a -> bool) =
wenzelm@19691
  1244
  let
wenzelm@19691
  1245
    fun part [] = []
wenzelm@19691
  1246
      | part (x :: ys) =
wenzelm@19691
  1247
          let val (xs, xs') = List.partition (fn y => eq (x, y)) ys
wenzelm@19691
  1248
          in (x::xs)::(part xs') end
wenzelm@19691
  1249
  in part end;
wenzelm@19691
  1250
wenzelm@19691
  1251
clasohm@0
  1252
wenzelm@233
  1253
(* generating identifiers *)
clasohm@0
  1254
paulson@4063
  1255
(** Freshly generated identifiers; supplied prefix MUST start with a letter **)
clasohm@0
  1256
local
paulson@4063
  1257
(*Maps 0-63 to A-Z, a-z, 0-9 or _ or ' for generating random identifiers*)
paulson@4063
  1258
fun char i =      if i<26 then chr (ord "A" + i)
wenzelm@5904
  1259
             else if i<52 then chr (ord "a" + i - 26)
wenzelm@5904
  1260
             else if i<62 then chr (ord"0" + i - 52)
wenzelm@5904
  1261
             else if i=62 then "_"
wenzelm@5904
  1262
             else  (*i=63*)    "'";
paulson@4063
  1263
paulson@4063
  1264
val charVec = Vector.tabulate (64, char);
paulson@4063
  1265
wenzelm@5904
  1266
fun newid n =
wenzelm@5904
  1267
  let
wenzelm@4284
  1268
  in  implode (map (fn i => Vector.sub(charVec,i)) (radixpand (64,n)))  end;
paulson@2003
  1269
wenzelm@4284
  1270
val seedr = ref 0;
clasohm@0
  1271
paulson@4063
  1272
in
wenzelm@4284
  1273
wenzelm@12346
  1274
fun gensym pre = pre ^ (#1(newid (!seedr), inc seedr));
paulson@2003
  1275
paulson@4063
  1276
end;
paulson@4063
  1277
paulson@4063
  1278
wenzelm@233
  1279
(* lexical scanning *)
clasohm@0
  1280
wenzelm@233
  1281
(*scan a list of characters into "words" composed of "letters" (recognized by
wenzelm@233
  1282
  is_let) and separated by any number of non-"letters"*)
wenzelm@233
  1283
fun scanwords is_let cs =
clasohm@0
  1284
  let fun scan1 [] = []
wenzelm@233
  1285
        | scan1 cs =
wenzelm@233
  1286
            let val (lets, rest) = take_prefix is_let cs
wenzelm@233
  1287
            in implode lets :: scanwords is_let rest end;
wenzelm@233
  1288
  in scan1 (#2 (take_prefix (not o is_let) cs)) end;
clasohm@24
  1289
wenzelm@4212
  1290
wenzelm@16439
  1291
(* stamps and serial numbers *)
wenzelm@16439
  1292
wenzelm@16439
  1293
type stamp = unit ref;
wenzelm@16439
  1294
val stamp: unit -> stamp = ref;
wenzelm@16439
  1295
wenzelm@16439
  1296
type serial = int;
wenzelm@16439
  1297
local val count = ref 0
wenzelm@16439
  1298
in fun serial () = inc count end;
wenzelm@16439
  1299
wenzelm@19512
  1300
val serial_string = string_of_int o serial;
wenzelm@19512
  1301
wenzelm@16535
  1302
wenzelm@16535
  1303
(* generic objects *)
wenzelm@16535
  1304
wenzelm@16535
  1305
(*note that the builtin exception datatype may be extended by new
wenzelm@16535
  1306
  constructors at any time*)
wenzelm@16535
  1307
structure Object = struct type T = exn end;
wenzelm@16535
  1308
clasohm@1364
  1309
end;
clasohm@1364
  1310
wenzelm@15745
  1311
structure BasicLibrary: BASIC_LIBRARY = Library;
wenzelm@15745
  1312
open BasicLibrary;