src/Pure/section_utils.ML
 author wenzelm Mon, 20 Oct 1997 10:39:26 +0200 changeset 3934 a9c8960e4da6 parent 3536 8fb4150e2ad3 child 3974 d3c2159b75fa permissions -rw-r--r--
Sign.base_name;
```
(*  Title: 	Pure/section-utils
ID:         \$Id\$
Author: 	Lawrence C Paulson, Cambridge University Computer Laboratory

Utilities for writing new theory sections
*)

fun ap t u = t\$u;
fun app t (u1,u2) = t \$ u1 \$ u2;

(*Make distinct individual variables a1, a2, a3, ..., an. *)
fun mk_frees a [] = []
| mk_frees a (T::Ts) = Free(a,T) :: mk_frees (bump_string a) Ts;

(*Make a definition lhs==rhs*)
fun mk_defpair (lhs, rhs) =
let val Const(name, _) = head_of lhs
in (Sign.base_name name ^ "_def", Logic.mk_equals (lhs, rhs)) end;

fun get_def thy s = get_axiom thy (s^"_def");

(*Read an assumption in the given theory*)

(*Read a term from string "b", with expected type T*)
fun readtm sign T b =
handle ERROR => error ("The error(s) above occurred for " ^ b);

(*From HOL/ex/meson.ML: raises exception if no rules apply -- unlike RL*)
fun tryres (th, rl::rls) = (th RS rl handle THM _ => tryres(th,rls))
| tryres (th, []) = raise THM("tryres", 0, [th]);

fun gen_make_elim elim_rls rl =
standard (tryres (rl, elim_rls @ [revcut_rl]));

(** String manipulation **)

(*Skipping initial blanks, find the first identifier*)
fun scan_to_id s =
s |> explode |> take_prefix is_blank |> #2 |> Scanner.scan_id |> #1
handle LEXICAL_ERROR => error ("Expected to find an identifier in " ^ s);

fun is_backslash c = c = "\\";

(*Apply string escapes to a quoted string; see Def of Standard ML, page 3
Does not handle the \ddd form;  no error checking*)
fun escape [] = []
| escape cs = (case take_prefix (not o is_backslash) cs of
(front, []) => front
| (front, _::"n"::rest) => front @ ("\n" :: escape rest)
| (front, _::"t"::rest) => front @ ("\t" :: escape rest)
| (front, _::"^"::c::rest) => front @ (chr(ord(c)-64) :: escape rest)
| (front, _::"\""::rest) => front @ ("\"" :: escape rest)
| (front, _::"\\"::rest) => front @ ("\\" :: escape rest)
| (front, b::c::rest) =>
if is_blank c   (*remove any further blanks and the following \ *)
then front @ escape (tl (snd (take_prefix is_blank rest)))
else error ("Unrecognized string escape: " ^ implode(b::c::rest)));

(*Remove the first and last charaters -- presumed to be quotes*)
val trim = implode o escape o rev o tl o rev o tl o explode;

(*Check for some named theory*)
fun require_thy thy name sect =
if exists (equal name o !) (stamps_of_thy thy) then ()
else error ("Need theory " ^ quote name ^ " as an ancestor for " ^ sect);
```