(* Title: HOL/Tools/string_code.ML
Author: Florian Haftmann, TU Muenchen
Code generation for character and string literals.
*)
signature STRING_CODE =
sig
val add_literal_list_string: string -> theory -> theory
val add_literal_char: string -> theory -> theory
val add_literal_string: string -> theory -> theory
end;
structure String_Code : STRING_CODE =
struct
open Basic_Code_Thingol;
val cs_nibbles = [@{const_name Nibble0}, @{const_name Nibble1},
@{const_name Nibble2}, @{const_name Nibble3},
@{const_name Nibble4}, @{const_name Nibble5},
@{const_name Nibble6}, @{const_name Nibble7},
@{const_name Nibble8}, @{const_name Nibble9},
@{const_name NibbleA}, @{const_name NibbleB},
@{const_name NibbleC}, @{const_name NibbleD},
@{const_name NibbleE}, @{const_name NibbleF}];
fun decode_char tt =
let
fun idx c = find_index (curry (op =) c) cs_nibbles;
fun decode ~1 _ = NONE
| decode _ ~1 = NONE
| decode n m = SOME (chr (n * 16 + m));
in case tt
of (IConst { sym = Code_Symbol.Constant c1, ... }, IConst { sym = Code_Symbol.Constant c2, ... }) => decode (idx c1) (idx c2)
| _ => NONE
end;
fun implode_string literals ts =
let
fun implode_char (IConst { sym = Code_Symbol.Constant @{const_name Char}, ... } `$ t1 `$ t2) =
decode_char (t1, t2)
| implode_char _ = NONE;
val ts' = map_filter implode_char ts;
in if length ts = length ts'
then (SOME o Code_Printer.str o Code_Printer.literal_string literals o implode) ts'
else NONE
end;
fun add_literal_list_string target =
let
fun pretty literals pr _ vars fxy [(t1, _), (t2, _)] =
case Option.map (cons t1) (List_Code.implode_list t2)
of SOME ts => (case implode_string literals ts
of SOME p => p
| NONE =>
Code_Printer.literal_list literals (map (pr vars Code_Printer.NOBR) ts))
| NONE =>
List_Code.default_list (Code_Printer.infix_cons literals) (pr vars) fxy t1 t2;
in
Code_Target.set_printings (Code_Symbol.Constant (@{const_name Cons},
[(target, SOME (Code_Printer.complex_const_syntax (2, pretty)))]))
end;
fun add_literal_char target =
let
fun pretty literals _ thm _ _ [(t1, _), (t2, _)] =
case decode_char (t1, t2)
of SOME c => (Code_Printer.str o Code_Printer.literal_char literals) c
| NONE => Code_Printer.eqn_error thm "Illegal character expression";
in
Code_Target.set_printings (Code_Symbol.Constant (@{const_name Char},
[(target, SOME (Code_Printer.complex_const_syntax (2, pretty)))]))
end;
fun add_literal_string target =
let
fun pretty literals _ thm _ _ [(t, _)] =
case List_Code.implode_list t
of SOME ts => (case implode_string literals ts
of SOME p => p
| NONE => Code_Printer.eqn_error thm "Illegal string literal expression")
| NONE => Code_Printer.eqn_error thm "Illegal string literal expression";
in
Code_Target.set_printings (Code_Symbol.Constant (@{const_name STR},
[(target, SOME (Code_Printer.complex_const_syntax (1, pretty)))]))
end;
end;