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268 | ------------------------------------------------------------------------------
-- G N A T C O L L --
-- --
-- Copyright (C) 2008-2018, AdaCore --
-- --
-- This library is free software; you can redistribute it and/or modify it --
-- under terms of the GNU General Public License as published by the Free --
-- Software Foundation; either version 3, or (at your option) any later --
-- version. This library is distributed in the hope that it will be useful, --
-- but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHAN- --
-- TABILITY or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
------------------------------------------------------------------------------
with Ada.Characters.Handling; use Ada.Characters.Handling;
with Ada.Strings.Unbounded; use Ada.Strings.Unbounded;
with GNAT.Strings; use GNAT.Strings;
package body GNATCOLL.Templates is
procedure Find_Identifier
(Str : String;
Delimiter : Character;
First : in out Integer;
Last : out Integer;
First_After : out Integer);
-- Set Last to the last character of the identifier name.
-- First should point to the first candidate character, but could be
-- moved forward if it points to a curly brace.
----------
-- Free --
----------
procedure Free (Substrings : in out Substitution_Array) is
begin
for S in Substrings'Range loop
Free (Substrings (S).Name);
Free (Substrings (S).Value);
end loop;
end Free;
---------------------
-- Find_Identifier --
---------------------
procedure Find_Identifier
(Str : String;
Delimiter : Character;
First : in out Integer;
Last : out Integer;
First_After : out Integer)
is
begin
if Str (First) = Delimiter then
-- We are escaping the delimiter by doubling it
Last := First;
First_After := First + 1;
elsif Str (First) = '{' then
First := First + 1;
Last := First;
while Last <= Str'Last and then Str (Last) /= '}' loop
Last := Last + 1;
end loop;
First_After := Last + 1;
Last := Last - 1;
elsif Str (First) = '(' then
First := First + 1;
Last := First;
while Last <= Str'Last and then Str (Last) /= ')' loop
Last := Last + 1;
end loop;
First_After := Last + 1;
Last := Last - 1;
elsif Is_Digit (Str (First)) then
Last := First + 1;
while Last <= Str'Last
and then Is_Digit (Str (Last))
loop
Last := Last + 1;
end loop;
if Last <= Str'Last
and then Str (Last) = '-'
then
Last := Last + 1;
end if;
First_After := Last;
Last := Last - 1;
elsif Is_Alphanumeric (Str (First)) then
Last := First + 1;
while Last <= Str'Last
and then (Is_Alphanumeric (Str (Last)) or else Str (Last) = '_')
loop
Last := Last + 1;
end loop;
First_After := Last;
Last := Last - 1;
else
Last := First;
First_After := Last + 1;
end if;
end Find_Identifier;
----------------
-- Substitute --
----------------
function Substitute
(Str : String;
Substrings : Substitution_Array := No_Substitution;
Callback : Substitute_Callback := null;
Delimiter : Character := Default_Delimiter;
Recursive : Boolean := False;
Errors : Error_Handling := Keep_As_Is) return String
is
Result : Unbounded_String;
First, Last : Natural := Str'First;
Found : Boolean;
Identifier_First, Identifier_Last, First_After : Natural;
Quoted : Boolean := False;
begin
while First <= Str'Last loop
Last := First;
-- Skip constant substrings
while Last <= Str'Last and then Str (Last) /= Delimiter loop
if Str (Last) = '"' then
Quoted := not Quoted;
end if;
Last := Last + 1;
end loop;
if Last = Str'Last then
Last := Last + 1;
end if;
Append (Result, Str (First .. Last - 1));
exit when Last > Str'Last;
-- Find name of identifier
First := Last + 1;
Identifier_First := First;
Find_Identifier (Str, Delimiter, Identifier_First, Last, First_After);
-- Does the identifier contain a default value?
Identifier_Last := Last;
for D in Identifier_First .. Identifier_Last - 1 loop
if Str (D) = ':' and then Str (D + 1) = '-' then
Identifier_Last := D - 1;
exit;
end if;
end loop;
Found := False;
for S in Substrings'Range loop
if Substrings (S).Name.all =
Str (Identifier_First .. Identifier_Last)
then
if Recursive then
Append
(Result, Substitute
(Str => Substrings (S).Value.all,
Substrings => Substrings,
Callback => Callback,
Delimiter => Delimiter,
Recursive => Recursive));
else
Append (Result, Substrings (S).Value.all);
end if;
Found := True;
exit;
end if;
end loop;
-- When doubled, the delimiter is always replaced with itself by
-- default.
if not Found
and then Identifier_Last = Identifier_First
and then Str (Identifier_First) = Delimiter
then
-- We are escaping the Substitution_Char by doubling it
Append (Result, Delimiter);
Found := True;
elsif not Found and then Callback /= null then
begin
declare
Sub : constant String := Callback
(Str (Identifier_First .. Identifier_Last), Quoted);
begin
if Recursive then
Append
(Result, Substitute
(Str => Sub,
Substrings => Substrings,
Callback => Callback,
Delimiter => Delimiter,
Recursive => Recursive));
else
Append (Result, Sub);
end if;
Found := True;
end;
exception
when Invalid_Substitution =>
Found := False;
end;
end if;
-- If still not found, try the default value if it was specified
if not Found
and then Identifier_Last < Last
then
Append (Result, Str (Identifier_Last + 3 .. Last));
Found := True;
end if;
if not Found then
case Errors is
when Keep_As_Is =>
Append (Result, Str (First - 1 .. First_After - 1));
when Replace_With_Empty =>
null;
when Report_Error =>
raise Invalid_Substitution;
end case;
end if;
First := First_After;
end loop;
return To_String (Result);
end Substitute;
end GNATCOLL.Templates;
|