1730 lines
59 KiB
Ada
1730 lines
59 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT COMPILER COMPONENTS --
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-- --
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-- S Y S T E M . R E G E X P --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 1999-2015, AdaCore --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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with Ada.Unchecked_Deallocation;
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with System.Case_Util;
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package body System.Regexp is
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Initial_Max_States_In_Primary_Table : constant := 100;
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-- Initial size for the number of states in the indefinite state
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-- machine. The number of states will be increased as needed.
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--
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-- This is also used as the maximal number of meta states (groups of
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-- states) in the secondary table.
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Open_Paren : constant Character := '(';
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Close_Paren : constant Character := ')';
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Open_Bracket : constant Character := '[';
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Close_Bracket : constant Character := ']';
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type State_Index is new Natural;
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type Column_Index is new Natural;
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type Regexp_Array is array
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(State_Index range <>, Column_Index range <>) of State_Index;
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-- First index is for the state number. Second index is for the character
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-- type. Contents is the new State.
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type Regexp_Array_Access is access Regexp_Array;
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-- Use this type through the functions Set below, so that it can grow
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-- dynamically depending on the needs.
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type Mapping is array (Character'Range) of Column_Index;
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-- Mapping between characters and column in the Regexp_Array
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type Boolean_Array is array (State_Index range <>) of Boolean;
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type Regexp_Value
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(Alphabet_Size : Column_Index;
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Num_States : State_Index) is
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record
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Map : Mapping;
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States : Regexp_Array (1 .. Num_States, 0 .. Alphabet_Size);
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Is_Final : Boolean_Array (1 .. Num_States);
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Case_Sensitive : Boolean;
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end record;
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-- Deterministic finite-state machine
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-----------------------
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-- Local Subprograms --
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-----------------------
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procedure Set
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(Table : in out Regexp_Array_Access;
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State : State_Index;
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Column : Column_Index;
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Value : State_Index);
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-- Sets a value in the table. If the table is too small, reallocate it
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-- dynamically so that (State, Column) is a valid index in it.
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function Get
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(Table : Regexp_Array_Access;
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State : State_Index;
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Column : Column_Index) return State_Index;
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-- Returns the value in the table at (State, Column). If this index does
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-- not exist in the table, returns zero.
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procedure Free is new Ada.Unchecked_Deallocation
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(Regexp_Array, Regexp_Array_Access);
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------------
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-- Adjust --
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------------
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procedure Adjust (R : in out Regexp) is
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Tmp : Regexp_Access;
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begin
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if R.R /= null then
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Tmp := new Regexp_Value (Alphabet_Size => R.R.Alphabet_Size,
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Num_States => R.R.Num_States);
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Tmp.all := R.R.all;
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R.R := Tmp;
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end if;
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end Adjust;
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-------------
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-- Compile --
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-------------
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function Compile
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(Pattern : String;
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Glob : Boolean := False;
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Case_Sensitive : Boolean := True) return Regexp
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is
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S : String := Pattern;
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-- The pattern which is really compiled (when the pattern is case
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-- insensitive, we convert this string to lower-cases
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Map : Mapping := (others => 0);
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-- Mapping between characters and columns in the tables
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Alphabet_Size : Column_Index := 0;
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-- Number of significant characters in the regular expression.
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-- This total does not include special operators, such as *, (, ...
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procedure Check_Well_Formed_Pattern;
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-- Check that the pattern to compile is well-formed, so that subsequent
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-- code can rely on this without performing each time the checks to
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-- avoid accessing the pattern outside its bounds. However, not all
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-- well-formedness rules are checked. In particular, rules about special
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-- characters not being treated as regular characters are not checked.
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procedure Create_Mapping;
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-- Creates a mapping between characters in the regexp and columns
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-- in the tables representing the regexp. Test that the regexp is
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-- well-formed Modifies Alphabet_Size and Map
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procedure Create_Primary_Table
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(Table : out Regexp_Array_Access;
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Num_States : out State_Index;
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Start_State : out State_Index;
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End_State : out State_Index);
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-- Creates the first version of the regexp (this is a non deterministic
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-- finite state machine, which is unadapted for a fast pattern
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-- matching algorithm). We use a recursive algorithm to process the
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-- parenthesis sub-expressions.
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--
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-- Table : at the end of the procedure : Column 0 is for any character
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-- ('.') and the last columns are for no character (closure). Num_States
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-- is set to the number of states in the table Start_State is the number
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-- of the starting state in the regexp End_State is the number of the
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-- final state when the regexp matches.
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procedure Create_Primary_Table_Glob
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(Table : out Regexp_Array_Access;
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Num_States : out State_Index;
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Start_State : out State_Index;
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End_State : out State_Index);
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-- Same function as above, but it deals with the second possible
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-- grammar for 'globbing pattern', which is a kind of subset of the
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-- whole regular expression grammar.
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function Create_Secondary_Table
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(First_Table : Regexp_Array_Access;
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Start_State : State_Index;
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End_State : State_Index) return Regexp;
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-- Creates the definitive table representing the regular expression
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-- This is actually a transformation of the primary table First_Table,
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-- where every state is grouped with the states in its 'no-character'
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-- columns. The transitions between the new states are then recalculated
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-- and if necessary some new states are created.
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--
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-- Note that the resulting finite-state machine is not optimized in
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-- terms of the number of states : it would be more time-consuming to
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-- add a third pass to reduce the number of states in the machine, with
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-- no speed improvement...
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procedure Raise_Exception (M : String; Index : Integer);
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pragma No_Return (Raise_Exception);
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-- Raise an exception, indicating an error at character Index in S
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-------------------------------
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-- Check_Well_Formed_Pattern --
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-------------------------------
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procedure Check_Well_Formed_Pattern is
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J : Integer;
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Past_Elmt : Boolean := False;
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-- Set to True everywhere an elmt has been parsed, if Glob=False,
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-- meaning there can be now an occurrence of '*', '+' and '?'.
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Past_Term : Boolean := False;
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-- Set to True everywhere a term has been parsed, if Glob=False,
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-- meaning there can be now an occurrence of '|'.
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Parenthesis_Level : Integer := 0;
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Curly_Level : Integer := 0;
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Last_Open : Integer := S'First - 1;
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-- The last occurrence of an opening parenthesis, if Glob=False,
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-- or the last occurrence of an opening curly brace, if Glob=True.
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procedure Raise_Exception_If_No_More_Chars (K : Integer := 0);
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-- If no more characters are raised, call Raise_Exception
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--------------------------------------
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-- Raise_Exception_If_No_More_Chars --
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--------------------------------------
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procedure Raise_Exception_If_No_More_Chars (K : Integer := 0) is
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begin
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if J + K > S'Last then
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Raise_Exception ("Ill-formed pattern while parsing", J);
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end if;
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end Raise_Exception_If_No_More_Chars;
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-- Start of processing for Check_Well_Formed_Pattern
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begin
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J := S'First;
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while J <= S'Last loop
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case S (J) is
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when Open_Bracket =>
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J := J + 1;
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Raise_Exception_If_No_More_Chars;
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if not Glob then
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if S (J) = '^' then
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J := J + 1;
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Raise_Exception_If_No_More_Chars;
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end if;
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end if;
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-- The first character never has a special meaning
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if S (J) = ']' or else S (J) = '-' then
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J := J + 1;
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Raise_Exception_If_No_More_Chars;
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end if;
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-- The set of characters cannot be empty
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if S (J) = ']' then
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Raise_Exception
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("Set of characters cannot be empty in regular "
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& "expression", J);
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end if;
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declare
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Possible_Range_Start : Boolean := True;
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-- Set True everywhere a range character '-' can occur
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begin
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loop
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exit when S (J) = Close_Bracket;
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-- The current character should be followed by a
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-- closing bracket.
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Raise_Exception_If_No_More_Chars (1);
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if S (J) = '-'
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and then S (J + 1) /= Close_Bracket
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then
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if not Possible_Range_Start then
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Raise_Exception
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("No mix of ranges is allowed in "
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& "regular expression", J);
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end if;
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J := J + 1;
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Raise_Exception_If_No_More_Chars;
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-- Range cannot be followed by '-' character,
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-- except as last character in the set.
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Possible_Range_Start := False;
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else
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Possible_Range_Start := True;
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end if;
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if S (J) = '\' then
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J := J + 1;
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Raise_Exception_If_No_More_Chars;
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end if;
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J := J + 1;
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end loop;
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end;
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-- A closing bracket can end an elmt or term
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Past_Elmt := True;
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Past_Term := True;
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when Close_Bracket =>
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-- A close bracket must follow a open_bracket, and cannot be
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-- found alone on the line.
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Raise_Exception
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("Incorrect character ']' in regular expression", J);
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when '\' =>
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if J < S'Last then
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J := J + 1;
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-- Any character can be an elmt or a term
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Past_Elmt := True;
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Past_Term := True;
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else
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-- \ not allowed at the end of the regexp
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Raise_Exception
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("Incorrect character '\' in regular expression", J);
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end if;
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when Open_Paren =>
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if not Glob then
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Parenthesis_Level := Parenthesis_Level + 1;
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Last_Open := J;
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-- An open parenthesis does not end an elmt or term
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Past_Elmt := False;
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Past_Term := False;
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end if;
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when Close_Paren =>
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if not Glob then
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Parenthesis_Level := Parenthesis_Level - 1;
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if Parenthesis_Level < 0 then
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Raise_Exception
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("')' is not associated with '(' in regular "
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& "expression", J);
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end if;
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if J = Last_Open + 1 then
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Raise_Exception
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("Empty parentheses not allowed in regular "
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& "expression", J);
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end if;
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if not Past_Term then
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Raise_Exception
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("Closing parenthesis not allowed here in regular "
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& "expression", J);
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end if;
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-- A closing parenthesis can end an elmt or term
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Past_Elmt := True;
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Past_Term := True;
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end if;
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when '{' =>
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if Glob then
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Curly_Level := Curly_Level + 1;
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Last_Open := J;
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else
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-- Any character can be an elmt or a term
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Past_Elmt := True;
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Past_Term := True;
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end if;
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-- No need to check for ',' as the code always accepts them
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when '}' =>
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if Glob then
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Curly_Level := Curly_Level - 1;
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if Curly_Level < 0 then
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Raise_Exception
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("'}' is not associated with '{' in regular "
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& "expression", J);
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end if;
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if J = Last_Open + 1 then
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Raise_Exception
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("Empty curly braces not allowed in regular "
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& "expression", J);
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end if;
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else
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-- Any character can be an elmt or a term
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Past_Elmt := True;
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Past_Term := True;
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end if;
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when '*' | '?' | '+' =>
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if not Glob then
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-- These operators must apply to an elmt sub-expression,
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-- and cannot be found if one has not just been parsed.
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if not Past_Elmt then
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Raise_Exception
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("'*', '+' and '?' operators must be "
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& "applied to an element in regular expression", J);
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end if;
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Past_Elmt := False;
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Past_Term := True;
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end if;
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when '|' =>
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if not Glob then
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-- This operator must apply to a term sub-expression,
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-- and cannot be found if one has not just been parsed.
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if not Past_Term then
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Raise_Exception
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("'|' operator must be "
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& "applied to a term in regular expression", J);
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end if;
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Past_Elmt := False;
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Past_Term := False;
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end if;
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when others =>
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if not Glob then
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-- Any character can be an elmt or a term
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Past_Elmt := True;
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Past_Term := True;
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end if;
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end case;
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J := J + 1;
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end loop;
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-- A closing parenthesis must follow an open parenthesis
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if Parenthesis_Level /= 0 then
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Raise_Exception
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("'(' must always be associated with a ')'", J);
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end if;
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-- A closing curly brace must follow an open curly brace
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if Curly_Level /= 0 then
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Raise_Exception
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("'{' must always be associated with a '}'", J);
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end if;
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end Check_Well_Formed_Pattern;
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--------------------
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-- Create_Mapping --
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--------------------
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procedure Create_Mapping is
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procedure Add_In_Map (C : Character);
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-- Add a character in the mapping, if it is not already defined
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----------------
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-- Add_In_Map --
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----------------
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procedure Add_In_Map (C : Character) is
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begin
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if Map (C) = 0 then
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Alphabet_Size := Alphabet_Size + 1;
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Map (C) := Alphabet_Size;
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end if;
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end Add_In_Map;
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J : Integer := S'First;
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Parenthesis_Level : Integer := 0;
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Curly_Level : Integer := 0;
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Last_Open : Integer := S'First - 1;
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-- Start of processing for Create_Mapping
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begin
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while J <= S'Last loop
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case S (J) is
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when Open_Bracket =>
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J := J + 1;
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if S (J) = '^' then
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J := J + 1;
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end if;
|
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|
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if S (J) = ']' or else S (J) = '-' then
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J := J + 1;
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end if;
|
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|
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-- The first character never has a special meaning
|
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loop
|
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if J > S'Last then
|
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Raise_Exception
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("Ran out of characters while parsing ", J);
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end if;
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exit when S (J) = Close_Bracket;
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if S (J) = '-'
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and then S (J + 1) /= Close_Bracket
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then
|
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declare
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Start : constant Integer := J - 1;
|
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|
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begin
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J := J + 1;
|
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|
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if S (J) = '\' then
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J := J + 1;
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end if;
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for Char in S (Start) .. S (J) loop
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Add_In_Map (Char);
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end loop;
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end;
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else
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if S (J) = '\' then
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J := J + 1;
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end if;
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Add_In_Map (S (J));
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end if;
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J := J + 1;
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end loop;
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|
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-- A close bracket must follow a open_bracket and cannot be
|
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-- found alone on the line
|
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|
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when Close_Bracket =>
|
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Raise_Exception
|
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("Incorrect character ']' in regular expression", J);
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|
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when '\' =>
|
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if J < S'Last then
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J := J + 1;
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Add_In_Map (S (J));
|
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|
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else
|
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-- Back slash \ not allowed at the end of the regexp
|
|
|
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Raise_Exception
|
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("Incorrect character '\' in regular expression", J);
|
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end if;
|
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|
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when Open_Paren =>
|
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if not Glob then
|
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Parenthesis_Level := Parenthesis_Level + 1;
|
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Last_Open := J;
|
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else
|
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Add_In_Map (Open_Paren);
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end if;
|
|
|
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when Close_Paren =>
|
|
if not Glob then
|
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Parenthesis_Level := Parenthesis_Level - 1;
|
|
|
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if Parenthesis_Level < 0 then
|
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Raise_Exception
|
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("')' is not associated with '(' in regular "
|
|
& "expression", J);
|
|
end if;
|
|
|
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if J = Last_Open + 1 then
|
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Raise_Exception
|
|
("Empty parenthesis not allowed in regular "
|
|
& "expression", J);
|
|
end if;
|
|
|
|
else
|
|
Add_In_Map (Close_Paren);
|
|
end if;
|
|
|
|
when '.' =>
|
|
if Glob then
|
|
Add_In_Map ('.');
|
|
end if;
|
|
|
|
when '{' =>
|
|
if not Glob then
|
|
Add_In_Map (S (J));
|
|
else
|
|
Curly_Level := Curly_Level + 1;
|
|
end if;
|
|
|
|
when '}' =>
|
|
if not Glob then
|
|
Add_In_Map (S (J));
|
|
else
|
|
Curly_Level := Curly_Level - 1;
|
|
end if;
|
|
|
|
when '*' | '?' =>
|
|
if not Glob then
|
|
if J = S'First then
|
|
Raise_Exception
|
|
("'*', '+', '?' and '|' operators cannot be in "
|
|
& "first position in regular expression", J);
|
|
end if;
|
|
end if;
|
|
|
|
when '|' | '+' =>
|
|
if not Glob then
|
|
if J = S'First then
|
|
|
|
-- These operators must apply to a sub-expression,
|
|
-- and cannot be found at the beginning of the line
|
|
|
|
Raise_Exception
|
|
("'*', '+', '?' and '|' operators cannot be in "
|
|
& "first position in regular expression", J);
|
|
end if;
|
|
|
|
else
|
|
Add_In_Map (S (J));
|
|
end if;
|
|
|
|
when others =>
|
|
Add_In_Map (S (J));
|
|
end case;
|
|
|
|
J := J + 1;
|
|
end loop;
|
|
|
|
-- A closing parenthesis must follow an open parenthesis
|
|
|
|
if Parenthesis_Level /= 0 then
|
|
Raise_Exception
|
|
("'(' must always be associated with a ')'", J);
|
|
end if;
|
|
|
|
if Curly_Level /= 0 then
|
|
Raise_Exception
|
|
("'{' must always be associated with a '}'", J);
|
|
end if;
|
|
end Create_Mapping;
|
|
|
|
--------------------------
|
|
-- Create_Primary_Table --
|
|
--------------------------
|
|
|
|
procedure Create_Primary_Table
|
|
(Table : out Regexp_Array_Access;
|
|
Num_States : out State_Index;
|
|
Start_State : out State_Index;
|
|
End_State : out State_Index)
|
|
is
|
|
Empty_Char : constant Column_Index := Alphabet_Size + 1;
|
|
|
|
Current_State : State_Index := 0;
|
|
-- Index of the last created state
|
|
|
|
procedure Add_Empty_Char
|
|
(State : State_Index;
|
|
To_State : State_Index);
|
|
-- Add a empty-character transition from State to To_State
|
|
|
|
procedure Create_Repetition
|
|
(Repetition : Character;
|
|
Start_Prev : State_Index;
|
|
End_Prev : State_Index;
|
|
New_Start : out State_Index;
|
|
New_End : in out State_Index);
|
|
-- Create the table in case we have a '*', '+' or '?'.
|
|
-- Start_Prev .. End_Prev should indicate respectively the start and
|
|
-- end index of the previous expression, to which '*', '+' or '?' is
|
|
-- applied.
|
|
|
|
procedure Create_Simple
|
|
(Start_Index : Integer;
|
|
End_Index : Integer;
|
|
Start_State : out State_Index;
|
|
End_State : out State_Index);
|
|
-- Fill the table for the regexp Simple. This is the recursive
|
|
-- procedure called to handle () expressions If End_State = 0, then
|
|
-- the call to Create_Simple creates an independent regexp, not a
|
|
-- concatenation Start_Index .. End_Index is the starting index in
|
|
-- the string S.
|
|
--
|
|
-- Warning: it may look like we are creating too many empty-string
|
|
-- transitions, but they are needed to get the correct regexp.
|
|
-- The table is filled as follow ( s means start-state, e means
|
|
-- end-state) :
|
|
--
|
|
-- regexp state_num | a b * empty_string
|
|
-- ------- ------------------------------
|
|
-- a 1 (s) | 2 - - -
|
|
-- 2 (e) | - - - -
|
|
--
|
|
-- ab 1 (s) | 2 - - -
|
|
-- 2 | - - - 3
|
|
-- 3 | - 4 - -
|
|
-- 4 (e) | - - - -
|
|
--
|
|
-- a|b 1 | 2 - - -
|
|
-- 2 | - - - 6
|
|
-- 3 | - 4 - -
|
|
-- 4 | - - - 6
|
|
-- 5 (s) | - - - 1,3
|
|
-- 6 (e) | - - - -
|
|
--
|
|
-- a* 1 | 2 - - -
|
|
-- 2 | - - - 4
|
|
-- 3 (s) | - - - 1,4
|
|
-- 4 (e) | - - - 3
|
|
--
|
|
-- (a) 1 (s) | 2 - - -
|
|
-- 2 (e) | - - - -
|
|
--
|
|
-- a+ 1 | 2 - - -
|
|
-- 2 | - - - 4
|
|
-- 3 (s) | - - - 1
|
|
-- 4 (e) | - - - 3
|
|
--
|
|
-- a? 1 | 2 - - -
|
|
-- 2 | - - - 4
|
|
-- 3 (s) | - - - 1,4
|
|
-- 4 (e) | - - - -
|
|
--
|
|
-- . 1 (s) | 2 2 2 -
|
|
-- 2 (e) | - - - -
|
|
|
|
function Next_Sub_Expression
|
|
(Start_Index : Integer;
|
|
End_Index : Integer) return Integer;
|
|
-- Returns the index of the last character of the next sub-expression
|
|
-- in Simple. Index cannot be greater than End_Index.
|
|
|
|
--------------------
|
|
-- Add_Empty_Char --
|
|
--------------------
|
|
|
|
procedure Add_Empty_Char
|
|
(State : State_Index;
|
|
To_State : State_Index)
|
|
is
|
|
J : Column_Index := Empty_Char;
|
|
|
|
begin
|
|
while Get (Table, State, J) /= 0 loop
|
|
J := J + 1;
|
|
end loop;
|
|
|
|
Set (Table, State, J, To_State);
|
|
end Add_Empty_Char;
|
|
|
|
-----------------------
|
|
-- Create_Repetition --
|
|
-----------------------
|
|
|
|
procedure Create_Repetition
|
|
(Repetition : Character;
|
|
Start_Prev : State_Index;
|
|
End_Prev : State_Index;
|
|
New_Start : out State_Index;
|
|
New_End : in out State_Index)
|
|
is
|
|
begin
|
|
New_Start := Current_State + 1;
|
|
|
|
if New_End /= 0 then
|
|
Add_Empty_Char (New_End, New_Start);
|
|
end if;
|
|
|
|
Current_State := Current_State + 2;
|
|
New_End := Current_State;
|
|
|
|
Add_Empty_Char (End_Prev, New_End);
|
|
Add_Empty_Char (New_Start, Start_Prev);
|
|
|
|
if Repetition /= '+' then
|
|
Add_Empty_Char (New_Start, New_End);
|
|
end if;
|
|
|
|
if Repetition /= '?' then
|
|
Add_Empty_Char (New_End, New_Start);
|
|
end if;
|
|
end Create_Repetition;
|
|
|
|
-------------------
|
|
-- Create_Simple --
|
|
-------------------
|
|
|
|
procedure Create_Simple
|
|
(Start_Index : Integer;
|
|
End_Index : Integer;
|
|
Start_State : out State_Index;
|
|
End_State : out State_Index)
|
|
is
|
|
J : Integer := Start_Index;
|
|
Last_Start : State_Index := 0;
|
|
|
|
begin
|
|
Start_State := 0;
|
|
End_State := 0;
|
|
while J <= End_Index loop
|
|
case S (J) is
|
|
when Open_Paren =>
|
|
declare
|
|
J_Start : constant Integer := J + 1;
|
|
Next_Start : State_Index;
|
|
Next_End : State_Index;
|
|
|
|
begin
|
|
J := Next_Sub_Expression (J, End_Index);
|
|
Create_Simple (J_Start, J - 1, Next_Start, Next_End);
|
|
|
|
if J < End_Index
|
|
and then (S (J + 1) = '*' or else
|
|
S (J + 1) = '+' or else
|
|
S (J + 1) = '?')
|
|
then
|
|
J := J + 1;
|
|
Create_Repetition
|
|
(S (J),
|
|
Next_Start,
|
|
Next_End,
|
|
Last_Start,
|
|
End_State);
|
|
|
|
else
|
|
Last_Start := Next_Start;
|
|
|
|
if End_State /= 0 then
|
|
Add_Empty_Char (End_State, Last_Start);
|
|
end if;
|
|
|
|
End_State := Next_End;
|
|
end if;
|
|
end;
|
|
|
|
when '|' =>
|
|
declare
|
|
Start_Prev : constant State_Index := Start_State;
|
|
End_Prev : constant State_Index := End_State;
|
|
Start_J : constant Integer := J + 1;
|
|
Start_Next : State_Index := 0;
|
|
End_Next : State_Index := 0;
|
|
|
|
begin
|
|
J := Next_Sub_Expression (J, End_Index);
|
|
|
|
-- Create a new state for the start of the alternative
|
|
|
|
Current_State := Current_State + 1;
|
|
Last_Start := Current_State;
|
|
Start_State := Last_Start;
|
|
|
|
-- Create the tree for the second part of alternative
|
|
|
|
Create_Simple (Start_J, J, Start_Next, End_Next);
|
|
|
|
-- Create the end state
|
|
|
|
Add_Empty_Char (Last_Start, Start_Next);
|
|
Add_Empty_Char (Last_Start, Start_Prev);
|
|
Current_State := Current_State + 1;
|
|
End_State := Current_State;
|
|
Add_Empty_Char (End_Prev, End_State);
|
|
Add_Empty_Char (End_Next, End_State);
|
|
end;
|
|
|
|
when Open_Bracket =>
|
|
Current_State := Current_State + 1;
|
|
|
|
declare
|
|
Next_State : State_Index := Current_State + 1;
|
|
|
|
begin
|
|
J := J + 1;
|
|
|
|
if S (J) = '^' then
|
|
J := J + 1;
|
|
|
|
Next_State := 0;
|
|
|
|
for Column in 0 .. Alphabet_Size loop
|
|
Set (Table, Current_State, Column,
|
|
Value => Current_State + 1);
|
|
end loop;
|
|
end if;
|
|
|
|
-- Automatically add the first character
|
|
|
|
if S (J) = '-' or else S (J) = ']' then
|
|
Set (Table, Current_State, Map (S (J)),
|
|
Value => Next_State);
|
|
J := J + 1;
|
|
end if;
|
|
|
|
-- Loop till closing bracket found
|
|
|
|
loop
|
|
exit when S (J) = Close_Bracket;
|
|
|
|
if S (J) = '-'
|
|
and then S (J + 1) /= ']'
|
|
then
|
|
declare
|
|
Start : constant Integer := J - 1;
|
|
|
|
begin
|
|
J := J + 1;
|
|
|
|
if S (J) = '\' then
|
|
J := J + 1;
|
|
end if;
|
|
|
|
for Char in S (Start) .. S (J) loop
|
|
Set (Table, Current_State, Map (Char),
|
|
Value => Next_State);
|
|
end loop;
|
|
end;
|
|
|
|
else
|
|
if S (J) = '\' then
|
|
J := J + 1;
|
|
end if;
|
|
|
|
Set (Table, Current_State, Map (S (J)),
|
|
Value => Next_State);
|
|
end if;
|
|
J := J + 1;
|
|
end loop;
|
|
end;
|
|
|
|
Current_State := Current_State + 1;
|
|
|
|
-- If the next symbol is a special symbol
|
|
|
|
if J < End_Index
|
|
and then (S (J + 1) = '*' or else
|
|
S (J + 1) = '+' or else
|
|
S (J + 1) = '?')
|
|
then
|
|
J := J + 1;
|
|
Create_Repetition
|
|
(S (J),
|
|
Current_State - 1,
|
|
Current_State,
|
|
Last_Start,
|
|
End_State);
|
|
|
|
else
|
|
Last_Start := Current_State - 1;
|
|
|
|
if End_State /= 0 then
|
|
Add_Empty_Char (End_State, Last_Start);
|
|
end if;
|
|
|
|
End_State := Current_State;
|
|
end if;
|
|
|
|
when '*' | '+' | '?' | Close_Paren | Close_Bracket =>
|
|
Raise_Exception
|
|
("Incorrect character in regular expression :", J);
|
|
|
|
when others =>
|
|
Current_State := Current_State + 1;
|
|
|
|
-- Create the state for the symbol S (J)
|
|
|
|
if S (J) = '.' then
|
|
for K in 0 .. Alphabet_Size loop
|
|
Set (Table, Current_State, K,
|
|
Value => Current_State + 1);
|
|
end loop;
|
|
|
|
else
|
|
if S (J) = '\' then
|
|
J := J + 1;
|
|
end if;
|
|
|
|
Set (Table, Current_State, Map (S (J)),
|
|
Value => Current_State + 1);
|
|
end if;
|
|
|
|
Current_State := Current_State + 1;
|
|
|
|
-- If the next symbol is a special symbol
|
|
|
|
if J < End_Index
|
|
and then (S (J + 1) = '*' or else
|
|
S (J + 1) = '+' or else
|
|
S (J + 1) = '?')
|
|
then
|
|
J := J + 1;
|
|
Create_Repetition
|
|
(S (J),
|
|
Current_State - 1,
|
|
Current_State,
|
|
Last_Start,
|
|
End_State);
|
|
|
|
else
|
|
Last_Start := Current_State - 1;
|
|
|
|
if End_State /= 0 then
|
|
Add_Empty_Char (End_State, Last_Start);
|
|
end if;
|
|
|
|
End_State := Current_State;
|
|
end if;
|
|
|
|
end case;
|
|
|
|
if Start_State = 0 then
|
|
Start_State := Last_Start;
|
|
end if;
|
|
|
|
J := J + 1;
|
|
end loop;
|
|
end Create_Simple;
|
|
|
|
-------------------------
|
|
-- Next_Sub_Expression --
|
|
-------------------------
|
|
|
|
function Next_Sub_Expression
|
|
(Start_Index : Integer;
|
|
End_Index : Integer) return Integer
|
|
is
|
|
J : Integer := Start_Index;
|
|
Start_On_Alter : Boolean := False;
|
|
|
|
begin
|
|
if S (J) = '|' then
|
|
Start_On_Alter := True;
|
|
end if;
|
|
|
|
loop
|
|
exit when J = End_Index;
|
|
J := J + 1;
|
|
|
|
case S (J) is
|
|
when '\' =>
|
|
J := J + 1;
|
|
|
|
when Open_Bracket =>
|
|
loop
|
|
J := J + 1;
|
|
exit when S (J) = Close_Bracket;
|
|
|
|
if S (J) = '\' then
|
|
J := J + 1;
|
|
end if;
|
|
end loop;
|
|
|
|
when Open_Paren =>
|
|
J := Next_Sub_Expression (J, End_Index);
|
|
|
|
when Close_Paren =>
|
|
return J;
|
|
|
|
when '|' =>
|
|
if Start_On_Alter then
|
|
return J - 1;
|
|
end if;
|
|
|
|
when others =>
|
|
null;
|
|
end case;
|
|
end loop;
|
|
|
|
return J;
|
|
end Next_Sub_Expression;
|
|
|
|
-- Start of processing for Create_Primary_Table
|
|
|
|
begin
|
|
Table.all := (others => (others => 0));
|
|
Create_Simple (S'First, S'Last, Start_State, End_State);
|
|
Num_States := Current_State;
|
|
end Create_Primary_Table;
|
|
|
|
-------------------------------
|
|
-- Create_Primary_Table_Glob --
|
|
-------------------------------
|
|
|
|
procedure Create_Primary_Table_Glob
|
|
(Table : out Regexp_Array_Access;
|
|
Num_States : out State_Index;
|
|
Start_State : out State_Index;
|
|
End_State : out State_Index)
|
|
is
|
|
Empty_Char : constant Column_Index := Alphabet_Size + 1;
|
|
|
|
Current_State : State_Index := 0;
|
|
-- Index of the last created state
|
|
|
|
procedure Add_Empty_Char
|
|
(State : State_Index;
|
|
To_State : State_Index);
|
|
-- Add a empty-character transition from State to To_State
|
|
|
|
procedure Create_Simple
|
|
(Start_Index : Integer;
|
|
End_Index : Integer;
|
|
Start_State : out State_Index;
|
|
End_State : out State_Index);
|
|
-- Fill the table for the S (Start_Index .. End_Index).
|
|
-- This is the recursive procedure called to handle () expressions
|
|
|
|
--------------------
|
|
-- Add_Empty_Char --
|
|
--------------------
|
|
|
|
procedure Add_Empty_Char
|
|
(State : State_Index;
|
|
To_State : State_Index)
|
|
is
|
|
J : Column_Index;
|
|
|
|
begin
|
|
J := Empty_Char;
|
|
while Get (Table, State, J) /= 0 loop
|
|
J := J + 1;
|
|
end loop;
|
|
|
|
Set (Table, State, J, Value => To_State);
|
|
end Add_Empty_Char;
|
|
|
|
-------------------
|
|
-- Create_Simple --
|
|
-------------------
|
|
|
|
procedure Create_Simple
|
|
(Start_Index : Integer;
|
|
End_Index : Integer;
|
|
Start_State : out State_Index;
|
|
End_State : out State_Index)
|
|
is
|
|
J : Integer;
|
|
Last_Start : State_Index := 0;
|
|
|
|
begin
|
|
Start_State := 0;
|
|
End_State := 0;
|
|
|
|
J := Start_Index;
|
|
while J <= End_Index loop
|
|
case S (J) is
|
|
|
|
when Open_Bracket =>
|
|
Current_State := Current_State + 1;
|
|
|
|
declare
|
|
Next_State : State_Index := Current_State + 1;
|
|
|
|
begin
|
|
J := J + 1;
|
|
|
|
if S (J) = '^' then
|
|
J := J + 1;
|
|
Next_State := 0;
|
|
|
|
for Column in 0 .. Alphabet_Size loop
|
|
Set (Table, Current_State, Column,
|
|
Value => Current_State + 1);
|
|
end loop;
|
|
end if;
|
|
|
|
-- Automatically add the first character
|
|
|
|
if S (J) = '-' or else S (J) = ']' then
|
|
Set (Table, Current_State, Map (S (J)),
|
|
Value => Current_State);
|
|
J := J + 1;
|
|
end if;
|
|
|
|
-- Loop till closing bracket found
|
|
|
|
loop
|
|
exit when S (J) = Close_Bracket;
|
|
|
|
if S (J) = '-'
|
|
and then S (J + 1) /= ']'
|
|
then
|
|
declare
|
|
Start : constant Integer := J - 1;
|
|
|
|
begin
|
|
J := J + 1;
|
|
|
|
if S (J) = '\' then
|
|
J := J + 1;
|
|
end if;
|
|
|
|
for Char in S (Start) .. S (J) loop
|
|
Set (Table, Current_State, Map (Char),
|
|
Value => Next_State);
|
|
end loop;
|
|
end;
|
|
|
|
else
|
|
if S (J) = '\' then
|
|
J := J + 1;
|
|
end if;
|
|
|
|
Set (Table, Current_State, Map (S (J)),
|
|
Value => Next_State);
|
|
end if;
|
|
J := J + 1;
|
|
end loop;
|
|
end;
|
|
|
|
Last_Start := Current_State;
|
|
Current_State := Current_State + 1;
|
|
|
|
if End_State /= 0 then
|
|
Add_Empty_Char (End_State, Last_Start);
|
|
end if;
|
|
|
|
End_State := Current_State;
|
|
|
|
when '{' =>
|
|
declare
|
|
End_Sub : Integer;
|
|
Start_Regexp_Sub : State_Index;
|
|
End_Regexp_Sub : State_Index;
|
|
Create_Start : State_Index := 0;
|
|
|
|
Create_End : State_Index := 0;
|
|
-- Initialized to avoid junk warning
|
|
|
|
begin
|
|
while S (J) /= '}' loop
|
|
|
|
-- First step : find sub pattern
|
|
|
|
End_Sub := J + 1;
|
|
while S (End_Sub) /= ','
|
|
and then S (End_Sub) /= '}'
|
|
loop
|
|
End_Sub := End_Sub + 1;
|
|
end loop;
|
|
|
|
-- Second step : create a sub pattern
|
|
|
|
Create_Simple
|
|
(J + 1,
|
|
End_Sub - 1,
|
|
Start_Regexp_Sub,
|
|
End_Regexp_Sub);
|
|
|
|
J := End_Sub;
|
|
|
|
-- Third step : create an alternative
|
|
|
|
if Create_Start = 0 then
|
|
Current_State := Current_State + 1;
|
|
Create_Start := Current_State;
|
|
Add_Empty_Char (Create_Start, Start_Regexp_Sub);
|
|
Current_State := Current_State + 1;
|
|
Create_End := Current_State;
|
|
Add_Empty_Char (End_Regexp_Sub, Create_End);
|
|
|
|
else
|
|
Current_State := Current_State + 1;
|
|
Add_Empty_Char (Current_State, Create_Start);
|
|
Create_Start := Current_State;
|
|
Add_Empty_Char (Create_Start, Start_Regexp_Sub);
|
|
Add_Empty_Char (End_Regexp_Sub, Create_End);
|
|
end if;
|
|
end loop;
|
|
|
|
if End_State /= 0 then
|
|
Add_Empty_Char (End_State, Create_Start);
|
|
end if;
|
|
|
|
End_State := Create_End;
|
|
Last_Start := Create_Start;
|
|
end;
|
|
|
|
when '*' =>
|
|
Current_State := Current_State + 1;
|
|
|
|
if End_State /= 0 then
|
|
Add_Empty_Char (End_State, Current_State);
|
|
end if;
|
|
|
|
Add_Empty_Char (Current_State, Current_State + 1);
|
|
Add_Empty_Char (Current_State, Current_State + 3);
|
|
Last_Start := Current_State;
|
|
|
|
Current_State := Current_State + 1;
|
|
|
|
for K in 0 .. Alphabet_Size loop
|
|
Set (Table, Current_State, K,
|
|
Value => Current_State + 1);
|
|
end loop;
|
|
|
|
Current_State := Current_State + 1;
|
|
Add_Empty_Char (Current_State, Current_State + 1);
|
|
|
|
Current_State := Current_State + 1;
|
|
Add_Empty_Char (Current_State, Last_Start);
|
|
End_State := Current_State;
|
|
|
|
when others =>
|
|
Current_State := Current_State + 1;
|
|
|
|
if S (J) = '?' then
|
|
for K in 0 .. Alphabet_Size loop
|
|
Set (Table, Current_State, K,
|
|
Value => Current_State + 1);
|
|
end loop;
|
|
|
|
else
|
|
if S (J) = '\' then
|
|
J := J + 1;
|
|
end if;
|
|
|
|
-- Create the state for the symbol S (J)
|
|
|
|
Set (Table, Current_State, Map (S (J)),
|
|
Value => Current_State + 1);
|
|
end if;
|
|
|
|
Last_Start := Current_State;
|
|
Current_State := Current_State + 1;
|
|
|
|
if End_State /= 0 then
|
|
Add_Empty_Char (End_State, Last_Start);
|
|
end if;
|
|
|
|
End_State := Current_State;
|
|
|
|
end case;
|
|
|
|
if Start_State = 0 then
|
|
Start_State := Last_Start;
|
|
end if;
|
|
|
|
J := J + 1;
|
|
end loop;
|
|
end Create_Simple;
|
|
|
|
-- Start of processing for Create_Primary_Table_Glob
|
|
|
|
begin
|
|
Table.all := (others => (others => 0));
|
|
Create_Simple (S'First, S'Last, Start_State, End_State);
|
|
Num_States := Current_State;
|
|
end Create_Primary_Table_Glob;
|
|
|
|
----------------------------
|
|
-- Create_Secondary_Table --
|
|
----------------------------
|
|
|
|
function Create_Secondary_Table
|
|
(First_Table : Regexp_Array_Access;
|
|
Start_State : State_Index;
|
|
End_State : State_Index) return Regexp
|
|
is
|
|
Last_Index : constant State_Index := First_Table'Last (1);
|
|
|
|
type Meta_State is array (0 .. Last_Index) of Boolean;
|
|
pragma Pack (Meta_State);
|
|
-- Whether a state from first_table belongs to a metastate.
|
|
|
|
No_States : constant Meta_State := (others => False);
|
|
|
|
type Meta_States_Array is array (State_Index range <>) of Meta_State;
|
|
type Meta_States_List is access all Meta_States_Array;
|
|
procedure Unchecked_Free is new Ada.Unchecked_Deallocation
|
|
(Meta_States_Array, Meta_States_List);
|
|
Meta_States : Meta_States_List;
|
|
-- Components of meta-states. A given state might belong to
|
|
-- several meta-states.
|
|
-- This array grows dynamically.
|
|
|
|
type Char_To_State is array (0 .. Alphabet_Size) of State_Index;
|
|
type Meta_States_Transition_Arr is
|
|
array (State_Index range <>) of Char_To_State;
|
|
type Meta_States_Transition is access all Meta_States_Transition_Arr;
|
|
procedure Unchecked_Free is new Ada.Unchecked_Deallocation
|
|
(Meta_States_Transition_Arr, Meta_States_Transition);
|
|
Table : Meta_States_Transition;
|
|
-- Documents the transitions between each meta-state. The
|
|
-- first index is the meta-state, the second column is the
|
|
-- character seen in the input, the value is the new meta-state.
|
|
|
|
Temp_State_Not_Null : Boolean;
|
|
|
|
Current_State : State_Index := 1;
|
|
-- The current meta-state we are creating
|
|
|
|
Nb_State : State_Index := 1;
|
|
-- The total number of meta-states created so far.
|
|
|
|
procedure Closure
|
|
(Meta_State : State_Index;
|
|
State : State_Index);
|
|
-- Compute the closure of the state (that is every other state which
|
|
-- has a empty-character transition) and add it to the state
|
|
|
|
procedure Ensure_Meta_State (Meta : State_Index);
|
|
-- grows the Meta_States array as needed to make sure that there
|
|
-- is enough space to store the new meta state.
|
|
|
|
-----------------------
|
|
-- Ensure_Meta_State --
|
|
-----------------------
|
|
|
|
procedure Ensure_Meta_State (Meta : State_Index) is
|
|
Tmp : Meta_States_List := Meta_States;
|
|
Tmp2 : Meta_States_Transition := Table;
|
|
|
|
begin
|
|
if Meta_States = null then
|
|
Meta_States := new Meta_States_Array
|
|
(1 .. State_Index'Max (Last_Index, Meta) + 1);
|
|
Meta_States (Meta_States'Range) := (others => No_States);
|
|
|
|
Table := new Meta_States_Transition_Arr
|
|
(1 .. State_Index'Max (Last_Index, Meta) + 1);
|
|
Table.all := (others => (others => 0));
|
|
|
|
elsif Meta > Meta_States'Last then
|
|
Meta_States := new Meta_States_Array
|
|
(1 .. State_Index'Max (2 * Tmp'Last, Meta));
|
|
Meta_States (Tmp'Range) := Tmp.all;
|
|
Meta_States (Tmp'Last + 1 .. Meta_States'Last) :=
|
|
(others => No_States);
|
|
Unchecked_Free (Tmp);
|
|
|
|
Table := new Meta_States_Transition_Arr
|
|
(1 .. State_Index'Max (2 * Tmp2'Last, Meta) + 1);
|
|
Table (Tmp2'Range) := Tmp2.all;
|
|
Table (Tmp2'Last + 1 .. Table'Last) :=
|
|
(others => (others => 0));
|
|
Unchecked_Free (Tmp2);
|
|
end if;
|
|
end Ensure_Meta_State;
|
|
|
|
-------------
|
|
-- Closure --
|
|
-------------
|
|
|
|
procedure Closure
|
|
(Meta_State : State_Index;
|
|
State : State_Index)
|
|
is
|
|
begin
|
|
if not Meta_States (Meta_State)(State) then
|
|
Meta_States (Meta_State)(State) := True;
|
|
|
|
-- For each transition on empty-character
|
|
|
|
for Column in Alphabet_Size + 1 .. First_Table'Last (2) loop
|
|
exit when First_Table (State, Column) = 0;
|
|
Closure (Meta_State, First_Table (State, Column));
|
|
end loop;
|
|
end if;
|
|
end Closure;
|
|
|
|
-- Start of processing for Create_Secondary_Table
|
|
|
|
begin
|
|
-- Create a new state
|
|
|
|
Ensure_Meta_State (Current_State);
|
|
Closure (Current_State, Start_State);
|
|
|
|
while Current_State <= Nb_State loop
|
|
|
|
-- We will be trying, below, to create the next meta-state
|
|
|
|
Ensure_Meta_State (Nb_State + 1);
|
|
|
|
-- For every character in the regexp, calculate the possible
|
|
-- transitions from Current_State.
|
|
|
|
for Column in 0 .. Alphabet_Size loop
|
|
Temp_State_Not_Null := False;
|
|
|
|
for K in Meta_States (Current_State)'Range loop
|
|
if Meta_States (Current_State)(K)
|
|
and then First_Table (K, Column) /= 0
|
|
then
|
|
Closure (Nb_State + 1, First_Table (K, Column));
|
|
Temp_State_Not_Null := True;
|
|
end if;
|
|
end loop;
|
|
|
|
-- If at least one transition existed
|
|
|
|
if Temp_State_Not_Null then
|
|
|
|
-- Check if this new state corresponds to an old one
|
|
|
|
for K in 1 .. Nb_State loop
|
|
if Meta_States (K) = Meta_States (Nb_State + 1) then
|
|
Table (Current_State)(Column) := K;
|
|
|
|
-- Reset data, for the next time we try that state
|
|
|
|
Meta_States (Nb_State + 1) := No_States;
|
|
exit;
|
|
end if;
|
|
end loop;
|
|
|
|
-- If not, create a new state
|
|
|
|
if Table (Current_State)(Column) = 0 then
|
|
Nb_State := Nb_State + 1;
|
|
Ensure_Meta_State (Nb_State + 1);
|
|
Table (Current_State)(Column) := Nb_State;
|
|
end if;
|
|
end if;
|
|
end loop;
|
|
|
|
Current_State := Current_State + 1;
|
|
end loop;
|
|
|
|
-- Returns the regexp
|
|
|
|
declare
|
|
R : Regexp_Access;
|
|
|
|
begin
|
|
R := new Regexp_Value (Alphabet_Size => Alphabet_Size,
|
|
Num_States => Nb_State);
|
|
R.Map := Map;
|
|
R.Case_Sensitive := Case_Sensitive;
|
|
|
|
for S in 1 .. Nb_State loop
|
|
R.Is_Final (S) := Meta_States (S)(End_State);
|
|
end loop;
|
|
|
|
for State in 1 .. Nb_State loop
|
|
for K in 0 .. Alphabet_Size loop
|
|
R.States (State, K) := Table (State)(K);
|
|
end loop;
|
|
end loop;
|
|
|
|
Unchecked_Free (Meta_States);
|
|
Unchecked_Free (Table);
|
|
|
|
return (Ada.Finalization.Controlled with R => R);
|
|
end;
|
|
end Create_Secondary_Table;
|
|
|
|
---------------------
|
|
-- Raise_Exception --
|
|
---------------------
|
|
|
|
procedure Raise_Exception (M : String; Index : Integer) is
|
|
begin
|
|
raise Error_In_Regexp with M & " at offset" & Index'Img;
|
|
end Raise_Exception;
|
|
|
|
-- Start of processing for Compile
|
|
|
|
begin
|
|
-- Special case for the empty string: it always matches, and the
|
|
-- following processing would fail on it.
|
|
|
|
if S = "" then
|
|
return (Ada.Finalization.Controlled with
|
|
R => new Regexp_Value'
|
|
(Alphabet_Size => 0,
|
|
Num_States => 1,
|
|
Map => (others => 0),
|
|
States => (others => (others => 1)),
|
|
Is_Final => (others => True),
|
|
Case_Sensitive => True));
|
|
end if;
|
|
|
|
if not Case_Sensitive then
|
|
System.Case_Util.To_Lower (S);
|
|
end if;
|
|
|
|
-- Check the pattern is well-formed before any treatment
|
|
|
|
Check_Well_Formed_Pattern;
|
|
|
|
Create_Mapping;
|
|
|
|
-- Creates the primary table
|
|
|
|
declare
|
|
Table : Regexp_Array_Access;
|
|
Num_States : State_Index;
|
|
Start_State : State_Index;
|
|
End_State : State_Index;
|
|
R : Regexp;
|
|
|
|
begin
|
|
Table := new Regexp_Array (1 .. Initial_Max_States_In_Primary_Table,
|
|
0 .. Alphabet_Size + 10);
|
|
if not Glob then
|
|
Create_Primary_Table (Table, Num_States, Start_State, End_State);
|
|
else
|
|
Create_Primary_Table_Glob
|
|
(Table, Num_States, Start_State, End_State);
|
|
end if;
|
|
|
|
-- Creates the secondary table
|
|
|
|
R := Create_Secondary_Table (Table, Start_State, End_State);
|
|
Free (Table);
|
|
return R;
|
|
end;
|
|
end Compile;
|
|
|
|
--------------
|
|
-- Finalize --
|
|
--------------
|
|
|
|
procedure Finalize (R : in out Regexp) is
|
|
procedure Free is new
|
|
Ada.Unchecked_Deallocation (Regexp_Value, Regexp_Access);
|
|
begin
|
|
Free (R.R);
|
|
end Finalize;
|
|
|
|
---------
|
|
-- Get --
|
|
---------
|
|
|
|
function Get
|
|
(Table : Regexp_Array_Access;
|
|
State : State_Index;
|
|
Column : Column_Index) return State_Index
|
|
is
|
|
begin
|
|
if State <= Table'Last (1)
|
|
and then Column <= Table'Last (2)
|
|
then
|
|
return Table (State, Column);
|
|
else
|
|
return 0;
|
|
end if;
|
|
end Get;
|
|
|
|
-----------
|
|
-- Match --
|
|
-----------
|
|
|
|
function Match (S : String; R : Regexp) return Boolean is
|
|
Current_State : State_Index := 1;
|
|
|
|
begin
|
|
if R.R = null then
|
|
raise Constraint_Error;
|
|
end if;
|
|
|
|
for Char in S'Range loop
|
|
|
|
if R.R.Case_Sensitive then
|
|
Current_State := R.R.States (Current_State, R.R.Map (S (Char)));
|
|
else
|
|
Current_State :=
|
|
R.R.States (Current_State,
|
|
R.R.Map (System.Case_Util.To_Lower (S (Char))));
|
|
end if;
|
|
|
|
if Current_State = 0 then
|
|
return False;
|
|
end if;
|
|
|
|
end loop;
|
|
|
|
return R.R.Is_Final (Current_State);
|
|
end Match;
|
|
|
|
---------
|
|
-- Set --
|
|
---------
|
|
|
|
procedure Set
|
|
(Table : in out Regexp_Array_Access;
|
|
State : State_Index;
|
|
Column : Column_Index;
|
|
Value : State_Index)
|
|
is
|
|
New_Lines : State_Index;
|
|
New_Columns : Column_Index;
|
|
New_Table : Regexp_Array_Access;
|
|
|
|
begin
|
|
if State <= Table'Last (1)
|
|
and then Column <= Table'Last (2)
|
|
then
|
|
Table (State, Column) := Value;
|
|
else
|
|
-- Doubles the size of the table until it is big enough that
|
|
-- (State, Column) is a valid index.
|
|
|
|
New_Lines := Table'Last (1) * (State / Table'Last (1) + 1);
|
|
New_Columns := Table'Last (2) * (Column / Table'Last (2) + 1);
|
|
New_Table := new Regexp_Array (Table'First (1) .. New_Lines,
|
|
Table'First (2) .. New_Columns);
|
|
New_Table.all := (others => (others => 0));
|
|
|
|
for J in Table'Range (1) loop
|
|
for K in Table'Range (2) loop
|
|
New_Table (J, K) := Table (J, K);
|
|
end loop;
|
|
end loop;
|
|
|
|
Free (Table);
|
|
Table := New_Table;
|
|
Table (State, Column) := Value;
|
|
end if;
|
|
end Set;
|
|
|
|
end System.Regexp;
|