diff options
Diffstat (limited to 'gcc/ada/g-regpat.ads')
| -rw-r--r-- | gcc/ada/g-regpat.ads | 100 |
1 files changed, 83 insertions, 17 deletions
diff --git a/gcc/ada/g-regpat.ads b/gcc/ada/g-regpat.ads index b3af0d82618..ba00b04a5cd 100644 --- a/gcc/ada/g-regpat.ads +++ b/gcc/ada/g-regpat.ads @@ -7,7 +7,7 @@ -- S p e c -- -- -- -- Copyright (C) 1986 by University of Toronto. -- --- Copyright (C) 1996-2001 Ada Core Technologies, Inc. -- +-- Copyright (C) 1996-2002 Ada Core Technologies, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- @@ -27,7 +27,8 @@ -- however invalidate any other reasons why the executable file might be -- -- covered by the GNU Public License. -- -- -- --- GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ @@ -74,10 +75,13 @@ pragma Preelaborate (Regpat); -- regexp ::= expr -- ::= ^ expr -- anchor at the beginning of string -- ::= expr $ -- anchor at the end of string + -- expr ::= term -- ::= term | term -- alternation (term or term ...) + -- term ::= item -- ::= item item ... -- concatenation (item then item) + -- item ::= elmt -- match elmt -- ::= elmt * -- zero or more elmt's -- ::= elmt + -- one or more elmt's @@ -93,6 +97,7 @@ pragma Preelaborate (Regpat); -- non-greedy version -- ::= elmt { num , num2 }? -- matches between num and num2 times -- non-greedy version + -- elmt ::= nchr -- matches given character -- ::= [range range ...] -- matches any character listed -- ::= [^ range range ...] -- matches any character not listed @@ -100,10 +105,12 @@ pragma Preelaborate (Regpat); -- -- except newlines -- ::= ( expr ) -- parens used for grouping -- ::= \ num -- reference to num-th parenthesis + -- range ::= char - char -- matches chars in given range -- ::= nchr -- ::= [: posix :] -- any character in the POSIX range -- ::= [:^ posix :] -- not in the POSIX range + -- posix ::= alnum -- alphanumeric characters -- ::= alpha -- alphabetic characters -- ::= ascii -- ascii characters (0 .. 127) @@ -120,6 +127,7 @@ pragma Preelaborate (Regpat); -- char ::= any character, including special characters -- ASCII.NUL is not supported. + -- nchr ::= any character except \()[].*+?^ or \char to match char -- \n means a newline (ASCII.LF) -- \t means a tab (ASCII.HT) @@ -217,7 +225,7 @@ pragma Preelaborate (Regpat); -- the first parenthesis pair. -- declare - -- Matches : Match_Array; + -- Matches : Match_Array (0 .. 1); -- Regexp : String := "a(b|c)d"; -- Str : String := "gacdg"; @@ -227,6 +235,33 @@ pragma Preelaborate (Regpat); -- -- returns 'c' -- end; + -- Finding all occurrences + -- ======================= + + -- Finding all the occurrences of a regular expression in a string cannot + -- be done by simply passing a slice of the string. This wouldn't work for + -- anchored regular expressions (the ones starting with "^" or ending with + -- "$"). + -- Instead, you need to use the last parameter to Match (Data_First), as in + -- the following loop: + + -- declare + -- Str : String := + -- "-- first line" & ASCII.LF & "-- second line"; + -- Matches : Match_array (0 .. 0); + -- Regexp : Pattern_Matcher := Compile ("^--", Multiple_Lines); + -- Current : Natural := Str'First; + -- begin + -- loop + -- Match (Regexp, Str, Matches, Current); + -- exit when Matches (0) = No_Match; + -- + -- -- Process the match at position Matches (0).First + -- + -- Current := Matches (0).Last + 1; + -- end loop; + -- end; + -- String Substitution -- =================== @@ -239,7 +274,7 @@ pragma Preelaborate (Regpat); -- declare -- Regexp : String := "([a-z]+) +([a-z]+)"; -- Str : String := " first second third "; - -- Matches : Match_Array; + -- Matches : Match_Array (0 .. 2); -- begin -- Match (Compile (Regexp), Str, Matches); @@ -380,9 +415,8 @@ pragma Preelaborate (Regpat); function Paren_Count (Regexp : Pattern_Matcher) return Match_Count; pragma Inline (Paren_Count); - -- Return the number of parenthesis pairs in Regexp. - + -- -- This is the maximum index that will be filled if a Match_Array is -- used as an argument to Match. -- @@ -413,8 +447,23 @@ pragma Preelaborate (Regpat); (Expression : String; Data : String; Matches : out Match_Array; - Size : Program_Size := 0); - -- Match Expression against Data and store result in Matches. + Size : Program_Size := 0; + Data_First : Integer := -1; + Data_Last : Positive := Positive'Last); + -- Match Expression against Data (Data_First .. Data_Last) and store + -- result in Matches. + -- + -- Data_First defaults to Data'First if unspecified (that is the + -- dummy value of -1 is interpreted to mean Data'First). + -- + -- Data_Last defaults to Data'Last if unspecified (that is the + -- dummy value of Positive'Last is interpreted to mean Data'Last) + -- + -- It is important that Data contains the whole string (or file) you + -- want to matched against, even if you start in the middle, since + -- otherwise regular expressions starting with "^" or ending with "$" will + -- be improperly processed. + -- -- Function raises Storage_Error if Size is too small for Expression, -- or Expression_Error if Expression is not a legal regular expression. -- If Size is 0, then the appropriate size is automatically calculated @@ -425,19 +474,26 @@ pragma Preelaborate (Regpat); function Match (Expression : String; Data : String; - Size : Program_Size := 0) + Size : Program_Size := 0; + Data_First : Integer := -1; + Data_Last : Positive := Positive'Last) return Natural; - -- Return the position where Data matches, or (Data'First - 1) if there is - -- no match. + -- Return the position where Data matches, or (Data'First - 1) if + -- there is no match. + -- -- Function raises Storage_Error if Size is too small for Expression -- or Expression_Error if Expression is not a legal regular expression + -- -- If Size is 0, then the appropriate size is automatically calculated -- by this package, but this is slightly slower. + -- See description of Data_First and Data_Last above. function Match (Expression : String; Data : String; - Size : Program_Size := 0) + Size : Program_Size := 0; + Data_First : Integer := -1; + Data_Last : Positive := Positive'Last) return Boolean; -- Return True if Data matches Expression. Match raises Storage_Error -- if Size is too small for Expression, or Expression_Error if Expression @@ -445,6 +501,8 @@ pragma Preelaborate (Regpat); -- -- If Size is 0, then the appropriate size is automatically calculated -- by this package, but this is slightly slower. + -- + -- See description of Data_First and Data_Last above. ------------------------------------------------ -- Matching a pre-compiled regular expression -- @@ -455,25 +513,33 @@ pragma Preelaborate (Regpat); -- compile it once. function Match - (Self : Pattern_Matcher; - Data : String) + (Self : Pattern_Matcher; + Data : String; + Data_First : Integer := -1; + Data_Last : Positive := Positive'Last) return Natural; -- Return the position where Data matches, or (Data'First - 1) if there is -- no match. Raises Expression_Error if Expression is not a legal regular -- expression. + -- + -- See description of Data_First and Data_Last above. pragma Inline (Match); -- All except the last one below. procedure Match - (Self : Pattern_Matcher; - Data : String; - Matches : out Match_Array); + (Self : Pattern_Matcher; + Data : String; + Matches : out Match_Array; + Data_First : Integer := -1; + Data_Last : Positive := Positive'Last); -- Match Data using the given pattern matcher and store result in Matches. -- Raises Expression_Error if Expression is not a legal regular expression. -- The expression matches if Matches (0) /= No_Match. -- -- At most Matches'Length parenthesis are returned. + -- + -- See description of Data_First and Data_Last above. ----------- -- Debug -- |