intistr.sa
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-------------------------> GNU Sather - sourcefile <-------------------------
-- Copyright (C) 2000 by K Hopper, University of Waikato, New Zealand --
-- This file is part of the GNU Sather library. It is free software; you may --
-- redistribute and/or modify it under the terms of the GNU Library General --
-- Public License (LGPL) as published by the Free Software Foundation; --
-- either version 2 of the license, 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 MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See Doc/LGPL for more details. --
-- The license text is also available from: Free Software Foundation, Inc., --
-- 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA --
--------------> Please email comments to <bug-sather@gnu.org> <--------------
partial class INTI_STR < $TEXT, $EXACT_FMT
partial class INTI_STR < $TEXT, $EXACT_FMT is
-- This partial class provides numeric whole number conversion routines,
-- to and from character strings.
-- Version 1.1 Mar 99. Copyright K Hopper, U of Waikato
-- Development History
-- -------------------
-- Date Who By Detail
-- ---- ------ ------
-- 15 Sep 98 kh Original from Modula-2 standard
-- 30 Mar 99 kh Revised for V8 of text classes
private const log10D : CARD := 4 ;
private const Decimal : CARD := 10 ^ log10D ; -- decimal base; D <= B
private const Default_Base : CARD := 10 ; -- for conversions!
private opt_sign(cursor : STR_CURSOR) : BOOL
pre ~void(cursor)
and ~cursor.is_done
post true
is
--This private routine checks to see if a minus or plus sign are in
-- the indicated string next. If and only if any such sign is negative then
-- true is returned! The sign (if present) has been skipped over on return.
loc_ch : CHAR := cursor.item ;
loc_lib : LIBCHARS := cursor.buffer.index_lib ;
res : BOOL := (loc_ch = loc_lib.Minus_Sign.char) ;
if (loc_ch = loc_lib.Minus_Sign.char)
or (loc_ch = loc_lib.Plus_Sign.char) then
cursor.advance
end ;
return res
end ;
private scan(cursor : STR_CURSOR,out negative : BOOL) : FLIST{CARD}
pre ~void(cursor)
and ~cursor.is_done
post (void(result)
and (initial(cursor.index) = cursor.index))
or (initial(cursor.index) < cursor.index)
is
--This routine is the integer number scanner which returns void with
-- an unchanged string if there is a format problem, otherwise the digit string!
start_index : CARD := cursor.index ;
loc_lib : LIBCHARS := cursor.buffer.index_lib ;
loc_format : NUMBER_FMT := cursor.buffer.index_lib.culture.numeric.format ;
negative := opt_sign(cursor) ;
if ~cursor.item.is_digit(loc_lib) then
cursor.set_index(start_index) ;
return void
end ;
return loc_format.digit_string(cursor,true,Default_Base)
end ;
is_inti(str : STR) : CONVERSION_RESULTS
pre true
post (result = CONVERSION_RESULTS::All_Right)
or (result = CONVERSION_RESULTS::Out_of_Range)
or (result = CONVERSION_RESULTS::Empty)
is
--This routine checks that the format of of the leading characters of
-- the given string in the given repertoire and encoding corresponds to that
-- required for a real number, returning the relevant result state.
if str.size = 0 then
return CONVERSION_RESULTS::Empty
end ;
negative : BOOL ; -- not needed in this routine
loc_cursor : STR_CURSOR := str.cursor ;
start_index : CARD := 0 ;
loc_dummy : FLIST{CARD} := scan(loc_cursor,out negative) ;
if start_index = loc_cursor.index then -- bad or too large
return CONVERSION_RESULTS::Bad_Format
else
loc_cursor.set_index(start_index) ;
return CONVERSION_RESULTS::All_Right
end
end ;
build(loc_cursor : STR_CURSOR) : SAME
pre ~void(loc_cursor)
and ~loc_cursor.is_done
post (void(result)
and (initial(loc_cursor.index) = loc_cursor.index))
or (initial(loc_cursor.index) < loc_cursor.index)
is
--This routine creates the integer number corresponding to the textual
-- representation contained in the string indicated. If the string indicated
-- does not contain an exact number as the next non-blank item in the string
-- then zero is returned and the cursor has not been moved!
start_index : CARD := loc_cursor.index ;
negative : BOOL ;
me : SAME := create(0) ;
loc_digits : FLIST{CARD} := scan(loc_cursor,out negative) ;
loc_res : CARD := 0 ;
loc_index : CARD := loc_cursor.index ;
loop
loc_res := loc_res * 10 + loc_digits.elt! ;
if loc_cursor.index - loc_index = log10D then
me := u_times_plus(me, Decimal, loc_res) ;
loc_res := 0 ;
loc_index := loc_cursor.index
end
end ;
if loc_cursor.index > loc_index then
me := u_times_plus(me, 10^(loc_cursor.index - loc_index), loc_res)
end ;
if negative then
me.len := -me.len
end ;
return me
end ;
create(str : STR,index : CARD) : SAME
pre (str.size > index)
post true
is
-- This routine creates an infinite integer from its decimal string
-- representation starting at the given index in str. If no number is
-- there then zero is returned.
loc_cursor : STR_CURSOR := str.cursor ;
loc_cursor.set_index(index) ;
return build(loc_cursor)
end ;
create(str : STR) : SAME
pre is_inti(str) = CONVERSION_RESULTS::All_Right
post true
is
--This routine returns the whole number corresponding to
-- the given string in the default repertoire and encoding.
return build(str.cursor)
end ;
create(str : FSTR,index : CARD) : SAME
pre ~void(str)
and (index < str.size)
post true
is
--This routine creates an infinite integer from its decimal string
-- representation starting at the given index in str. If no number is
-- there then zero is returned.
loc_cursor : STR_CURSOR := str.str.cursor ;
loc_cursor.set_index(index) ;
return build(loc_cursor)
end ;
create(str : FSTR) : SAME
pre ~void(str)
and (str.size > 0)
post true
is
--This routine creates an infinite integer out of the text string str,
-- starting at the beginning of it.
return build(str.str.cursor)
end ;
private to_digits(base : CARD) : FLIST{CARD}
pre ~void(self)
and (base > 0)
post (result.size > 0)
is
-- This routine converts self into a list of digits with the least
-- significant digit first.
loc_val : SAME := self.abs ; -- the sign is not considered here
res : FLIST{CARD} := FLIST{CARD}::create ;
loc_div : SAME := create(base) ; -- numeric base
loop
loc_tmp : SAME := loc_val % loc_div ;
res := res.push(loc_tmp.card) ;
loc_val := loc_val / loc_div ;
if loc_val = zero then
break!
end
end ;
return res
end ;
digits : FLIST{CARD}
pre ~void(self)
post result.size > 0
is
--This public routine returns the number of decimal digits in the
-- string representation of self.abs.
return to_digits(10)
end ;
str(lib : LIBCHARS) : STR
pre ~void(lib)
post (result.size > 0)
is
-- This routine returns a string representation of self using the given
-- repertoire and encoding.
res : STR := STR::create(lib) ;
if self < zero then
res := res + lib.Minus_Sign.char
end ;
return res + lib.culture.numeric.format.fmt(to_digits(Default_Base),0,false,lib).tgt_str
end ;
decimal_str : STR
post (result.size > 0)
is
-- This routine returns a string representation of self using the given
-- repertoire and encoding.
lib::=LIBCHARS::default;
res : STR := ""; --STR::create(lib) ;
if self < zero then
res := res + lib.Minus_Sign.char
end ;
return res + lib.culture.numeric.format.fmt_no_sep(to_digits(Default_Base),0,false,lib).tgt_str
end ;
str : STR
pre true
post (result.size > 0)
is
--This routine returns a string representation of self using the given
-- repertoire and encoding.
return str(LIBCHARS::default)
end ;
fmt(format : EXACT_DESCR,lib : LIBCHARS) : STR
pre ~void(format)
and ~void(lib)
post result.size > 0
is
--This routine returns a formatted representation of self in the given
-- repertoire and encoding as dictated by the given format description.
res : STR := str(lib) ;
loc_fill : STR := STR::create(lib) + format.filler.char ;
if res.size < format.whole_digits then -- needs a filler
res := loc_fill.repeat(format.whole_digits - res.size) + res
end ;
return res
end ;
fmt(format : EXACT_DESCR) : STR
pre ~void(format)
post result.size > 0
is
--This routine returns a formatted representation of self in the default
-- repertoire and encoding as dictated by the given format description.
return fmt(format,LIBCHARS::default)
end ;
end ; -- INTI_STR