(* WholeConv.mod implement the ISO WholeConv specification.
Copyright (C) 2008-2023 Free Software Foundation, Inc.
Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
This file is part of GNU Modula-2.
GNU Modula-2 is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GNU Modula-2 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 the GNU
General Public License for more details.
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/>. *)
IMPLEMENTATION MODULE WholeConv ;
FROM CharClass IMPORT IsNumeric, IsWhiteSpace ;
IMPORT EXCEPTIONS ;
FROM ConvTypes IMPORT ScanClass ;
TYPE
WholeConvException = (noException, invalidSigned, invalidUnsigned) ;
VAR
wholeConv: EXCEPTIONS.ExceptionSource ;
(*
ScanInt - represents the start state of a finite state scanner
for signed whole numbers - assigns class of inputCh
to chClass and a procedure representing the next state
to nextState.
*)
PROCEDURE ScanInt (inputCh: CHAR;
VAR chClass: ConvTypes.ScanClass;
VAR nextState: ConvTypes.ScanState) ;
BEGIN
IF IsNumeric(inputCh)
THEN
nextState := scanRemainingDigits ;
chClass := valid
ELSIF (inputCh='+') OR (inputCh='-')
THEN
nextState := scanFirstDigit ;
chClass := valid
ELSIF IsWhiteSpace(inputCh)
THEN
nextState := scanSpace ;
chClass := padding
ELSE
nextState := ScanInt ;
chClass := invalid
END
END ScanInt ;
PROCEDURE scanFirstDigit (ch: CHAR;
VAR chClass: ConvTypes.ScanClass;
VAR nextState: ConvTypes.ScanState) ;
BEGIN
IF IsNumeric(ch)
THEN
chClass := valid ;
nextState := scanRemainingDigits
ELSE
chClass := invalid
END
END scanFirstDigit ;
PROCEDURE scanRemainingDigits (ch: CHAR;
VAR chClass: ConvTypes.ScanClass;
VAR nextState: ConvTypes.ScanState) ;
BEGIN
IF IsNumeric(ch)
THEN
chClass := valid
ELSE
chClass := terminator
END
END scanRemainingDigits ;
PROCEDURE scanSpace (ch: CHAR;
VAR chClass: ConvTypes.ScanClass;
VAR nextState: ConvTypes.ScanState) ;
BEGIN
IF IsWhiteSpace(ch)
THEN
chClass := padding
ELSIF (ch='+') OR (ch='-')
THEN
chClass := valid ;
nextState := scanFirstDigit
ELSE
chClass := invalid
END
END scanSpace ;
(*
FormatInt - returns the format of the string value for
conversion to INTEGER.
*)
PROCEDURE FormatInt (str: ARRAY OF CHAR) : ConvResults ;
VAR
proc : ConvTypes.ScanState ;
chClass: ConvTypes.ScanClass ;
i, h : CARDINAL ;
BEGIN
i := 1 ;
h := LENGTH(str) ;
ScanInt(str[0], chClass, proc) ;
WHILE (i<h) AND (chClass=padding) DO
proc(str[i], chClass, proc) ;
INC(i)
END ;
IF chClass=terminator
THEN
RETURN( strEmpty )
END ;
WHILE (i<h) AND (chClass=valid) DO
proc(str[i], chClass, proc) ;
INC(i)
END ;
CASE chClass OF
padding : RETURN( strWrongFormat ) |
terminator,
valid : RETURN( strAllRight ) |
invalid : RETURN( strWrongFormat )
END
END FormatInt ;
(*
ValueInt - returns the value corresponding to the signed whole
number string value str if str is well-formed;
otherwise raises the WholeConv exception.
*)
PROCEDURE ValueInt (str: ARRAY OF CHAR) : INTEGER;
VAR
proc : ConvTypes.ScanState ;
chClass: ConvTypes.ScanClass ;
i, h : CARDINAL ;
v : INTEGER ;
value : CARDINAL ;
neg : BOOLEAN ;
BEGIN
IF FormatInt(str)=strAllRight
THEN
value := 0 ;
neg := FALSE ;
i := 0 ;
h := LENGTH(str) ;
proc := ScanInt ;
chClass := valid ;
WHILE (i<h) AND ((chClass=valid) OR (chClass=padding)) DO
IF str[i]='-'
THEN
neg := NOT neg
ELSIF str[i]='+'
THEN
(* ignore *)
ELSIF IsNumeric(str[i])
THEN
value := value*10+(ORD(str[i])-ORD('0'))
END ;
proc(str[i], chClass, proc) ;
INC(i)
END ;
IF neg
THEN
v := -value
ELSE
v := value
END ;
RETURN( v )
ELSE
EXCEPTIONS.RAISE(wholeConv, ORD(invalidSigned),
'WholeConv.' + __FUNCTION__ + ': signed number is invalid')
END
END ValueInt ;
(*
LengthInt - returns the number of characters in the string
representation of int.
*)
PROCEDURE LengthInt (int: INTEGER) : CARDINAL ;
VAR
c, l: CARDINAL ;
BEGIN
IF int<0
THEN
l := 2 ;
IF int=MIN(INTEGER)
THEN
c := VAL(CARDINAL, MAX(INTEGER))+1
ELSE
c := -int
END
ELSE
l := 1 ;
c := int
END ;
WHILE c>9 DO
c := c DIV 10 ;
INC(l)
END ;
RETURN( l )
END LengthInt ;
(*
ScanCard - represents the start state of a finite state scanner for
unsigned whole numbers - assigns class of inputCh to
chClass and a procedure representing the next state to
nextState.
*)
PROCEDURE ScanCard (inputCh: CHAR;
VAR chClass: ConvTypes.ScanClass;
VAR nextState: ConvTypes.ScanState) ;
BEGIN
IF IsNumeric(inputCh)
THEN
nextState := scanRemainingDigits ;
chClass := valid
ELSIF inputCh='+'
THEN
nextState := scanFirstDigit ;
chClass := valid
ELSIF IsWhiteSpace(inputCh)
THEN
nextState := scanSpace ;
chClass := padding
ELSE
nextState := ScanCard ;
chClass := invalid
END
END ScanCard ;
(*
FormatCard - returns the format of the string value for
conversion to CARDINAL.
*)
PROCEDURE FormatCard (str: ARRAY OF CHAR) : ConvResults ;
VAR
proc : ConvTypes.ScanState ;
chClass: ConvTypes.ScanClass ;
i, h : CARDINAL ;
BEGIN
i := 1 ;
h := LENGTH(str) ;
ScanCard(str[0], chClass, proc) ;
WHILE (i<h) AND (chClass=padding) DO
proc(str[i], chClass, proc) ;
INC(i)
END ;
IF chClass=terminator
THEN
RETURN( strEmpty )
END ;
WHILE (i<h) AND (chClass=valid) DO
proc(str[i], chClass, proc) ;
INC(i)
END ;
CASE chClass OF
padding : RETURN( strWrongFormat ) |
terminator,
valid : RETURN( strAllRight ) |
invalid : RETURN( strWrongFormat )
END
END FormatCard ;
(*
ValueCard - returns the value corresponding to the unsigned
whole number string value str if str is well-formed;
otherwise raises the WholeConv exception.
*)
PROCEDURE ValueCard (str: ARRAY OF CHAR) : CARDINAL ;
VAR
proc : ConvTypes.ScanState ;
chClass: ConvTypes.ScanClass ;
i, h : CARDINAL ;
value : CARDINAL ;
BEGIN
IF FormatCard(str)=strAllRight
THEN
value := 0 ;
i := 0 ;
h := LENGTH(str) ;
ScanCard(str[0], chClass, proc) ;
proc := ScanCard ;
chClass := valid ;
WHILE (i<h) AND ((chClass=valid) OR (chClass=padding)) DO
IF str[i]='+'
THEN
(* ignore *)
ELSIF IsNumeric(str[i])
THEN
value := value*10+(ORD(str[i])-ORD('0'))
END ;
proc(str[i], chClass, proc) ;
INC(i)
END ;
RETURN( value )
ELSE
EXCEPTIONS.RAISE(wholeConv, ORD(invalidUnsigned),
'WholeConv:' + __FUNCTION__ + ': unsigned number is invalid')
END
END ValueCard ;
(*
LengthCard - returns the number of characters in the string
representation of, card.
*)
PROCEDURE LengthCard (card: CARDINAL) : CARDINAL ;
VAR
l: CARDINAL ;
BEGIN
l := 1 ;
WHILE card>9 DO
card := card DIV 10 ;
INC(l)
END ;
RETURN( l )
END LengthCard ;
(*
IsWholeConvException - returns TRUE if the current coroutine is
in the exceptional execution state because
of the raising of an exception in a routine
from this module; otherwise returns FALSE.
*)
PROCEDURE IsWholeConvException () : BOOLEAN ;
BEGIN
RETURN( EXCEPTIONS.IsCurrentSource(wholeConv) )
END IsWholeConvException ;
BEGIN
EXCEPTIONS.AllocateSource(wholeConv)
END WholeConv.