[m-rev.] for review: format ints with thousand separators

[Ian MacLarty]

On Thu, Feb 03, 2005 at 05:21:16PM +1100, Zoltan Somogyi wrote:
> On 03-Feb-2005, Julien Fischer <juliensf at cs.mu.OZ.AU> wrote:
> > > +string__int_to_base_string_group_2(NegN, Base, Curr, Period, Sep, Str) :-
> > > +	(
> > > +		Curr = Period, Period > 0
> > > +	->
> > > +		string__int_to_base_string_group_2(NegN, Base, 0, Period, Sep,
> > > +			Str1),
> > > +		string__append(Str1, Sep, Str)
> 
> I think you need to document the meaning of the Curr and Period arguments.
> 

Okay.

> > > +		(
> > > +			NegN > -Base
> > > +		->
> > > +			N = -NegN,
> > > +			char__det_int_to_digit(N, DigitChar),
> > > +			string__char_to_string(DigitChar, Str)
> > > +		;
> > > +			NegN1 = NegN // Base,
> > > +			N10 = (NegN1 * Base) - NegN,
> > > +			char__det_int_to_digit(N10, DigitChar),
> > > +			string__char_to_string(DigitChar, DigitString),
> > > +			string__int_to_base_string_group_2(NegN1, Base,
> > > +				Curr + 1, Period, Sep, Str1),
> > > +			string__append(Str1, DigitString, Str)
> > > +		)
> > > +	).
> 
> Noting both here and in int_to_base_string that this code is basically
> duplicated would be a good idea.
> 

Okay.

Here's an interdiff:

diff -u library/string.m library/string.m
--- library/string.m	3 Feb 2005 05:50:13 -0000
+++ library/string.m	3 Feb 2005 06:47:53 -0000
@@ -123,11 +123,10 @@
 	%
 :- func string__int_to_string_thousands(int) = string.
 :- mode string__int_to_string_thousands(in) = uo is det.
-:- pred string__int_to_string_thousands(int, string).
-:- mode string__int_to_string_thousands(in, uo) is det.
 
 	% string__int_to_base_string(Int, Base, String):
-	% Convert an integer to a string in a given Base (between 2 and 36).
+	% Convert an integer to a string in a given Base.
+	% An exception is thrown if Base is not between 2 and 36.
 	%
 :- func string__int_to_base_string(int, int) = string.
 :- mode string__int_to_base_string(in, in) = uo is det.
@@ -137,13 +136,13 @@
 	% string__int_to_base_string_group(Int, Base, GroupLength, Seperator,
 	%	String):
 	% Convert an integer to a string in a given Base (between 2 and 36)
-	% and insert Seperator between every GroupLength digits.  Useful
-	% for formatting numbers like "1,300,000".
+	% and insert Seperator between every GroupLength digits.  
+	% If GroupLength is less than one then no seperators will appear in the
+	% output.  An exception is thrown if Base is not between 2 and 36.
+	% Useful for formatting numbers like "1,300,000".
 	%
 :- func string__int_to_base_string_group(int, int, int, string) = string.
 :- mode string__int_to_base_string_group(in, in, in, in) = uo is det.
-:- pred string__int_to_base_string_group(int, int, int, string, string).
-:- mode string__int_to_base_string_group(in, in, in, in, uo) is det.
 
 	% Convert a float to a string.
 	% In the current implementation the resulting float will be in the
@@ -941,6 +940,10 @@
 :- pred string__int_to_base_string_2(int, int, string).
 :- mode string__int_to_base_string_2(in, in, uo) is det.
 
+	% string__int_to_base_string_2/3 is almost identical to
+	% string__int_to_base_string_group_2/6 below so any changes here might
+	% also need to be applied to string__int_to_base_string_group_2/3.
+	%
 string__int_to_base_string_2(NegN, Base, Str) :-
 	(
 		NegN > -Base
@@ -960,16 +963,12 @@
 string__from_char_list(CharList, Str) :-
 	string__to_char_list(Str, CharList).
 
-string__int_to_string_thousands(N) = Str :-
-	string__int_to_base_string_group(N, 10, 3, ",", Str).
-
-string__int_to_string_thousands(N, Str) :-
-	string__int_to_base_string_group(N, 10, 3, ",", Str).
+string__int_to_string_thousands(N) = 
+	string__int_to_base_string_group(N, 10, 3, ",").
 
+	% Period is how many digits should be between each seperator.
+	%
 string__int_to_base_string_group(N, Base, Period, Sep) = Str :-
-	string__int_to_base_string_group(N, Base, Period, Sep, Str).
-
-string__int_to_base_string_group(N, Base, Period, Sep, Str) :-
 	(
 		Base >= 2, Base =< 36
 	->
@@ -982,6 +981,8 @@
 :- pred string__int_to_base_string_group_1(int::in, int::in, int::in, 
 	string::in, string::uo) is det.
 
+	% Period is how many digits should be between each seperator.
+	%
 string__int_to_base_string_group_1(N, Base, Period, Sep, Str) :-
 	% Note that in order to handle MININT correctly,
 	% we need to do the conversion of the absolute
@@ -1002,6 +1003,13 @@
 :- pred string__int_to_base_string_group_2(int::in, int::in, int::in, int::in,
 	string::in, string::uo) is det.
 
+	% Period is how many digits should be between each seperator.
+	% Curr is how many digits have been processed since the last seperator
+	% was inserted.
+	% string__int_to_base_string_group_2/6 is almost identical to 
+	% string__int_to_base_string_2/3 above so any changes here might also 
+	% need to be applied to string__int_to_base_string_2/3.
+	%
 string__int_to_base_string_group_2(NegN, Base, Curr, Period, Sep, Str) :-
 	(
 		Curr = Period, Period > 0


Ian.
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