OpenEuphoria

Re: Source changes

• Posted by Derek Parnell <ddparnell at bigp?nd.com> Jul 02, 2007
• 662 views

CChris wrote:

> 1/ some people, perhaps many of them, are looking for a function that converts
> a string into a numerical value and hardly anything else. Derek Parnell hinted
> that he would submit a tidied up version of w32to_number().
> 2/ If I understand well what has been said, many people will switch to that
> function and leave value() alone anyway. This will certainly decrease the
> amount
> of possible groaning, as w32to_number(), or whatever it will be eventually
> named,
> will be "simpler" (= return less data? not sure, but oh well). 

I've started the process. I'm packaging this function plus a few others into a
new library, whose purpose will be to contain text conversion routines. Thus a
new library called "convtext.e" will be added to the Euphoria include folder. It
will contain a set of related functions that convert text strings into numbers
and visa versa.

-- Proposed Routines --
This set will attempt to convert the text to the requested format, but if
they are unable to they do not fail, instead they return zero.

 toInteger(sequence TextIn)  -- converts the text to an integer.
 toNumber(sequence TextIn)  -- converts the text to an integer or atom as 
                            -- appropriate.
 toDigits(sequence TextIn)  -- converts the text to an integer or atom as 
                            -- appropriate, but disregards all non-digits
                            -- except the first decimal-separator.
 toBase(sequence TextIn, integer Base)  -- converts the text to an
                                        -- integer or atom as appropriate,
                                        -- but disregards all non-digits as
                                        -- defined by the 'number-base'
                                        -- supplied.
 

This set will attempt to convert the text to the requested format, but if
they are unable to they do not fail, instead they return a sequence containing
the position in the input where conversion stopped, and the result of the
conversion as at that point.

 CInt(sequence TextIn)  -- converts the text to an integer.
 CNum(sequence TextIn)  -- converts the text to an integer or atom as 
                        -- appropriate.
 
This set will test the text for conversion but will not actually convert it,
instead they return a true/false value.

 isInteger(sequence TextIn)  -- checks that the text could be converted
                             -- to an integer
 isNumber(sequence TextIn)  -- checks that the text could be converted
                            -- to an integer or atom

Those routines will allow for decimal-separators, number-grouping, leading sign
(+/-) or trailing sign, currency symbol, scientific notation, number-bases from 2
to 94, parenthetical negatives, and scaling symbols.

The user will be able to set the values for decimal-separator, number-groups,
currency symbols, and scaling symbols. By default they will be set to ".", ",_ ",
"$¢£¤¥₣₤₧₪₫€", and "%‰" (unicode only).

This next function takes a sequence of text strings and returns the same
sequence but with as many strings as possible converted to numbers.

 makeNumbers(sequence RecordData) 

  e.g.  makeNumbers({"Derek", "Parnell", "555 7748", "19", "North Road"})
would return 
   {"Derek", "Parnell", 5557748, 19, "North Road"}


This set of routines converts a number to a text string, some using locale
settings.

 StringInt( integer Data )
 StringNumber( atom Data )
 StringFormat( atom Data, sequence Format)
 DateFormat ( sequence Data, sequence Format)
 TimeFormat ( atom Data, sequence Format)
 CurrencyFormat (atom Data)

This library can also be used for other text conversions as the need arises.


Comments please...

-- 
Derek Parnell
Melbourne, Australia
Skype name: derek.j.parnell