OpenEuphoria

2. Re: Should to_number return a sequence?

• Posted by SDPringle 1 week ago
• 516 views

It seems like to_number would return a number by the name itself. For erroneous inputs, it just returns zero unless you specify a non-zero second parameter.

https://openeuphoria.org/docs/std_convert.html#_2293_to_number

4. Re: Should to_number return a sequence?

• Posted by xecronix 1 week ago
• 487 views

I added a is_number function to my wiki. It might be useful to someone. https://openeuphoria.org/wiki/view/Is%20Number%20Function.wc

6. Re: Should to_number return a sequence?

• Posted by xecronix 1 week ago
• 464 views

Thank you for the bug report. I'm appreciative for sure. I made a fix and a test. The wiki is updated. I'll look at all your suggestions. In the meantime, this was the stopgap I applied.

    -- we'll skip the sign if it has one 
    if find(maybe[i], "+-") then 
        i += 1 
    end if 
     
    -- The index might have just moved.  Make sure there is at least 1 more character to consider. 
    if i > length(maybe) then  -- <<-- New code 
        return 0 
    end if 

$ eui is_number.ex 
Testing for FALSE (0): 
Testing is_number function with input [ ]              result: [0] 
Testing is_number function with input [.]              result: [0] 
Testing is_number function with input [-]              result: [0] 
Testing is_number function with input [+]              result: [0] 
Testing is_number function with input [..]             result: [0] 
Testing is_number function with input [.-]             result: [0] 
Testing is_number function with input [.+]             result: [0] 
Testing is_number function with input [-.]             result: [0] 
Testing is_number function with input [+.]             result: [0] 
Testing is_number function with input [0..]            result: [0] 
Testing is_number function with input [.0.]            result: [0] 
Testing is_number function with input [--]             result: [0] 
Testing is_number function with input [++]             result: [0] 
Testing is_number function with input [1 4]            result: [0] 
Testing is_number function with input [A]              result: [0] 
Testing is_number function with input [-a]             result: [0] 
Testing is_number function with input [+a]             result: [0] 
Testing is_number function with input [-.a]            result: [0] 
Testing is_number function with input [+.a]            result: [0] 
Testing is_number function with input [.a]             result: [0] 
Testing is_number function with input [1a]             result: [0] 
Testing is_number function with input [.1a ]           result: [0] 
Testing is_number function with input []               result: [0] 
Testing for TRUE (1): 
Testing is_number function with input [0]              result: [1] 
Testing is_number function with input [0.]             result: [1] 
Testing is_number function with input [.0]             result: [1] 
Testing is_number function with input [-.0]            result: [1] 
Testing is_number function with input [+.0]            result: [1] 
Testing is_number function with input [0.0]            result: [1] 
Testing is_number function with input [-0.0]           result: [1] 
Testing is_number function with input [+0.0]           result: [1] 
Testing is_number function with input [123]            result: [1] 
Testing is_number function with input [123.]           result: [1] 
Testing is_number function with input [.123]           result: [1] 
Testing is_number function with input [-.123]          result: [1] 
Testing is_number function with input [+.123]          result: [1] 
Testing is_number function with input [123.123]        result: [1] 
Testing is_number function with input [-123.123]       result: [1] 
Testing is_number function with input [+123.123]       result: [1] 
Testing is_number function with input [00032]          result: [1] 
Testing is_number function with input [-00032]         result: [1] 
Testing is_number function with input [+00032]         result: [1] 
Testing is_number function with input [00032.000]      result: [1] 
Testing is_number function with input [-00032.050]     result: [1] 
Testing is_number function with input [+00032.0]       result: [1] 
 
 
What would Euphoria do??  atom d = atom(to_number(test_str, -1)) 
 
Testing for FALSE (0): 
What would Euphoria do with input [ ]                  result: [0] 
What would Euphoria do with input [.]                  result: [0] 
What would Euphoria do with input [-]                  result: [0] 
What would Euphoria do with input [+]                  result: [0] 
What would Euphoria do with input [..]                 result: [0] 
What would Euphoria do with input [.-]                 result: [0] 
What would Euphoria do with input [.+]                 result: [0] 
What would Euphoria do with input [-.]                 result: [0] 
What would Euphoria do with input [+.]                 result: [0] 
What would Euphoria do with input [0..]                result: [0] 
What would Euphoria do with input [.0.]                result: [0] 
What would Euphoria do with input [--]                 result: [0] 
What would Euphoria do with input [++]                 result: [0] 
What would Euphoria do with input [1 4]                result: [0] 
What would Euphoria do with input [A]                  result: [0] 
What would Euphoria do with input [-a]                 result: [0] 
What would Euphoria do with input [+a]                 result: [0] 
What would Euphoria do with input [-.a]                result: [0] 
What would Euphoria do with input [+.a]                result: [0] 
What would Euphoria do with input [.a]                 result: [0] 
What would Euphoria do with input [1a]                 result: [0] 
What would Euphoria do with input [.1a ]               result: [0] 
What would Euphoria do with input []                   result: [0] 
Testing for TRUE (1): 
What would Euphoria do with input [0]                  result: [1] 
What would Euphoria do with input [0.]                 result: [1] 
What would Euphoria do with input [.0]                 result: [1] 
What would Euphoria do with input [-.0]                result: [1] 
What would Euphoria do with input [+.0]                result: [1] 
What would Euphoria do with input [0.0]                result: [1] 
What would Euphoria do with input [-0.0]               result: [1] 
What would Euphoria do with input [+0.0]               result: [1] 
What would Euphoria do with input [123]                result: [1] 
What would Euphoria do with input [123.]               result: [1] 
What would Euphoria do with input [.123]               result: [1] 
What would Euphoria do with input [-.123]              result: [1] 
What would Euphoria do with input [+.123]              result: [1] 
What would Euphoria do with input [123.123]            result: [1] 
What would Euphoria do with input [-123.123]           result: [1] 
What would Euphoria do with input [+123.123]           result: [1] 
What would Euphoria do with input [00032]              result: [1] 
What would Euphoria do with input [-00032]             result: [1] 
What would Euphoria do with input [+00032]             result: [1] 
What would Euphoria do with input [00032.000]          result: [1] 
What would Euphoria do with input [-00032.050]         result: [1] 
What would Euphoria do with input [+00032.0]           result: [1] 
 
 

8. Re: Should to_number return a sequence?

• Posted by euphoric (admin) 1 week ago
• 449 views

Yikes! That is a terrible implementation of a to_number() function*.

If you want all that other functionality, create proper functions for them. Then do,

if can_be_a_number(can_this_be_a_number_var) then 
  return to_number(can_this_be_a_number_var) 
else 
  return Null 
end if 

to_number() should return a number or Null (?) if it cannot convert the given object. O or maybe even crash?.

If you want to wrap it yourself, do something like, safe_to_number(can_this_be_a_number_var,X,Y,...).

*I could be wrong.

10. Re: Should to_number return a sequence?

• Posted by euphoric (admin) 6 days ago
• 400 views

I think parse_num() is a great replacement name for that function. It can return a sequence. { TRUE/FALSE, RETURNED_VALUE }. RETURNED_VALUE is only relevant if the first element is TRUE.

Isn't there a value() function that basically does this already?

(I searched the manual for value but could not find anything. Not even a search through Google worked.)

I've always wondered if every return value in Euphoria should be of { SUCCESS_BOOL, RETURNED_VALUE }, but that seems way too verbose.

12. Re: Should to_number return a sequence?

• Posted by irv 5 days ago
• 347 views

How about returning the original string when the conversion fails?

include std/get.e 
include std/types.e 
include std/console.e 
 
function val (object s) 
   if atom(s) then return s end if 
   for i = 1 to length(s) do 
     if s[i] > '9' then return s end if 
   end for 
   sequence v = value(s) 
    if v[1] = GET_SUCCESS then 
      return v[2] 
    else 
      return s 
    end if 
end function 
 
object a 
 
object tests = {"3.14","-1","+2.34",42,"99hello","Hi 44"} 
 
for i = 1 to length(tests) do 
 
	a = val(tests[i]) 
 
	if string(a) then  
	   display("[] failed!",{a}) -- show a warning or something 
	else  
	   display("[] => [] success",{tests[i],a}) -- use it. 
	end if 
 
end for 
 

irv@irv-desktop:~$ eui test 
3.14 => 3.14 success 
-1 => -1 success 
+2.34 => 2.34 success 
42 => 42 success 
99hello failed! 
Hi 44 failed! 

14. Re: Should to_number return a sequence?

• Posted by xecronix 5 days ago
• 314 views

function parse_num(sequence s) 
    atom b = is_number(s), v = 0 
    if b then 
        v = to_number(s) 
    end if 
    return {b, v} 
end function 

Thanks for the code suggestion. Your version is clearer than what I wrote, for sure. I especially like the single exit point of the function. My version skipped 1 additional variable allocation, 2 assignment operations, and one variable lookup, but probably wasn't worth the additional clarity your version provides.

I don't think it's a matter of one approach beats another. In fact, I know now exactly how to get the answer as to whether or not a string is a number or not. I know how to do it Euphoria or Phix. I know how to do it cross dialect if I wanted to. Honestly, to everyone reading this who actually worked on the to_number function, thank you. It works and does what I need.

And, if you're interested in my personal UX, this is my 2 cents, FWIW. Functions that vary in return types seem confusing. That's not to say varied return types are invalid patterns. Just that it will require the end user to spend more time in the documentation learning about the cool features (and nuances) Euphoria/Phix has to offer detracting from the time spent using the cool features. Not a bad thing. Simply a matter of fact.

What follows is no ones fault but my own. But I'm going to describe my UX when looking up how to convert a string to a number. First, I was programming in Phix. So, I looked there first for docs but didn't any function that did what I wanted. Maybe it exists. I didn't find it. So, I hopped over to OpenEuphoria and found to_number. I thought to myself, that seems like it will work but, what if the string is not a number? So I started skimming the docs. What I read sort of went like this. Words, words, words. Blah, blah, blah. More words. Ah, there it is. -1 returns this data in a sequence, something else the sequence has blah blah. Ok, got it. It returns a sequence. Cool! And moved on. Just being honest. That's what happened.

So, basically, the fact that it worked as I expected in Phix was just pure luck. And when I tried to use the function in Euphoria I was surprised, but validated by my Phix experience. Thankfully, I had written tests that caught the problem. Anyway, I wrote a quick is_number function to get past the moment and started this thread.

My take-a-way is slow down reading the docs. Assume nothing. I can only hope this conversation had value to you, the readers. To ensure that I've contributed in some meaningful way, I created 2 wiki pages. You gave me your time and expertise. I tried to give back.

Also, FWIW. Euphoria has been my favorite language for a long time. Sadly, I haven't used it much over the years. Professionally, the languages I needed most were (in order) PHP, Javascript, C#, Java, C, Perl, Ruby, Cpp, VB Script, VB, and Python. For fun, I program in Euphoria, now Phix (which I really like), and Pascal. I've stopped programming in BASIC. But I've tried many of those including QBasic, BlitzBASIC, DarkBASIC (under 2K lines), PureBASIC (under 2k lines), RapidQ (loved this one), FreeBASIC (also great), and LibertyBASIC. In most languages I just mentioned I wrote at least 2000 lines of code. Some of the languages 100000 lines or more. Perhaps 300K+ in one of them. The reason I mention my experience is because I want you to know when I say I think Euhporia/Phix could possibly be the best language out there, the opinion is coming from a place of authority. I've tried a bunch.

Thank you.

16. Re: Should to_number return a sequence?

• Posted by xecronix 5 days ago
• 295 views

Message moved - Offer to contribute to documentation