How to make a custom function as inbuilt

Question

I have a custom function like following:

SyntaxInformation[
   TwoNumberSameQ] = {"ArgumentsPattern" -> {_, _, OptionsPattern[]}};
Options[TwoNumberSameQ] = {ShowDifference -> False};
TwoNumberSameQ[x_, OptionsPattern[]] := {x, 
  OptionValue[ShowDifference]}
TwoNumberSameQ[a_, b_, OptionsPattern[]] := 
 If[OptionValue[ShowDifference], 
  If[a === b, True, {False, Abs[a - b]}], If[a === b, True, False]]

Usage:

TwoNumberSameQ[3,4]

False

TwoNumberSameQ[3,4,ShowDifference->True]

{False, 1}

 TwoNumberSameQ[3,3]

True

I have some dissatisfaction to this function.But the documentation have a little relative explanation for this area.

Question one

How to make the option have a black color like as a in-built function,but blue like:

Question two

How to make TwoNumberSameQ's definition more concise.I just test one option but result so many repetitive code.I cannot imagine how mess when I set three or more option.

Addtional quesiton

If I can make the option have some optional values to choice.I'll be happy more. :)

score 6 · Accepted Answer · edited Apr 13 '17 at 12:55

6

Global` symbols are blue unless they have a value but if you use any other context that is on $ContextPath the symbol color will be black just because it was created.

So use System` by mentioning option name when it is parsed for the first time:
```
Options[TwoNumberSameQ] = {System`ShowDifference -> True}
```
or define your function in Begin/EndPackage where the option name is exported. Keep in mind conflicts so choose your names wisely.
```
BeginPackage["Numbers`"];

  TwoNumberSameQ; ShowDifference;

Begin["`Private`"];

  (* your definitions *)
End[];

EndPackage[];
```

I believe rest of your questions was already answered in:

edited Apr 13 '17 at 12:55

Community

1

answered Jul 11 '16 at 18:07

Kuba

136,707
13
279
740

You mean I should creat a specific context for those options? – yode Jul 11 '16 at 18:10
Maybe Szabolcs have prompt me the color render scheme in this answer,but I cann't apply it in such case.It's pitty.I don't very familiar these.Do you think the following question have a value to ask still? – yode Jul 11 '16 at 18:17
It's seem not anyone can get my English.I mean since those question already have solution so that I should close this post? :) – yode Jul 11 '16 at 19:40
@yode I know your pain! :) p.s. I think you can live that unless someone complains. – Kuba Jul 11 '16 at 20:17
Thanks for your consideration sincerely. – yode Jul 11 '16 at 20:30

How to make a custom function as inbuilt

Question one

Question two

Addtional quesiton

1 Answers1