Create a function that accepts a parameter?

Questions
1

Is it possible to write a function in CL that takes a numerical parameter (or even multiple) and returns a string?
Like if I have variables a=-3 and b=4 that I want to send to it and return some sort of string (intending to send more than one variable to the same function).

function(input):
  when input < 0 "${input}"
  when input >0 "+${input}"
  otherwise ""

function(a) would return “-3”
function(b) would return “+4”

I know how to do this by defining two separate variables but wondering if there is a more efficient way with a function like this?

2

Sorry - not yet. For functions like “format these numbers to output an equation”, there’s also a good chance that could be a built-in function within CL. There are a lot of tricky conditions like “leave this term out if the coefficient is zero” and “leave out the “+” if all the previous terms were left out”. I’d be interested in seeing what you’re working on / trying to do.

3

If I am understanding your question correctly, I think to use one variable you just need to nest the conditional statements.

function(input):
  when input < 0 "${input}" otherwise when input >0 "+${input}" otherwise ""
4

Here is a basic example I slapped together.

With more complex functions, the conditionals can be more annoying with conditionals surrounding negatives, 1, 0 and positives.

5

I used to have something when I did script work in some google apps scripts around coefficients for equations to try and clean up the math. I had one function for coefficients that would rewrite expressions to subtraction when there were negative coefficients present, eliminate the coefficient when the value was 1 and leave nothing if the constant value was zero. I feel like it’d be super helpful to have a function like that to avoid having to anticipate so many scenarios for outcomes if that makes sense.
This is the code I had in google apps script that did what I’m talking about:

function coeff(value, type){
 var part = value;
  try{var parts=part.split(/[\/]/);}catch(err){var parts=[];}
 if(parts.length==2)
 {
 if (type=="lead"||type=="leading")
 {
   if(value==1){return "";}
   else if (value==-1){return "-";}
   else {return value;}
 }
 else if (type=="constant")
 {
   if(value<0 || eval(value)<0){return " - "+Math.abs(parts[0])+"/"+Math.abs(parts[1]);}
   else{return "+"+value;}  
 }
 else if(type=="scientific")
 {
   value = Math.round(value*100000000)/100000000;
   value=value.toExponential()+"";
   value=value.replace(/e(\+)?/,"*10^");
 return value;
   //return value.toExponential().replace(/e(\+)?/,"*10^");  
 }
 else
 {
   if(value==1||value=="1"){return "+";}
   else if(value==-1 || value=="-1"){return " - ";}
   else if(value<0 || eval(value)<0){return " - "+Math.abs(parts[0])+"/"+Math.abs(parts[1]);}
   else{return "+"+value;}  
 } 
 }
 else
 {
   if (type=="lead"||type=="leading")
 {
   if(value==1){return "";}
   else if (value==-1){return "-";}
   else {return value;}
 }
 else if (type=="constant")
 {
   if(value<0 || eval(value)<0){return " - "+Math.abs(value);}
   else{return "+"+value;}  
 }
 else if(type=="scientific")
 {
   value = Math.round(value*100000000)/100000000;
   value=value.toExponential()+"";
   value=value.replace(/e(\+)?/,"*10^");
 return value;
   //return value.toExponential().replace(/e(\+)?/,"*10^");  
 }
 else
 {
   if(value==1||value=="1"){return "+";}
   else if(value==-1 || value=="-1"){return " - ";}
   else if(value<0 || eval(value)<0){return " - "+Math.abs(value);}
   else{return "+"+value;}  
 }
 } 
}