Setting up diagnostic error messages in large Mathematica projects

Question

Whenever I create a large Mathematica project I run into this problem: Preventing avalanche of runtime errors in Mathematica, i.e., Mathematica\'s error message are opaque,

Answer 1

Perhaps we have been over thinking this. What if we just tweaked the pattern matching on the arguments a little. For instance, if we modified the function to check for a numeric quantity and added some code to print an error if it fails. For instance,

 TypeNumeric[x_] :=   If[! NumericQ[Evaluate[x]],
 Print["error at "]; Print[Stack[]];    Print["Expression "]; Print[x];    Print["Did   
 not return a numeric value"];Return[False], 
 (*Else*)
 Return[True];] 
 SetAttributes[TypeNumeric, HoldAll];

Step 2: If you have a function, f[x_] that requires a numeric quantity, just write it with the standard pattern test and all should be well

Input:
f[x_?TypeNumeric] := Sqrt[x]
f[Log[y]]
f[Log[5]]
Output:
error at 
{f}
Expression 
Log[y]
Did not return a numeric value
f[Log[y]]

Sqrt[Log[5]]

I believe this will work and, it makes robust type checking as simple as a writing a function or two. The problem is that this could be hugely inefficient because this code evaluates the expression x twice, once for the type checking and once for real. This could be bad if an expensive function call is involved.

I haven't figured out the way around this second problem and would welcome suggestions on that front. Are continuations the way out of this problem?

Hope this helps.