Trace and TracePrint are slow, How to Trace to a file for speed

Question

Trace and TracePrint generates or prints a list of all expressions used in the evaluation of its argument. For complicated expressions that can be thousands of lines. Large Trace tasks can be very slow and even crash the kernel.

How can one TracePrint directly to a text file?

Answer 1

This will call TraceScan and save each line (WriteLine) to a text file.

A time-out can be defined (default 1 minute), and the function returns a clickable File for seamless opening.

ClearAll[TraceToFile]
SetAttributes[TraceToFile, HoldFirst]
TraceToFile[expr_, filename_String, timeout_: 60] := With[
  {
   file = OpenWrite[filename]
   },
  Echo[timeout, "Timeout: "];
  Echo[FileNameJoin[{Directory[], filename}], "File: "];
  Echo[ToString[Hold[expr], InputForm], "Expresion"];
  TimeConstrained[
   TraceScan[
    WriteLine[
      file,
      StringTake[ToString[#, InputForm], {10, -2}]
      ] &,
    expr
    ], timeout];
  Close[file];
  File[FileNameJoin[{Directory[], filename}]]
  ]

Example

fib[0] = fib[1] = 1; fib[n_] := fib[n - 1] + fib[n - 2];

First@AbsoluteTiming[TracePrint[fib[12]]]
(* 20.8437 *)


First@AbsoluteTiming@TraceToFile[fib[12], "TraceTest.txt"]
(* 0.320829 *)