sysTrace

sysTrace(
  [const state])  // on = true, off = false

Query trace state or turn tracing on/off by an arg of true/false.

Trace will show each P-Code instruction together with the 2 top stack elements while executing. Currently there is no source code tracing facility (may however come in a future release).

If a logfile was opened, the trace information will be written to it.

Returns current trace state.

Example:

trace(true); // turn tracing on

The trace output may look somewhat as:

test.css: var main()
 
address opcode parameter       tos             tos-1
------- ------ --------------- --------------- ---------------
     19 push   x               <stack bottom>
     20 incv                   x               <stack bottom>
     21 jmp    7               <stack bottom>
      7 push   x               <stack bottom>
      8 load                   x               <stack bottom>
      9 push   5               3               <stack bottom>
     10 lss                    5               3
     11 jf     22              1               <stack bottom>
      .  .      .              .               .