The Debugger Inspector Commands

• The following commands are extensions of the debugger that allow the user to examine data and execute program statements. They are intended to be used in conjunction with the debugger functions to step through the execution of an HFL program.
• bt [<depth>]
  • Displays a backtrace of the current call stack, showing the calling sequence up to the current statement being excuted.
  • If backtrace depth specified, starts backtrace that number of level before the current statement.
  • Otherwise show entire backtrace call stack.
  • EXAMPLE:

  • ? bt
    CALL STACK:
    ---------------------------------------------------
      make_gallery()
      load($fmt, 'cache')
      nav_bar? {
            $navFnames = fnamesNavBeforeAfter($page_filename)
            MakeNavMenuType("table")
          ....
          }
      MakeNavMenuType("table")
      if ($menu_type == "table")
      DisableNavbarLabel($nav_curr, "main_link_inactive", "nav_curr")
      tr {
            td: 1 THRU -1 {}
          ....
          }
      td: 1 THRU -1 {
            szStripped = stripTrailWS("$alltext")
            logP(-1, "IN DisableNavbarLabel")
            if (szStripped == $nav_curr)
          ....
          }
      logP(-1, "IN DisableNavbarLabel")
    ---------------------------------------------------
    

• scopes [<depth>]

  sc [<depth>]
  • Displays the contents of the current scope stack. The scope stack has one level for each nested scope.
  • Each level is numbered, and shows the cell range, scope type and scope. If depth is specified, only displays that many levels.
  • EXAMPLE:

  • ? sc
    CURRENT SCOPE: |page make_gallery() load: nav_bar:1 MakeNavMenuType() if:$menu_type
    == "table" DisableNavbarLabel() tr:1 td:1|
    
    SCOPE STACK [9]:
    ---------------------------------------------------
    [ 9]    106 THRU   106  tag       td:1
    [ 8]    112 THRU   112  tag       tr:1
    [ 7]      8 THRU     8  tag       DisableNavbarLabel()
    [ 6]      8 THRU     8  tag       if:$menu_type == "table"
    [ 5]      8 THRU     8  tag       MakeNavMenuType()
    [ 4]      8 THRU     8  tag       nav_bar:1
    [ 3]      2 THRU     2  tag       load:
    [ 2]      2 THRU     2  tag       make_gallery()
    [ 1]      2 THRU     2  tag       page
    ---------------------------------------------------
    

  • NOTE that there is often a correlation between the display results of the 'bt' backtrace command, and what is displayed for the scope stack. But they are displaying different data, and there can be differences.
• var <variable-name>

  v <variable-name>
  • Displays the value of the given variable.
  • EXAMPLE:

  • ? x $nav_curr = "Photo Gallery"
    Photo Gallery
    ? v $nav_curr
    VAR |$nav_curr| = |Photo Gallery|
    

• vars
  • Displays the value of all variables in the current scope, including globals, locals, and the special variables such as '$1'.
  • This can produce a large listing.
• array <array-var>

  a <array-var>
  • Displays the entries of the array of the array variable.
  • If the <array-var> argument does not refer to an array it will emit the message:
    • |<array-var>| IS NOT AN ARRAY
  • EXAMPLE:

  • ? x var $pets = ["dog", "cat", "bird"]
    ARRAY(0x50ab184)
    ? a $pets
    
    ARRAY |$pets|:
    -----------
    dog
    cat
    bird
    -----------
    

• x <expr>

  eval <expr>
  • Parses and evaluates expression <expr>, and displays its result. You can do pretty much anything that can be done in code, such as declare variables, call functions, apply properties to scopes, load files, etc.
  • EXAMPLES:

  • ? x 2+3
    5
    
    ? x print("The sum of 2 and 3 is "+(2+3));
    The sum of 2 and 3 is 5
    
    ? x p:2{color:red;}
    
    ? x load('test.hfl')
    TEST.HFL LOADED
    

• c

  cls
  • Clears the shell window.
  • This helps when the displayed output is too much, or you wish to create a listing and want it to be the only thing you can see.
• q
  • Stops (quits) all execution of HFL and exits the compiler