--- !ditz.rubyforge.org,2008-03-06/issue 
title: clean up execution error (e.g. duk_pcall) return codes
desc: |-
  Separate between "error from call" and "error setting up call"?
  
  If this is distinguished in the return code of the call, all call sites
  will have to deal with it.
  
  One approach is to push an error on the stack even in "error setting
  up call" case, but allow the caller to detect the case by inspecting
  the error object.  For instance, make the error object an instance of
  a special error like APIError and add an API call to detect error type,
  like::
  
    if (duk_get_error_code(ctx, -1) == DUK_ERR_API_ERROR) {
        ...
    }
  
  What to do if the input arguments and stack are incompatible, and
  return stack semantics cannot be met?  For instance, if there are
  not enough arguments on the value stack to match a "nargs" parameter,
  we can't pop off enough arguments.
  
  Options include:
  
  1. Disregard these as programmer errors and call the fatal handler.
  
  2. Throw an ordinary error.  If the duk_pcall/duk_safe_call was called
     from a context without error catching, the error becomes fatal
     anyway.  But this way, there is a chance that an outer error handler
     will catch the error.
  
  3. Return a special error code indicating that the stack is in an
     inconsistent (unexpected) state.  All call sites would then need
     to take this into account.
type: :task
component: duk
release: v0.10
reporter: sva <sami.vaarala@iki.fi>
status: :unstarted
disposition: 
creation_time: 2013-08-27 21:15:20.899635 Z
references: []

id: 729e2709818e510a45e64eacf68326be3e7542a2
log_events: 
- - 2013-08-27 21:15:21.072680 Z
  - sva <sami.vaarala@iki.fi>
  - created
  - ""
- - 2013-09-29 10:05:52.918270 Z
  - sva <sami.vaarala@iki.fi>
  - assigned to release v0.8 from v0.7
  - ""
- - 2013-10-31 00:12:38.191342 Z
  - sva <sami.vaarala@iki.fi>
  - assigned to release v0.9 from v0.8
  - ""
- - 2013-12-19 00:58:15.420084 Z
  - sva <sami.vaarala@iki.fi>
  - assigned to release v0.10 from v0.9
  - ""