---
name: "current"
section: "3nx"
platform: "linux"
package: "nsf"
version: "2.4.0-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/current"
---

# current(3nx)

Return information about the method callstack

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## NAME

nx::current - Return information about the method callstack

## SYNOPSIS

**current** ?*option*?

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## DESCRIPTION

- **current** ?*option*?

  This introspection command provides information about various details, to be identified using *option*, on the callstack. The command is invoked from a method body. If *option* is not provided, **nx::current** will default to option **object** (see below). **nx::current** operates on the Tcl callstack and is aware of NX-specific callstack and stackframe details. Except for the options **callinglevel** and **level**, calling **nx::current** outside an NX object or method will result in an error. *option* can be any of the following:

  - •

    **activelevel** returns the actual callstack level which calls into the currently executing method directly. This **activelevel** might correspond the **callinglevel**, but this is not necessarily the case. The **activelevel** also includes intermediate calls, such as **nx::next** invocations. The level is reported as an absolute level number (# followed by a digit) to be directly used as the first argument to **uplevel** or **upvar**.

  - •

    **args** returns the list of argument values passed into the currently executing method implementation.

  - •

    **calledclass** returns the name of the class that provides the method implementation to which the intercepted method call is to be redirected (only available from within filter methods).

  - •

    **calledmethod** returns the original method name requested by intercepted method call (only available from within filter methods).

  - •

    **callingclass** returns the name of the class which provides the method implementation calling into the currently executing method. See also **callingobject**.

  - •

    **callinglevel** resolves the callstack level of the originating invocation of the currently executing method implementation. Callstack levels introduced by method interception (e.g., filters) and by method combination (**nx::next**) are ignored. The level is reported as an absolute level number (**#** followed by a digit) to be directly used as the first argument to **uplevel** or **upvar**. See also **activelevel**. If called outside NX, **1** is returned (which is the default for **upvar** and **uplevel**).

  - •

    **callingobject** returns the name of the object which is calling into the currently executing method. See also **callingclass**.

  - •

    **class** returns the name of the class providing the currently executing method implementation. The returned method-providing class may be different to the class of the current object. If called from within a method implementation provided by the current object itself, an empty string is returned.

  - •

    **filterreg** returns the object (class) on which the currently executing method was registered as a filter method (only available from within filter methods).

  - •

    **isnextcall** will return 1, if the currently executing method implementation was invoked via **nx::next**; 0 otherwise.

  - •

    **level** will return a number indicating the stack level of the currently executed method or script, or an empty string when executed outside an NX context (e.g., in a Tcl proc or a namespace script). The resulting value can be directly passed as *level* to **info level**.

  - •

    **method** returns the name of the currently executing method. If an ensemble-method call, the name of the bottom-most ("leaf") method is returned.

  - •

    **methodpath** returns the combined name of the currently executing method (including all ensemble levels) in an ensemble-method call. Otherwise, for a regular method call, the result corresponds to the result of option **method**.

  - •

    **nextmethod** returns the name of the next most specific method implementation to be called when invoking **nx::next**.

  - •

    **object** gives the name of the object on which the currently executing method implementation is evaluated.

## COPYRIGHT

```
Copyright (c) 2014-16 Stefan Sobernig <stefan.sobernig@wu.ac.at>, Gustaf Neumann <gustaf.neumann@wu.ac.at>; available under the Creative Commons Attribution 3.0 Austria license (CC BY 3.0 AT).
```