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SectionRef
  child · exists · has_parent · has_trueparent · is_cas · nchild · parent · root · sec · trueparent

# SectionRef

class `SectionRef`
  Syntax:
    `section sref = new SectionRef()`
  Description:

    SectionRef keeps a pointer/reference to a section The reference is to the currently accessed section at the time the object was created.

    This class allows sections to be referenced as normal object variables for assignment and passing as arguments.

`SectionRef.``sec`()
  Syntax:
    `sref.sec`
  Description:

    special syntax that makes the reference the currently accessed section. This class allows sections to be referenced as normal object variables for assignment and passing as arguments. The usage is

        create soma, axon
        axon.diam=2
        soma.diam=10
        access axon
        objref s1, s2
        soma s1 = new SectionRef()  // s1 holds a reference to the soma
        print s1.sec.diam           // print the diameter of the soma
        s2 = s1                             // s2 also holds a reference to the soma
        s2.sec { psection() }               // print all info about soma
        axon s2 = new SectionRef()
        proc c() {
            $o1.sec connect $o2.sec(0), 1
        }
        c(s1, s2)
        topology()

    This last is a procedure that takes two SectionRef args and connects them end to end.

`SectionRef.``parent`()
  Syntax:
    `sref.parent`
  Description:
    parent of sref.sec becomes the currently accessed section. Generally it is used in a context like `sref.parent { statement }` just like a normal section name and does NOT need a section_pop If there is a chance that a section does not have a parent then `SectionRef.has_parent()` should be called first to avoid an execution error. Note that the parent is the current parent of sref.sec, not necessarily the parent when the SectionRef was created.

`SectionRef.``trueparent`()
  Syntax:
    `sref.trueparent`
  Description:
    trueparent of sref.sec becomes the currently accessed section. This is normally identical to `SectionRef.parent()` except when the parent's `parent_connection()` is equal to the parent's `section_orientation()`. If there is a chance that a section does not have a trueparent then `SectionRef.has_trueparent()` should be called first to avoid an execution error.

`SectionRef.``child`()
  Syntax:
    `sref.child[i]`
  Description:

    the ith child of sref.sec becomes the currently accessed section. Generally it is used in a context like

        for i=0, sref.nchild-1 sref.child[i] { statement }

    Note that the children are the current children of sref.sec, not necessarily the same as when the SectionRef was created since sections may be deleted or re-connected subsequent to the instantiation of the SectionRef.

`SectionRef.``root`()
  Syntax:
    `sref.root`
  Description:
    root of sref.sec becomes the currently accessed section.

`SectionRef.``has_parent`()
  Syntax:
    `boolean = sref.has_parent`
  Description:
    returns 1 if sref.sec has a parent and 0 if sref.sec is a root section. Invoking sref.parent when sref.sec is a root section will print an error message and halt execution.

`SectionRef.``has_trueparent`()
  Syntax:
    `boolean = sref.has_trueparent`
  Description:
    returns 1 if the sref.sec parent node is not the root node and 0 otherwise. Invoking sref.trueparent when it is the root node will print an error message and halt execution.

`SectionRef.``nchild`()
  Syntax:
    `integer = sref.nchild`
  Description:
    Return the number of child sections connected to sref.sec

`SectionRef.``is_cas`()
  Syntax:
    `boolean = sref.is_cas()`
  Description:
    Returns 1 if this section reference is the currently accessed section, 0 otherwise.

`SectionRef.``exists`()
  Syntax:
    `boolean = sref.exists()`
  Description:
    Returns 1 if the section has not been deleted, 0 otherwise.

  See also

  `delete_section()`, `section_exists()`

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