.. index:: assignvarsp .. _assignvarsp/0:

.. rst-class:: right

protocol

assignvarsp

Assignable variables (supporting backtracable assignment of non-variable terms) protocol.

| Availability: | logtalk_load(assignvars(loader))

| Author: Nobukuni Kino and Paulo Moura | Version: 1:0:1 | Date: 2019-06-10

| Compilation flags: | static

| Dependencies: | (none)

| Remarks: | (none)

| Inherited public predicates: | (none)

.. contents:: :local: :backlinks: top

Public predicates

.. index:: assignable/1 .. _assignvarsp/0::assignable/1:

assignable/1 ^^^^^^^^^^^^^^^^

Makes Variable an assignable variable. Initial state will be empty.

| Compilation flags: | static

| Template: | assignable(Variable) | Mode and number of proofs: | assignable(--assignvar) - one

| Exceptions: | Variable is not a variable: | type_error(variable,Variable)

---

.. index:: assignable/2 .. _assignvarsp/0::assignable/2:

assignable/2 ^^^^^^^^^^^^^^^^

Makes Variable an assignable variable and sets its initial state to Value.

| Compilation flags: | static

| Template: | assignable(Variable,Value) | Mode and number of proofs: | assignable(--assignvar,@nonvar) - one

| Exceptions: | Variable is not a variable: | type_error(variable,Variable) | Value is not instantiated: | instantiation_error

---

.. index:: (<=)/2 .. _assignvarsp/0::(<=)/2:

(<=)/2 ^^^^^^^^^^

Sets the state of the assignable variable Variable to Value (initializing the variable if needed).

| Compilation flags: | static

| Template: | Variable<=Value | Mode and number of proofs: | (?assignvar)<=(@nonvar) - one

| Exceptions: | Value is not instantiated: | instantiation_error

---

.. index:: (=>)/2 .. _assignvarsp/0::(=>)/2:

(=>)/2 ^^^^^^^^^^

Unifies Value with the current state of the assignable variable Variable.

| Compilation flags: | static

| Template: | Variable=>Value | Mode and number of proofs: | +assignvar=> ?nonvar - zero_or_one

| Exceptions: | Variable is not instantiated: | instantiation_error

---

Protected predicates

(none)

Private predicates

(none)

Operators

op(100,xfx,<=) ^^^^^^^^^^^^^^^^^^

| Scope: | public

op(100,xfx,=>) ^^^^^^^^^^^^^^^^^^

| Scope: | public

.. seealso::

:ref:`assignvars <assignvars/0>`