.. index:: edcg .. _edcg/0:

.. rst-class:: right

object

edcg

Multiple hidden parameters: an extension to Prolog's DCG notation. Ported to Logtalk as a hook object.

| Availability: | logtalk_load(edcg(loader))

| Author: Peter Van Roy; adapted to Logtalk by Paulo Moura. | Version: 1:4:2 | Date: 2020-04-08

| Copyright: Copyright (C) 1992 Peter Van Roy | License: MIT

| Compilation flags: | static, context_switching_calls

| Implements: | public :ref:`expanding <expanding/0>` | Provides: | :ref:`logtalk::message_tokens//2 <logtalk/0::message_tokens//2>` | Uses: | :ref:`list <list/0>` | :ref:`logtalk <logtalk/0>`

| Remarks:

• Usage: Compile source files with objects (or categories) defining EDCGs using the compiler option hook(edcg).

| Inherited public predicates: |  :ref:`expanding/0::goal_expansion/2`  :ref:`expanding/0::term_expansion/2`  

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

Public predicates

(no local declarations; see entity ancestors if any)

Protected predicates

(no local declarations; see entity ancestors if any)

Private predicates

.. index:: pred_info/3 .. _edcg/0::pred_info/3:

pred_info/3 ^^^^^^^^^^^^^^^

Declares predicates that have the listed hidden parameters.

| Compilation flags: | dynamic

| Template: | pred_info(Name,Arity,HiddenParameters) | Mode and number of proofs: | pred_info(?atom,?integer,?list(atom)) - zero_or_more

---

.. index:: acc_info/7 .. _edcg/0::acc_info/7:

acc_info/7 ^^^^^^^^^^^^^^

Long form for declaring accumulators.

| Compilation flags: | dynamic

| Template: | acc_info(Accumulator,Term,Left,Right,Joiner,LStart,RStart) | Mode and number of proofs: | acc_info(?atom,?term,?term,?term,?callable,?term,?term) - zero_or_more

---

.. index:: acc_info/5 .. _edcg/0::acc_info/5:

acc_info/5 ^^^^^^^^^^^^^^

Short form for declaring accumulators.

| Compilation flags: | dynamic

| Template: | acc_info(Accumulator,Term,Left,Right,Joiner) | Mode and number of proofs: | acc_info(?atom,?term,?term,?term,?callable) - zero_or_more

---

.. index:: pass_info/2 .. _edcg/0::pass_info/2:

pass_info/2 ^^^^^^^^^^^^^^^

Long form for declaring passed arguments. Passed arguments are conceptually the same as accumulators with =/2 as the joiner function.

| Compilation flags: | dynamic

| Template: | pass_info(Argument,PStart) | Mode and number of proofs: | pass_info(?atom,?term) - zero_or_more

---

.. index:: pass_info/1 .. _edcg/0::pass_info/1:

pass_info/1 ^^^^^^^^^^^^^^^

Short form for declaring passed arguments. Passed arguments are conceptually the same as accumulators with =/2 as the joiner function.

| Compilation flags: | dynamic

| Template: | pass_info(Argument) | Mode and number of proofs: | pass_info(?atom) - zero_or_more

---

Operators

op(1200,xfx,-->>) ^^^^^^^^^^^^^^^^^^^^^

| Scope: | public