.. index:: single: debuggerp .. _debuggerp/0:

.. rst-class:: right

protocol

`debuggerp`

Debugger protocol.

| Availability: | logtalk_load(debugger(loader))

| Author: Paulo Moura | Version: 3:6:0 | Date: 2025-09-05

| Compilation flags: | static

| Dependencies: | (none)

| Remarks:

Debugger help: Type the character h (condensed help) or the character ? (extended help) at a leashed port.
Predicate breakpoint: Specified as a ground term Functor/Arity.
Non-terminal breakpoint: Specified as a ground term Functor//Arity.
Entity predicate breakpoint: Specified as a term Entity::Functor/Arity. Entity must be an object or category and may not be ground if parametric.
Entity non-terminal breakpoint: Specified as a term Entity::Functor//Arity. Entity must be an object or category and may not be ground if parametric.
Clause breakpoint: Specified as an Entity-Line term with both Entity and Line bound. Line must be the first source file line of an entity clause.
Conditional breakpoint: Specified using Entity and Line for the clause head and a condition. Line must be the first source file line of an entity clause.
Hit count breakpoint: Specified using Entity and Line for the clause head and an unification count expression as a condition. Line must be the first source file line of an entity clause.
Triggered breakpoint: Specified using Entity and Line for the clause head and another breakpoint as a condition. Line must be the first source file line of an entity clause.
Context breakpoint: Specified as a (Sender, This, Self, Goal) tuple.
Log point: Specified using Entity and Line for the clause head and a message.
Leash port shorthands: none - [], loose - [fact,rule,call], half - [fact,rule,call,redo], tight - [fact,rule,call,redo,fail,exception], and full - [fact,rule,call,exit,redo,fail,exception].

| Inherited public predicates: | (none)

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

Public predicates

.. index:: reset/0 .. _debuggerp/0::reset/0:

reset/0 ^^^^^^^^^^^

Resets all debugging settings (including breakpoints, log points, and leashed ports) and turns off debugging.

| Compilation flags: | static

| Mode and number of proofs: | reset - one

| See also: | :ref:`debuggerp/0::nospyall/0`

.. index:: debug/0 .. _debuggerp/0::debug/0:

debug/0 ^^^^^^^^^^^

Starts debugging for all defined breakpoints.

| Compilation flags: | static

| Mode and number of proofs: | debug - one

.. index:: nodebug/0 .. _debuggerp/0::nodebug/0:

nodebug/0 ^^^^^^^^^^^^^

Stops debugging for all defined breakpoints. Also turns off tracing. Does not remove defined breakpoints.

| Compilation flags: | static

| Mode and number of proofs: | nodebug - one

| See also: | :ref:`debuggerp/0::reset/0`

.. index:: debugging/0 .. _debuggerp/0::debugging/0:

debugging/0 ^^^^^^^^^^^^^^^

Reports current debugging settings, including breakpoints and log points.

| Compilation flags: | static

| Mode and number of proofs: | debugging - one

.. index:: debugging/1 .. _debuggerp/0::debugging/1:

debugging/1 ^^^^^^^^^^^^^^^

Enumerates, by backtracking, all entities compiled in debug mode.

| Compilation flags: | static

| Template: | debugging(Entity) | Mode and number of proofs: | debugging(?entity_identifier) - zero_or_more

.. index:: trace/0 .. _debuggerp/0::trace/0:

trace/0 ^^^^^^^^^^^

Starts tracing all calls compiled in debug mode.

| Compilation flags: | static

| Mode and number of proofs: | trace - one

.. index:: notrace/0 .. _debuggerp/0::notrace/0:

notrace/0 ^^^^^^^^^^^^^

Stops tracing of calls compiled in debug mode. Debugger will still stop at defined breakpoints.

| Compilation flags: | static

| Mode and number of proofs: | notrace - one

.. index:: leash/1 .. _debuggerp/0::leash/1:

leash/1 ^^^^^^^^^^^

Sets the debugger leash ports using an abbreviation (none, loose, half, tight, or full) or a list of ports (valid ports are fact, rule, call, exit, redo, fail, and exception).

| Compilation flags: | static

.. index:: leashing/1 .. _debuggerp/0::leashing/1:

leashing/1 ^^^^^^^^^^^^^^

Enumerates, by backtracking, all leashed ports (valid ports are fact, rule, call, exit, redo, fail, and exception).

| Compilation flags: | static

| Template: | leashing(Port) | Mode and number of proofs: | leashing(?atom) - zero_or_more

.. index:: spy/1 .. _debuggerp/0::spy/1:

spy/1 ^^^^^^^^^

Sets a predicate or clause breakpoint (removing any existing log point or breakpoint defined for the same location, or a list of breakpoints. Fails if a breakpoint is invalid.

| Compilation flags: | static

.. index:: spying/1 .. _debuggerp/0::spying/1:

spying/1 ^^^^^^^^^^^^

Enumerates, by backtracking, all defined predicate and clause breakpoints.

| Compilation flags: | static

| Template: | spying(Breakpoint) | Mode and number of proofs: | spying(?spy_point) - zero_or_more

.. index:: nospy/1 .. _debuggerp/0::nospy/1:

nospy/1 ^^^^^^^^^^^

Removes all matching predicate and clause breakpoints.

| Compilation flags: | static

.. index:: spy/3 .. _debuggerp/0::spy/3:

spy/3 ^^^^^^^^^

Sets a conditional or triggered breakpoint (removing any existing log point or breakpoint defined for the same location) at a clause head. The condition can be a unification count expression, a lambda expression, or another breakpoint. Fails if the breakpoint is invalid.

| Compilation flags: | static

| Template: | spy(Entity,Line,Condition) | Mode and number of proofs: | spy(+atom,+integer,@callable) - zero_or_one

| Remarks:

Unification count expression conditions: >(Count), >=(Count), =:=(Count), =<(Count), <(Count), mod(M), and Count.
Lambda expression conditions: [Count,N,Goal]>>Condition and [Goal]>>Condition where Count is the unification count, N is the invocation number, and Goal is the goal that unified with the clause head; Condition is called in the context of user.
Triggered breakpoint conditions: Entity-Line.

.. index:: spying/3 .. _debuggerp/0::spying/3:

spying/3 ^^^^^^^^^^^^

Enumerates, by backtracking, all conditional and triggered breakpoints.

| Compilation flags: | static

| Template: | spying(Entity,Line,Condition) | Mode and number of proofs: | spying(?atom,?integer,?callable) - zero_or_more

.. index:: nospy/3 .. _debuggerp/0::nospy/3:

nospy/3 ^^^^^^^^^^^

Removes all matching conditional and triggered breakpoints.

| Compilation flags: | static

| Template: | nospy(Entity,Line,Condition) | Mode and number of proofs: | nospy(@term,@term,@term) - one

.. index:: spy/4 .. _debuggerp/0::spy/4:

spy/4 ^^^^^^^^^

Sets a context breakpoint.

| Compilation flags: | static

| Template: | spy(Sender,This,Self,Goal) | Mode and number of proofs: | spy(@term,@term,@term,@term) - one

.. index:: spying/4 .. _debuggerp/0::spying/4:

spying/4 ^^^^^^^^^^^^

Enumerates, by backtracking, all defined context breakpoints.

| Compilation flags: | static

| Template: | spying(Sender,This,Self,Goal) | Mode and number of proofs: | spying(?term,?term,?term,?term) - zero_or_more

.. index:: nospy/4 .. _debuggerp/0::nospy/4:

nospy/4 ^^^^^^^^^^^

Removes all matching context breakpoints.

| Compilation flags: | static

| Template: | nospy(Sender,This,Self,Goal) | Mode and number of proofs: | nospy(@term,@term,@term,@term) - one

.. index:: nospyall/0 .. _debuggerp/0::nospyall/0:

nospyall/0 ^^^^^^^^^^^^^^

Removes all breakpoints and log points.

| Compilation flags: | static

| Mode and number of proofs: | nospyall - one

| See also: | :ref:`debuggerp/0::reset/0`

.. index:: log/3 .. _debuggerp/0::log/3:

log/3 ^^^^^^^^^

Sets a log point (removing any existing breakpoint defined for the same location) at a clause head. Fails if the log point is invalid.

| Compilation flags: | static

.. index:: logging/3 .. _debuggerp/0::logging/3:

logging/3 ^^^^^^^^^^^^^

Enumerates, by backtracking, all defined log points.

| Compilation flags: | static

.. index:: nolog/3 .. _debuggerp/0::nolog/3:

nolog/3 ^^^^^^^^^^^

Removes all matching log points.

| Compilation flags: | static

| Template: | nolog(Entity,Line,Message) | Mode and number of proofs: | nolog(@var_or(object_identifier),@var_or(integer),@var_or(atom)) - one | nolog(@var_or(category_identifier),@var_or(integer),@var_or(atom)) - one

.. index:: nologall/0 .. _debuggerp/0::nologall/0:

nologall/0 ^^^^^^^^^^^^^^

Removes all log points.

| Compilation flags: | static

| Mode and number of proofs: | nologall - one

| See also: | :ref:`debuggerp/0::reset/0`

.. index:: write_max_depth/1 .. _debuggerp/0::write_max_depth/1:

write_max_depth/1 ^^^^^^^^^^^^^^^^^^^^^

Current term write maximum depth. When not defined, the backend default is used.

| Compilation flags: | static

| Template: | write_max_depth(MaxDepth) | Mode and number of proofs: | write_max_depth(?non_negative_integer) - zero_or_one

.. index:: set_write_max_depth/1 .. _debuggerp/0::set_write_max_depth/1:

set_write_max_depth/1 ^^^^^^^^^^^^^^^^^^^^^^^^^

Sets the default term maximum write depth. For most backends, a value of zero means that the whole term is written.

| Compilation flags: | static

| Template: | set_write_max_depth(MaxDepth) | Mode and number of proofs: | set_write_max_depth(+non_negative_integer) - one

Protected predicates

(none)

Private predicates

(none)

Operators

(none)

.. seealso::

:ref:`debugger <debugger/0>`