object

# `lgtunit`

A unit test framework supporting predicate clause coverage, determinism testing, input/output testing, property-based testing, and multiple test dialects.

Author: Paulo Moura
Version: 7.12
Date: 2019/6/13
Compilation flags:
`static, context_switching_calls`
Implements:
`public` expanding
Provides:
logtalk::trace_event/2
Uses:
integer
list
logtalk
os
random
type
user
Remarks:

> - Usage: Define test objects as extensions of the `lgtunit` object and compile their source files using the compiler option `hook(lgtunit)`.

> - Portability: Deterministic unit tests are currently not available when using Lean Prolog or Quintus Prolog as backend compilers.

> - Known issues: Parameter variables cannot currently be used in the definition of test options.

- Public predicates

  - `cover/1`

  - `run/0`

  - `run/1`

  - `run/2`

  - `run_test_sets/1`

  - `deterministic/1`

  - `deterministic/2`

  - `assertion/1`

  - `assertion/2`

  - `quick_check/3`

  - `quick_check/2`

  - `quick_check/1`

  - `benchmark/2`

  - `benchmark_reified/3`

  - `benchmark/3`

  - `benchmark/4`

  - `variant/2`

  - `approximately_equal/3`

  - `essentially_equal/3`

  - `tolerance_equal/4`

  - `=~= / 2`

  - `epsilon/1`

- Protected predicates

  - `run_tests/0`

  - `run_tests/2`

  - `run_test_set/0`

  - `run_quick_check_tests/2`

  - `condition/0`

  - `setup/0`

  - `cleanup/0`

  - `make/1`

  - `note/1`

  - `suppress_text_output/0`

  - `suppress_binary_output/0`

  - `set_text_input/3`

  - `set_text_input/2`

  - `set_text_input/1`

  - `check_text_input/2`

  - `check_text_input/1`

  - `text_input_assertion/3`

  - `text_input_assertion/2`

  - `clean_text_input/0`

  - `set_binary_input/3`

  - `set_binary_input/2`

  - `set_binary_input/1`

  - `check_binary_input/2`

  - `check_binary_input/1`

  - `binary_input_assertion/3`

  - `binary_input_assertion/2`

  - `clean_binary_input/0`

  - `set_text_output/2`

  - `set_text_output/1`

  - `check_text_output/2`

  - `check_text_output/1`

  - `text_output_assertion/3`

  - `text_output_assertion/2`

  - `clean_text_output/0`

  - `set_binary_output/2`

  - `set_binary_output/1`

  - `check_binary_output/2`

  - `check_binary_output/1`

  - `binary_output_assertion/3`

  - `binary_output_assertion/2`

  - `clean_binary_output/0`

  - `create_text_file/2`

  - `create_binary_file/2`

  - `check_text_file/2`

  - `check_binary_file/2`

  - `clean_file/1`

  - `closed_input_stream/2`

  - `closed_output_stream/2`

  - `stream_position/1`

- Private predicates

  - `running_test_sets_/0`

  - `test/3`

  - `auxiliary_predicate_counter_/1`

  - `test_/2`

  - `skipped_/1`

  - `passed_/1`

  - `failed_/1`

  - `fired_/3`

  - `covered_/4`

- Operators

  - `op(700,xfx,=~=)`

## Public predicates

### `cover/1`

Declares entities being tested for which code coverage information should be collected.

Compilation flags:
`static`
Template:
`cover(Entity)`
Mode and number of proofs:
`cover(?entity_identifier)` - `zero_or_more`

### `run/0`

Runs the unit tests, writing the results to the current output stream.

Compilation flags:
`static`
Mode and number of proofs:
`run` - `one`

### `run/1`

Runs a unit test or a list of unit tests, writing the results to the current output stream. Runs the global setup and cleanup steps when defined, failing if either step fails.

Compilation flags:
`static`
Template:
`run(Tests)`
Mode and number of proofs:
`run(+atom)` - `zero_or_one`
`run(+list(atom))` - `zero_or_one`

### `run/2`

Runs the unit tests, writing the results to the specified file. Mode can be either `write` (to create a new file) or `append` (to add results to an existing file).

Compilation flags:
`static`
Template:
`run(File,Mode)`
Mode and number of proofs:
`run(+atom,+atom)` - `one`

### `run_test_sets/1`

Runs two or more test sets as a unified set generating a single code coverage report if one is requested. Fails if the list does not contains at least two test objects.

Compilation flags:
`static`
Template:
`run_test_sets(TestObjects)`
Mode and number of proofs:
`run_test_sets(+list(object_identifier))` - `zero_or_one`

### `deterministic/1`

True if the goal succeeds once without leaving choice-points.

Compilation flags:
`static`
Template:
`deterministic(Goal)`
Meta-predicate template:
`deterministic(0)`
Mode and number of proofs:
`deterministic(+callable)` - `zero_or_one`

### `deterministic/2`

Reified version of the `deterministic/1` predicate. True if the goal succeeds. Returns a boolean value (`true` or `false`) indicating if the goal succeeded without leaving choice-points.

Compilation flags:
`static`
Template:
`deterministic(Goal,Deterministic)`
Meta-predicate template:
`deterministic(0,*)`
Mode and number of proofs:
`deterministic(+callable,--atom)` - `zero_or_one`

### `assertion/1`

True if the assertion goal succeeds. Throws an error using the assertion goal as argument if the assertion goal throws an error or fails.

Compilation flags:
`static`
Template:
`assertion(Assertion)`
Meta-predicate template:
`assertion(::)`
Mode and number of proofs:
`assertion(+callable)` - `one`
Exceptions:
Assertion goal fails:
`assertion_failure(Assertion)`
Assertion goal throws Error:
`assertion_error(Assertion,Error)`

### `assertion/2`

True if the assertion goal succeeds. Throws an error using the description as argument if the assertion goal throws an error or fails. The description argument helps to distinguish between different assertions in the same test body.

Compilation flags:
`static`
Template:
`assertion(Description,Assertion)`
Meta-predicate template:
`assertion(*,0)`
Mode and number of proofs:
`assertion(+nonvar,+callable)` - `one`
Exceptions:
Assertion goal fails:
`assertion_failure(Description)`
Assertion goal throws Error:
`assertion_error(Description,Error)`

### `quick_check/3`

Reified version of the quick_check/2 predicate. Reports the result as `passed`, `failed(Goal)` where `Goal` is the test that failed, or `error(Error,Template)`.

Compilation flags:
`static`
Template:
`quick_check(Template,Result,Options)`
Mode and number of proofs:
`quick_check(@callable,-callable,++list(compound))` - `one`

### `quick_check/2`

Generates and runs random tests for a given predicate given its mode template. Fails when a random generated test fails printing the test. Accepts an option `n(NumberOfTests)`. Default is to run 100 random tests.

Compilation flags:
`static`
Template:
`quick_check(Template,Options)`
Mode and number of proofs:
`quick_check(@callable,++list(compound))` - `zero_or_one`

### `quick_check/1`

Generates and runs 100 random tests for a given predicate given its mode template. Fails when a random generated call fails printing the test.

Compilation flags:
`static`
Template:
`quick_check(Template)`
Mode and number of proofs:
`quick_check(@callable)` - `zero_or_one`

### `benchmark/2`

Benchmarks a goal and returns the total execution time in seconds. Uses cpu clock. Goals that may throw an exception should be wrapped by the `catch/3` control construct.

Compilation flags:
`static`
Template:
`benchmark(Goal,Time)`
Meta-predicate template:
`benchmark(0,*)`
Mode and number of proofs:
`benchmark(+callable,-float)` - `one`

### `benchmark_reified/3`

Benchmarks a goal and returns the total execution time in seconds plus its result (`success`, `failure`, or `error(Error))`. Uses CPU clock.

Compilation flags:
`static`
Template:
`benchmark_reified(Goal,Time,Result)`
Meta-predicate template:
`benchmark_reified(0,*,*)`
Mode and number of proofs:
`benchmark_reified(+callable,-float,-callable)` - `one`

### `benchmark/3`

Benchmarks a goal by repeating it the specified number of times and returning the total execution time in seconds. Uses CPU clock. Goals that may throw an exception should be wrapped by the `catch/3` control construct.

Compilation flags:
`static`
Template:
`benchmark(Goal,Repetitions,Time)`
Meta-predicate template:
`benchmark(0,*,*)`
Mode and number of proofs:
`benchmark(@callable,+positive_integer,-float)` - `one`

### `benchmark/4`

Benchmarks a goal by repeating it the specified number of times and returning the total execution time in seconds using the given clock (`cpu` or `wall`). Goals that may throw an exception should be wrapped by the `catch/3` control construct.

Compilation flags:
`static`
Template:
`benchmark(Goal,Repetitions,Clock,Time)`
Meta-predicate template:
`benchmark(0,*,*,*)`
Mode and number of proofs:
`benchmark(@callable,+positive_integer,+atom,-float)` - `one`

### `variant/2`

True when the two arguments are a variant of each other. I.e. if is possible to rename the term variables to make them identical. Useful for checking expected test results that contain variables.

Compilation flags:
`static`
Template:
`variant(Term1,Term2)`
Mode and number of proofs:
`variant(@term,@term)` - `zero_or_one`

### `approximately_equal/3`

Compares two numbers for approximate equality given an epsilon value using the de facto standard formula `abs(Number1 - Number2) =< max(abs(Number1), abs(Number2)) * Epsilon`. Type-checked.

Compilation flags:
`static`
Template:
`approximately_equal(Number1,Number2,Epsilon)`
Mode and number of proofs:
`approximately_equal(+number,+number,+number)` - `zero_or_one`

### `essentially_equal/3`

Compares two numbers for essential equality given an epsilon value using the de facto standard formula `abs(Number1 - Number2) =< min(abs(Number1), abs(Number2)) * Epsilon`. Type-checked.

Compilation flags:
`static`
Template:
`essentially_equal(Number1,Number2,Epsilon)`
Mode and number of proofs:
`essentially_equal(+number,+number,+number)` - `zero_or_one`

### `tolerance_equal/4`

Compares two numbers for close equality given relative and absolute tolerances using the de facto standard formula `abs(Number1 - Number2) =< max(RelativeTolerance * max(abs(Number1), abs(Number2)), AbsoluteTolerance)`. Type-checked.

Compilation flags:
`static`
Template:
`tolerance_equal(Number1,Number2,RelativeTolerance,AbsoluteTolerance)`
Mode and number of proofs:
`tolerance_equal(+number,+number,+number,+number)` - `zero_or_one`

### `=~= / 2`

Compares two numbers (or lists of numbers) for approximate equality using `100*epsilon` for the absolute error and, if that fails, `99.999%` accuracy for the relative error. But these precision values may not be adequate for all cases. Type-checked.

Compilation flags:
`static`
Template:
`=~=(Number1,Number2)`
Mode and number of proofs:
`=~=(+number,+number)` - `zero_or_one`
`=~=(+list(number),+list(number))` - `zero_or_one`

### `epsilon/1`

Returns the value of epsilon used in the definition of the `(=~=)/2` predicate.

Compilation flags:
`static`
Template:
`epsilon(Epsilon)`
Mode and number of proofs:
`epsilon(-float)` - `one`

## Protected predicates

### `run_tests/0`

Runs all defined unit tests.

Compilation flags:
`static`
Mode and number of proofs:
`run_tests` - `one`

### `run_tests/2`

Runs a list of defined tests.

Compilation flags:
`static`
Template:
`run_tests(Tests,File)`
Mode and number of proofs:
`run_tests(+list(callable),+atom)` - `one`

### `run_test_set/0`

Runs a test set as part of running two or more test sets as a unified set.

Compilation flags:
`static`
Mode and number of proofs:
`run_test_set` - `one`

### `run_quick_check_tests/2`

Runs a list of defined tests using the given options.

Compilation flags:
`static`
Template:
`run_quick_check_tests(Template,Options)`
Mode and number of proofs:
`run_quick_check_tests(@callable,+list)` - `one_or_error`

### `condition/0`

Verifies conditions for running the tests. Defaults to the goal `true`.

Compilation flags:
`static`
Mode and number of proofs:
`condition` - `zero_or_one`

### `setup/0`

Setup environment before running the test set. Defaults to the goal `true`.

Compilation flags:
`static`
Mode and number of proofs:
`setup` - `zero_or_one`

### `cleanup/0`

Cleanup environment after running the test set. Defaults to the goal `true`.

Compilation flags:
`static`
Mode and number of proofs:
`cleanup` - `zero_or_one`

### `make/1`

Make target for automatically running the test set when calling the `logtalk_make/1` built-in predicate. No default. Possible values are `all` and `check`.

Compilation flags:
`static`
Mode and number of proofs:
`make(?atom)` - `zero_or_one`

### `note/1`

Note to be printed after the test results. Defaults to the empty atom.

Compilation flags:
`static`
Mode and number of proofs:
`note(?atom)` - `zero_or_one`

### `suppress_text_output/0`

Suppresses text output. Useful to avoid irrelevant text output from predicates being tested to clutter the test logs.

Compilation flags:
`static`
Mode and number of proofs:
`suppress_text_output` - `one`

### `suppress_binary_output/0`

Suppresses binary output. Useful to avoid irrelevant binary output from predicates being tested to clutter the test logs.

Compilation flags:
`static`
Mode and number of proofs:
`suppress_binary_output` - `one`

### `set_text_input/3`

Creates a temporary file with the given text contents and opens it for reading referenced by the given alias and using the additional options. If no `eof_action/1` option is specified, its value will be the default used by the backend compiler.

Compilation flags:
`static`
Template:
`set_text_input(Alias,Contents,Options)`
Mode and number of proofs:
`set_text_input(+atom,+atom,+list(stream_option))` - `one`

### `set_text_input/2`

Creates a temporary file with the given text contents and opens it for reading referenced by the given alias and using the default end-of-file action for the used backend compiler.

Compilation flags:
`static`
Template:
`set_text_input(Alias,Contents)`
Mode and number of proofs:
`set_text_input(+atom,+atom)` - `one`

### `set_text_input/1`

Creates a temporary file with the given text contents, opens it for reading using the default end-of-file action for the used backend compiler, and sets the current input stream to the file.

Compilation flags:
`static`
Template:
`set_text_input(Contents)`
Mode and number of proofs:
`set_text_input(+atom)` - `one`

### `check_text_input/2`

Checks that the temporary file (referenced with the given alias) being written have the expected text contents.

Compilation flags:
`static`
Template:
`check_text_input(Alias,Contents)`
Mode and number of proofs:
`check_text_input(+atom,+atom)` - `zero_or_one`

### `check_text_input/1`

Checks that the temporary file being written have the expected text contents.

Compilation flags:
`static`
Template:
`check_text_input(Contents)`
Mode and number of proofs:
`check_text_input(+atom)` - `zero_or_one`

### `text_input_assertion/3`

Returns an assertion for checking that the temporary file (referenced with the given alias) being written have the expected text contents.

Compilation flags:
`static`
Template:
`text_input_assertion(Alias,Contents,Assertion)`
Mode and number of proofs:
`text_input_assertion(+atom,+atom,--callable)` - `one`

### `text_input_assertion/2`

Returns an assertion for checking that the temporary file being written have the expected text contents.

Compilation flags:
`static`
Template:
`text_input_assertion(Contents,Assertion)`
Mode and number of proofs:
`text_input_assertion(+atom,--callable)` - `one`

### `clean_text_input/0`

Cleans the temporary file used when testing text input.

Compilation flags:
`static`
Mode and number of proofs:
`clean_text_input` - `one`

### `set_binary_input/3`

Creates a temporary file with the given binary contents and opens it for reading referenced by the given alias and using the additional options. If no `eof_action/1` option is specified, its value will be the default used by the backend compiler.

Compilation flags:
`static`
Template:
`set_binary_input(Alias,Bytes,Options)`
Mode and number of proofs:
`set_binary_input(+atom,+list(byte),+list(stream_option))` - `one`

### `set_binary_input/2`

Creates a temporary file with the given binary contents and opens it for reading referenced by the given alias and using the default end-of-file action for the used backend compiler.

Compilation flags:
`static`
Template:
`set_binary_input(Alias,Bytes)`
Mode and number of proofs:
`set_binary_input(+atom,+list(byte))` - `one`

### `set_binary_input/1`

Creates a temporary file with the given binary contents, opens it for reading using the default end-of-file action for the used backend compiler, and sets the current input stream to the file.

Compilation flags:
`static`
Template:
`set_binary_input(Bytes)`
Mode and number of proofs:
`set_binary_input(+list(byte))` - `one`

### `check_binary_input/2`

Checks that the temporary file (referenced with the given alias) have the expected binary contents.

Compilation flags:
`static`
Template:
`check_binary_input(Alias,Bytes)`
Mode and number of proofs:
`check_binary_input(+atom,+list(byte))` - `zero_or_one`

### `check_binary_input/1`

Checks that the temporary file have the expected binary contents.

Compilation flags:
`static`
Template:
`check_binary_input(Bytes)`
Mode and number of proofs:
`check_binary_input(+list(byte))` - `zero_or_one`

### `binary_input_assertion/3`

Returns an assertion for checking that the temporary file (referenced with the given alias) have the expected binary contents.

Compilation flags:
`static`
Template:
`binary_input_assertion(Alias,Bytes,Assertion)`
Mode and number of proofs:
`binary_input_assertion(+atom,+list(byte),--callable)` - `one`

### `binary_input_assertion/2`

Returns an assertion for checking that the temporary file have the expected binary contents.

Compilation flags:
`static`
Template:
`binary_input_assertion(Bytes,Assertion)`
Mode and number of proofs:
`binary_input_assertion(+list(byte),--callable)` - `one`

### `clean_binary_input/0`

Cleans the temporary file used when testing binary input.

Compilation flags:
`static`
Mode and number of proofs:
`clean_binary_input` - `one`

### `set_text_output/2`

Creates a temporary file with the given text contents and referenced with the given alias.

Compilation flags:
`static`
Template:
`set_text_output(Alias,Contents)`
Mode and number of proofs:
`set_text_output(+atom,+atom)` - `one`

### `set_text_output/1`

Creates a temporary file with the given text contents and sets the current output stream to the file.

Compilation flags:
`static`
Template:
`set_text_output(Contents)`
Mode and number of proofs:
`set_text_output(+atom)` - `one`

### `check_text_output/2`

Checks that the temporary file (referenced with the given alias) being written have the expected text contents.

Compilation flags:
`static`
Template:
`check_text_output(Alias,Contents)`
Mode and number of proofs:
`check_text_output(+atom,+atom)` - `zero_or_one`

### `check_text_output/1`

Checks that the temporary file being written have the expected text contents.

Compilation flags:
`static`
Template:
`check_text_output(Contents)`
Mode and number of proofs:
`check_text_output(+atom)` - `zero_or_one`

### `text_output_assertion/3`

Returns an assertion for checking that the temporary file (referenced with the given alias) being written have the expected text contents.

Compilation flags:
`static`
Template:
`text_output_assertion(Alias,Contents,Assertion)`
Mode and number of proofs:
`text_output_assertion(+atom,+atom,--callable)` - `one`

### `text_output_assertion/2`

Returns an assertion for checking that the temporary file being written have the expected text contents.

Compilation flags:
`static`
Template:
`text_output_assertion(Contents,Assertion)`
Mode and number of proofs:
`text_output_assertion(+atom,--callable)` - `one`

### `clean_text_output/0`

Cleans the temporary file used when testing text output.

Compilation flags:
`static`
Mode and number of proofs:
`clean_text_output` - `one`

### `set_binary_output/2`

Creates a temporary file with the given binary contents and referenced with the given alias.

Compilation flags:
`static`
Template:
`set_binary_output(Alias,Bytes)`
Mode and number of proofs:
`set_binary_output(+atom,+list(byte))` - `one`

### `set_binary_output/1`

Creates a temporary file with the given binary contents and sets the current output stream to the file.

Compilation flags:
`static`
Template:
`set_binary_output(Bytes)`
Mode and number of proofs:
`set_binary_output(+list(byte))` - `one`

### `check_binary_output/2`

Checks that the temporary file (referenced with the given alias) have the expected binary contents.

Compilation flags:
`static`
Template:
`check_binary_output(Alias,Bytes)`
Mode and number of proofs:
`check_binary_output(+atom,+list(byte))` - `zero_or_one`

### `check_binary_output/1`

Checks that the temporary file have the expected binary contents.

Compilation flags:
`static`
Template:
`check_binary_output(Bytes)`
Mode and number of proofs:
`check_binary_output(+list(byte))` - `zero_or_one`

### `binary_output_assertion/3`

Returns an assertion for checking that the temporary file (referenced with the given alias) have the expected binary contents.

Compilation flags:
`static`
Template:
`binary_output_assertion(Alias,Bytes,Assertion)`
Mode and number of proofs:
`binary_output_assertion(+atom,+list(byte),--callable)` - `one`

### `binary_output_assertion/2`

Returns an assertion for checking that the temporary file have the expected binary contents.

Compilation flags:
`static`
Template:
`binary_output_assertion(Bytes,Assertion)`
Mode and number of proofs:
`binary_output_assertion(+list(byte),--callable)` - `one`

### `clean_binary_output/0`

Cleans the temporary file used when testing binary output.

Compilation flags:
`static`
Mode and number of proofs:
`clean_binary_output` - `one`

### `create_text_file/2`

Creates a text file with the given contents.

Compilation flags:
`static`
Template:
`create_text_file(File,Contents)`
Mode and number of proofs:
`create_text_file(+atom,+atom)` - `one`

### `create_binary_file/2`

Creates a binary file with the given contents.

Compilation flags:
`static`
Template:
`create_binary_file(File,Bytes)`
Mode and number of proofs:
`create_binary_file(+atom,+list(byte))` - `one`

### `check_text_file/2`

Checks that the contents of a text file match the expected contents.

Compilation flags:
`static`
Template:
`check_text_file(File,Contents)`
Mode and number of proofs:
`check_text_file(+atom,+atom)` - `zero_or_one`

### `check_binary_file/2`

Checks the contents of a binary file match the expected contents.

Compilation flags:
`static`
Template:
`check_binary_file(File,Bytes)`
Mode and number of proofs:
`check_binary_file(+atom,+list(byte))` - `zero_or_one`

### `clean_file/1`

Closes any existing stream associated with the file and deletes the file if it exists.

Compilation flags:
`static`
Template:
`clean_file(File)`
Mode and number of proofs:
`clean_file(+atom)` - `one`

### `closed_input_stream/2`

Opens a temporary file with the given options for reading, closes it, and returns its stream handle.

Compilation flags:
`static`
Template:
`closed_input_stream(Stream,Options)`
Mode and number of proofs:
`closed_input_stream(-stream,+list(stream_option))` - `one`

### `closed_output_stream/2`

Opens a temporary file with the given options for writing, closes it, and returns its stream handle.

Compilation flags:
`static`
Template:
`closed_output_stream(Stream,Options)`
Mode and number of proofs:
`closed_output_stream(-stream,+list(stream_option))` - `zero_or_one`

### `stream_position/1`

Returns a syntactically valid stream position.

Compilation flags:
`static`
Template:
`stream_position(Position)`
Mode and number of proofs:
`stream_position(-stream_position)` - `one`

## Private predicates

### `running_test_sets_/0`

Internal flag used when running two or more test sets as a unified set.

Compilation flags:
`dynamic`
Mode and number of proofs:
`running_test_sets_` - `zero_or_one`

### `test/3`

Specifies a unit test.

Compilation flags:
`static`
Template:
`test(Identifier,Variables,Outcome)`
Mode and number of proofs:
`test(?atom,?list(variable),?nonvar)` - `zero_or_more`

### `auxiliary_predicate_counter_/1`

Counter for generarting unique auxiliary predicate names.

Compilation flags:
`dynamic`
Template:
`auxiliary_predicate_counter_(Counter)`
Mode and number of proofs:
`auxiliary_predicate_counter_(?integer)` - `one_or_more`

### `test_/2`

Table of defined tests.

Compilation flags:
`dynamic`
Template:
`test_(Identifier,Test)`
Mode and number of proofs:
`test_(?atom,?compound)` - `zero_or_more`

### `skipped_/1`

Counter for skipped tests.

Compilation flags:
`dynamic`
Template:
`skipped_(Counter)`
Mode and number of proofs:
`skipped_(?integer)` - `zero_or_one`

### `passed_/1`

Counter for passed tests.

Compilation flags:
`dynamic`
Template:
`passed_(Counter)`
Mode and number of proofs:
`passed_(?integer)` - `zero_or_one`

### `failed_/1`

Counter for failed tests.

Compilation flags:
`dynamic`
Template:
`failed_(Counter)`
Mode and number of proofs:
`failed_(?callable)` - `zero_or_one`

### `fired_/3`

Fired clauses when running the unit tests.

Compilation flags:
`dynamic`
Template:
`fired_(Entity,Predicate,Clause)`
Mode and number of proofs:
`fired_(?entity_identifier,?predicate_indicator,?integer)` - `zero_or_more`

### `covered_/4`

Auxiliary predicate for collecting statistics on clause coverage.

Compilation flags:
`dynamic`
Template:
`covered_(Entity,Predicate,Covered,Total)`
Mode and number of proofs:
`covered_(?entity_identifier,?callable,?integer,?integer)` - `zero_or_more`

## Operators

### `op(700,xfx,=~=)`

Scope:
`public`