diff options
| -rw-r--r-- | erts/doc/src/erlang.xml | 42 | ||||
| -rw-r--r-- | erts/preloaded/src/erlang.erl | 8 | ||||
| -rw-r--r-- | lib/stdlib/doc/src/ets.xml | 2 |
3 files changed, 48 insertions, 4 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml index d6fe585c8d..fde04504c8 100644 --- a/erts/doc/src/erlang.xml +++ b/erts/doc/src/erlang.xml @@ -2613,6 +2613,48 @@ os_prompt% </pre> </func> <func> + <name name="match_spec_test" arity="3"/> + <fsummary>Test that a match specification works</fsummary> + <desc> + <p> + This function is a utility to test a match_spec used in calls to + <seealso marker="stdlib:ets#select/2">ets:select/2</seealso> and + <seealso marker="#trace_pattern/3">erlang:trace_pattern/3</seealso>. + The function both tests MatchSpec for "syntactic" correctness and + runs the match_spec against the object. If the match_spec contains + errors, the tuple {error, Errors} is returned where Errors is a list + of natural language descriptions of what was wrong with the match_spec. + </p> + <p> + If the <c><anno>Type</anno></c> is <c>table</c> the object to match + against should be a tuple. The function then returns + {ok,Result,[],Warnings} where Result is what would have been the + result in a real ets:select/2 call or false if the match_spec does + not match the object tuple. + </p> + + <p> + If <c><anno>Type</anno></c> is <c>trace</c> the object to match + against should be a list. The function returns + {ok, Result, Flags, Warnings} where Result is <c>true</c> if a trace + message should be emitted, <c>false</c> if a trace message should not + be emitted or the message term to be appended to the trace message. + Flags is a list containing all the trace flags that will be enabled, + at the moment this is only <c>return_trace</c>. + </p> + + <p> + This is a useful debugging and test tool, especially when writing complicated + match specifications. + </p> + <p> + See also + <seealso marker="stdlib:ets#test_ms/2">ets:test_ms/2</seealso>. + </p> + </desc> + </func> + + <func> <name name="max" arity="2"/> <fsummary>Returns the largest of two terms.</fsummary> <desc> diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl index 40d0abd321..3cc17014ff 100644 --- a/erts/preloaded/src/erlang.erl +++ b/erts/preloaded/src/erlang.erl @@ -1163,10 +1163,10 @@ map_size(_Map) -> erlang:nif_error(undefined). %% match_spec_test/3 --spec erlang:match_spec_test(P1, P2, P3) -> TestResult when - P1 :: [term()] | tuple(), - P2 :: term(), - P3 :: table | trace, +-spec erlang:match_spec_test(MatchAgainst, MatchSpec, Type) -> TestResult when + MatchAgainst :: [term()] | tuple(), + MatchSpec :: term(), + Type :: table | trace, TestResult :: {ok, term(), [return_trace], [ {error | warning, string()} ]} | {error, [ {error | warning, string()} ]}. match_spec_test(_P1, _P2, _P3) -> erlang:nif_error(undefined). diff --git a/lib/stdlib/doc/src/ets.xml b/lib/stdlib/doc/src/ets.xml index 4e430d101e..2d69c201bc 100644 --- a/lib/stdlib/doc/src/ets.xml +++ b/lib/stdlib/doc/src/ets.xml @@ -1621,6 +1621,8 @@ true</pre> if the match_spec does not match the object <c><anno>Tuple</anno></c>.</p> <p>This is a useful debugging and test tool, especially when writing complicated <c>ets:select/2</c> calls.</p> + <p>See also: <seealso marker="erts:erlang#match_spec_test/3"> + erlang:match_spec_test/3</seealso>.</p> </desc> </func> <func> |