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| author | Hans Bolinder <[email protected]> | 2016-11-29 09:37:21 +0100 |
|---|---|---|
| committer | Hans Bolinder <[email protected]> | 2016-12-01 16:07:11 +0100 |
| commit | 91048957f0681dba853f5720d3618aa1c5d0255e (patch) | |
| tree | 6e15b3365bc2ea4b9d7042c1d023f71bb0002f2d /lib/stdlib/test/erl_pp_SUITE.erl | |
| parent | ca29c37928ad36cf4270fb3edffc2cf9752f2ed9 (diff) | |
| download | otp-91048957f0681dba853f5720d3618aa1c5d0255e.tar.gz otp-91048957f0681dba853f5720d3618aa1c5d0255e.tar.bz2 otp-91048957f0681dba853f5720d3618aa1c5d0255e.zip | |
stdilb: Check for bad type constraints in function types
The parser recognizes the 'is_subtype(V, T)' syntax for constraints,
and of course the new 'V :: T' syntax, but other variants result in an
error message. Up to now, the parser and linter have let badly formed
constraints through, and relied upon Dialyzer to emit warnings.
is_subtype/2 cannot easily be taken out from the parser. Not only
would we need find a way to emit a (linter) warning, but there also
needs to be an option for suppressing the linter warning as
compilation with +warnings_as_errors has to work. (Notice that the
abstract format representation for 'V :: T' is the same as for
'is_subtype(V, T)'.)
This correction was triggered by an email from Robert, and Kostis
created pull request 1214 to provide a fix. However, Kostis' fix
disallowed is_subtype() altogether, which breaks backward
compatibility.
As of Erlang/OTP 19.0 (ticket OTP-11879), the 'is_subtype(V, T)' is no
longer documented.
Diffstat (limited to 'lib/stdlib/test/erl_pp_SUITE.erl')
| -rw-r--r-- | lib/stdlib/test/erl_pp_SUITE.erl | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/lib/stdlib/test/erl_pp_SUITE.erl b/lib/stdlib/test/erl_pp_SUITE.erl index 13c5662741..31ea3210a8 100644 --- a/lib/stdlib/test/erl_pp_SUITE.erl +++ b/lib/stdlib/test/erl_pp_SUITE.erl @@ -825,12 +825,13 @@ type_examples() -> %% is_subtype(V, T) syntax, we need a few examples of the syntax. {ex31,<<"-spec t1(FooBar :: t99()) -> t99();" "(t2()) -> t2();" - "('\\'t::4'()) -> '\\'t::4'() when is_subtype('\\'t::4'(), t24);" - "(t23()) -> t23() when is_subtype(t23(), atom())," - " is_subtype(t23(), t14());" - "(t24()) -> t24() when is_subtype(t24(), atom())," - " is_subtype(t24(), t14())," - " is_subtype(t24(), '\\'t::4'()).">>}, + "('\\'t::4'()) -> {'\\'t::4'(), B}" + " when is_subtype(B, '\\'t::4'());" + "(t23()) -> C when is_subtype(C, atom())," + " is_subtype(C, t14());" + "(t24()) -> D when is_subtype(D, atom())," + " is_subtype(D, t14())," + " is_subtype(D, '\\'t::4'()).">>}, {ex32,<<"-spec mod:t2() -> any(). ">>}, {ex33,<<"-opaque attributes_data() :: " "[{'column', column()} | {'line', info_line()} |" |