diff options
Diffstat (limited to 'lib/compiler/src/beam_types.hrl')
| -rw-r--r-- | lib/compiler/src/beam_types.hrl | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/lib/compiler/src/beam_types.hrl b/lib/compiler/src/beam_types.hrl index 825eca4c64..09f87d61ba 100644 --- a/lib/compiler/src/beam_types.hrl +++ b/lib/compiler/src/beam_types.hrl @@ -37,10 +37,15 @@ %% -- cons Cons (nonempty list). %% -- nil The empty list. %% - #t_tuple{} Tuple. -%% - #t_abstract{} Psuedo-type used in the validator to track tuples -% under construction, match context positions, etc. %% %% none No type (bottom element). +%% +%% We also use #t_union{} to represent conflicting types produced by certain +%% expressions, e.g. the "#t_atom{} or #t_tuple{}" of lists:keyfind/3, which is +%% very useful for preserving type information when we would otherwise have +%% reduced it to 'any'. Since few operations can make direct use of this extra +%% type information, types should generally be normalized to one of the above +%% before use. -define(ATOM_SET_SIZE, 5). @@ -54,7 +59,6 @@ -record(t_tuple, {size=0 :: integer(), exact=false :: boolean(), elements=#{} :: tuple_elements()}). --record(t_abstract, {kind :: atom()}). %% Known element types, unknown elements are assumed to be 'any'. The key is %% a 1-based integer index for tuples, and a plain literal for maps (that is, @@ -65,8 +69,20 @@ -type elements() :: tuple_elements() | map_elements(). --type type() :: any | none | - list | number | - #t_atom{} | #t_bitstring{} | #t_bs_context{} | #t_fun{} | - #t_integer{} | #t_map{} | #t_tuple{} | #t_abstract{} | - 'cons' | 'float' | 'nil'. +-type normal_type() :: any | none | + list | number | + #t_atom{} | #t_bitstring{} | #t_bs_context{} | + #t_fun{} | #t_integer{} | #t_map{} | #t_tuple{} | + 'cons' | 'float' | 'nil'. + +-type record_key() :: {Arity :: integer(), Tag :: normal_type() }. +-type record_set() :: ordsets:ordset({record_key(), #t_tuple{}}). +-type tuple_set() :: #t_tuple{} | record_set(). + +-record(t_union, {atom=none :: none | #t_atom{}, + list=none :: none | list | cons | nil, + number=none :: none | number | float | #t_integer{}, + tuple_set=none :: none | tuple_set(), + other=none :: normal_type()}). + +-type type() :: #t_union{} | normal_type(). |