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Diffstat (limited to 'lib/compiler/src/beam_types.hrl')
| -rw-r--r-- | lib/compiler/src/beam_types.hrl | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/lib/compiler/src/beam_types.hrl b/lib/compiler/src/beam_types.hrl new file mode 100644 index 0000000000..09f87d61ba --- /dev/null +++ b/lib/compiler/src/beam_types.hrl @@ -0,0 +1,88 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2019. All Rights Reserved. +%% +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at +%% +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. +%% +%% %CopyrightEnd% +%% + +%% Common term types for passes operating on beam SSA and assembly. Helper +%% functions for wrangling these can be found in beam_types.erl +%% +%% The type lattice is as follows: +%% +%% any Any Erlang term (top element). +%% +%% - #t_atom{} Atom, or a set thereof. +%% - #t_bitstring{} Bitstring. +%% - #t_bs_context{} Match context. +%% - #t_fun{} Fun. +%% - #t_map{} Map. +%% - number Any number. +%% -- float Floating point number. +%% -- integer Integer. +%% - list Any list. +%% -- cons Cons (nonempty list). +%% -- nil The empty list. +%% - #t_tuple{} Tuple. +%% +%% 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). + +-record(t_atom, {elements=any :: 'any' | [atom()]}). +-record(t_fun, {arity=any :: arity() | 'any'}). +-record(t_integer, {elements=any :: 'any' | {integer(),integer()}}). +-record(t_bitstring, {unit=1 :: pos_integer()}). +-record(t_bs_context, {slots=0 :: non_neg_integer(), + valid=0 :: non_neg_integer()}). +-record(t_map, {elements=#{} :: map_elements()}). +-record(t_tuple, {size=0 :: integer(), + exact=false :: boolean(), + elements=#{} :: tuple_elements()}). + +%% 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, +%% not wrapped in a #b_literal{}, just the value itself). + +-type tuple_elements() :: #{ Key :: pos_integer() => type() }. +-type map_elements() :: #{ Key :: term() => type() }. + +-type elements() :: tuple_elements() | map_elements(). + +-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(). |