cxxheaderparser/tests/test_concepts.py
Dustin Spicuzza e935959ad3 Implement basic concept parsing
- requires clauses are collected into a Value and not interpreted at
  this time
2023-10-10 03:45:55 -04:00

404 lines
16 KiB
Python

from cxxheaderparser.simple import NamespaceScope, ParsedData, parse_string
from cxxheaderparser.tokfmt import Token
from cxxheaderparser.types import (
Concept,
Function,
FundamentalSpecifier,
NameSpecifier,
PQName,
Parameter,
TemplateArgument,
TemplateDecl,
TemplateNonTypeParam,
TemplateSpecialization,
TemplateTypeParam,
Type,
Value,
Variable,
)
def test_concept_basic_constraint() -> None:
content = """
template <class T, class U>
concept Derived = std::is_base_of<U, T>::value;
template <Derived<Base> T> void f(T); // T is constrained by Derived<T, Base>
"""
data = parse_string(content, cleandoc=True)
assert data == ParsedData(
namespace=NamespaceScope(
functions=[
Function(
return_type=Type(
typename=PQName(segments=[FundamentalSpecifier(name="void")])
),
name=PQName(segments=[NameSpecifier(name="f")]),
parameters=[
Parameter(
type=Type(
typename=PQName(segments=[NameSpecifier(name="T")])
)
)
],
template=TemplateDecl(
params=[
TemplateNonTypeParam(
type=Type(
typename=PQName(
segments=[
NameSpecifier(
name="Derived",
specialization=TemplateSpecialization(
args=[
TemplateArgument(
arg=Type(
typename=PQName(
segments=[
NameSpecifier(
name="Base"
)
]
)
)
)
]
),
)
]
)
),
name="T",
)
]
),
)
],
concepts=[
Concept(
template=TemplateDecl(
params=[
TemplateTypeParam(typekey="class", name="T"),
TemplateTypeParam(typekey="class", name="U"),
]
),
name="Derived",
raw_constraint=Value(
tokens=[
Token(value="std"),
Token(value="::"),
Token(value="is_base_of"),
Token(value="<"),
Token(value="U"),
Token(value=","),
Token(value="T"),
Token(value=">"),
Token(value="::"),
Token(value="value"),
]
),
)
],
)
)
def test_concept_basic_constraint2() -> None:
content = """
template <class T> constexpr bool is_meowable = true;
template <class T> constexpr bool is_cat = true;
template <class T>
concept Meowable = is_meowable<T>;
template <class T>
concept BadMeowableCat = is_meowable<T> && is_cat<T>;
"""
data = parse_string(content, cleandoc=True)
assert data == ParsedData(
namespace=NamespaceScope(
variables=[
Variable(
name=PQName(segments=[NameSpecifier(name="is_meowable")]),
type=Type(
typename=PQName(segments=[FundamentalSpecifier(name="bool")])
),
value=Value(tokens=[Token(value="true")]),
constexpr=True,
template=TemplateDecl(
params=[TemplateTypeParam(typekey="class", name="T")]
),
),
Variable(
name=PQName(segments=[NameSpecifier(name="is_cat")]),
type=Type(
typename=PQName(segments=[FundamentalSpecifier(name="bool")])
),
value=Value(tokens=[Token(value="true")]),
constexpr=True,
template=TemplateDecl(
params=[TemplateTypeParam(typekey="class", name="T")]
),
),
],
concepts=[
Concept(
template=TemplateDecl(
params=[TemplateTypeParam(typekey="class", name="T")]
),
name="Meowable",
raw_constraint=Value(
tokens=[
Token(value="is_meowable"),
Token(value="<"),
Token(value="T"),
Token(value=">"),
]
),
),
Concept(
template=TemplateDecl(
params=[TemplateTypeParam(typekey="class", name="T")]
),
name="BadMeowableCat",
raw_constraint=Value(
tokens=[
Token(value="is_meowable"),
Token(value="<"),
Token(value="T"),
Token(value=">"),
Token(value="&&"),
Token(value="is_cat"),
Token(value="<"),
Token(value="T"),
Token(value=">"),
]
),
),
],
)
)
def test_concept_basic_requires() -> None:
content = """
template <typename T>
concept Hashable = requires(T a) {
{ std::hash<T>{}(a) } -> std::convertible_to<std::size_t>;
};
template <Hashable T> void f(T) {}
"""
data = parse_string(content, cleandoc=True)
assert data == ParsedData(
namespace=NamespaceScope(
functions=[
Function(
return_type=Type(
typename=PQName(segments=[FundamentalSpecifier(name="void")])
),
name=PQName(segments=[NameSpecifier(name="f")]),
parameters=[
Parameter(
type=Type(
typename=PQName(segments=[NameSpecifier(name="T")])
)
)
],
has_body=True,
template=TemplateDecl(
params=[
TemplateNonTypeParam(
type=Type(
typename=PQName(
segments=[NameSpecifier(name="Hashable")]
)
),
name="T",
)
]
),
)
],
concepts=[
Concept(
template=TemplateDecl(
params=[TemplateTypeParam(typekey="typename", name="T")]
),
name="Hashable",
raw_constraint=Value(
tokens=[
Token(value="requires"),
Token(value="("),
Token(value="T"),
Token(value="a"),
Token(value=")"),
Token(value="{"),
Token(value="{"),
Token(value="std"),
Token(value="::"),
Token(value="hash"),
Token(value="<"),
Token(value="T"),
Token(value=">"),
Token(value="{"),
Token(value="}"),
Token(value="("),
Token(value="a"),
Token(value=")"),
Token(value="}"),
Token(value="->"),
Token(value="std"),
Token(value="::"),
Token(value="convertible_to"),
Token(value="<"),
Token(value="std"),
Token(value="::"),
Token(value="size_t"),
Token(value=">"),
Token(value=";"),
Token(value="}"),
]
),
)
],
)
)
def test_concept_nested_requirements() -> None:
content = """
template<class T>
concept Semiregular = DefaultConstructible<T> &&
CopyConstructible<T> && CopyAssignable<T> && Destructible<T> &&
requires(T a, std::size_t n)
{
requires Same<T*, decltype(&a)>; // nested: "Same<...> evaluates to true"
{ a.~T() } noexcept; // compound: "a.~T()" is a valid expression that doesn't throw
requires Same<T*, decltype(new T)>; // nested: "Same<...> evaluates to true"
requires Same<T*, decltype(new T[n])>; // nested
{ delete new T }; // compound
{ delete new T[n] }; // compound
};
"""
data = parse_string(content, cleandoc=True)
assert data == ParsedData(
namespace=NamespaceScope(
concepts=[
Concept(
template=TemplateDecl(
params=[TemplateTypeParam(typekey="class", name="T")]
),
name="Semiregular",
raw_constraint=Value(
tokens=[
Token(value="DefaultConstructible"),
Token(value="<"),
Token(value="T"),
Token(value=">"),
Token(value="&&"),
Token(value="CopyConstructible"),
Token(value="<"),
Token(value="T"),
Token(value=">"),
Token(value="&&"),
Token(value="CopyAssignable"),
Token(value="<"),
Token(value="T"),
Token(value=">"),
Token(value="&&"),
Token(value="Destructible"),
Token(value="<"),
Token(value="T"),
Token(value=">"),
Token(value="&&"),
Token(value="requires"),
Token(value="("),
Token(value="T"),
Token(value="a"),
Token(value=","),
Token(value="std"),
Token(value="::"),
Token(value="size_t"),
Token(value="n"),
Token(value=")"),
Token(value="{"),
Token(value="requires"),
Token(value="Same"),
Token(value="<"),
Token(value="T"),
Token(value="*"),
Token(value=","),
Token(value="decltype"),
Token(value="("),
Token(value="&"),
Token(value="a"),
Token(value=")"),
Token(value=">"),
Token(value=";"),
Token(value="{"),
Token(value="a"),
Token(value="."),
Token(value="~T"),
Token(value="("),
Token(value=")"),
Token(value="}"),
Token(value="noexcept"),
Token(value=";"),
Token(value="requires"),
Token(value="Same"),
Token(value="<"),
Token(value="T"),
Token(value="*"),
Token(value=","),
Token(value="decltype"),
Token(value="("),
Token(value="new"),
Token(value="T"),
Token(value=")"),
Token(value=">"),
Token(value=";"),
Token(value="requires"),
Token(value="Same"),
Token(value="<"),
Token(value="T"),
Token(value="*"),
Token(value=","),
Token(value="decltype"),
Token(value="("),
Token(value="new"),
Token(value="T"),
Token(value="["),
Token(value="n"),
Token(value="]"),
Token(value=")"),
Token(value=">"),
Token(value=";"),
Token(value="{"),
Token(value="delete"),
Token(value="new"),
Token(value="T"),
Token(value="}"),
Token(value=";"),
Token(value="{"),
Token(value="delete"),
Token(value="new"),
Token(value="T"),
Token(value="["),
Token(value="n"),
Token(value="]"),
Token(value="}"),
Token(value=";"),
Token(value="}"),
]
),
)
]
)
)