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add quickstart sample to show proper usage of nulity writes/reads
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re #409
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@biojppm
biojppm committed Mar 18, 2024
1 parent 3ef11e1 commit 8931537
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Showing 2 changed files with 160 additions and 17 deletions.
169 changes: 155 additions & 14 deletions samples/quickstart.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2135,8 +2135,9 @@ void sample_tree_arena()
//-----------------------------------------------------------------------------

/** ryml provides facilities for serializing the C++ fundamental
types. This is achieved through to_chars()/from_chars().
See an example below for user scalar types. */
types, including boolean and null values. This is achieved through
to_chars()/from_chars(). See an example below for user scalar
types. */
void sample_fundamental_types()
{
ryml::Tree tree;
Expand All @@ -2160,23 +2161,28 @@ void sample_fundamental_types()
CHECK(tree.to_arena((void*)1) == "0x1"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x1");
CHECK(tree.to_arena(float(0.124)) == "0.124"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.124");
CHECK(tree.to_arena(double(0.234)) == "0.234"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.234");
CHECK(tree.to_arena(bool(true)) == "1"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.2341");
CHECK(tree.to_arena(bool(false)) == "0"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410");

// write boolean values - see also sample_formatting()
CHECK(tree.to_arena(bool(true)) == "1"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.2341");
CHECK(tree.to_arena(bool(false)) == "0"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410");
CHECK(tree.to_arena(c4::fmt::boolalpha(true)) == "true"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410true");
CHECK(tree.to_arena(c4::fmt::boolalpha(false)) == "false"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410truefalse");

// write special float values
const float fnan = std::numeric_limits<float >::quiet_NaN();
const double dnan = std::numeric_limits<double>::quiet_NaN();
const float finf = std::numeric_limits<float >::infinity();
const double dinf = std::numeric_limits<double>::infinity();
CHECK(tree.to_arena( finf) == ".inf"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410.inf");
CHECK(tree.to_arena( dinf) == ".inf"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410.inf.inf");
CHECK(tree.to_arena(-finf) == "-.inf"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410.inf.inf-.inf");
CHECK(tree.to_arena(-dinf) == "-.inf"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410.inf.inf-.inf-.inf");
CHECK(tree.to_arena( fnan) == ".nan"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410.inf.inf-.inf-.inf.nan");
CHECK(tree.to_arena( dnan) == ".nan"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410.inf.inf-.inf-.inf.nan.nan");
CHECK(tree.to_arena( finf) == ".inf"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410truefalse.inf");
CHECK(tree.to_arena( dinf) == ".inf"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410truefalse.inf.inf");
CHECK(tree.to_arena(-finf) == "-.inf"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410truefalse.inf.inf-.inf");
CHECK(tree.to_arena(-dinf) == "-.inf"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410truefalse.inf.inf-.inf-.inf");
CHECK(tree.to_arena( fnan) == ".nan"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410truefalse.inf.inf-.inf-.inf.nan");
CHECK(tree.to_arena( dnan) == ".nan"); CHECK(tree.arena() == "abcde0101234-45-56-67-70x10.1240.23410truefalse.inf.inf-.inf-.inf.nan.nan");

// read special float values
tree = ryml::parse_in_arena(R"({ninf: -.inf, pinf: .inf, nan: .nan})");
C4_SUPPRESS_WARNING_GCC_CLANG_WITH_PUSH("-Wfloat-equal");
tree = ryml::parse_in_arena(R"({ninf: -.inf, pinf: .inf, nan: .nan})");
float f = 0.f;
double d = 0.;
CHECK(f == 0.f);
Expand All @@ -2188,6 +2194,141 @@ void sample_fundamental_types()
tree["nan" ] >> f; CHECK(std::isnan(f));
tree["nan" ] >> d; CHECK(std::isnan(d));
C4_SUPPRESS_WARNING_GCC_CLANG_POP

// reading empty/null values - see also sample_formatting()
tree = ryml::parse_in_arena(R"(
plain:
squoted: ''
dquoted: ""
literal: |
folded: >
all_null: [~, null, Null, NULL]
non_null: [nULL, non_null, non null, null it is not]
)");
// all of these scalars have zero-length:
CHECK(tree["plain"].val().len == 0);
CHECK(tree["squoted"].val().len == 0);
CHECK(tree["dquoted"].val().len == 0);
CHECK(tree["literal"].val().len == 0);
CHECK(tree["folded"].val().len == 0);
// but only the empty scalar has null string:
CHECK(tree["plain"].val().str == nullptr);
CHECK(tree["squoted"].val().str != nullptr);
CHECK(tree["dquoted"].val().str != nullptr);
CHECK(tree["literal"].val().str != nullptr);
CHECK(tree["folded"].val().str != nullptr);
// likewise, scalar comparison to nullptr has the same results:
CHECK(tree["plain"].val() == nullptr);
CHECK(tree["squoted"].val() != nullptr);
CHECK(tree["dquoted"].val() != nullptr);
CHECK(tree["literal"].val() != nullptr);
CHECK(tree["folded"].val() != nullptr);
// the tree and node classes provide the corresponding predicate
// functions .key_is_val() and .val_is_null():
CHECK(tree["plain"].val_is_null());
CHECK( ! tree["squoted"].val_is_null());
CHECK( ! tree["dquoted"].val_is_null());
CHECK( ! tree["literal"].val_is_null());
CHECK( ! tree["folded"].val_is_null());
for(ryml::ConstNodeRef child : tree["all_null"].children())
{
CHECK(child.val() != nullptr); // it is pointing at a string, so it is not nullptr!
CHECK(child.val_is_null());
}
// matching to null is case-sensitive. only the cases shown above
// match to null:
for(ryml::ConstNodeRef child : tree["non_null"].children())
{
CHECK(child.val() != nullptr);
CHECK( ! child.val_is_null());
}
// Because the meaning of null/~/empty will vary from application
// to application, ryml makes no assumption on what should be
// serialized as null. It leaves this decision to the user. But
// it also provides the proper toolbox for the user to implement
// its intended solution.
//
// writing/disambiguating null values:
ryml::csubstr null = {};
ryml::csubstr nonnull = "";
ryml::csubstr strnull = "null";
ryml::csubstr tilde = "~";
CHECK(null .len == 0); CHECK(null .str == nullptr); CHECK(null == nullptr);
CHECK(nonnull.len == 0); CHECK(nonnull.str != nullptr); CHECK(nonnull != nullptr);
CHECK(strnull.len != 0); CHECK(strnull.str != nullptr); CHECK(strnull != nullptr);
CHECK(tilde .len != 0); CHECK(tilde .str != nullptr); CHECK(tilde != nullptr);
tree.clear();
tree.clear_arena();
tree.rootref() |= ryml::MAP;
// serializes as an empty plain scalar:
tree["empty_null"] << null; CHECK(tree.arena() == "");
// serializes as an empty quoted scalar:
tree["empty_nonnull"] << nonnull; CHECK(tree.arena() == "");
// serializes as the normal 'null' string:
tree["str_null"] << strnull; CHECK(tree.arena() == "null");
// serializes as the normal '~' string:
tree["str_tilde"] << tilde; CHECK(tree.arena() == "null~");
// this is the resulting yaml:
CHECK(ryml::emitrs_yaml<std::string>(tree) ==
R"(empty_null:
empty_nonnull: ''
str_null: null
str_tilde: ~
)");
// To enforce a particular concept of what is a null string, you
// can use the appropriate condition based on pointer nulity or
// other appropriate criteria.
//
// As an example, proper comparison to nullptr:
auto null_if_nullptr = [](ryml::csubstr s) {
return s.str == nullptr ? "null" : s;
};
tree["empty_null"] << null_if_nullptr(null);
tree["empty_nonnull"] << null_if_nullptr(nonnull);
tree["str_null"] << null_if_nullptr(strnull);
tree["str_tilde"] << null_if_nullptr(tilde);
// this is the resulting yaml:
std::cout << tree;
CHECK(ryml::emitrs_yaml<std::string>(tree) ==
R"(empty_null: null
empty_nonnull: ''
str_null: null
str_tilde: ~
)");
//
// As another example, nulity check based on the YAML nulity
// predicate:
auto null_if_predicate = [](ryml::csubstr s) {
return ryml::Tree::scalar_is_null(s) ? "null" : s;
};
tree["empty_null"] << null_if_predicate(null);
tree["empty_nonnull"] << null_if_predicate(nonnull);
tree["str_null"] << null_if_predicate(strnull);
tree["str_tilde"] << null_if_predicate(tilde);
// this is the resulting yaml:
CHECK(ryml::emitrs_yaml<std::string>(tree) ==
R"(empty_null: null
empty_nonnull: ''
str_null: null
str_tilde: null
)");
//
// As another example, nulity check based on the YAML nulity
// predicate, but returning "~" to simbolize nulity:
auto tilde_if_predicate = [](ryml::csubstr s) {
return ryml::Tree::scalar_is_null(s) ? "~" : s;
};
tree["empty_null"] << tilde_if_predicate(null);
tree["empty_nonnull"] << tilde_if_predicate(nonnull);
tree["str_null"] << tilde_if_predicate(strnull);
tree["str_tilde"] << tilde_if_predicate(tilde);
// this is the resulting yaml:
CHECK(ryml::emitrs_yaml<std::string>(tree) ==
R"(empty_null: ~
empty_nonnull: ''
str_null: ~
str_tilde: ~
)");
}


Expand Down Expand Up @@ -2576,7 +2717,9 @@ void sample_formatting()
CHECK("1.234e+06" == cat_sub(buf, fmt::real(1234234.234234234, 4, FTOA_FLEX))); // AKA %g
CHECK("1.23e+06" == cat_sub(buf, fmt::real(1234234.234234234, 3, FTOA_FLEX))); // AKA %g
CHECK("1.2e+06" == cat_sub(buf, fmt::real(1234234.234234234, 2, FTOA_FLEX))); // AKA %g
// AKA %a (hexadecimal formatting of floats)
// FTOA_HEXA: AKA %a (hexadecimal formatting of floats)
CHECK("0x1.e8480p+19" == cat_sub(buf, fmt::real(1000000.000000000, 5, FTOA_HEXA))); // AKA %a
CHECK("0x1.2d53ap+20" == cat_sub(buf, fmt::real(1234234.234234234, 5, FTOA_HEXA))); // AKA %a
// Earlier versions of emscripten's sprintf() (from MUSL) do not
// respect some precision values when printing in hexadecimal
// format.
Expand All @@ -2587,8 +2730,6 @@ void sample_formatting()
#else
#define _c4emscripten_alt(alt1, alt2) alt1
#endif
CHECK("0x1.e8480p+19" == cat_sub(buf, fmt::real(1000000.000000000, 5, FTOA_HEXA))); // AKA %a
CHECK("0x1.2d53ap+20" == cat_sub(buf, fmt::real(1234234.234234234, 5, FTOA_HEXA))); // AKA %a
CHECK(_c4emscripten_alt("0x1.2d54p+20", "0x1.2d538p+20")
== cat_sub(buf, fmt::real(1234234.234234234, 4, FTOA_HEXA))); // AKA %a
CHECK("0x1.2d5p+20" == cat_sub(buf, fmt::real(1234234.234234234, 3, FTOA_HEXA))); // AKA %a
Expand Down
8 changes: 5 additions & 3 deletions src/c4/yml/tree.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -634,9 +634,11 @@ class RYML_EXPORT Tree
/** true when the node has an anchor named a */
C4_ALWAYS_INLINE bool has_anchor(size_t node, csubstr a) const { return _p(node)->m_key.anchor == a || _p(node)->m_val.anchor == a; }

C4_ALWAYS_INLINE bool key_is_null(size_t node) const { RYML_ASSERT(has_key(node)); NodeData const* C4_RESTRICT n = _p(node); return !n->m_type.is_key_quoted() && _is_null(n->m_key.scalar); }
C4_ALWAYS_INLINE bool val_is_null(size_t node) const { RYML_ASSERT(has_val(node)); NodeData const* C4_RESTRICT n = _p(node); return !n->m_type.is_val_quoted() && _is_null(n->m_val.scalar); }
static bool _is_null(csubstr s) noexcept
C4_ALWAYS_INLINE bool key_is_null(size_t node) const { RYML_ASSERT(has_key(node)); NodeData const* C4_RESTRICT n = _p(node); return !n->m_type.is_key_quoted() && scalar_is_null(n->m_key.scalar); }
C4_ALWAYS_INLINE bool val_is_null(size_t node) const { RYML_ASSERT(has_val(node)); NodeData const* C4_RESTRICT n = _p(node); return !n->m_type.is_val_quoted() && scalar_is_null(n->m_val.scalar); }

/** @todo move this function to node_type.hpp */
static bool scalar_is_null(csubstr s) noexcept
{
return s.str == nullptr ||
s == "~" ||
Expand Down

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