lsst::afw::table::SubSchema Class Reference

A proxy type for name lookups in a Schema. More...

#include <Schema.h>

Public Member Functions
std::string	join (std::string const &a, std::string const &b) const
	Join strings using the field delimiter appropriate for this Schema. More...
std::string	join (std::string const &a, std::string const &b, std::string const &c) const
std::string	join (std::string const &a, std::string const &b, std::string const &c, std::string const &d) const
template<typename T >
SchemaItem< T >	find (std::string const &name) const
	Find a nested SchemaItem by name. More...
template<typename F >
void	findAndApply (std::string const &name, F &&func) const
	Find a nested SchemaItem by name and run a functor on it. More...
template<typename F >
void	apply (F &&func) const
	Run functor on the SchemaItem represented by this SubSchema. More...
SubSchema	operator[] (std::string const &name) const
	Return a nested proxy. More...
std::string const &	getPrefix () const
	Return the prefix that defines this SubSchema relative to its parent Schema. More...
std::set< std::string >	getNames (bool topOnly=false) const
	Return a set of nested names that start with the SubSchema's prefix. More...
template<typename T >
	operator Key< T > () const
	Implicit conversion to the appropriate Key type. More...
template<typename T >
	operator Field< T > () const
	Implicit conversion to the appropriate Key type. More...

Friends
class	Schema

Detailed Description

A proxy type for name lookups in a Schema.

Elements of schema names are assumed to be separated by underscores ("a_b_c"); an incomplete lookup is one that does not resolve to a field. Not that even complete lookups can have nested names; a Point field, for instance, has "x" and "y" nested names.

This proxy object is implicitly convertible to both the appropriate Key type and the appropriate Field type, if the name is a complete one, and supports additional find() operations for nested names.

SubSchema is implemented as a proxy that essentially calls Schema::find after concatenating strings. It does not provide any performance advantage over using Schema::find directly. It is also lazy, so looking up a name prefix that does not exist within the schema is not considered an error until the proxy is used.

Some examples:

Schema schema(false);
Key<int> a_i = schema.addField<int>("a_i", "integer field");
Key< Point<double> > a_p = schema.addField< Point<double> >("a_p", "point field");

assert(schema["a_i"] == a_i);
SubSchema a = schema["a"];
assert(a["i"] == a_i);
Field<int> f_a_i = schema["a_i"];
assert(f_a_i.getDoc() == "integer field");
assert(schema["a_i"] == "a_i");
assert(schema.find("a_p_x") == a_p.getX());

Definition at line 367 of file Schema.h.

Member Function Documentation

apply()

template<typename F >

void lsst::afw::table::SubSchema::apply ( F &&  func ) const

inline

Run functor on the SchemaItem represented by this SubSchema.

The given functor must have an overloaded function call operator that accepts any SchemaItem type (the same as a functor provided to apply or Schema::forEach).

Exceptions

Throws

pex::exceptions::NotFoundError if the SubSchemas prefix does not correspond to the full name of a regular field (not a named subfield).

Definition at line 412 of file Schema.h.

                               {
        _impl->findAndApply(_aliases->apply(_name), std::forward<F>(func));
    }

find()

template<typename T >

SchemaItem< T > lsst::afw::table::SubSchema::find

(

std::string const &

name

)

const

Find a nested SchemaItem by name.

Definition at line 584 of file Schema.cc.

                                                         {
    return _impl->find<T>(_aliases->apply(join(_name, name)));
}

findAndApply()

template<typename F >

void lsst::afw::table::SubSchema::findAndApply ( std::string const &  name, F &&  func  ) const

inline

Find a nested SchemaItem by name and run a functor on it.

Names corresponding to named subfields are not accepted. The given functor must have an overloaded function call operator that accepts any SchemaItem type (the same as a functor provided to apply or Schema::forEach).

Definition at line 396 of file Schema.h.

                                                             {
        _impl->findAndApply(_aliases->apply(join(_name, name)), std::forward<F>(func));
    }

getNames()

std::set< std::string > lsst::afw::table::SubSchema::getNames

(

bool

topOnly = false

)

const

Return a set of nested names that start with the SubSchema's prefix.

Returns an instance of Python's builtin set in Python.

See also

Schema::getNames

Definition at line 592 of file Schema.cc.

{ return _impl->getNames(topOnly, _name); }

getPrefix()

std::string const& lsst::afw::table::SubSchema::getPrefix ( ) const

inline

Return the prefix that defines this SubSchema relative to its parent Schema.

Definition at line 420 of file Schema.h.

{ return _name; }

join() [1/3]

std::string lsst::afw::table::SubSchema::join	(	std::string const &	a,
		std::string const &	b
	)		const

Join strings using the field delimiter appropriate for this Schema.

Definition at line 575 of file Schema.cc.

                                                                      {
    // delegate to utility funcs at top of this file
    return afw::table::join(a, b, getDelimiter());
}

join() [2/3]

std::string lsst::afw::table::SubSchema::join ( std::string const &  a, std::string const &  b, std::string const &  c  ) const

inline

Definition at line 374 of file Schema.h.

                                                                                     {
        return join(join(a, b), c);
    }

join() [3/3]

std::string lsst::afw::table::SubSchema::join ( std::string const &  a, std::string const &  b, std::string const &  c, std::string const &  d  ) const

inline

Definition at line 377 of file Schema.h.

                                               {
        return join(join(a, b), join(c, d));
    }

operator Field< T >()

template<typename T >

lsst::afw::table::SubSchema::operator Field< T > ( ) const

inline

Implicit conversion to the appropriate Key type.

Implicit conversion operators that are invoked via assignment cannot be translated to Python. Instead, the Python wrappers provide an equivalent asField() method.

Definition at line 450 of file Schema.h.

                              {
        return _impl->find<T>(_aliases->apply(_name)).field;
    }

operator Key< T >()

template<typename T >

lsst::afw::table::SubSchema::operator Key< T > ( ) const

inline

Implicit conversion to the appropriate Key type.

Implicit conversion operators that are invoked via assignment cannot be translated to Python. Instead, the Python wrappers provide an equivalent asKey() method.

Definition at line 438 of file Schema.h.

                            {
        return _impl->find<T>(_aliases->apply(_name)).key;
    }

operator[]()

SubSchema lsst::afw::table::SubSchema::operator[]

(

std::string const &

name

)

const

Return a nested proxy.

Definition at line 588 of file Schema.cc.

                                                           {
    return SubSchema(_impl, _aliases, join(_name, name));
}

Friends And Related Function Documentation

Schema

friend class Schema

friend

Definition at line 455 of file Schema.h.

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The documentation for this class was generated from the following files:

• /j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/afw/22.0.1-42-gca6935d93+ba5e5ca3eb/include/lsst/afw/table/Schema.h
• /j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/afw/22.0.1-42-gca6935d93+ba5e5ca3eb/src/table/Schema.cc