default namespace core = "http://www.gtk.org/introspection/core/1.0"
namespace c = "http://www.gtk.org/introspection/c/1.0"
namespace glib = "http://www.gtk.org/introspection/glib/1.0"

grammar {
  start = Repository

  ## Root node of a GIR repository. It contains  namespaces, which can in turn be implemented in several libraries
  Repository =
    element repository {
      ## version number of the repository
      attribute version { xsd:string }?,
      ## prefixes to filter out from C identifiers for data structures and types. For example, GtkWindow will be Window. If c:symbol-prefixes is not used, then this element is used for both
      attribute c:identifier-prefixes { xsd:string }?,
      ## prefixes to filter out from C functions. For example, gtk_window_new will lose gtk_
      attribute c:symbol-prefixes { xsd:string }?,

      # Other elements a repository can contain
      (Include*
       & CInclude*
       & Package*
       & Namespace*)
    }

  ## Namespace which maps metadata entries to C functionality. This a similar concept to namespace in C++, but for GObject-based C libraries
  Namespace =
    element namespace {
      ## name of the namespace. For example, 'Gtk'
      attribute name { xsd:string }?,
      ## version number of the namespace
      attribute version { xsd:string }?,
      ## prefixes to filter out from C identifiers for data structures and types. For example, GtkWindow will be Window. If c:symbol-prefixes is not used, then this element is used for both
      attribute c:identifier-prefixes { xsd:string }?,
      ## prefixes to filter out from C functions. For example, gtk_window_new will lose gtk_
      attribute c:symbol-prefixes { xsd:string }?,
      ## Deprecated: the same as c:identifier-prefixes. Only used for backward compatibility 
      attribute c:prefix { xsd:string }?,
      ## Path to the shared library implementing the namespace. It can be a comma-separated list, with relative path only
      attribute shared-library { xsd:string }?,

      # Other elements a namespace can contain
      (Alias*
       & Class*
       & Interface*
       & Record*
       & Enum*
       & Function*
       & Union*
       & BitField*
       & Callback*
       & Constant*
       & Annotation*
       & Boxed*)
    }

  Annotation =
    ## element defining an annotation from the source code, usually a user-defined annotation associated to a parameter or a return value
    element attribute {
      ## name of the attribute
      attribute name { xsd:string },
      ## value of the attribute
      attribute value { xsd:string }
    }

  CInclude =
    ## Dependant C header file which should be included in C programs
    element c:include {
      ## File name of the C header file. The path can be relative.
      attribute name { xsd:string },

      empty
    }

  Include =
    ## Dependant namespace to include with the current namespace. For example, Gtk will need the namespace GLib
    element include {
      ## name of the dependant namespace to include
      attribute name { xsd:string },
      ## version of the dependant namespace to use
      attribute version { xsd:string }?,

      empty
    }

  Package =
    ## Deprecated: package name containing the library
    element package {
      ## name of the package
      attribute name { xsd:string },

      empty
    }

  Alias =
    ## Type's name substitution, representing a typedef in C
    element alias {
      # Attributes of an Alias (see definition below)
      Info.attrs,
      ## the new name or typedef'd name
      attribute name { xsd:string },
      ## the corresponding C type's name
      attribute c:type { xsd:string },

      # Other elements an alias can contain
      (Info.elements
       & Type)
    }

  Interface =
    ## Abstract interface to other classes
    element interface {
      # Attributes of an Interface (see definition below)
      Info.attrs,
      ## name of the interface
      attribute name { xsd:string },
      ## Type name compatible with the GObject type system
      attribute glib:type-name { xsd:string },
      ## Function to get the GObject compatible type of the interface 
      attribute glib:get-type { xsd:string },
      ## prefix to filter out from C functions. For example, gtk_window_new will lose gtk_
      attribute c:symbol-prefix { xsd:string }?,
      ## Corresponding C type
      attribute c:type { xsd:string }?,
      ## GObject compatible C structure defining the Interface
      attribute glib:type-struct { xsd:string }?,

      # Other elements an interface can contain
      (Info.elements
       & Prerequisite*
       & Implements*
       & Function*
       & Constructor?
       & Method*
       & VirtualMethod*
       & Field*
       & Property*
       & Signal*
       & Callback*
       & Constant*)
    }

  Class =
    ## GObject inherited class definition
    element class {
      Info.attrs,
      
      ## Name of the class
      attribute name { xsd:string },
      ## GObject compatible type name of the class
      attribute glib:type-name { xsd:string },
      ## Function to get the GObject compatible type of the class
      attribute glib:get-type { xsd:string },
      ## Name of the parent class if any
      attribute parent { xsd:string }?,
      ## GObject compatible C structure defining the class
      attribute glib:type-struct { xsd:string }?,
      ## GObject compatible function to reference or increase the reference count of the class
      attribute glib:ref-func { xsd:string }?,
      ## GObject compatible function to unreference or decrease the reference count of the class
      attribute glib:unref-func { xsd:string }?,
      ## GObject compatible function to set a value of a property of the class
      attribute glib:set-value-func { xsd:string }?,
      ## GObject compatible function to get a value of a property of the class
      attribute glib:get-value-func { xsd:string }?,
      ## C type of the class
      attribute c:type { xsd:string }?,
      ## prefix to filter out from C functions. For example, gtk_window_new will lose gtk_
      attribute c:symbol-prefix { xsd:string }?,
      ## Binary attribute to declare the class abstract or not
      attribute abstract { "0" | "1" }?,
      ## Binary attribute to declare the class fundamental or not (top-level class which do not derives from any other type)
      attribute glib:fundamental { "0" | "1" }?,

      # Other elements a class can contain
      (Info.elements
       & Implements*
       & Constructor*
       & Method*
       & Function*
       & VirtualMethod*
       & Field*
       & Property*
       & Signal*
       & Union*
       & Constant*
       & Record*
       & Callback*)
    }

  Boxed =
    ## Boxed type (wrapper to opaque C structures registered by the type system)
    element glib:boxed {
      Info.attrs,
      ## GObject compatible type name of the boxed type
      attribute glib:name { xsd:string },
      ## prefix to filter out from C functions. For example, gtk_window_new will lose gtk_
      attribute c:symbol-prefix { xsd:string }?,
      ## GObject compatible type name of the boxed type
      attribute glib:type-name { xsd:string }?,
      ## Function to get the GObject compatible type of the boxed type
      attribute glib:get-type { xsd:string }?,

      # Other elements a Boxed type can contain
      (Info.elements
       & Function*)
    }

  Record =
    ## Record definition, equivalent to a C struct, that is a simple structure, not a class
    element record {
      Info.attrs,
      ## name of the record
      attribute name { xsd:string },
      ## Corresponding C type of the record
      attribute c:type { xsd:string }?,
      ## Binary attribute to tell if the record is disguised, i.e. whether the c:type is a typedef that doesn't look like a pointer, but is one internally
	  ## Its second meaning is "private" and is set when any typedef struct is parsed which doesn't also include a full struct with fields (https://gitlab.gnome.org/GNOME/gobject-introspection/issues/101)
      attribute disguised { "0" | "1" }?,
      ## GObject compatible C type of the record
      attribute glib:type-name { xsd:string }?,
      ## Function to get the GObject compatible type of the record
      attribute glib:get-type { xsd:string }?,
      ## prefix to filter out from C functions. For example, gtk_window_new will lose gtk_
      attribute c:symbol-prefix { xsd:string }?,
      ## Binary attribute to tell if the record is foreign, that is it is not available in a g-i supported library
      attribute foreign { "0" | "1" }?,
      ## Name of the GObject compatible gtype this record represents. If empty, this record will be hidden from generated public APIs.
      attribute glib:is-gtype-struct-for { xsd:string }?,

      # Other elements a record can contain
        # mandatory 
      (Info.elements
       & Field*
       & Function*
       & Union*
       & Method*
       & Constructor*
       & Property*)
    }

  # Some base information for most elements like version, deprecation, stability, if they are introspectable or not, etc...
  Info.attrs = (
    ## Binary attribute which is "0" (false) if the element is not introspectable. It doesn't exist in the bindings, due in general to missing information in the annotations in the original C code
    attribute introspectable { "0" | "1" }?,
    ## Binary attribute which is "1" (true) if the element has been deprecated
    attribute deprecated { xsd:string }?,
    ## Version number from which this element is deprecated
    attribute deprecated-version { xsd:string }?,
    ## version number of an element
    attribute version { xsd:string }?,
    ## give the statibility status of the element. Can take the values "Stable", "Unstable" or "Private"
    attribute stability { xsd:string }?
  )

  # Documentation of elements
  DocElements = (
    ## Version of the documentation
    element doc-version {
      ## Preserve the original formatting of the documentation from the source code
      attribute xml:space { "preserve" }?,
      ## Preserve the original formatting of the documentation from the source code. Recommended to use this instead of xml:space
      attribute xml:whitespace { "preserve" }?,
      ## the text of the version of the documentation
      text
    }? &
    ## give the stability of the documentation
    element doc-stability {
      ## Preserve the original formatting of the documentation from the source code
      attribute xml:space { "preserve" }?,
      ## Preserve the original formatting of the documentation from the source code. Recommended to use this instead of xml:space
      attribute xml:whitespace { "preserve" }?,
      ## a text value about the stability of the documentation. Usually a simple description like stable or unstable
      text
    }? &
    ## documentation of an element
    element doc {
      ## Preserve the original formatting of the documentation from the source code
      attribute xml:space { "preserve" }?,
      ## Keep the whitespace as they were in the source code
      attribute xml:whitespace { "preserve" }?,
      ## The file containing this documentation
      attribute filename { xsd:string },
      ## The first line of the documentation in the source code
      attribute line { xsd:string },
      ## The first column of the documentation in the source code
      attribute column { xsd:string },
      ## the text of the documentation
      text
    }? &
    ## Deprecated documentation of an element. Kept for historical reasons in general
    element doc-deprecated {
      ## Preserve the original formatting of the documentation from the source code
      attribute xml:space { "preserve" }?,
      ## Keep the whitespace as they were in the source code
      attribute xml:whitespace { "preserve" }?,
      ## the text of the deprecated documentation
      text
    }? &
    ## Position of the documentation in the original source code
    element source-position {
      ## File name of the source of the documentation
      attribute filename { xsd:string },
      ## The first line of the documentation in the source code
      attribute line { xsd:string },
      ## The first column of the documentation in the source code
      attribute column { xsd:string }
    }?
  )

  # Information about elements can be a documentation of annotations
  Info.elements = (
    DocElements
    & Annotation*
  )

  Constant =
    ## A constant entity, similar to const variable in C
    element constant {
        Info.attrs,
        ## name of the constant
        attribute name { xsd:string },
        ## value of the constant
        attribute value { xsd:string },
        ## corresponding C type of the constant in C
        attribute c:type { xsd:string }?,
        ## corresponding C identifier in the source code
        attribute c:identifier { xsd:string }?,

        # Other elements a record can contain
        (Info.elements
         & AnyType?)
    }

  Property =
    ## Property, that is a variable or members with getter and setter functions
    element property {
      Info.attrs,
      ## name of the property
      attribute name { xsd:string },
      ## Binary attribute, true if the property is writeable, that is it has a setter function
      attribute writable { "0" | "1" }?,
      ## Binary attribute, true if the property is readable, that is it has a getter function
      attribute readable { "0" | "1" }?,
      ## Binary attribute, true if the property will be set upon construction
      attribute construct { "0" | "1" }?,
      ## Binary attribute, true if the property can only be set upon construction
      attribute construct-only { "0" | "1" }?,
      # Define the transfer of ownership of the property element
      TransferOwnership?,

      # Other elements a property can contain
      (Info.elements
       & AnyType)
    }

  Signal =
    ## A signal as defined in the GObject system (https://developer.gnome.org/gobject/stable/signal.html)
    element glib:signal {
      Info.attrs,
      ## name of the signal
      attribute name { xsd:string },
      ## Binary attribute, true if the signal has a detailed parameter (https://developer.gnome.org/gobject/stable/signal.html#signal-detail# and https://developer.gnome.org/gobject/unstable/gobject-Signals.html#GSignalFlags)
      attribute detailed { "0" | "1" }?,
      ## When to run the signal during the 5 steps of signal emission (https://developer.gnome.org/gobject/stable/signal.html#signal-emission and https://developer.gnome.org/gobject/unstable/gobject-Signals.html#GSignalFlags)
      attribute when { "first" | "last" | "cleanup" }?,
      ## Binary attribute, true if the signal can be freely emitted on alive objects from user code (https://developer.gnome.org/gobject/unstable/gobject-Signals.html#GSignalFlags)
      attribute action { "0" | "1" }?,
      ## Binary attribute, true if no emission hooks are supported for this signal (https://developer.gnome.org/gobject/unstable/gobject-Signals.html#GSignalFlags) 
      attribute no-hooks { "0" | "1" }?,
      ## Binary attribute, true if signals emitted for an object while currently being in emission for this very object will not be emitted recursively, but instead cause the first emission to be restarted (https://developer.gnome.org/gobject/unstable/gobject-Signals.html#GSignalFlags)
      attribute no-recurse { "0" | "1" }?,

      # Other elements a property can contain
      (Info.elements
       & Callable.params?
       & Callable.return?)
    }

  Field =
    ## A field of struct of union structure, that is a C bit field, that is a fixed length in bits variable
    element field {
      Info.attrs,
      ## name of the field
      attribute name { xsd:string },
      ## Binary attribute, true if the field is writeable
      attribute writable { "0" | "1" }?,
      ## Binary attribute, true if the field is readable
      attribute readable { "0" | "1" }?,
      ## Binary attribute, true if the field is private to the structure or has public ("0") visibility
      attribute private { "0" | "1" }?,
      ## number of bits of the field
      attribute bits { xsd:integer }?,

      # Other elements a property can contain
      (Info.elements
       & (Callback | AnyType))
    }

  Callback =
    ## A callback closure, that is a function called when a signal is emitted (as an answer to that signal)
    element callback {
      Info.attrs,
      ## name of the callback
      attribute name { xsd:string },
      ## the C type returned by the callback closure (i.e. function)
      attribute c:type { xsd:string }?,
      ## Binary attribute, true if the callback can throw an error
      attribute throws { "0" | "1" }?,

      # Other elements a property can contain
      (Info.elements
       & Callable.params?
       & Callable.return?)
    }

  Implements  =
    ## Give the name of the interface it implements. This element is generally used within a class element
    element implements {
      ## name of the interface implemented by a class
      attribute name { xsd:string }
    }

  Prerequisite  =
    ## Interface which is pre-required to implement another interface. This node is generally using within an interface element
    element prerequisite {
      ## name of the required interface
      attribute name { xsd:string }
    }

  # A generic grammar element to represent either a simple Type or an Array of the same Type
  AnyType = (Type | ArrayType)

  Type =
    # A simple type of data (as opposed to an array)
    element type {
      ## name of the type
      attribute name { xsd:string }?,
      ## the C representation of the type
      attribute c:type { xsd:string }?,
      ## Binary attribute which is "0" (false) if the element is not introspectable. It doesn't exist in the bindings, due in general to missing information in the annotations in the original C code
      attribute introspectable { "0" | "1" }?,

      (DocElements & AnyType*)
    }

  ArrayType =
    ## An array type of data where each element is of the same type
    element array {
      ## name of the array type
      attribute name { xsd:string }?,
      ## Binary attribute, true if the last element of the array is zero. For example, in an array of pointers, the last pointer would be NULL
      attribute zero-terminated { "0" | "1" }?,
      ## size of an array of predetermined fixed size. For example a C array declared as char arr[5].
      attribute fixed-size { xsd:integer }?,
      ## Binary attribute which is "0" (false) if the element is not introspectable. It doesn't exist in the bindings, due in general to missing information in the annotations in the original C code
      attribute introspectable { "0" | "1" }?,
	  ## 0-based index of parameter element that specifies the length of the array
      attribute length { xsd:integer }?,
      ## the C representation of the array type
      attribute c:type { xsd:string }?,

      # Type of the values contained in the array
      AnyType
    }

  TransferOwnership =
    ## attributes used by many elements for the transfer of ownership, with for example, a returned value. "none" if the recipient does not own the value, "container" if the recipient owns the container but not the value (for arrays or lists for example) , "full" the recipient owns the entire value. For details, see https://wiki.gnome.org/Projects/GObjectIntrospection/Annotations#Memory_and_lifecycle_management
    attribute transfer-ownership { "none" | "container" | "full" }

  Constructor =
    ## A constructor of a class
    element constructor {
      Callable.attrs,

      (Info.elements
       & Callable.params?
       & Callable.return?)
    }

  ## Attributes of a Callable (functions, callbacks, closures, etc...)
  Callable.attrs = (
    Info.attrs,
    ## name of the Callable
    attribute name { xsd:string },
    # C identifier in the source code of the Callable
    attribute c:identifier { xsd:string }?,
    ## Callable it is shadowed by. For example, in C++, only one version of an overloaded callable will appear
    attribute shadowed-by { xsd:string }?,
    ## Callable it shadows. For example, in C++, only one version of an overloaded callable will appear
    attribute shadows { xsd:string }?,
    ## Binary attribute, true if the callable can throw an error
    attribute throws { "0" | "1" }?,
    ## if for backward compatibility reason the callable has a name in the source code but should be known by another one, this attribute contains the new name    
    attribute moved-to { xsd:string }?
  )

  VarArgs =
    ## an element, usually found in a parameter element for variadic parameter in a function or callable
    element varargs {
      empty
    }

  # Refer to https://wiki.gnome.org/Projects/GObjectIntrospection/Annotations#Support_for_GObject_closures 
  Callable.params =
    ## parameters element of a callable, that is in general parameters of a function or similar
    element parameters {
      ## parameter element of a list of parameters
      element parameter {
        ## name of the parameter
        attribute name { xsd:string }?,
        ## Binary attribute, true if the parameter can have a null value
        attribute nullable { "0" | "1" }?,
        ## Deprecated. Replaced by nullable and optional
        attribute allow-none { "0" | "1" }?,
      ## Binary attribute which is "0" (false) if the element is not introspectable. It doesn't exist in the bindings, due in general to missing information in the annotations in the original C code
        attribute introspectable { "0" | "1" }?,
        ## the parameter is a user_data for callbacks. The value points to a different parameter that is the actual callback
        attribute closure { xsd:integer }?,
        ## the parameter is a destroy_data for callbacks. The value points to a different parameter that is the actual callback
        attribute destroy { xsd:integer }?,
        ## the parameter is a callback, the value indicates the lifetime of the call. For language bindings which want to know when the resources required to do the call can be freed. "notified" valid until a GDestroyNotify argument is called, "async" only valid for the duration of the first callback invocationi (can only be called once), "call" only valid for the duration of the call, can be called multiple times during the call. 
        attribute scope { "notified" | "async" | "call" }?,
        ## direction of the parameter. "in" goes into the callable, "out" for output parameters from the callable (reference in C++, var in Pascal, etc...), "inout" for both (like a pre-allocated structure which will be filled-in by the callable)
        attribute direction { "out" | "in" | "inout" }?,
        ## Binary attribute, true if the caller should allocate the parameter before calling the callable
        attribute caller-allocates { "0" | "1" }?,
        ## Binary attribute, true if the parameter is optional
        attribute optional { "0" | "1" }?,
        ##  Binary attribute, true if the parameter can be omitted from the introspected output
        attribute skip { "0" | "1" }?,
        TransferOwnership?,

        (DocElements
         & (AnyType | VarArgs))
      }* &

      ## instance-parameter is a parameter of a C function which is an instance of an existing object. So the callable is surely a method of a class, and this parameter points to the instance of the object. In C++, this would be equivalent to the pointer this which is not passed to the method, in Python it's equivalent to self.
      element instance-parameter {
        ## name of the instance-parameter
        attribute name { xsd:string },
        ## Binary attribute, true if the parameter can have a null value
        attribute nullable { "0" | "1" }?,
        ## Deprecated. Replaced by nullable and optional
        attribute allow-none { "0" | "1" }?,
        ## direction of the parameter. "in" goes into the callable, "out" for output parameters from the callable (reference in C++, var in Pascal, etc...), "inout" for both (like a pre-allocated structure which will be filled-in by the callable)
        attribute direction { "out" | "in" | "inout" }?,
        ## Binary attribute, true if the caller should allocate the parameter before calling the callable
        attribute caller-allocates { "0" | "1" }?,
        TransferOwnership?,

        (DocElements
         & Type)
      }?
    }

  Callable.return =
    ## return value of a callable
    element return-value {
      ## Binary attribute which is "0" (false) if the element is not introspectable. It doesn't exist in the bindings, due in general to missing information in the annotations in the original C code
      attribute introspectable { "0" | "1" }?,
      ## Binary attribute, true if the parameter can have a null value
      attribute nullable { "0" | "1" }?,
      ## the parameter is a user_data for callbacks. The value points to a different parameter that is the actual callback
      attribute closure { xsd:integer }?,
      ## the parameter is a callback, the value indicates the lifetime of the call. For language bindings which want to know when the resources required to do the call can be freed. "notified" valid until a GDestroyNotify argument is called, "async" only valid for the duration of the first callback invocationi (can only be called once), "call" only valid for the duration of the call, can be called multiple times during the call. 
      attribute scope { "notified" | "async" | "call" }?,
      ## the parameter is a destroy_data for callbacks. The value points to a different parameter that is the actual callback
      attribute destroy { xsd:integer }?,
      ##  Binary attribute, true if the parameter can be omitted from the introspected output
      attribute skip { "0" | "1" }?,
      ## Deprecated. Replaced by nullable and optional
      attribute allow-none { "0" | "1" }?,
      TransferOwnership?,

      (DocElements
       & AnyType)
    }

  Function =
    ## element defining a standalone function (as usual in most programming languages)
    element function {
      Callable.attrs,

      (Callable.params?
       & Callable.return?
       & DocElements)
    }

  Method =
    ## element defining a method from a class
    element method {
      Callable.attrs,

      (Info.elements
       & Callable.params?
       & Callable.return?)
    }

  VirtualMethod =
    ## element defining a virtual method from a class, concept similar to C++
    element virtual-method {
      Callable.attrs,
      ## name of the callable called when invoking this virtual method
      attribute invoker { xsd:string }?,

      (Info.elements
       & Callable.params?
       & Callable.return?)
    }

  Union =
    ## element defining a type of data being a union of type, similar to union in C/C++ but extended with fields and methods
    element union {
      Info.attrs,
      ## name of the union
      attribute name { xsd:string }?,
      ## C type defining the union
      attribute c:type { xsd:string }?,
      ## prefix to filter out from C functions. For example, gtk_window_new will lose gtk_
      attribute c:symbol-prefix { xsd:string }?,
      ## GObject compatible type name
      attribute glib:type-name { xsd:string }?,
      ## function to retrieve the GObject compatible type of the element
      attribute glib:get-type { xsd:string }?,

      (Info.elements
       & Field*
       & Constructor*
       & Method*
       & Function*
       & Record*)
    }

  BitField =
    ## element defining a bit field (as in C)
    element bitfield {
      Info.attrs,
      ## name of the bit field
      attribute name { xsd:string },
      ## corresponding C type of the bit field type
      attribute c:type { xsd:string },
      ## GObject compatible type name
      attribute glib:type-name { xsd:string }?,
      ## function to retrieve the GObject compatible type of the element
      attribute glib:get-type { xsd:string }?,

      (Info.elements
       & Member*
       & Function*)
    }

  Enum =
    ## element defining a enumeration type similar to enum in C/C++
    element enumeration {
      Info.attrs,
      ## name of the enumeration
      attribute name { xsd:string },
      ## corresponding C type of the enumeration type
      attribute c:type { xsd:string },
      ## GObject compatible type name
      attribute glib:type-name { xsd:string }?,
      ## function to retrieve the GObject compatible type of the element
      attribute glib:get-type { xsd:string }?,
      ## Error domain of this enumeration in a stringified form
      attribute glib:error-domain { xsd:string }?,

      (Info.elements
       & Member*
       & Function*)
    }

  Member =
    ## element defining a member of a bit field or an enumeration
    element member {
      Info.attrs,
      ## name of the member
      attribute name { xsd:string },
      ## value of the member
      attribute value { xsd:string },
      ## corresponding C type of the member
      attribute c:identifier { xsd:string },
      ## short nickname of the member (from GEnumValue/GFlagsValue)
      attribute glib:nick { xsd:string }?,
      ## name of the member (from GEnumValue/GFlagsValue)
      attribute glib:name { xsd:string }?,

      Info.elements
    }
}