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Diffstat (limited to 'lv2/ns/ext/atom/atom.ttl')
| -rw-r--r-- | lv2/ns/ext/atom/atom.ttl | 455 |
1 files changed, 241 insertions, 214 deletions
diff --git a/lv2/ns/ext/atom/atom.ttl b/lv2/ns/ext/atom/atom.ttl index c28b610..7d534d0 100644 --- a/lv2/ns/ext/atom/atom.ttl +++ b/lv2/ns/ext/atom/atom.ttl @@ -27,10 +27,11 @@ doap:name "LV2 Atom" ; doap:shortdesc "A generic value container and several data types." ; doap:license <http://opensource.org/licenses/isc> ; - rdfs:seeAlso <atom-buffer.h> ; + rdfs:seeAlso <atom-helpers.h> , + <forge.h> ; doap:release [ - doap:revision "0.3" ; - doap:created "2012-01-28" + doap:revision "0.4" ; + doap:created "2012-02-07" ] ; doap:maintainer [ a foaf:Person ; @@ -39,68 +40,118 @@ rdfs:seeAlso <http://drobilla.net/drobilla.rdf> ] ; lv2:documentation """ -<p>This extension defines a generic format for a typed piece of data, called an -lv2:Atom (e.g. integers, strings, buffers, data structures, -etc). Atoms allow LV2 plugins and hosts to communicate, process, serialise, -and store values of any type via a generic mechanism (e.g. LV2 ports, events, -disk, shared memory, network). Atoms are, with one exception, Plain -Old Data (POD) and may be safely copied (e.g. with a simple call to -<code>memcpy</code>).</p> +<p>This extension defines a generic container for data, called an <q>Atom</q>, +and several basic Atom types which can be used to express structured data. +Atoms allow LV2 plugins and hosts to communicate, process, serialise, and store +values of any type via a generic mechanism (e.g. ports, files, networks, +ringbuffers, etc.). Atoms are, with one exception, Plain Old Data (POD) which +may safely be copied (e.g. with a simple call to <code>memcpy</code>).</p> <p>Since Atom communication can be implemented generically, plugins that understand some type can be used together in a host that does not understand that type, and plugins (e.g. routers, delays) can process atoms of unknown type.</p> -<p>An Atom can be trivially constructed in-place from an -<a href="http://lv2plug.in/ns/ext/event#Event">Event</a> as defined by the -<a href="http://lv2plug.in/ns/ext/event">LV2 Event</a> extension. In other -words, an Event is simply an Atom with a time stamp header. Atoms SHOULD -be used anywhere a "value" needs to be stored or communicated, to allow -implementations to be polymorphic and extensible.</p> +<p>Atoms can and should be used anywhere values of various types must be stored +or transmitted. This extension defines port types, atom:ValuePort and +atom:MessagePort, which are connected to an Atom. The atom:Sequence type in +conjunction with atom:MessagePort is intended to replace the <a +href="http://lv2plug.in/ns/ext/event">LV2 event</a> extension.</p> -<p>Atoms (the start of the LV2_Atom header) MUST be 32-bit aligned.</p> - -<p>Atoms can be communicated in many ways. Since an Atom is the payload of an -Event, an <a href="http://lv2plug.in/ns/ext/event#EventPort">EventPort</a> can -be used for communicating Atoms in realtime with sub-sample time stamp -accuracy. This extension also defines two port types for connecting directly -to a single Atom: atom:ValuePort and atom:MessagePort, which both have the same -buffer format but different semantics (with respect to how the run() callback -interprets the Atom).</p> +<p>The types defined in this extension should be powerful enough to express +almost any structure. Implementers SHOULD build structures out of the types +provided here, rather than define new binary formats (e.g. use atom:Object +rather than a new C <code>struct</code> type). New binary formats are an +implementation burden which harms interoperabilty, and should only be defined +where absolutely necessary.</p> <p>Implementing this extension requires a facility for mapping URIs to integers, such as the <a href="http://lv2plug.in/ns/ext/urid">LV2 URID</a> extension.</p> """ . +atom:cType + a rdf:Property , + owl:DatatypeProperty ; + rdfs:label "C type" ; + rdfs:domain rdfs:Class ; + rdfs:range xsd:string ; + rdfs:comment """ +The identifier for a C type describing the in-memory representation of +an instance of this class. +""" . + atom:Atom a rdfs:Class ; rdfs:label "Atom" ; atom:cType "LV2_Atom" ; lv2:documentation """ <p>Abstract base class for all atoms. An LV2_Atom has a 32-bit -<code>type</code> and <code>size</code> followed by a <code>body</code> of -<code>size</code> bytes.</p> +<code>type</code> and <code>size</code> followed by a body of <code>size</code> +bytes. Atoms MUST be 64-bit aligned.</p> <p>All concrete Atom types (subclasses of this class) MUST define a precise -binary layout for <code>body</code>.</p> +binary layout for their body.</p> -<p>The <code>type</code> field is the URI of a subclass of Atom mapped to an -integer using the <a href="http://lv2plug.in/ns/ext/uri-map">URI Map</a> -extension's LV2_URI_Map_Feature::uri_to_id() with -<code>map = "http://lv2plug.in/ns/ext/event"</code>. If a plugin or host -does not understand <code>type</code>, that atom SHOULD be gracefully ignored -(or copied if it does not have type 0).</p> +<p>The <code>type</code> field is the URI of an Atom type mapped to an integer. +Implementations SHOULD gracefully ignore, or pass through, atoms with unknown +types.</p> <p>All atoms are POD by definition except references, which as a special case have <code>type = 0</code>. An Atom MUST NOT contain a Reference. It is safe to copy any non-reference Atom with a simple <code>memcpy</code>, even if the -implementation does not understand <code>type</code>. Though this extension reserves -the type 0 for references, actual specification of how references are used is left -to another extension.</p> +implementation does not understand <code>type</code>. Though this extension +reserves the type 0 for references, the details of reference handling are +currently unspecified. A future revision of this extension, or a different +extension, may define how to use non-POD data and references. Implementations +MUST NOT send references to another implementation unless the receiver is +explicitly known to support references (e.g. by supporting a feature). The +atom with both <code>type</code> <em>and</em> <code>size</code> 0 is +<q>null</q>, which is not considered a Reference.</p> """ . +atom:Bang + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Bang" ; + rdfs:comment "Generic activity or trigger, with no body." . + +atom:Number + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Number" . + +atom:Int32 + a rdfs:Class ; + rdfs:subClassOf atom:Number ; + rdfs:label "Signed 32-bit integer" ; + atom:cType "LV2_Atom_Int32" . + +atom:Int64 + a rdfs:Class ; + rdfs:subClassOf atom:Number ; + rdfs:label "Signed 64-bit integer" ; + atom:cType "LV2_Atom_Int64" . + +atom:Float + a rdfs:Class ; + rdfs:subClassOf atom:Number ; + rdfs:label "32-bit IEEE-754 floating point number" ; + atom:cType "LV2_Atom_Float" . + +atom:Double + a rdfs:Class ; + rdfs:subClassOf atom:Number ; + rdfs:label "64-bit IEEE-754 floating point number" ; + atom:cType "LV2_Atom_Double" . + +atom:Bool + a rdfs:Class ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Boolean" ; + atom:cType "LV2_Atom_Bool" ; + rdfs:comment "An Int32 where 0 is false and any other value is true." . + atom:String a rdfs:Class ; rdfs:subClassOf atom:Atom ; @@ -128,7 +179,7 @@ atom:Literal <p>A UTF-8 encoded string literal, with an optional datatype or language.</p> <p>This type is compatible with rdf:Literal and is capable of expressing a -string in any language, or a value of any type. A Literal has a +string in any language or a value of any type. A Literal has a <code>datatype</code> and <code>lang</code> followed by string data in UTF-8 encoding. The length of the string data in bytes is <code>size - sizeof(LV2_Atom_Literal)</code>, including the terminating NULL character. The @@ -143,22 +194,26 @@ both.</p> <p>For example, a Literal can be "Hello" in English:</p> <pre class="c-code"> void set_to_hello_in_english(LV2_Atom_Literal* lit) { - lit->type = map(expand("atom:Literal")); - lit->size = 14; - lit->datatype = 0; - lit->lang = map("http://lexvo.org/id/term/en"); - memcpy(lit->str, "Hello", sizeof("Hello")); // Assumes enough space + lit->atom.type = map(expand("atom:Literal")); + lit->atom.size = 14; + lit->datatype = 0; + lit->lang = map("http://lexvo.org/id/term/en"); + memcpy(LV2_ATOM_CONTENTS(LV2_Atom_Literal, lit), + "Hello", + sizeof("Hello")); // Assumes enough space } </pre> <p>or a Turtle string:</p> <pre class="c-code"> void set_to_turtle_string(LV2_Atom_Literal* lit, const char* ttl) { - lit->type = map(expand("atom:Literal")); - lit->size = 64; - lit->datatype = map("http://www.w3.org/2008/turtle#turtle"); - lit->lang = 0; - memcpy(lit->str, ttl, strlen(ttl) + 1); // Assumes enough space + lit->atom.type = map(expand("atom:Literal")); + lit->atom.size = 64; + lit->datatype = map("http://www.w3.org/2008/turtle#turtle"); + lit->lang = 0; + memcpy(LV2_ATOM_CONTENTS(LV2_Atom_Literal, lit), + ttl, + strlen(ttl) + 1); // Assumes enough space } </pre> """ . @@ -169,21 +224,7 @@ atom:URID rdfs:label "Integer ID mapped from a URI" ; atom:cType "LV2_Atom_ID" ; lv2:documentation """ -<p>An unsigned 32-bit integer mapped from a URI using the <a -href="http://lv2plug.in/ns/ext/uri-map">URI Map</a> extension's -LV2_URI_Map_Feature::uri_to_id() with <code>map = NULL</code>.</p> -""" . - -atom:BlankID - a rdfs:Class ; - rdfs:subClassOf atom:Atom ; - rdfs:label "Integer ID for a blank node" ; - atom:cType "LV2_Atom_ID" ; - lv2:documentation """ -<p>An unsigned 32-bit integer identifier for a blank node. A BlankID is only -meaningful within a limited scope (e.g. the Atom in which it appears), and -MUST NOT be used as a global identifier. In particular, a BlankID is NOT a -URID, and can not be mapped to/from a URI.</p> +<p>An unsigned 32-bit integer mapped from a URI (e.g. with LV2_URID_Map).</p> """ . atom:Vector @@ -192,7 +233,7 @@ atom:Vector rdfs:label "Vector" ; atom:cType "LV2_Atom_Vector" ; lv2:documentation """ -<p>A homogeneous sequence of atoms with equivalent type and size.</p> +<p>A homogeneous series of atom bodies with equivalent type and size.</p> <p>An LV2_Atom_Vector is a 32-bit <code>elem_count</code> and <code>elem_type</code> followed by <code>elem_count</code> atom bodies of type @@ -221,125 +262,84 @@ atom:Tuple rdfs:subClassOf atom:Atom ; rdfs:label "Tuple" ; lv2:documentation """ -<p>A sequence of lv2:Atom with varying <code>type</code> -and <code>size</code>.</p> +<p>A series of Atoms with varying <code>type</code> and <code>size</code>.</p> -<p>The body of a Tuple is simply a sequence of complete atoms, each aligned to -32 bits.</p> +<p>The body of a Tuple is simply a series of complete atoms, each aligned to +64 bits.</p> """ . -atom:Thing +atom:Property a rdfs:Class ; rdfs:subClassOf atom:Atom ; - rdfs:label "Thing" ; - atom:cType "LV2_Thing" ; + rdfs:label "Property" ; + atom:cType "LV2_Atom_Property" ; lv2:documentation """ -<p>Abstract base class for a "Thing", i.e. an atom:Atom with a number of -properties. An LV2_Object is an unsigned 32-bit integer <code>context</code> -and <code>id</code> followed by a sequence of LV2_Atom_Property .</p> - -<p>The <code>context</code> is mapped using the <a -href="http://lv2plug.in/ns/ext/uri-map">URI Map</a> extension's -LV2_URI_Map_Feature::uri_to_id() with <code>map = NULL</code>, and may be 0 -(the default context).</p> - -<p>Note this is an abstract class, i.e. no Atom can exist with <code>type = -uri_to_id(atom:Thing)</code>. An Object is either an atom:Resource or an -atom:Blank, but the <code>body</code> always has the same binary format, -LV2_Object. Thus, both named and anonymous objects can be handled with common -code using only a 64-bit header for both.</p> +<p>A property of an atom:Object. An LV2_Atom_Property has a URID +<code>key</code> and <code>context</code>, and an Atom <code>value</code>. +This corresponds to an RDF Property, where the <q>key</q> is the <q>predicate</q> +and the <q>value</q> is the object.</p> + +<p>The <code>context</code> field can be used to specify a different context +for each property, where this is useful. Otherwise, it may be 0.</p> """ . -atom:Resource +atom:Object a rdfs:Class ; - rdfs:subClassOf atom:Thing ; - atom:cType "LV2_Thing" ; + rdfs:subClassOf atom:Atom ; + rdfs:label "Object" ; + atom:cType "LV2_Atom_Object" ; lv2:documentation """ -<p>An atom:Thing where <code>id</code> is the URI of the resource mapped to an -atom:URID.</p> +<p>An <q>Object</q> is an atom with a set of properties. This corresponds to +an RDF Resource, and can be thought of as a dictionary with URID keys.</p> + +<p>An LV2_Atom_Object has a uint32_t <code>id</code> and uint32_t +<code>type</code>, followed by a series of atom:Property bodies (without +headers, i.e. LV2_Atom_Property_Body). The LV2_Atom_Object::type field is +semantically equivalent to a property with key rdf:type, but is included in the +structure to allow for fast dispatch.</p> + +<p>This is an abstract Atom type, an Object is always either a atom:Resource +or a atom:Blank.</p> """ . -atom:Blank +atom:Resource a rdfs:Class ; - rdfs:subClassOf atom:Thing ; - atom:cType "LV2_Thing" ; + rdfs:subClassOf atom:Object ; + rdfs:label "Resource" ; + atom:cType "LV2_Atom_Object" ; lv2:documentation """ -<p>An atom:Thing where <code>id</code> is the blank node ID of the object, -which is only meaningful within a certain limited scope (e.g. the container of -the Blank) and MUST NOT be used as a global ID. In particular, <code>id</code> -is NOT a URID.</p> +<p>An atom:Object where the <code>id</code> field is a URID, i.e. an Object +with a URI.</p> """ . -atom:Message +atom:Blank a rdfs:Class ; - rdfs:subClassOf atom:Thing ; - atom:cType "LV2_Thing" ; + rdfs:subClassOf atom:Object ; + rdfs:label "Blank" ; + atom:cType "LV2_Atom_Object" ; lv2:documentation """ -<p>A atom:Thing where <code>id</code> is a message type ID. Conceptually, a -Message is identical to a Blank, but is a distinct type with a single type -field to allow simple and fast dispatch by handling code.</p> - -<p>A Message may be serialised as a Blank by adding an rdf:type property with -the value <code>id</code> unmapped to a URI.</p> -""" . +<p>An atom:Object where the LV2_Atom_Object::id is a blank node ID (NOT a URI). +The ID of a Blank is valid only within the context the Blank appears in. For +ports this is the context of the associated run() call, i.e. all ports share +the same context so outputs can contain IDs that correspond to IDs of blanks in +the input.</p> """ . atom:Event a rdfs:Class ; rdfs:label "Event" ; atom:cType "LV2_Atom_Event" ; lv2:documentation """ -<p>An atom with a time stamp header prepended, typically for sample accurate -transmission via LV2 ports. See struct LV2_Atom_Event.</p> +<p>An atom with a time stamp header prepended, typically an element of an +atom:Sequence. Note this is not an Atom type.</p> """ . -atom:Bang - a rdfs:Class ; - rdfs:subClassOf atom:Atom ; - rdfs:label "Bang (activity) (size = 0)" . - -atom:Number +atom:Sequence a rdfs:Class ; rdfs:subClassOf atom:Atom ; - rdfs:label "Number (abstract class)." . - -atom:Int32 - a rdfs:Class ; - rdfs:subClassOf atom:Number ; - rdfs:label "Signed 32-bit integer" ; - atom:cType "LV2_Atom_Int32" . - -atom:Int64 - a rdfs:Class ; - rdfs:subClassOf atom:Number ; - rdfs:label "Signed 64-bit integer" ; - atom:cType "LV2_Atom_Int64" . - -atom:Bool - a rdfs:Class ; - rdfs:subClassOf atom:Atom ; - rdfs:label "An atom:Int32 where 0 is false and all other values true" ; - atom:cType "LV2_Atom_Int32" . - -atom:Float - a rdfs:Class ; - rdfs:subClassOf atom:Number ; - rdfs:label "32-bit IEEE-754 floating point number" ; - atom:cType "LV2_Atom_Float" . - -atom:Double - a rdfs:Class ; - rdfs:subClassOf atom:Number ; - rdfs:label "64-bit IEEE-754 floating point number" ; - atom:cType "LV2_Atom_Double" . - -atom:blobSupport - a lv2:Feature ; - rdfs:label "Blob support" ; + rdfs:label "Sequence" ; + atom:cType "LV2_Atom_Sequence" ; lv2:documentation """ -<p>Support for dynamically allocated blobs. If a host supports this feature, -it MUST pass a LV2_Feature with <code>URI</code> -http://lv2plug.in/ns/ext/atom#blobSupport and <code>data</code> pointing to a -LV2_Blob_Support.</p> +<p>A sequence of atom:Event, i.e. a series of time-stamped Atoms.</p> """ . atom:AtomPort @@ -347,21 +347,20 @@ atom:AtomPort rdfs:subClassOf lv2:Port ; rdfs:label "Atom Port" ; lv2:documentation """ -<p>A port which contains an lv2:Atom. Ports of this type will -be connected to a 32-bit aligned LV2_Atom immediately followed by -<code>size</code> bytes of data.</p> - -<p>This is an abstract port type, i.e. a port MUST NOT only be an AtomPort, -but must be a more descriptive type that is a subclass of AtomPort which -defines the port's semantics (typically atom:ValuePort or atom:MessagePort). -</p> - -<p>Before calling a method on the plugin that writes to an AtomPort output, -the host MUST set the size of the Atom in that output to the amount of -available memory immediately following the Atom header. The plugin MUST -write a valid Atom to that port (leaving it untouched is illegal). If there -is no reasonable value to write to the port, the plugin MUST write NULL -(the Atom with both <code>type = 0</code> and <code>size = 0</code>).</p> +<p>A port which contains an lv2:Atom. Ports of this type will be connected to +a 64-bit aligned LV2_Atom immediately followed by <code>size</code> bytes of +data.</p> + +<p>This is an abstract port type with incomplete semantics which can not be +used directly as a port type. Atom ports should be either a atom:ValuePort or +a atom:MessagePort.</p> + +<p>Before calling a method on a plugin that writes to an AtomPort output, the +host MUST set the size of the Atom in that output to the amount of available +memory immediately following the Atom header. The plugin MUST write a valid +Atom to that port; leaving it untouched is illegal. If there is no reasonable +value to write to the port, the plugin MUST write null (the Atom with both +<code>type</code> and <code>size</code> 0).</p> """ . atom:ValuePort @@ -369,67 +368,95 @@ atom:ValuePort rdfs:subClassOf atom:AtomPort ; rdfs:label "Value Port" ; lv2:documentation """ -<p>An AtomPort that interprets its data as a persistent and time-independent -"value".</p> + +<p>An AtomPort that contains a persistent <em>value</em>. A <q>value</q> is +time-independent and may be used numerous times. A ValuePort is <q>pure</q> in +the sense that it may affect output but MUST NOT affect persistent plugin state +in any externally visible way.</p> + <ul> -<li>If a plugin has fixed input values for all ports, all ValuePort outputs -are also fixed regardless of the number of times the plugin is run.</li> -<li>If a plugin has fixed input values for all ports except a ValuePort, -each value V of that ValuePort corresponds to a single set of outputs -for all ports.</li> -<li>If a ValuePort contains a reference then the blob it refers to is -constant; plugin MUST NOT modify the blob in any way.</li> +<li>If a plugin has fixed values for all inputs, all ValuePort outputs are also +fixed regardless of the number of times the plugin is run.</li> + +<li>If a plugin has fixed input values for all ports except a ValuePort, each +value of that port corresponds to a single set of values for all +ValuePort outputs.</li> + +<li>If the plugin saves state other than port values (e.g. using the <a +href="http://lv2plug.in/ns/ext/state">LV2 State</a> extension), changing only +the value of a ValuePort input MUST NOT change that state. In other words, +value port changes MUST NOT trigger a state change that requires a save.</li> </ul> -<p>Value ports can be thought of as purely functional ports: if a plugin -callback has only value ports, then the plugin callback is a pure function.</p> + +<p>Value ports are essentially purely functional ports: if a plugin has only +value ports, that plugin is purely functional. Hosts may elect to cache output +and avoid calling run() if the output is already known according to these +rules.</p> """ . atom:MessagePort a rdfs:Class ; rdfs:subClassOf atom:AtomPort ; rdfs:label "Message Port" ; - rdfs:comment """ -An AtomPort that "receives", "consumes", "executes", or "sends" its value. -The Atom contained in a MessagePort is considered transient and/or -time-dependent, and is only valid for a single run invocation. Unlike a -ValuePort, a MessagePort may be used to manipulate internal plugin state. - -Intuitively, a MessagePort contains a "message" or "command" or "event" -which is reacted to, NOT a "value" or "signal" (which is computed with). -""" . - -atom:cType - a rdf:Property , - owl:DatatypeProperty ; - rdfs:label "C type" ; - rdfs:domain rdfs:Class ; - rdfs:range xsd:string ; - rdfs:comment """ -The identifier for a C type describing the in-memory representation of -an instance of this class. + lv2:documentation """ +<p>An AtomPort that contains transient data which is <em>consumed</em> or +<em>sent</em>. The Atom contained in a MessagePort is time-dependent and only +valid for a single run invocation. Unlike a ValuePort, a MessagePort may be +used to manipulate internal plugin state.</p> + +<p>Intuitively, a MessagePort contains a <q>message</q> or <q>event</q> which +is reacted to <em>once</em> (not a <q>value</q> which is computed with any +number of times).</p> """ . -atom:EventPort - a rdfs:Class ; - rdfs:label "Event port" ; - rdfs:subClassOf lv2:Port ; +atom:bufferType + a rdf:Property ; + rdfs:domain atom:AtomPort ; + rdfs:label "buffer type" ; lv2:documentation """ -<p>A port used for communicating time-stamped atoms in the audio context. -Ports of this type are connected to an LV2_Atom_Buffer, which contains a flat -time-stamped sequence of atom:Event.</p> +<p>Indicates that an AtomPort may be connected to a certain Atom type. A port +MAY support several buffer types. The host MUST NOT connect a port to an Atom +with a type not explicitly listed with this property. The value of this +property MUST be a sub-class of atom:Atom. For example, an input port that is +connected directly to an LV2_Atom_Double value is described like so:</p> + +<pre class="turtle-code"> +<plugin> + lv2:port [ + a lv2:InputPort , atom:ValuePort ; + atom:bufferType atom:Double ; + ] . +</pre> -<p>This port type is intended as a simpler and atom compatible successor to <a -href="http://lv2plug.in/ns/ext/event#EventPort">ev:EventPort</a>.</p> +<p>Note this property only indicates the atom types a port may be directly +connected to, it is not <q>recursive</q>. If a port can be connected to a +collection, use atom:supports to indicate which element types are understood. +If a port supports heterogeneous collections (collections that can contain +several types of elements at once), implementations MUST gracefully handle any +types that are present in the collection, even if those types are not +explicitly supported.</p> """ . atom:supports a rdf:Property ; - rdfs:domain lv2:Port ; - rdfs:range atom:Atom ; rdfs:label "supports" ; lv2:documentation """ -<p>Indicates that a Port supports a certain atom:Atom type. This is distinct from -the port type - e.g. the port type ValuePort can hold atoms with many different -types. This property is used to describe which Atom types a Port expects to -receive or send.</p> +<p>Indicates that a particular Atom type is supported.</p> + +<p>This property is defined loosely, it may be used to indicate that anything +<q>supports</q> an Atom type, wherever that may be useful. It applies +<q>recursively</q> where collections are involved.</p> + +<p>In particular, this property can be used to describe which event types are +supported by a port. For example, a port that receives MIDI events is +described like so:</p> + +<pre class="turtle-code"> +<plugin> + lv2:port [ + a lv2:InputPort , atom:MessagePort ; + atom:bufferType atom:Sequence ; + atom:supports midi:MidiEvent ; + ] . +</pre> """ . |