URI Template

A strict RFC 6570 URI Template implementation. More...

Classes
class	sourcemeta::core::URITemplate
class	sourcemeta::core::URITemplateParseError
class	sourcemeta::core::URITemplateExpansionError
class	sourcemeta::core::URITemplateRouterVariableMismatchError
class	sourcemeta::core::URITemplateRouterInvalidSegmentError
class	sourcemeta::core::URITemplateRouterInvalidOperationIdError
class	sourcemeta::core::URITemplateRouterDuplicateOperationIdError
class	sourcemeta::core::URITemplateRouterSaveError
class	sourcemeta::core::URITemplateRouterReadError
class	sourcemeta::core::URITemplateRouter
class	sourcemeta::core::URITemplateRouterView
struct	sourcemeta::core::URITemplateTokenLiteral
struct	sourcemeta::core::URITemplateVariableSpecification
struct	sourcemeta::core::URITemplateTokenVariable
struct	sourcemeta::core::URITemplateTokenReservedExpansion
struct	sourcemeta::core::URITemplateTokenFragmentExpansion
struct	sourcemeta::core::URITemplateTokenLabelExpansion
struct	sourcemeta::core::URITemplateTokenPathExpansion
struct	sourcemeta::core::URITemplateTokenPathParameterExpansion
struct	sourcemeta::core::URITemplateTokenQueryExpansion
struct	sourcemeta::core::URITemplateTokenQueryContinuationExpansion

Typedefs
using	sourcemeta::core::URITemplateValue
using	sourcemeta::core::URITemplateParseResult
using	sourcemeta::core::URITemplateToken

Enumerations
enum class	sourcemeta::core::URITemplateExpansionMode : std::uint8_t { URITemplateExpansionMode::URI , URITemplateExpansionMode::IRI }

Detailed Description

A strict RFC 6570 URI Template implementation.

This functionality is included as follows:

#include <sourcemeta/core/uritemplate.h>

---

Class Documentation

sourcemeta::core::URITemplate

class sourcemeta::core::URITemplate

A parsed URI Template per RFC 6570. This class behaves like a view. The source string must outlive the template

Public Member Functions
	URITemplate (const std::string_view source)
auto	size () const noexcept -> std::uint64_t
	Get the number of tokens in the template.
auto	empty () const noexcept -> bool
	Check if the template is empty.
auto	at (std::size_t index) const &-> const URITemplateToken &
	Get the token at the given index.
auto	at (std::size_t index) &&-> URITemplateToken
	Get the token at the given index (move overload).
auto	expand (const std::function< URITemplateValue(std::string_view)> &callback, URITemplateExpansionMode mode=URITemplateExpansionMode::URI) const -> std::string
template<typename Container, typename = std::void_t<typename Container::key_type>>
auto	expand (const Container &variables, const URITemplateExpansionMode mode=URITemplateExpansionMode::URI) const -> std::string
	Expand the template using an associative container (string values only).
Static Public Member Functions
static auto	is_uritemplate (std::string_view input) noexcept -> bool

Constructor & Destructor Documentation

URITemplate()

sourcemeta::core::URITemplate::URITemplate

(

const std::string_view

source

)

Parse a URI Template from a string view. For example:

#include <sourcemeta/core/uritemplate.h>
 
const std::string source{"http://example.com/~{username}/"};
const sourcemeta::core::URITemplate uri_template{source};

Member Function Documentation

expand()

auto sourcemeta::core::URITemplate::expand ( const std::function< URITemplateValue(std::string_view)> & callback, URITemplateExpansionMode mode = URITemplateExpansionMode::URI ) const -> std::string

nodiscard

Expand the template by looking up variable values via a callback. The callback is called repeatedly for composite values

is_uritemplate()

auto sourcemeta::core::URITemplate::is_uritemplate ( std::string_view input ) -> bool

staticnodiscardnoexcept

Check whether the given string is a valid RFC 6570 URI Template without building the parsed representation. For example:

#include <sourcemeta/core/uritemplate.h>
 
#include <cassert>
 
assert(sourcemeta::core::URITemplate::is_uritemplate(
    "http://example.com/~{username}/"));
assert(!sourcemeta::core::URITemplate::is_uritemplate("{var"));

sourcemeta::core::URITemplateParseError

class sourcemeta::core::URITemplateParseError

An error that represents a URI Template parsing failure

Inheritance diagram for sourcemeta::core::URITemplateParseError:

Public Member Functions
	URITemplateParseError (const std::uint64_t column)
	Construct an error given the column number where parsing failed.
auto	column () const noexcept -> std::uint64_t
	Get the column number of the error.

sourcemeta::core::URITemplateExpansionError

class sourcemeta::core::URITemplateExpansionError

An error that represents a URI Template expansion failure

Inheritance diagram for sourcemeta::core::URITemplateExpansionError:

Public Member Functions
	URITemplateExpansionError (const std::string &message)
	Construct an error with a descriptive message.

sourcemeta::core::URITemplateRouterVariableMismatchError

class sourcemeta::core::URITemplateRouterVariableMismatchError

An error that represents a variable name mismatch when adding routes

Inheritance diagram for sourcemeta::core::URITemplateRouterVariableMismatchError:

Public Member Functions
	URITemplateRouterVariableMismatchError (const std::string_view left, const std::string_view right)
	Construct an error given the existing and conflicting variable names.
auto	left () const noexcept -> const std::string &
	Get the existing variable name.
auto	right () const noexcept -> const std::string &
	Get the conflicting variable name.

sourcemeta::core::URITemplateRouterInvalidSegmentError

class sourcemeta::core::URITemplateRouterInvalidSegmentError

An error for invalid segments when adding routes

Inheritance diagram for sourcemeta::core::URITemplateRouterInvalidSegmentError:

Public Member Functions
	URITemplateRouterInvalidSegmentError (const char *message, const std::string_view segment)
	Construct an error given a descriptive message and the offending segment.
auto	segment () const noexcept -> const std::string &
	Get the offending segment.

sourcemeta::core::URITemplateRouterInvalidOperationIdError

class sourcemeta::core::URITemplateRouterInvalidOperationIdError

An error that represents an operation identifier that does not match the permitted format

Inheritance diagram for sourcemeta::core::URITemplateRouterInvalidOperationIdError:

Public Member Functions
	URITemplateRouterInvalidOperationIdError (const std::string_view operation_id)
	Construct an error given the offending operation identifier.
auto	operation_id () const noexcept -> const std::string &
	Get the offending operation identifier.

sourcemeta::core::URITemplateRouterDuplicateOperationIdError

class sourcemeta::core::URITemplateRouterDuplicateOperationIdError

An error that represents an operation identifier that conflicts with a previously registered route

Inheritance diagram for sourcemeta::core::URITemplateRouterDuplicateOperationIdError:

Public Member Functions
	URITemplateRouterDuplicateOperationIdError (const std::string_view operation_id)
	Construct an error given the conflicting operation identifier.
auto	operation_id () const noexcept -> const std::string &
	Get the conflicting operation identifier.

sourcemeta::core::URITemplateRouterSaveError

class sourcemeta::core::URITemplateRouterSaveError

An error that represents a failure to save the router to disk

Inheritance diagram for sourcemeta::core::URITemplateRouterSaveError:

Public Member Functions
	URITemplateRouterSaveError (std::filesystem::path path, const char *message)
	Construct an error given the target path and a descriptive message.
auto	path () const noexcept -> const std::filesystem::path &
	Get the path that could not be saved.

sourcemeta::core::URITemplateRouterReadError

class sourcemeta::core::URITemplateRouterReadError

An error that represents a failure to read the router from disk

Inheritance diagram for sourcemeta::core::URITemplateRouterReadError:

Public Member Functions
	URITemplateRouterReadError (std::filesystem::path path)
	Construct an error given the target path.
auto	path () const noexcept -> const std::filesystem::path &
	Get the path that could not be read.

sourcemeta::core::URITemplateRouter

class sourcemeta::core::URITemplateRouter

A URI Template path router. Keep in mind that the URI Template specification DOES NOT define matching, only expansion. So this is an opinionated non-standard adaptation of URI Template for path routing purposes. The supported operators are:

• {var} for a single path segment (RFC 6570 Level 1 simple expansion)
• {+var} for greedy capture to the end of the path, requiring at least one trailing segment (RFC 6570 Level 2 reserved expansion)
• {/var*} for optional greedy capture to the end of the path, where zero trailing segments are also allowed (RFC 6570 Level 3 path-segment operator with Level 4 explode modifier). Must be the last component of the template. The captured value is empty when no trailing segments are present

Public Types
enum class	NodeType : std::uint8_t {   Root = 0 , Literal = 1 , Variable = 2 , Expansion = 3 ,   OptionalExpansion = 4 }
	The type of a node in the router trie. More...
using	Identifier = std::uint16_t
	A handler identifier 0 means "no handler".
using	Index = std::uint8_t
	The variable index type.
using	Callback
	The match callback (index, name, value).
using	ArgumentValue = std::variant<std::string_view, std::int64_t, bool>
	The value of a route argument.
using	Argument = std::pair<std::string_view, ArgumentValue>
	A named route argument.
using	ArgumentCallback
	The argument callback (name, value).
Public Member Functions
	URITemplateRouter ()=default
	Construct an empty router.
	URITemplateRouter (std::string_view base_path, std::string_view base_url={})
	URITemplateRouter (const URITemplateRouter &)=delete
	URITemplateRouter (URITemplateRouter &&)=delete
auto	add (const std::string_view uri_template, const std::string_view operation_id, const Identifier identifier, const Identifier context=0, const std::span< const Argument > arguments={}) -> void
auto	otherwise (const Identifier context, const std::span< const Argument > arguments={}) -> void
auto	match (const std::string_view path, const Callback &callback) const -> std::pair< Identifier, Identifier >
auto	describes (const std::string_view path, const std::string_view base_path={}) const noexcept -> bool
auto	root () const noexcept -> const Node &
	Access the root node of the trie.
auto	arguments (const Identifier identifier, const ArgumentCallback &callback) const -> void
	Access the stored arguments for a given route identifier.
auto	arguments () const noexcept -> const std::vector< std::pair< Identifier, std::vector< Argument > > > &
	Access all stored route arguments.
auto	base_path () const noexcept -> std::string_view
	Access the base path prefix.
auto	base_url () const noexcept -> std::string_view
	Access the base URL associated with the router.
auto	size () const noexcept -> std::size_t
	Get the number of registered routes.
auto	at (const std::size_t index) const -> Identifier
	Get the identifier of the route at the given positional index.
auto	context (const Identifier identifier) const -> Identifier
auto	path (const Identifier identifier) const -> std::string
auto	operation (const std::string_view operation_id) const -> std::pair< Identifier, Identifier >
auto	operation_id (const Identifier identifier) const -> std::string_view
Friends
class	URITemplateRouterView

Member Typedef Documentation

ArgumentCallback

using sourcemeta::core::URITemplateRouter::ArgumentCallback

Initial value:

 
std::function<void(std::string_view, const ArgumentValue &)>

The argument callback (name, value).

Callback

using sourcemeta::core::URITemplateRouter::Callback

Initial value:

 
std::function<void(Index, std::string_view, std::string_view)>

The match callback (index, name, value).

Member Enumeration Documentation

NodeType

enum class sourcemeta::core::URITemplateRouter::NodeType : std::uint8_t

strong

The type of a node in the router trie.

Enumerator
Root	The root of the trie.
Literal	A fixed literal path segment.
Variable	A single path segment capture.
Expansion	A greedy capture requiring at least one trailing segment.
OptionalExpansion	A greedy capture allowing zero trailing segments.

Constructor & Destructor Documentation

URITemplateRouter()

sourcemeta::core::URITemplateRouter::URITemplateRouter ( std::string_view base_path, std::string_view base_url = {} )

explicit

Construct a router with a base path prefix. During matching, the base path is stripped from incoming request paths before matching. An optional base URL can be associated with the router as opaque metadata, never used for matching

Member Function Documentation

add()

auto sourcemeta::core::URITemplateRouter::add	(	const std::string_view	uri_template,
		const std::string_view	operation_id,
		const Identifier	identifier,
		const Identifier	context = 0,
		const std::span< const Argument >	arguments = {} ) -> void

Add a route to the router. Make sure the string lifetime survives the router. The operation identifier must match the regular expression ^[a-zA-Z][a-zA-Z0-9_-]{0,63}$ and must be unique across all routes registered on this router

context()

auto sourcemeta::core::URITemplateRouter::context ( const Identifier identifier ) const -> Identifier

nodiscard

Get the context identifier associated with a registered route identifier

describes()

auto sourcemeta::core::URITemplateRouter::describes ( const std::string_view path, const std::string_view base_path = {} ) const -> bool

nodiscardnoexcept

Determine whether a path lies within the space described by the explicitly registered routes, as a whole-segment prefix of one or more routes, as an exact route, or as a path captured by a route expansion. The fallback registered through the catch-all is never considered. Like matching, the path is not normalized before evaluation. When a base path is given, it is evaluated as if prepended to the path, avoiding a concatenation at the call site

match()

auto sourcemeta::core::URITemplateRouter::match ( const std::string_view path, const Callback & callback ) const -> std::pair< Identifier, Identifier >

nodiscard

Match a path against the router. Note the callback might fire for initial matches even though the entire match might still fail

operation()

auto sourcemeta::core::URITemplateRouter::operation ( const std::string_view operation_id ) const -> std::pair< Identifier, Identifier >

nodiscard

Resolve an operation identifier to its registered route. Returns (identifier, context) on hit and (0, 0) if no route is registered under the given operation identifier

operation_id()

auto sourcemeta::core::URITemplateRouter::operation_id ( const Identifier identifier ) const -> std::string_view

nodiscard

Get the operation identifier associated with a registered route identifier

otherwise()

auto sourcemeta::core::URITemplateRouter::otherwise	(	const Identifier	context,
		const std::span< const Argument >	arguments = {} ) -> void

Register a fallback context and arguments to be returned when matching a path that does not correspond to any registered route

path()

auto sourcemeta::core::URITemplateRouter::path ( const Identifier identifier ) const -> std::string

nodiscard

Reconstruct and return the URI Template path string originally registered for the given identifier

sourcemeta::core::URITemplateRouterView

class sourcemeta::core::URITemplateRouterView

A read-only view of a serialized URI Template router

Public Member Functions
	URITemplateRouterView (const std::filesystem::path &path)
	Construct a view by loading a serialized router from a file.
	URITemplateRouterView (const std::uint8_t *data, std::size_t size)
	URITemplateRouterView (const URITemplateRouterView &)=delete
	URITemplateRouterView (URITemplateRouterView &&)=delete
auto	match (const std::string_view path, const URITemplateRouter::Callback &callback) const -> std::pair< URITemplateRouter::Identifier, URITemplateRouter::Identifier >
auto	describes (const std::string_view path, const std::string_view base_path={}) const noexcept -> bool
auto	arguments (const URITemplateRouter::Identifier identifier, const URITemplateRouter::ArgumentCallback &callback) const -> void
	Access the stored arguments for a given route identifier.
auto	base_path () const noexcept -> std::string_view
	Access the base path prefix.
auto	base_url () const noexcept -> std::string_view
	Access the base URL associated with the router.
auto	size () const noexcept -> std::size_t
	Get the number of registered routes.
auto	operation (const std::string_view operation_id) const -> std::pair< URITemplateRouter::Identifier, URITemplateRouter::Identifier >
auto	at (const std::size_t index) const -> URITemplateRouter::Identifier
	Get the identifier of the route at the given positional index.
auto	context (const URITemplateRouter::Identifier identifier) const -> URITemplateRouter::Identifier
auto	path (const URITemplateRouter::Identifier identifier) const -> std::string
auto	operation_id (const URITemplateRouter::Identifier identifier) const -> std::string_view
Static Public Member Functions
static auto	save (const URITemplateRouter &router, const std::filesystem::path &path) -> void
	Save a router to a binary file.

Constructor & Destructor Documentation

URITemplateRouterView()

sourcemeta::core::URITemplateRouterView::URITemplateRouterView	(	const std::uint8_t *	data,
		std::size_t	size )

Construct a view over an externally-owned buffer. The buffer must outlive the view

Member Function Documentation

context()

auto sourcemeta::core::URITemplateRouterView::context ( const URITemplateRouter::Identifier identifier ) const -> URITemplateRouter::Identifier

nodiscard

Get the context identifier associated with a registered route identifier

describes()

auto sourcemeta::core::URITemplateRouterView::describes ( const std::string_view path, const std::string_view base_path = {} ) const -> bool

nodiscardnoexcept

Determine whether a path lies within the space described by the explicitly registered routes, as a whole-segment prefix of one or more routes, as an exact route, or as a path captured by a route expansion. The fallback registered through the catch-all is never considered. Like matching, the path is not normalized before evaluation. When a base path is given, it is evaluated as if prepended to the path, avoiding a concatenation at the call site

match()

auto sourcemeta::core::URITemplateRouterView::match ( const std::string_view path, const URITemplateRouter::Callback & callback ) const -> std::pair< URITemplateRouter::Identifier, URITemplateRouter::Identifier >

nodiscard

Match a path against the router. Note the callback might fire for initial matches even though the entire match might still fail

operation()

auto sourcemeta::core::URITemplateRouterView::operation ( const std::string_view operation_id ) const -> std::pair< URITemplateRouter::Identifier, URITemplateRouter::Identifier >

nodiscard

Resolve an operation identifier to its registered route. Returns (identifier, context) on hit and (0, 0) if no route is registered under the given operation identifier

operation_id()

auto sourcemeta::core::URITemplateRouterView::operation_id ( const URITemplateRouter::Identifier identifier ) const -> std::string_view

nodiscard

Get the operation identifier associated with a registered route identifier

path()

auto sourcemeta::core::URITemplateRouterView::path ( const URITemplateRouter::Identifier identifier ) const -> std::string

nodiscard

Reconstruct and return the URI Template path string originally registered for the given identifier

sourcemeta::core::URITemplateTokenLiteral

struct sourcemeta::core::URITemplateTokenLiteral

A literal string segment in a URI Template

Public Attributes
std::string_view	value
	The literal string content.

sourcemeta::core::URITemplateVariableSpecification

struct sourcemeta::core::URITemplateVariableSpecification

A variable specification within a URI Template expression

Public Attributes
std::string_view	name
	The variable name.
std::uint16_t	length {0}
	The maximum prefix length to apply to the value.
bool	explode {false}
	Whether the variable is exploded into multiple values.

sourcemeta::core::URITemplateTokenVariable

struct sourcemeta::core::URITemplateTokenVariable

A simple string variable expansion {var} in a URI Template (Level 1)

Public Attributes
std::vector< URITemplateVariableSpecification >	variables
	The variable specifications to expand.
Static Public Attributes
static constexpr char	separator = ','
	The character that separates expanded values.
static constexpr bool	named = false
	Whether the expansion includes variable names.
static constexpr bool	allow_reserved = false
	Whether reserved characters are preserved unencoded.

sourcemeta::core::URITemplateTokenReservedExpansion

struct sourcemeta::core::URITemplateTokenReservedExpansion

A reserved expansion {+var} in a URI Template (Level 2)

Public Attributes
std::vector< URITemplateVariableSpecification >	variables
	The variable specifications to expand.
Static Public Attributes
static constexpr char	op = '+'
	The operator character that introduces the expression.
static constexpr char	separator = ','
	The character that separates expanded values.
static constexpr bool	named = false
	Whether the expansion includes variable names.
static constexpr bool	allow_reserved = true
	Whether reserved characters are preserved unencoded.

sourcemeta::core::URITemplateTokenFragmentExpansion

struct sourcemeta::core::URITemplateTokenFragmentExpansion

A fragment expansion {#var} in a URI Template (Level 2)

Public Attributes
std::vector< URITemplateVariableSpecification >	variables
	The variable specifications to expand.
Static Public Attributes
static constexpr char	op = '#'
	The operator character that introduces the expression.
static constexpr char	separator = ','
	The character that separates expanded values.
static constexpr char	prefix = '#'
	The character prepended to the expansion output.
static constexpr bool	named = false
	Whether the expansion includes variable names.
static constexpr bool	allow_reserved = true
	Whether reserved characters are preserved unencoded.

sourcemeta::core::URITemplateTokenLabelExpansion

struct sourcemeta::core::URITemplateTokenLabelExpansion

A label expansion {.var} in a URI Template (Level 3)

Public Attributes
std::vector< URITemplateVariableSpecification >	variables
	The variable specifications to expand.
Static Public Attributes
static constexpr char	op = '.'
	The operator character that introduces the expression.
static constexpr char	separator = '.'
	The character that separates expanded values.
static constexpr char	prefix = '.'
	The character prepended to the expansion output.
static constexpr bool	named = false
	Whether the expansion includes variable names.
static constexpr bool	allow_reserved = false
	Whether reserved characters are preserved unencoded.

sourcemeta::core::URITemplateTokenPathExpansion

struct sourcemeta::core::URITemplateTokenPathExpansion

A path expansion {/var} in a URI Template (Level 3)

Public Attributes
std::vector< URITemplateVariableSpecification >	variables
	The variable specifications to expand.
Static Public Attributes
static constexpr char	op = '/'
	The operator character that introduces the expression.
static constexpr char	separator = '/'
	The character that separates expanded values.
static constexpr char	prefix = '/'
	The character prepended to the expansion output.
static constexpr bool	named = false
	Whether the expansion includes variable names.
static constexpr bool	allow_reserved = false
	Whether reserved characters are preserved unencoded.

sourcemeta::core::URITemplateTokenPathParameterExpansion

struct sourcemeta::core::URITemplateTokenPathParameterExpansion

A path parameter expansion {;var} in a URI Template (Level 3)

Public Attributes
std::vector< URITemplateVariableSpecification >	variables
	The variable specifications to expand.
Static Public Attributes
static constexpr char	op = ';'
	The operator character that introduces the expression.
static constexpr char	separator = ';'
	The character that separates expanded values.
static constexpr char	prefix = ';'
	The character prepended to the expansion output.
static constexpr bool	named = true
	Whether the expansion includes variable names.
static constexpr bool	allow_reserved = false
	Whether reserved characters are preserved unencoded.

sourcemeta::core::URITemplateTokenQueryExpansion

struct sourcemeta::core::URITemplateTokenQueryExpansion

A query expansion {?var} in a URI Template (Level 3)

Public Attributes
std::vector< URITemplateVariableSpecification >	variables
	The variable specifications to expand.
Static Public Attributes
static constexpr char	op = '?'
	The operator character that introduces the expression.
static constexpr char	separator = '&'
	The character that separates expanded values.
static constexpr char	prefix = '?'
	The character prepended to the expansion output.
static constexpr bool	named = true
	Whether the expansion includes variable names.
static constexpr bool	allow_reserved = false
	Whether reserved characters are preserved unencoded.
static constexpr char	empty_suffix = '='
	The character appended to names with empty values.

sourcemeta::core::URITemplateTokenQueryContinuationExpansion

struct sourcemeta::core::URITemplateTokenQueryContinuationExpansion

A query continuation expansion {&var} in a URI Template (Level 3)

Public Attributes
std::vector< URITemplateVariableSpecification >	variables
	The variable specifications to expand.
Static Public Attributes
static constexpr char	op = '&'
	The operator character that introduces the expression.
static constexpr char	separator = '&'
	The character that separates expanded values.
static constexpr char	prefix = '&'
	The character prepended to the expansion output.
static constexpr bool	named = true
	Whether the expansion includes variable names.
static constexpr bool	allow_reserved = false
	Whether reserved characters are preserved unencoded.
static constexpr char	empty_suffix = '='
	The character appended to names with empty values.

Typedef Documentation

URITemplateParseResult

using sourcemeta::core::URITemplateParseResult

Initial value:

 
std::optional<std::pair<URITemplateToken, std::size_t>>

The result of parsing a token: the token and how many characters were consumed

URITemplateToken

using sourcemeta::core::URITemplateToken

Initial value:

std::variant<
   URITemplateTokenLiteral, URITemplateTokenVariable,
   URITemplateTokenReservedExpansion, URITemplateTokenFragmentExpansion,
   URITemplateTokenLabelExpansion, URITemplateTokenPathExpansion,
   URITemplateTokenPathParameterExpansion, URITemplateTokenQueryExpansion,
   URITemplateTokenQueryContinuationExpansion>

A token in a parsed URI Template

URITemplateValue

using sourcemeta::core::URITemplateValue

Initial value:

std::optional<
   std::tuple<std::string_view, std::optional<std::string_view>, bool>>

The return type for URI Template variable callbacks (value, key?, has_more)

Enumeration Type Documentation

URITemplateExpansionMode

enum class sourcemeta::core::URITemplateExpansionMode : std::uint8_t

strong

The alphabet that expansion encodes variable values against

Enumerator
URI	Encode against the URI alphabet as defined by RFC 6570.
IRI	Encode against the IRI alphabet, passing internationalized characters through unencoded rather than percent encoding them. RFC 6570 Section 1.1 acknowledges that "a URI Template is also an IRI template", but only by expanding to a URI and converting the result per RFC 3987 Section 3.2, a conversion that also decodes percent encoded triplets already present in variable values, whereas this mode never decodes anything. Passed through characters are not validated against the RFC 3987 grammar, which is left to the caller