CLASS

Config::BINDish::AST - the standard Config::BINDish AST tree representation

DESCRIPTION

As a module Config::BINDish::AST defines all standard AST node classes used by Config::BINDish::Actions to build the resulting representation of the parsed configuration.

As a class Config::BINDish::AST is the base class for all other AST classes.

Labels

A little bit of special attention must be paid to labeling functionality of AST. Let's consider how an option is parsed:

the-answer 42;

In the above example both the-answer and 42 are considered to be values and as such they result in two instances of Config::BINDish::AST::Value. Both objects then become children of an Config::BINDish::AST::Option instance. Roughly, the parsed tree will look like:

Option
 `---- Value
 `---- Value

To distinguish one value from another we can attach labels to them. So, the value representing option name will get tagged as "option-name"; and 42 will become "option-value".

See methods mark-as, labels, is-marked, child, children below.

METHODS

dup(*%twiddles)

This method is close in its functionality to the standard Raku clone method, but adjusted for the needs of AST class family.

set-parent(Config::BINDish::AST::Node:D $parent)

Sets AST instance parent node.

multi parent()

Returns current parent node.

multi parent(Config::BINDish::AST:U \parent-type)

Returns the closest parent node of type parent-type. For example, to get the enclosing block of a Config::BINDish::AST::Value one can do:

$value.parent(Config::BINDish::AST::Block);

multi mark-as(*@labels)

Sets labels for AST instance.

is-marked(Str:D $label -- Bool:D)>

Returns True if AST object is marked with $label.

labels()

Returns a list of all AST object labels.

ast-name()

Returns current node name, based on the node class name. If the name starts with Config::BINDish::AST:: then this part is stripped off. Otherwise the class name is considered to be the name.

dump(Int:D :$level = 0 -- Str:D)>

Returns current node' string representation which consists of its ast-name and gist. The string would be indented by $level white spaces.

register-type(Str:D $ast-name, Mu \ast-type)

Method registers an ast-type class under $ast-name. new-ast method (see below) can later create a node instance based on its registered name.

new-ast(Str:D $node-type, |profile -- Config::BINDish::AST:D)>

Creates a new instance of ast node based on its name. The name can be either a registered AST node name, see register-type method above; or a short name under Config::BINDish::AST:: namespace. If no associated AST type object is found then a failure wrapped around Config::BINDish::X::AST::DoesnExists is returned.

For example, with the following statement:

Config::BINDish::AST.register-type("MyAppNode", MyApp::Config::AST::Node);

it is then possible to:

Config::BINDish::AST.new-ast("MyAppNode", :foo(42), :bar("The Answer")); # An instance of My::App::Config::AST::Node

For one of the standard AST nodes one can:

Config::BINDish::AST.new-ast('Block', :name(...), :class(...), ...); # An instance of Config::BINDish::AST::Block

top-node(--> Config::BINDish::AST)

Returns the topmost node, or, in other words, the root of the AST tree.

AST NODE CLASSES AND ROLES

Roles

• Config::BINDish::AST::Container

• Config::BINDish::AST::Blockish

Classes

• Config::BINDish::AST::Block

• Config::BINDish::AST::Comment

• Config::BINDish::AST::Option

• Config::BINDish::AST::Node

• Config::BINDish::AST::NOP

• Config::BINDish::AST::Stmts

• Config::BINDish::AST::TOP

• Config::BINDish::AST::Value

SEE ALSO

• Config::BINDish

• Config::BINDish::Actions

• README

• INDEX

COPYRIGHT

(c) 2023, Vadim Belman [email protected]

LICENSE

Artistic License 2.0

See the LICENSE file in this distribution.