Struct Rule 

pub struct Rule {
    pub name: String,
    pub hook: Option<Hook>,
    pub value: RuleValue,
}

Definition for a rule (a.k.a. derivation)

A rule is a derivation step that can be used to generate the Abstract Syntax Tree (AST).

There are two types of derivations:

• Union: a union of derivations. The first derivation that succeeds is used. For example: rule Biz = Foo | Bar, where Foo and Bar are also defined by the keyword rule The AST generator will try to derive Foo first, and if it fails, it will try to derive Bar.
• Derivation: Derive into smaller rules. Each part is represented by a parameter analogous to a function parameter. For example: rule Foo(bat: Bar, baz: Baz);, where Bar and Baz are also defined by the keyword rule The AST generator will derive Bar and Baz in order, and then combine them into a Foo AST node.

With Union rules, only other rules can be specified as part of the union. With derivation rules, token types can also be specified.

Fields

name: String

Name of the rule. The AST and PT generated types depend on this name.

hook: Option<Hook>

Optional parser hook

value: RuleValue

Value of the rule

Implementations

impl Rule

pub fn struct_name(&self) -> String

Get the base name of the struct for this rule, which is the UpperCamelCase of the name

Trait Implementations

impl Clone for Rule

fn clone(&self) -> Rule

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Rule

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.