Enum dynparser::ast::Node

pub enum Node {
    Val(String),
    Rule((String, Vec<Node>)),
    EOF,
}

Information of a node

Variants

Val(String)

The node is terminal (atom) with a name

Rule((String, Vec<Node>))

The node is not terminal (rule) with a name and a vec of nodes

EOF

Reached end of file

Implementations

impl Node

pub fn flatten(&self) -> Vec<Node>

Flattening tree

It’s very commont to visit nodes in order The grammar checked the consistency of input Flattening the AST, could be interesting in order to process the tree

   use dynparser::ast::{self, flat};
   
   let ast_before_flatten = ast::Node::Rule((
       "first".to_string(),
       vec![
           ast::Node::Rule((
               "node1".to_string(),
               vec![
                   ast::Node::Val("hello".to_string()),
                   ast::Node::Rule(("node1.1".to_string(), vec![ast::Node::Val(" ".to_string())])),
               ],
           )),
           ast::Node::Rule((
               "node2".to_string(),
               vec![ast::Node::Val("world".to_string())],
           )),
       ],
   ));

   let vec_after_flatten =
       vec![
           flat::Node::BeginRule("first".to_string()),
           flat::Node::BeginRule("node1".to_string()),
           flat::Node::Val("hello".to_string()),
           flat::Node::BeginRule("node1.1".to_string()),
           flat::Node::Val(" ".to_string()),
           flat::Node::EndRule("node1.1".to_string()),
           flat::Node::EndRule("node1".to_string()),
           flat::Node::BeginRule("node2".to_string()),
           flat::Node::Val("world".to_string()),
           flat::Node::EndRule("node2".to_string()),
           flat::Node::EndRule("first".to_string()),
       ];

   assert!(ast_before_flatten.flatten() == vec_after_flatten)

impl Node

pub fn prune(&self, nodes2prune: &[&str]) -> Self

Remove nodes with one of the names in the list. It will remove the childs

   use dynparser::ast;

   let ast_before_prune: ast::Node = ast::Node::Rule((
       "root".to_string(),
       vec![ast::Node::Rule((
           "a".to_string(),
           vec![
               ast::Node::Rule(("_1".to_string(), vec![])),
               ast::Node::Rule(("_2".to_string(), vec![])),
           ],
       ))],
   ));

   let ast_after_prune = ast::Node::Rule((
       "root".to_string(),
       vec![ast::Node::Rule(("a".to_string(), vec![]))],
   ));

   assert!(ast_before_prune.prune(&vec!["_1", "_2"]) == ast_after_prune)

pub fn passthrow_except(&self, nodes2keep: &[&str]) -> Self

Remove nodes excepting names in the list. Childs will be connected to the parent node removed

use dynparser::ast;

let ast_before_passthrow: ast::Node = ast::Node::Rule((
    "root".to_string(),
    vec![ast::Node::Rule((
        "a".to_string(),
        vec![ast::Node::Rule((
            "_1".to_string(),
            vec![ast::Node::Rule(("_2".to_string(), vec![]))],
        ))],
    ))],
));

let ast_after_passthrow: ast::Node = ast::Node::Rule((
    "root".to_string(),
    vec![ast::Node::Rule((
        "a".to_string(),
        vec![ast::Node::Rule(("_2".to_string(), vec![]))],
    ))],
));

assert!(ast_before_passthrow.passthrow_except(&vec!["root", "a", "_2"]) == ast_after_passthrow)

pub fn compact(&self) -> Self

Concat consecutive Val nodes

   use dynparser::ast;
   
   let ast_before_compact: ast::Node = ast::Node::Rule((
       "root".to_string(),
       vec![ast::Node::Rule((
           "node".to_string(),
           vec![
               ast::Node::Val("hello".to_string()),
               ast::Node::Val(" ".to_string()),
               ast::Node::Val("world".to_string()),
           ],
       ))],
   ));

   let ast_after_compact = ast::Node::Rule((
       "root".to_string(),
       vec![ast::Node::Rule((
           "node".to_string(),
           vec![ast::Node::Val("hello world".to_string())],
       ))],
   ));

   assert!(ast_before_compact.compact() == ast_after_compact)

Trait Implementations

impl Debug for Node

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

Formats the value using the given formatter.

impl PartialEq<Node> for Node

fn eq(&self, other: &Node) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Node