Struct js_source_scopes::ScopeIndex

pub struct ScopeIndex { /* private fields */ }

An indexed structure of scopes that allows quick lookup by byte offset.

Construction of the index will validate that the scopes are well nested and parents fully contain their children. A list of scopes that are not well nested will result in an Err on construction.

Examples

use js_source_scopes::{ScopeIndex, ScopeLookupResult};

let scopes = vec![
    (5..25, Some(String::from("parent"))),
    (10..15, Some(String::from("child"))),
    (20..25, Some(String::from("child2"))),
    (30..50, None),
];

let idx = ScopeIndex::new(scopes).unwrap();
assert_eq!(idx.lookup(3), ScopeLookupResult::Unknown);
assert_eq!(idx.lookup(12), ScopeLookupResult::NamedScope("child"));
assert_eq!(idx.lookup(40), ScopeLookupResult::AnonymousScope);

Implementations

impl ScopeIndex

pub fn new(
    scopes: Vec<(Range<u32>, Option<String>)>
) -> Result<Self, ScopeIndexError>

Creates a new Scope index from the given list of Scopes.

pub fn lookup(&self, offset: u32) -> ScopeLookupResult<'_>

Looks up the scope corresponding to the given offset.

pub fn iter(&self) -> impl Iterator<Item = (u32, ScopeLookupResult<'_>)>

Returns an iterator over the scopes in this index and their starting offsets.

Scopes are returned in order of their starting offsets.

Trait Implementations

impl Debug for ScopeIndex

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

Formats the value using the given formatter.