Struct passerine::common::span::Span

pub struct Span {
    pub source: Option<Rc<Source>>,
    pub offset: usize,
    pub length: usize,
}

A Span refers to a section of a source, much like a &str, but with a reference to a Source rather than a String. A Span is meant to be paired with other datastructures, to be used during error reporting.

Fields

source: Option<Rc<Source>>

offset: usize

length: usize

Implementations

impl Span

pub fn new(source: &Rc<Source>, offset: usize, length: usize) -> Span

Create a new Span from an offset with a length. All Spans have access to the Source from whence they came, So they can't be misinterpreted or miscombined.

pub fn point(source: &Rc<Source>, offset: usize) -> Span

A Span that points at a specific point in the source.

pub fn empty() -> Span

Create a new empty Span. An empty Span has only a source, if combined with another Span, the resulting Span will just be the other.

pub fn is_empty(&self) -> bool

Checks if a Span is empty.

pub fn end(&self) -> usize

pub fn later_than(&self, other: &Span) -> bool

Compares two Spans. returns true if this span starts the latest or is the longest in the case of a tie but false there is a total tie or otherwise

pub fn combine(a: &Span, b: &Span) -> Span

Creates a new Span which spans the space of the previous two.

hello this is cool
^^^^^              | Span a
           ^^      | Span b
^^^^^^^^^^^^^      | combined

pub fn join(spans: Vec<Span>) -> Span

Combines a set of Spans (think fold-left over Span::combine).

pub fn contents(&self) -> String

Returns the contents of a Span. This indexes into the source file, so if the Span is along an invalid byte boundary or is empty, the program will panic.

Trait Implementations

impl Clone for Span

fn clone(&self) -> Span

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Span

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

Formats the value using the given formatter.

impl Display for Span

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

Given a Span, fmt will print out where the Span occurs in its source. Single-line Spans:

12 | x = blatant { error }
   |     ^^^^^^^^^^^^^^^^^

Multi-line Spans:

12 > x -> {
13 >    y = x + 1
14 >    another { error }
15 > }

impl Eq for Span

impl PartialEq<Span> for Span

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

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

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

This method tests for !=.

impl StructuralEq for Span

impl StructuralPartialEq for Span