Struct partiql_source_map::line_offset_tracker::LineOffsetTracker

pub struct LineOffsetTracker { /* private fields */ }

Keeps track of source offsets of newlines for the purposes of later calculating line and column information

Example

use partiql_source_map::location::{ByteOffset, LineAndCharPosition};
use partiql_source_map::line_offset_tracker::{LineOffsetError, LineOffsetTracker};

let source = "12345\n789012345\n789012345\n789012345";
let mut tracker = LineOffsetTracker::default();
tracker.record(6.into());
tracker.record(16.into());
tracker.record(26.into());

// We added 3 newlines, so there should be 4 lines of source
assert_eq!(tracker.num_lines(), 4);
assert_eq!(tracker.at(source, ByteOffset(0).into()), Ok(LineAndCharPosition::new(0,0)));
assert_eq!(tracker.at(source, ByteOffset(6).into()), Ok(LineAndCharPosition::new(1,0)));
assert_eq!(tracker.at(source, ByteOffset(30).into()), Ok(LineAndCharPosition::new(3,4)));
assert_eq!(tracker.at(source, ByteOffset(300).into()), Err(LineOffsetError::EndOfInput));

Implementations

impl LineOffsetTracker

pub fn record(&mut self, line_start: ByteOffset)

Record a newline at span in the source

pub fn append(&mut self, other: &LineOffsetTracker, offset: ByteOffset)

Append the line starts from another LineOffsetTracker to this one, adding offset to each.

pub fn num_lines(&self) -> usize

Calculate the number of lines of source seen so far.

pub fn at(
    &self,
    source: &str,
    BytePosition: BytePosition
) -> Result<LineAndCharPosition, LineOffsetError>

Calculates a LineAndCharPosition for a byte offset from the given &str

source is source &str into which the byte offset applies offset is the byte offset for which to find the LineAndCharPosition

If offset is larger than source.len(), then LineOffsetError::EndOfInput is returned If offset is in the middle of a unicode codepoint, then LineOffsetError::InsideUnicodeCodepoint is returned

Trait Implementations

impl Debug for LineOffsetTracker

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

Formats the value using the given formatter.

impl Default for LineOffsetTracker

fn default() -> Self

Returns the “default value” for a type.