typst/src/syntax/span.rs

110 lines
2.6 KiB
Rust

//! Spans map elements to the part of source code they originate from.
use std::fmt::{self, Debug, Display, Formatter};
use serde::Serialize;
/// Annotates a value with the part of the source code it corresponds to.
#[derive(Copy, Clone, Eq, PartialEq, Hash, Serialize)]
pub struct Spanned<T> {
pub v: T,
pub span: Span,
}
impl<T> Spanned<T> {
pub fn new(v: T, span: Span) -> Spanned<T> {
Spanned { v, span }
}
pub fn value(self) -> T {
self.v
}
pub fn map<F, V>(self, f: F) -> Spanned<V> where F: FnOnce(T) -> V {
Spanned { v: f(self.v), span: self.span }
}
pub fn map_v<V>(&self, new_v: V) -> Spanned<V> {
Spanned { v: new_v, span: self.span }
}
}
impl<T> Display for Spanned<T> where T: std::fmt::Display {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "({}, {}, ", self.span.start, self.span.end)?;
self.v.fmt(f)?;
write!(f, ")")
}
}
impl<T> Debug for Spanned<T> where T: std::fmt::Debug {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "({}, {}, ", self.span.start, self.span.end)?;
self.v.fmt(f)?;
write!(f, ")")
}
}
/// Describes a slice of source code.
#[derive(Copy, Clone, Eq, PartialEq, Hash, Serialize)]
pub struct Span {
pub start: Position,
pub end: Position,
}
impl Span {
pub const ZERO: Span = Span { start: Position::ZERO, end: Position::ZERO };
pub fn new(start: Position, end: Position) -> Span {
Span { start, end }
}
pub fn merge(a: Span, b: Span) -> Span {
Span {
start: a.start.min(b.start),
end: a.end.max(b.end),
}
}
pub fn at(pos: Position) -> Span {
Span { start: pos, end: pos }
}
pub fn expand(&mut self, other: Span) {
*self = Span::merge(*self, other)
}
}
impl Display for Span {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "({}, {})", self.start, self.end)
}
}
debug_display!(Span);
/// A line-column position in source code.
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Serialize)]
pub struct Position {
/// The 0-indexed line (inclusive).
pub line: usize,
/// The 0-indexed column (inclusive).
pub column: usize,
}
impl Position {
pub const ZERO: Position = Position { line: 0, column: 0 };
pub fn new(line: usize, column: usize) -> Position {
Position { line, column }
}
}
impl Display for Position {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "{}:{}", self.line, self.column)
}
}
debug_display!(Position);