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use std::borrow::Cow;
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct SpannedString<T> {
source: String,
spans: Vec<IndexedSpan<T>>,
}
#[derive(Debug, PartialEq, Eq)]
pub struct SpannedStr<'a, T>
where
T: 'a,
{
source: &'a str,
spans: &'a [IndexedSpan<T>],
}
pub trait SpannedText {
type S: AsRef<IndexedCow>;
fn source(&self) -> &str;
fn spans(&self) -> &[Self::S];
#[cfg_attr(feature = "cargo-clippy", allow(needless_lifetimes))]
fn as_ref<'a>(&'a self) -> SpannedTextRef<'a, Self> {
SpannedTextRef { r: self }
}
}
pub struct SpannedTextRef<'a, C>
where
C: 'a + SpannedText + ?Sized,
{
r: &'a C,
}
impl<T> Default for SpannedString<T> {
fn default() -> Self {
SpannedString::new()
}
}
impl<'a, T> SpannedText for &'a SpannedString<T> {
type S = IndexedSpan<T>;
fn source(&self) -> &str {
&self.source
}
fn spans(&self) -> &[IndexedSpan<T>] {
&self.spans
}
}
impl<'a, C> SpannedText for SpannedTextRef<'a, C>
where
C: 'a + SpannedText + ?Sized,
{
type S = C::S;
fn source(&self) -> &str {
self.r.source()
}
fn spans(&self) -> &[C::S] {
self.r.spans()
}
}
impl<'a, T> SpannedText for SpannedStr<'a, T>
where
T: 'a,
{
type S = IndexedSpan<T>;
fn source(&self) -> &str {
self.source
}
fn spans(&self) -> &[IndexedSpan<T>] {
self.spans
}
}
impl<S, T> From<S> for SpannedString<T>
where
S: Into<String>,
T: Default,
{
fn from(value: S) -> Self {
Self::single_span(value.into(), T::default())
}
}
impl<'a, T> SpannedStr<'a, T>
where
T: 'a,
{
pub fn new(source: &'a str, spans: &'a [IndexedSpan<T>]) -> Self {
SpannedStr { source, spans }
}
pub fn spans(&self) -> Vec<Span<'a, T>> {
self.spans
.iter()
.map(|span| span.resolve(self.source))
.collect()
}
pub fn spans_raw(&self) -> &'a [IndexedSpan<T>] {
self.spans
}
pub fn source(&self) -> &'a str {
self.source
}
pub fn is_empty(&self) -> bool {
self.source.is_empty() || self.spans.is_empty()
}
}
impl<'a, T> Clone for SpannedStr<'a, T> {
fn clone(&self) -> Self {
SpannedStr {
source: self.source,
spans: self.spans,
}
}
}
impl SpannedString<()> {
pub fn plain<S>(content: S) -> Self
where
S: Into<String>,
{
Self::single_span(content, ())
}
}
impl<T> SpannedString<T> {
pub fn new() -> Self {
Self::with_spans(String::new(), Vec::new())
}
pub fn with_spans<S>(source: S, spans: Vec<IndexedSpan<T>>) -> Self
where
S: Into<String>,
{
let source = source.into();
for span in &spans {
if let IndexedCow::Borrowed { end, .. } = span.content {
assert!(end <= source.len());
}
}
SpannedString { source, spans }
}
pub fn single_span<S>(source: S, attr: T) -> Self
where
S: Into<String>,
{
let source = source.into();
let spans = vec![IndexedSpan {
content: IndexedCow::Borrowed {
start: 0,
end: source.len(),
},
attr,
}];
Self::with_spans(source, spans)
}
pub fn append<S>(&mut self, other: S)
where
S: Into<Self>,
{
let other = other.into();
self.append_raw(&other.source, other.spans);
}
pub fn append_raw(&mut self, source: &str, spans: Vec<IndexedSpan<T>>) {
let offset = self.source.len();
let mut spans = spans;
for span in &mut spans {
span.content.offset(offset);
}
self.source.push_str(source);
self.spans.append(&mut spans);
}
#[cfg_attr(feature = "cargo-clippy", allow(needless_lifetimes))]
pub fn spans<'a>(&'a self) -> Vec<Span<'a, T>> {
self.spans
.iter()
.map(|span| span.resolve(&self.source))
.collect()
}
pub fn spans_raw(&self) -> &[IndexedSpan<T>] {
&self.spans
}
pub fn source(&self) -> &str {
&self.source
}
pub fn is_empty(&self) -> bool {
self.source.is_empty() || self.spans.is_empty()
}
}
impl<'a, T> From<&'a SpannedString<T>> for SpannedStr<'a, T> {
fn from(other: &'a SpannedString<T>) -> Self {
SpannedStr::new(&other.source, &other.spans)
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct IndexedSpan<T> {
pub content: IndexedCow,
pub attr: T,
}
impl<T> AsRef<IndexedCow> for IndexedSpan<T> {
fn as_ref(&self) -> &IndexedCow {
&self.content
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct Span<'a, T: 'a> {
pub content: &'a str,
pub attr: &'a T,
}
impl<T> IndexedSpan<T> {
pub fn resolve<'a>(&'a self, source: &'a str) -> Span<'a, T>
where
T: 'a,
{
Span {
content: self.content.resolve(source),
attr: &self.attr,
}
}
pub fn is_empty(&self) -> bool {
self.content.is_empty()
}
pub fn simple(content: &str, attr: T) -> Self {
IndexedSpan {
content: IndexedCow::Borrowed {
start: 0,
end: content.len(),
},
attr,
}
}
}
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum IndexedCow {
Borrowed {
start: usize,
end: usize,
},
Owned(String),
}
impl IndexedCow {
pub fn resolve<'a>(&'a self, source: &'a str) -> &'a str {
match *self {
IndexedCow::Borrowed { start, end } => &source[start..end],
IndexedCow::Owned(ref content) => content,
}
}
pub fn from_cow(cow: Cow<str>, source: &str) -> Self {
match cow {
Cow::Owned(value) => IndexedCow::Owned(value),
Cow::Borrowed(value) => {
let source_pos = source.as_ptr() as usize;
let value_pos = value.as_ptr() as usize;
assert!(value_pos >= source_pos);
assert!(value_pos + value.len() <= source_pos + source.len());
let start = value_pos - source_pos;
let end = start + value.len();
IndexedCow::Borrowed { start, end }
}
}
}
pub fn is_empty(&self) -> bool {
match *self {
IndexedCow::Borrowed { start, end } => start == end,
IndexedCow::Owned(ref content) => content.is_empty(),
}
}
pub fn offset(&mut self, offset: usize) {
if let IndexedCow::Borrowed {
ref mut start,
ref mut end,
} = *self
{
*start += offset;
*end += offset;
}
}
}