use std::slice::Iter;
use crate::{
HasSpan, Span,
attributes::Attrlist,
blocks::{Block, ContentModel, IsBlock},
internal::debug::DebugSliceReference,
strings::CowStr,
};
/// Content between the end of the document header and the first section title
/// in the document body is called the preamble.
#[derive(Clone, Eq, PartialEq)]
pub struct Preamble<'src> {
blocks: Vec<Block<'src>>,
source: Span<'src>,
}
impl<'src> Preamble<'src> {
pub(crate) fn from_blocks(blocks: Vec<Block<'src>>, source: Span<'src>) -> Self {
let preamble_source = if let Some(last_block) = blocks.last() {
let after_last = last_block.span().discard_all();
source.trim_remainder(after_last)
} else {
// This clause is here as a fallback, but should not be reachable in practice. A
// Preamble should only be constructed if there are content-bearing blocks
// before the first section.
source.trim_remainder(source)
};
Self {
blocks,
source: preamble_source,
}
}
}
impl<'src> IsBlock<'src> for Preamble<'src> {
fn content_model(&self) -> ContentModel {
ContentModel::Compound
}
fn raw_context(&self) -> CowStr<'src> {
"preamble".into()
}
fn nested_blocks(&'src self) -> Iter<'src, Block<'src>> {
self.blocks.iter()
}
fn title_source(&'src self) -> Option<Span<'src>> {
None
}
fn title(&self) -> Option<&str> {
None
}
fn anchor(&'src self) -> Option<Span<'src>> {
None
}
fn anchor_reftext(&'src self) -> Option<Span<'src>> {
None
}
fn attrlist(&'src self) -> Option<&'src Attrlist<'src>> {
None
}
}
impl<'src> HasSpan<'src> for Preamble<'src> {
fn span(&self) -> Span<'src> {
self.source
}
}
impl std::fmt::Debug for Preamble<'_> {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("Preamble")
.field("blocks", &DebugSliceReference(&self.blocks))
.field("source", &self.source)
.finish()
}
}
#[cfg(test)]
mod tests {
#![allow(clippy::panic)]
#![allow(clippy::unwrap_used)]
use crate::{blocks::ContentModel, tests::prelude::*};
fn doc_fixture() -> crate::Document<'static> {
Parser::default().parse("= Document Title\n\nSome early words go here.\n\n== First Section")
}
fn fixture_preamble<'src>(
doc: &'src crate::Document<'src>,
) -> &'src crate::blocks::Block<'src> {
doc.nested_blocks().next().unwrap()
}
#[test]
fn impl_clone() {
// Silly test to mark the #[derive(...)] line as covered.
let doc = doc_fixture();
let b1 = fixture_preamble(&doc);
let b2 = b1.clone();
assert_eq!(b1, &b2);
}
#[test]
fn impl_debug() {
let doc = doc_fixture();
let preamble = fixture_preamble(&doc);
let crate::blocks::Block::Preamble(preamble) = preamble else {
panic!("Unexpected block: {preamble:#?}");
};
dbg!(&preamble);
assert_eq!(
format!("{preamble:#?}"),
r#"Preamble {
blocks: &[
Block::Simple(
SimpleBlock {
content: Content {
original: Span {
data: "Some early words go here.",
line: 3,
col: 1,
offset: 18,
},
rendered: "Some early words go here.",
},
source: Span {
data: "Some early words go here.",
line: 3,
col: 1,
offset: 18,
},
style: SimpleBlockStyle::Paragraph,
title_source: None,
title: None,
anchor: None,
anchor_reftext: None,
attrlist: None,
},
),
],
source: Span {
data: "Some early words go here.",
line: 3,
col: 1,
offset: 18,
},
}"#
);
}
#[test]
fn impl_is_block() {
let doc = doc_fixture();
let preamble = fixture_preamble(&doc);
assert_eq!(
preamble,
&Block::Preamble(Preamble {
blocks: &[Block::Simple(SimpleBlock {
content: Content {
original: Span {
data: "Some early words go here.",
line: 3,
col: 1,
offset: 18,
},
rendered: "Some early words go here.",
},
source: Span {
data: "Some early words go here.",
line: 3,
col: 1,
offset: 18,
},
style: SimpleBlockStyle::Paragraph,
title_source: None,
title: None,
anchor: None,
anchor_reftext: None,
attrlist: None,
},),],
source: Span {
data: "Some early words go here.",
line: 3,
col: 1,
offset: 18,
},
},)
);
assert_eq!(preamble.content_model(), ContentModel::Compound);
assert!(preamble.rendered_content().is_none());
assert_eq!(preamble.raw_context().as_ref(), "preamble");
assert_eq!(preamble.resolved_context().as_ref(), "preamble");
assert!(preamble.declared_style().is_none());
let mut blocks = preamble.nested_blocks();
assert_eq!(
blocks.next().unwrap(),
&Block::Simple(SimpleBlock {
content: Content {
original: Span {
data: "Some early words go here.",
line: 3,
col: 1,
offset: 18,
},
rendered: "Some early words go here.",
},
source: Span {
data: "Some early words go here.",
line: 3,
col: 1,
offset: 18,
},
style: SimpleBlockStyle::Paragraph,
title_source: None,
title: None,
anchor: None,
anchor_reftext: None,
attrlist: None,
})
);
assert!(blocks.next().is_none());
assert!(preamble.id().is_none());
assert!(preamble.roles().is_empty());
assert!(preamble.options().is_empty());
assert!(preamble.title_source().is_none());
assert!(preamble.title().is_none());
assert!(preamble.anchor().is_none());
assert!(preamble.anchor_reftext().is_none());
assert!(preamble.attrlist().is_none());
assert_eq!(preamble.substitution_group(), SubstitutionGroup::Normal);
assert_eq!(
format!("{preamble:#?}"),
"Block::Preamble(\n Preamble {\n blocks: &[\n Block::Simple(\n SimpleBlock {\n content: Content {\n original: Span {\n data: \"Some early words go here.\",\n line: 3,\n col: 1,\n offset: 18,\n },\n rendered: \"Some early words go here.\",\n },\n source: Span {\n data: \"Some early words go here.\",\n line: 3,\n col: 1,\n offset: 18,\n },\n style: SimpleBlockStyle::Paragraph,\n title_source: None,\n title: None,\n anchor: None,\n anchor_reftext: None,\n attrlist: None,\n },\n ),\n ],\n source: Span {\n data: \"Some early words go here.\",\n line: 3,\n col: 1,\n offset: 18,\n },\n },\n)"
);
assert_eq!(
preamble.span(),
Span {
data: "Some early words go here.",
line: 3,
col: 1,
offset: 18,
}
);
}
}