New incremental parsing paradigm

Also move column offset into scanner.

This fixes #62
This commit is contained in:
Martin Haug 2022-02-21 22:49:50 +01:00
parent aac3afcba8
commit 20ac96f27a
5 changed files with 323 additions and 643 deletions

View File

@ -4,57 +4,11 @@ use std::sync::Arc;
use crate::syntax::{Green, GreenNode, NodeKind};
use super::{
is_newline, parse, parse_atomic, parse_atomic_markup, parse_block, parse_comment,
parse_markup, parse_markup_elements, parse_template, Scanner, TokenMode,
is_newline, parse, parse_block, parse_markup_elements, parse_template, TokenMode,
};
/// The conditions that a node has to fulfill in order to be replaced.
///
/// This can dictate if a node can be replaced at all and if yes, what can take
/// its place.
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub enum SuccessionRule {
/// Changing this node can never have an influence on the other nodes.
Safe,
/// This node has to be replaced with a single token of the same kind.
SameKind(Option<TokenMode>),
/// In code mode, this node can only be changed into a single atomic
/// expression, otherwise it is safe.
AtomicPrimary,
/// Changing an unsafe layer node in code mode changes what the parents or
/// the surrounding nodes would be and is therefore disallowed. Change the
/// parents or children instead. If it appears in Markup, however, it is
/// safe to change.
UnsafeLayer,
/// Changing an unsafe node or any of its children is not allowed. Change
/// the parents instead.
Unsafe,
}
/// The conditions under which a node can be inserted or remain in a tree.
///
/// These conditions all search the neighbors of the node and see if its
/// existence is plausible with them present. This can be used to encode some
/// context-free language components for incremental parsing.
#[derive(Debug, Copy, Clone, Eq, PartialEq)]
pub enum NeighbourRule {
/// These nodes depend on being at the start of a line. Reparsing of safe
/// left neighbors has to check this invariant. Additionally, when
/// exchanging the right sibling or inserting such a node the indentation of
/// the first right non-trivia, non-whitespace sibling must not be greater
/// than the current indentation.
AtStart,
/// These nodes depend on not being at the start of a line. Reparsing of
/// safe left neighbors has to check this invariant. Otherwise, this node is
/// safe.
NotAtStart,
/// These nodes could end up somewhere else up the tree if the parse was
/// happening from scratch. The parse result has to be checked for such
/// nodes. They are safe to add if followed up by other nodes.
NotAtEnd,
/// No additional requirements.
None,
}
type ReparseFunc =
fn(&str, &str, usize, isize, &[Green], bool) -> Option<(Vec<Green>, bool, usize)>;
/// Allows partial refreshs of the [`Green`] node tree.
///
@ -79,180 +33,185 @@ impl<'a> Reparser<'a> {
impl Reparser<'_> {
/// Find the innermost child that is incremental safe.
pub fn reparse(&self, green: &mut Arc<GreenNode>) -> Range<usize> {
self.reparse_step(Arc::make_mut(green), 0, TokenMode::Markup, true)
.unwrap_or_else(|| {
*green = parse(self.src);
0 .. self.src.len()
})
self.reparse_step(Arc::make_mut(green), 0, true).unwrap_or_else(|| {
*green = parse(self.src);
0 .. self.src.len()
})
}
fn reparse_step(
&self,
green: &mut GreenNode,
mut offset: usize,
parent_mode: TokenMode,
mut outermost: bool,
outermost: bool,
) -> Option<Range<usize>> {
let mode = green.kind().mode().unwrap_or(parent_mode);
let child_mode = green.kind().mode().unwrap_or(TokenMode::Code);
let original_count = green.children().len();
// Save the current indent if this is a markup node.
let indent = match green.kind() {
NodeKind::Markup(n) => *n,
_ => 0,
};
let mut first = None;
let mut search = SearchState::default();
let mut ahead_nontrivia = None;
// Whether the first node that should be replaced is at start.
let mut at_start = true;
let mut end_outermost = false;
// Find the the first child in the range of children to reparse.
for (i, child) in green.children_mut().iter_mut().enumerate() {
for (i, child) in green.children().iter().enumerate() {
let pos = GreenPos { idx: i, offset };
let child_span = offset .. offset + child.len();
// We look for the start in the element but we only take a position
// at the right border if this is markup or the last element.
//
// This is because in Markup mode, we want to examine all nodes next
// to a replacement but in code we want to atomically replace. At
// least one character on either side of the replacement must be
// reparsed with it to keep the Space / Text node coalescing intact.
if (child_mode == TokenMode::Markup
&& child_span.end + 1 >= self.replace_range.start)
|| child_span.contains(&self.replace_range.start)
{
first = Some((i, offset));
break;
match search {
SearchState::NoneFound => {
// The edit is contained within the span of the current element.
if child_span.contains(&self.replace_range.start)
&& child_span.end >= self.replace_range.end
{
// In Markup mode, we want to consider a non-whitespace
// neighbor if the edit is on the node boundary.
search = if child_span.end == self.replace_range.end
&& child_mode == TokenMode::Markup
{
SearchState::RequireNonWS(pos)
} else {
// println!("found containing block {:?}", green.kind());
SearchState::Contained(pos)
};
} else if child_span.contains(&self.replace_range.start) {
search = SearchState::Inside(pos);
} else {
if !child.kind().is_space()
&& child.kind() != &NodeKind::Semicolon
{
ahead_nontrivia = Some((pos, at_start));
}
at_start = child.kind().is_at_start(at_start);
}
}
SearchState::Inside(start) => {
if child_span.end == self.replace_range.end {
search = SearchState::RequireNonWS(start);
} else if child_span.end > self.replace_range.end {
search = SearchState::SpanFound(start, pos);
}
}
SearchState::RequireNonWS(start) => {
if !child.kind().is_trivia() {
search = SearchState::SpanFound(start, pos);
}
}
_ => unreachable!(),
}
offset += child.len();
at_start = child.kind().is_at_start(at_start);
}
let (first_idx, first_start) = first?;
let mut last = None;
// Find the the last child in the range of children to reparse.
for (i, child) in green.children_mut().iter_mut().enumerate().skip(first_idx) {
let child_span = offset .. offset + child.len();
// Similarly to above, the end of the edit must be in the
// reconsidered range. However, in markup mode, we need to extend
// the reconsidered range by up to two nodes so that spacing etc.
// results in the same tree.
//
// Therefore, there are two cases:
// 1. We are at the end of the string or in code mode and the
// current node perfectly matches the end of the replacement
// 2. The end is contained within this node, and, in Markup mode,
// is not the first thing in it.
let ignore_overhang =
i + 1 == original_count || child_mode != TokenMode::Markup;
if (self.replace_range.end == child_span.end && ignore_overhang)
|| (child_span.end > self.replace_range.end
&& (self.replace_range.end != child_span.start || ignore_overhang))
{
outermost &= i + 1 == original_count;
last = Some((i, offset + child.len()));
break;
} else if child_mode != TokenMode::Markup
|| !child.kind().succession_rule().safe_in_markup()
{
end_outermost = outermost && i + 1 == original_count;
if search.end().is_some() {
break;
}
offset += child.len();
}
let (last_idx, last_end) = last?;
let superseded_range = first_idx .. last_idx + 1;
let superseded_span = first_start .. last_end;
let last_kind = green.children()[last_idx].kind().clone();
// First, we try if the child itself has another, more specific
// applicable child.
if superseded_range.len() == 1 {
let child = &mut green.children_mut()[superseded_range.start];
if let SearchState::Contained(pos) = search {
let child = &mut green.children_mut()[pos.idx];
let prev_len = child.len();
if last_kind.succession_rule() != SuccessionRule::Unsafe
&& !matches!(last_kind, NodeKind::Strong | NodeKind::Emph)
{
if let Some(range) = match child {
Green::Node(node) => self.reparse_step(
Arc::make_mut(node),
first_start,
child_mode,
outermost,
),
Green::Token(_) => None,
} {
let new_len = child.len();
green.update_parent(new_len, prev_len);
return Some(range);
if let Some(range) = match child {
Green::Node(node) => {
self.reparse_step(Arc::make_mut(node), pos.offset, end_outermost)
}
Green::Token(_) => None,
} {
let new_len = child.len();
green.update_parent(new_len, prev_len);
return Some(range);
}
let superseded_span = pos.offset .. pos.offset + prev_len;
let func: Option<ReparseFunc> = match child.kind() {
NodeKind::Template => Some(parse_template),
NodeKind::Block => Some(parse_block),
_ => None,
};
if let Some(func) = func {
if let Some(result) = self.replace(
green,
func,
pos.idx .. pos.idx + 1,
superseded_span,
at_start,
end_outermost,
outermost,
) {
return Some(result);
}
}
}
// We only replace multiple children in markup mode.
if superseded_range.len() > 1 && mode == TokenMode::Code {
if !matches!(green.kind(), NodeKind::Markup(_)) {
return None;
}
// We now have a child that we can replace and a function to do so.
let func = last_kind.reparsing_func(child_mode, indent)?;
let succession = last_kind.succession_rule();
let (mut start, end) = search.end()?;
if let Some((ahead, ahead_at_start)) = ahead_nontrivia {
let ahead_kind = green.children()[ahead.idx].kind();
let mut markup_min_column = 0;
// If this is a markup node, we want to save its indent instead to pass
// the right indent argument.
if superseded_range.len() == 1 {
let child = &mut green.children_mut()[superseded_range.start];
if let NodeKind::Markup(n) = child.kind() {
markup_min_column = *n;
if start.offset == self.replace_range.start
|| ahead_kind.only_at_start()
|| ahead_kind == &NodeKind::LineComment
{
start = ahead;
at_start = ahead_at_start;
}
}
// The span of the to-be-reparsed children in the new source.
let superseded_span =
start.offset .. end.offset + green.children()[end.idx].len();
self.replace(
green,
parse_markup_elements,
start.idx .. end.idx + 1,
superseded_span,
at_start,
end_outermost,
outermost,
)
}
fn replace(
&self,
green: &mut GreenNode,
func: ReparseFunc,
superseded_idx: Range<usize>,
superseded_span: Range<usize>,
at_start: bool,
outermost: bool,
parent_outermost: bool,
) -> Option<Range<usize>> {
let differential: isize =
self.replace_len as isize - self.replace_range.len() as isize;
let newborn_span = superseded_span.start
..
superseded_span.end + self.replace_len - self.replace_range.len();
// For atomic primaries we need to pass in the whole remaining string to
// check whether the parser would eat more stuff illicitly.
let reparse_span = if succession == SuccessionRule::AtomicPrimary {
newborn_span.start .. self.src.len()
} else {
newborn_span.clone()
};
(superseded_span.end as isize + differential) as usize;
let superseded_start = superseded_idx.start;
let mut prefix = "";
for (i, c) in self.src[.. reparse_span.start].char_indices().rev() {
for (i, c) in self.src[.. newborn_span.start].char_indices().rev() {
if is_newline(c) {
break;
}
prefix = &self.src[i .. reparse_span.start];
prefix = &self.src[i .. newborn_span.start];
}
// Do the reparsing!
let (mut newborns, terminated) = func(
// // println!("reparsing...");
let (newborns, terminated, amount) = func(
&prefix,
&self.src[reparse_span.clone()],
&self.src[newborn_span.start ..],
newborn_span.len(),
differential,
&green.children()[superseded_start ..],
at_start,
markup_min_column,
)?;
// Make sure that atomic primaries ate only what they were supposed to.
if succession == SuccessionRule::AtomicPrimary {
let len = newborn_span.len();
if newborns.len() > 1 && newborns[0].len() == len {
newborns.truncate(1);
} else if newborns.iter().map(Green::len).sum::<usize>() != len {
return None;
}
}
// // println!("Reparse success");
// Do not accept unclosed nodes if the old node wasn't at the right edge
// of the tree.
@ -260,362 +219,64 @@ impl Reparser<'_> {
return None;
}
// If all post- and preconditions match, we are good to go!
if validate(
green.children(),
superseded_range.clone(),
at_start,
&newborns,
mode,
succession,
newborn_span.clone(),
self.src,
) {
green.replace_children(superseded_range, newborns);
Some(newborn_span)
} else {
None
if !parent_outermost && green.children()[superseded_start ..].len() == amount {
return None;
}
green.replace_children(superseded_start .. superseded_start + amount, newborns);
Some(newborn_span)
}
}
/// Validate that a node replacement is allowed by post- and preconditions.
fn validate(
superseded: &[Green],
superseded_range: Range<usize>,
mut at_start: bool,
newborns: &[Green],
mode: TokenMode,
post: SuccessionRule,
newborn_span: Range<usize>,
src: &str,
) -> bool {
// Atomic primaries must only generate one new child.
if post == SuccessionRule::AtomicPrimary && newborns.len() != 1 {
return false;
}
// Same kind in mode `inside` must generate only one child and that child
// must be of the same kind as previously.
if let SuccessionRule::SameKind(inside) = post {
let superseded_kind = superseded[superseded_range.start].kind();
let superseded_mode = superseded_kind.mode().unwrap_or(mode);
if inside.map_or(true, |m| m == superseded_mode)
&& (newborns.len() != 1 || superseded_kind != newborns[0].kind())
{
return false;
}
}
// Neighbor invariants are only relevant in markup mode.
if mode == TokenMode::Code {
return true;
}
// Check if there are any `AtStart` predecessors which require a certain
// indentation.
let s = Scanner::new(src);
let mut prev_pos = newborn_span.start;
for child in (&superseded[.. superseded_range.start]).iter().rev() {
prev_pos -= child.len();
if !child.kind().is_trivia() {
if child.kind().neighbour_rule() == NeighbourRule::AtStart {
let left_col = s.column(prev_pos);
// Search for the first non-trivia newborn.
let mut new_pos = newborn_span.start;
let mut child_col = None;
for child in newborns {
if !child.kind().is_trivia() {
child_col = Some(s.column(new_pos));
break;
}
new_pos += child.len();
}
if let Some(child_col) = child_col {
if child_col > left_col {
return false;
}
}
}
break;
}
}
// Compute the at_start state behind the new children.
for child in newborns {
at_start = child.kind().is_at_start(at_start);
}
// Ensure that a possible at-start or not-at-start precondition of
// a node after the replacement range is satisfied.
for child in &superseded[superseded_range.end ..] {
let neighbour_rule = child.kind().neighbour_rule();
if (neighbour_rule == NeighbourRule::AtStart && !at_start)
|| (neighbour_rule == NeighbourRule::NotAtStart && at_start)
{
return false;
}
if !child.kind().is_trivia() {
break;
}
at_start = child.kind().is_at_start(at_start);
}
// Verify that the last of the newborns is not `NotAtEnd`.
if newborns.last().map_or(false, |child| {
child.kind().neighbour_rule() == NeighbourRule::NotAtEnd
}) {
return false;
}
// We have to check whether the last non-trivia newborn is `AtStart` and
// verify the indent of its right neighbors in order to make sure its
// indentation requirements are fulfilled.
let mut child_pos = newborn_span.end;
for child in newborns.iter().rev() {
child_pos -= child.len();
if child.kind().is_trivia() {
continue;
}
if child.kind().neighbour_rule() == NeighbourRule::AtStart {
let child_col = s.column(child_pos)
+ match child.kind() {
NodeKind::Heading => child
.children()
.iter()
.filter(|n| n.kind() == &NodeKind::Eq)
.count(),
NodeKind::List => 1,
NodeKind::Enum => child.children().first().unwrap().len(),
_ => 0,
};
let mut right_pos = newborn_span.end;
for child in &superseded[superseded_range.end ..] {
if child.kind().is_trivia() {
right_pos += child.len();
continue;
}
if s.column(right_pos) > child_col {
return false;
}
break;
}
}
break;
}
true
#[derive(Clone, Copy, Debug, PartialEq)]
struct GreenPos {
idx: usize,
offset: usize,
}
impl NodeKind {
/// Return the correct reparsing function given the postconditions for the
/// type.
fn reparsing_func(
&self,
parent_mode: TokenMode,
indent: usize,
) -> Option<fn(&str, &str, bool, usize) -> Option<(Vec<Green>, bool)>> {
let mode = self.mode().unwrap_or(parent_mode);
match self.succession_rule() {
SuccessionRule::Unsafe | SuccessionRule::UnsafeLayer => None,
SuccessionRule::AtomicPrimary => match mode {
TokenMode::Code => Some(parse_atomic),
TokenMode::Markup => Some(parse_atomic_markup),
},
SuccessionRule::SameKind(x) if x == None || x == Some(mode) => match self {
NodeKind::Markup(_) => Some(parse_markup),
NodeKind::Template => Some(parse_template),
NodeKind::Block => Some(parse_block),
NodeKind::LineComment | NodeKind::BlockComment => Some(parse_comment),
_ => None,
},
_ => match mode {
TokenMode::Markup if indent == 0 => Some(parse_markup_elements),
_ => return None,
},
}
/// Encodes the state machine of the search for the node which is pending for
/// replacement.
#[derive(Clone, Copy, Debug, PartialEq)]
enum SearchState {
/// Neither an end nor a start have been found as of now.
/// The last non-whitespace child is continually saved.
NoneFound,
/// The search has concluded by finding a node that fully contains the
/// modifications.
Contained(GreenPos),
/// The search has found the start of the modified nodes.
Inside(GreenPos),
/// The search has found the end of the modified nodes but the change
/// touched its boundries so another non-trivia node is needed.
RequireNonWS(GreenPos),
/// The search has concluded by finding a start and an end index for nodes
/// with a pending reparse.
SpanFound(GreenPos, GreenPos),
}
impl Default for SearchState {
fn default() -> Self {
Self::NoneFound
}
}
/// Whether it is safe to do incremental parsing on this node.
pub fn succession_rule(&self) -> SuccessionRule {
impl SearchState {
fn end(&self) -> Option<(GreenPos, GreenPos)> {
match self {
// These are all replaceable by other tokens.
Self::Linebreak
| Self::Text(_)
| Self::TextInLine(_)
| Self::NonBreakingSpace
| Self::EnDash
| Self::EmDash
| Self::Escape(_)
| Self::Strong
| Self::Emph
| Self::Heading
| Self::Enum
| Self::List
| Self::Math(_) => SuccessionRule::Safe,
// Only markup is expected at the points where it does occur. The
// indentation must be preserved as well, also for the children.
Self::Markup(_) => SuccessionRule::SameKind(None),
// These can appear everywhere and must not change to other stuff
// because that could change the outer expression.
Self::LineComment | Self::BlockComment => SuccessionRule::SameKind(None),
// These can appear as bodies and would trigger an error if they
// became something else.
Self::Template => SuccessionRule::SameKind(None),
Self::Block => SuccessionRule::SameKind(Some(TokenMode::Code)),
// Whitespace in code mode has to remain whitespace or else the type
// of things would change.
Self::Space(_) => SuccessionRule::SameKind(Some(TokenMode::Code)),
// These are expressions that can be replaced by other expressions.
Self::Ident(_)
| Self::Bool(_)
| Self::Int(_)
| Self::Float(_)
| Self::Length(_, _)
| Self::Angle(_, _)
| Self::Percentage(_)
| Self::Str(_)
| Self::Fraction(_)
| Self::Array
| Self::Dict
| Self::Group
| Self::None
| Self::Auto => SuccessionRule::AtomicPrimary,
// More complex, but still an expression.
Self::ForExpr
| Self::WhileExpr
| Self::IfExpr
| Self::LetExpr
| Self::SetExpr
| Self::ShowExpr
| Self::WrapExpr
| Self::ImportExpr
| Self::IncludeExpr
| Self::BreakExpr
| Self::ContinueExpr
| Self::ReturnExpr => SuccessionRule::AtomicPrimary,
// These are complex expressions which may screw with their
// environments.
Self::Call
| Self::Unary
| Self::Binary
| Self::CallArgs
| Self::Named
| Self::Spread => SuccessionRule::UnsafeLayer,
// The closure is a bit magic with the let expression, and also it
// is not atomic.
Self::Closure | Self::ClosureParams => SuccessionRule::UnsafeLayer,
// Missing these creates errors for the parents.
Self::WithExpr | Self::ForPattern | Self::ImportItems => {
SuccessionRule::UnsafeLayer
}
// Replacing parenthesis changes if the expression is balanced and
// is therefore not safe.
Self::LeftBracket
| Self::RightBracket
| Self::LeftBrace
| Self::RightBrace
| Self::LeftParen
| Self::RightParen => SuccessionRule::Unsafe,
// These work similar to parentheses.
Self::Star | Self::Underscore => SuccessionRule::Unsafe,
// Replacing an operator can change whether the parent is an
// operation which makes it unsafe.
Self::Comma
| Self::Semicolon
| Self::Colon
| Self::Plus
| Self::Minus
| Self::Slash
| Self::Eq
| Self::EqEq
| Self::ExclEq
| Self::Lt
| Self::LtEq
| Self::Gt
| Self::GtEq
| Self::PlusEq
| Self::HyphEq
| Self::StarEq
| Self::SlashEq
| Self::Not
| Self::And
| Self::Or
| Self::With
| Self::Dots
| Self::Arrow => SuccessionRule::Unsafe,
// These keywords change what kind of expression the parent is and
// how far the expression would go.
Self::Let
| Self::Set
| Self::Show
| Self::Wrap
| Self::If
| Self::Else
| Self::For
| Self::In
| Self::As
| Self::While
| Self::Break
| Self::Continue
| Self::Return
| Self::Import
| Self::Include
| Self::From => SuccessionRule::Unsafe,
// This element always has to remain in the same column so better
// reparse the whole parent.
Self::Raw(_) => SuccessionRule::Unsafe,
// Changing the heading level, enum numbering, or list bullet
// changes the next layer.
Self::EnumNumbering(_) => SuccessionRule::Unsafe,
// This can be anything, so we don't make any promises.
Self::Error(_, _) | Self::Unknown(_) => SuccessionRule::Unsafe,
}
}
/// Whether it is safe to insert this node next to some nodes or vice versa.
pub fn neighbour_rule(&self) -> NeighbourRule {
match self {
Self::Heading | Self::Enum | Self::List => NeighbourRule::AtStart,
Self::TextInLine(_) => NeighbourRule::NotAtStart,
Self::Error(_, _) => NeighbourRule::NotAtEnd,
_ => NeighbourRule::None,
Self::NoneFound => None,
Self::Contained(s) => Some((*s, *s)),
Self::Inside(_) => None,
Self::RequireNonWS(_) => None,
Self::SpanFound(s, e) => Some((*s, *e)),
}
}
}
impl SuccessionRule {
/// Whether a node with this condition can be reparsed in markup mode.
pub fn safe_in_markup(&self) -> bool {
impl NodeKind {
/// Whether this node has to appear at the start of a line.
pub fn only_at_start(&self) -> bool {
match self {
Self::Safe | Self::UnsafeLayer => true,
Self::SameKind(mode) => mode.map_or(false, |m| m != TokenMode::Markup),
Self::Heading | Self::Enum | Self::List => true,
_ => false,
}
}
@ -639,59 +300,62 @@ mod tests {
#[test]
fn test_parse_incremental_simple_replacements() {
test("hello world", 7 .. 12, "walkers", 5 .. 14);
test("hello world", 7 .. 12, "walkers", 0 .. 14);
test("some content", 0..12, "", 0..0);
test("", 0..0, "do it", 0..5);
test("a d e", 1 .. 3, " b c d", 0 .. 9);
test("a #f() e", 1 .. 6, " b c d", 0 .. 9);
test("a\nb\nc\nd\ne\n", 5..5, "c", 3..8);
test("a\n\nb\n\nc\n\nd\n\ne\n", 7..7, "c", 4..11);
test("a\nb\nc\nd\ne\n", 5 .. 5, "c", 4 .. 7);
test("a\n\nb\n\nc\n\nd\n\ne\n", 7 .. 7, "c", 6 .. 10);
test("a\nb\nc *hel a b lo* d\nd\ne", 13..13, "c ", 6..20);
test("{a}", 1 .. 2, "b", 1 .. 2);
test("{(0, 1, 2)}", 5 .. 6, "11pt", 5 .. 9);
test("\n= A heading", 3 .. 3, "n evocative", 1 .. 23);
test("for~your~thing", 9 .. 9, "a", 4 .. 15);
test("~~ {a} ~~", 4 .. 5, "b", 3 .. 6);
test("{(0, 1, 2)}", 5 .. 6, "11pt", 0..14);
test("\n= A heading", 3 .. 3, "n evocative", 3 .. 23);
test("for~your~thing", 9 .. 9, "a", 8 .. 15);
test("a your thing a", 6 .. 7, "a", 0 .. 14);
test("{call(); abc}", 7 .. 7, "[]", 0 .. 15);
test("#call() abc", 7 .. 7, "[]", 0 .. 13);
test("hi[\n- item\n- item 2\n - item 3]", 11 .. 11, " ", 4 .. 34);
test("hi\n- item\nno item\n - item 3", 10 .. 10, "- ", 0 .. 32);
test("#grid(columns: (auto, 1fr, 40%), [*plonk*], rect(width: 100%, height: 1pt, fill: conifer), [thing])", 16 .. 20, "none", 16 .. 20);
test("#grid(columns: (auto, 1fr, 40%), [*plonk*], rect(width: 100%, height: 1pt, fill: conifer), [thing])", 33 .. 42, "[_gronk_]", 33 .. 42);
test("#grid(columns: (auto, 1fr, 40%), [*plonk*], rect(width: 100%, height: 1pt, fill: conifer), [thing])", 34 .. 41, "_bar_", 34 .. 39);
test("{let i=1; for x in range(5) {i}}", 6 .. 6, " ", 1 .. 9);
test("{let i=1; for x in range(5) {i}}", 13 .. 14, " ", 10 .. 32);
test("hello~~{x}", 7 .. 10, "#f()", 5 .. 11);
test("#call() abc", 7 .. 7, "[]", 0 .. 10);
// Investigate
test("hi[\n- item\n- item 2\n - item 3]", 11 .. 11, " ", 2 .. 35);
test("hi\n- item\nno item\n - item 3", 10 .. 10, "- ", 3..19);
test("#grid(columns: (auto, 1fr, 40%), [*plonk*], rect(width: 100%, height: 1pt, fill: conifer), [thing])", 16 .. 20, "none", 0..99);
test("#grid(columns: (auto, 1fr, 40%), [*plonk*], rect(width: 100%, height: 1pt, fill: conifer), [thing])", 33 .. 42, "[_gronk_]", 33..42);
test("#grid(columns: (auto, 1fr, 40%), [*plonk*], rect(width: 100%, height: 1pt, fill: conifer), [thing])", 34 .. 41, "_bar_", 33 .. 40);
test("{let i=1; for x in range(5) {i}}", 6 .. 6, " ", 0 .. 33);
test("{let i=1; for x in range(5) {i}}", 13 .. 14, " ", 0 .. 33);
// Investigate
test("hello~~{x}", 7 .. 10, "#f()", 0 .. 11);
test("this~is -- in my opinion -- spectacular", 8 .. 10, "---", 5 .. 25);
test("understanding `code` is complicated", 15 .. 15, "C ", 0 .. 37);
test("{ let x = g() }", 10 .. 12, "f(54", 2 .. 15);
test("understanding `code` is complicated", 15 .. 15, "C ", 14 .. 22);
test("{ let x = g() }", 10 .. 12, "f(54", 0 .. 17);
test("a #let rect with (fill: eastern)\nb", 16 .. 31, " (stroke: conifer", 2 .. 34);
test(r#"a ```typst hello``` b"#, 16 .. 17, "", 0 .. 20);
test(r#"a ```typst hello```"#, 16 .. 17, "", 0 .. 18);
test(r#"a ```typst hello```"#, 16 .. 17, "", 2 .. 18);
test("#for", 4 .. 4, "//", 0 .. 6);
}
#[test]
fn test_parse_incremental_whitespace_invariants() {
test("hello \\ world", 7 .. 8, "a ", 5 .. 14);
test("hello \\ world", 7 .. 8, " a", 5 .. 14);
test("x = y", 1 .. 1, " + y", 0 .. 7);
test("x = y", 1 .. 1, " + y\n", 0 .. 10);
test("abc\n= a heading\njoke", 3 .. 4, "\nmore\n\n", 0 .. 22);
test("abc\n= a heading\njoke", 3 .. 4, "\nnot ", 0 .. 20);
test("#let x = (1, 2 + ;~ Five\r\n\r", 20..23, "2.", 18..23);
test("hello \\ world", 7 .. 8, "a ", 6 .. 14);
test("hello \\ world", 7 .. 8, " a", 6 .. 14);
test("x = y", 1 .. 1, " + y", 0 .. 6);
test("x = y", 1 .. 1, " + y\n", 0 .. 7);
test("abc\n= a heading\njoke", 3 .. 4, "\nmore\n\n", 0 .. 21);
test("abc\n= a heading\njoke", 3 .. 4, "\nnot ", 0 .. 19);
test("#let x = (1, 2 + ;~ Five\r\n\r", 20 .. 23, "2.", 18 .. 23);
test("hey #myfriend", 4 .. 4, "\\", 0 .. 14);
test("hey #myfriend", 4 .. 4, "\\", 0 .. 6);
test("hey #myfriend", 4 .. 4, "\\", 3 .. 6);
test("= foo\nbar\n - a\n - b", 6 .. 9, "", 0..11)
}
#[test]
fn test_parse_incremental_type_invariants() {
test("a #for x in array {x}", 18 .. 21, "[#x]", 2 .. 22);
test("a #let x = 1 {5}", 3 .. 6, "if", 0 .. 15);
test("a {let x = 1 {5}} b", 3 .. 6, "if", 1 .. 16);
test("#let x = 1 {5}", 4 .. 4, " if", 0 .. 17);
test("a #for x in array {x}", 18 .. 21, "[#x]", 0 .. 22);
test("a #let x = 1 {5}", 3 .. 6, "if", 2 .. 11);
test("a {let x = 1 {5}} b", 3 .. 6, "if", 2 .. 16);
test("#let x = 1 {5}", 4 .. 4, " if", 0 .. 13);
test("{let x = 1 {5}}", 4 .. 4, " if", 0 .. 18);
test("a // b c #f()", 3 .. 4, "", 0 .. 12);
test("a // b c #f()", 3 .. 4, "", 2 .. 12);
test("{\nf()\n//g(a)\n}", 6 .. 8, "", 0 .. 12);
test("a{\nf()\n//g(a)\n}b", 7 .. 9, "", 1 .. 13);
test("a #while x {\n g(x) \n} b", 11 .. 11, "//", 0 .. 26);
@ -707,12 +371,12 @@ mod tests {
test(r"{{let x = z}; a = 1} b", 6 .. 6, "//", 0 .. 24);
test("a b c", 1 .. 1, " /* letters */", 0 .. 19);
test("a b c", 1 .. 1, " /* letters", 0 .. 16);
test("{if i==1 {a} else [b]; b()}", 12 .. 12, " /* letters */", 1 .. 35);
test("{if i==1 {a} else [b]; b()}", 12 .. 12, " /* letters */", 0 .. 41);
test("{if i==1 {a} else [b]; b()}", 12 .. 12, " /* letters", 0 .. 38);
test("~~~~", 2 .. 2, "[]", 0 .. 6);
test("a[]b", 2 .. 2, "{", 0 .. 5);
test("~~~~", 2 .. 2, "[]", 1 .. 5);
test("a[]b", 2 .. 2, "{", 1 .. 4);
test("[hello]", 2 .. 3, "]", 0 .. 7);
test("{a}", 1 .. 2, "b", 1 .. 2);
test("{a}", 1 .. 2, "b", 0 .. 3);
test("{ a; b; c }", 5 .. 6, "[}]", 0 .. 13);
test("#a()\n~", 3..4, "{}", 0..7);
test("[]\n~", 1..2, "#if i==0 {true}", 0..18);

View File

@ -28,103 +28,124 @@ pub fn parse(src: &str) -> Arc<GreenNode> {
}
}
/// Parse some markup. Returns `Some` if all of the input was consumed.
pub fn parse_markup(
prefix: &str,
src: &str,
_: bool,
min_column: usize,
) -> Option<(Vec<Green>, bool)> {
let mut p = Parser::with_prefix(prefix, src, TokenMode::Markup);
if min_column == 0 {
markup(&mut p, true);
} else {
markup_indented(&mut p, min_column);
}
p.consume()
}
/// Parse some markup without the topmost node. Returns `Some` if all of the
/// input was consumed.
pub fn parse_markup_elements(
prefix: &str,
src: &str,
end_pos: usize,
differential: isize,
reference: &[Green],
mut at_start: bool,
_: usize,
) -> Option<(Vec<Green>, bool)> {
) -> Option<(Vec<Green>, bool, usize)> {
let mut p = Parser::with_prefix(prefix, src, TokenMode::Markup);
let mut node: Option<&Green> = None;
let mut iter = reference.iter();
let mut offset = 0;
let mut replaced = 0;
let mut stopped = false;
while !p.eof() {
markup_node(&mut p, &mut at_start);
if p.prev_end() >= end_pos {
let recent = p.children.last().unwrap();
let recent_start = p.prev_end() - recent.len();
while offset <= recent_start {
if let Some(node) = node {
// The nodes are equal, at the same position and have the
// same content. The parsing trees have converged again, so
// the reparse may stop here.
if (offset as isize + differential) as usize == recent_start
&& node == recent
{
replaced -= 1;
stopped = true;
break;
}
}
let result = iter.next();
if let Some(node) = node {
offset += node.len();
}
node = result;
if node.is_none() {
break;
} else {
replaced += 1;
}
}
if stopped {
break;
}
}
}
p.consume()
}
/// Parse an atomic primary. Returns `Some` if all of the input was consumed.
pub fn parse_atomic(
prefix: &str,
src: &str,
_: bool,
_: usize,
) -> Option<(Vec<Green>, bool)> {
let mut p = Parser::with_prefix(prefix, src, TokenMode::Code);
primary(&mut p, true).ok()?;
p.consume_open_ended()
}
if p.eof() && !stopped {
replaced = reference.len();
}
/// Parse an atomic primary. Returns `Some` if all of the input was consumed.
pub fn parse_atomic_markup(
prefix: &str,
src: &str,
_: bool,
_: usize,
) -> Option<(Vec<Green>, bool)> {
let mut p = Parser::with_prefix(prefix, src, TokenMode::Markup);
markup_expr(&mut p);
p.consume_open_ended()
let (mut res, terminated) = p.consume_open_ended()?;
if stopped {
res.pop().unwrap();
}
Some((res, terminated, replaced))
}
/// Parse a template literal. Returns `Some` if all of the input was consumed.
pub fn parse_template(
prefix: &str,
src: &str,
end_pos: usize,
_: isize,
reference: &[Green],
_: bool,
_: usize,
) -> Option<(Vec<Green>, bool)> {
) -> Option<(Vec<Green>, bool, usize)> {
let mut p = Parser::with_prefix(prefix, src, TokenMode::Code);
if !p.at(&NodeKind::LeftBracket) {
return None;
}
template(&mut p);
p.consume()
let (mut green, terminated) = p.consume_open_ended()?;
let first = green.remove(0);
if first.len() != end_pos {
return None;
}
Some((vec![first], terminated, 1))
}
/// Parse a code block. Returns `Some` if all of the input was consumed.
pub fn parse_block(
prefix: &str,
src: &str,
end_pos: usize,
_: isize,
reference: &[Green],
_: bool,
_: usize,
) -> Option<(Vec<Green>, bool)> {
) -> Option<(Vec<Green>, bool, usize)> {
let mut p = Parser::with_prefix(prefix, src, TokenMode::Code);
if !p.at(&NodeKind::LeftBrace) {
return None;
}
block(&mut p);
p.consume()
}
/// Parse a comment. Returns `Some` if all of the input was consumed.
pub fn parse_comment(
prefix: &str,
src: &str,
_: bool,
_: usize,
) -> Option<(Vec<Green>, bool)> {
let mut p = Parser::with_prefix(prefix, src, TokenMode::Code);
comment(&mut p).ok()?;
p.consume()
let (mut green, terminated) = p.consume_open_ended()?;
let first = green.remove(0);
if first.len() != end_pos {
return None;
}
Some((vec![first], terminated, 1))
}
/// Parse markup.
@ -916,17 +937,6 @@ fn body(p: &mut Parser) -> ParseResult {
Ok(())
}
/// Parse a comment.
fn comment(p: &mut Parser) -> ParseResult {
match p.peek() {
Some(NodeKind::LineComment | NodeKind::BlockComment) => {
p.eat();
Ok(())
}
_ => Err(ParseError),
}
}
#[cfg(test)]
mod tests {
use std::fmt::Debug;

View File

@ -7,8 +7,6 @@ use crate::syntax::{ErrorPos, Green, GreenData, GreenNode, NodeKind};
/// A convenient token-based parser.
pub struct Parser<'s> {
/// Offsets the indentation on the first line of the source.
column_offset: usize,
/// An iterator over the source tokens.
tokens: Tokens<'s>,
/// Whether we are at the end of the file or of a group.
@ -22,7 +20,7 @@ pub struct Parser<'s> {
/// The stack of open groups.
groups: Vec<GroupEntry>,
/// The children of the currently built node.
children: Vec<Green>,
pub children: Vec<Green>,
/// Whether the last group was not correctly terminated.
unterminated_group: bool,
/// Whether a group terminator was found, that did not close a group.
@ -32,10 +30,13 @@ pub struct Parser<'s> {
impl<'s> Parser<'s> {
/// Create a new parser for the source string.
pub fn new(src: &'s str, mode: TokenMode) -> Self {
let mut tokens = Tokens::new(src, mode);
Self::with_offset(src, mode, 0)
}
fn with_offset(src: &'s str, mode: TokenMode, offset: usize) -> Self {
let mut tokens = Tokens::new(src, mode, offset);
let current = tokens.next();
Self {
column_offset: 0,
tokens,
eof: current.is_none(),
current,
@ -52,9 +53,7 @@ impl<'s> Parser<'s> {
/// that does not need to be parsed but taken into account for column
/// calculation.
pub fn with_prefix(prefix: &str, src: &'s str, mode: TokenMode) -> Self {
let mut p = Self::new(src, mode);
p.column_offset = Scanner::new(prefix).column(prefix.len());
p
Self::with_offset(src, mode, Scanner::new(prefix).column(prefix.len()))
}
/// End the parsing process and return the last child.
@ -226,7 +225,7 @@ impl<'s> Parser<'s> {
/// Determine the column index for the given byte index.
pub fn column(&self, index: usize) -> usize {
self.tokens.scanner().column_offset(index, self.column_offset)
self.tokens.scanner().column(index)
}
/// Continue parsing in a group.

View File

@ -10,13 +10,21 @@ pub struct Scanner<'s> {
/// The index at which the peekable character starts. Must be in bounds and
/// at a codepoint boundary to guarantee safety.
index: usize,
/// Offsets the indentation on the first line of the source.
column_offset: usize,
}
impl<'s> Scanner<'s> {
/// Create a new char scanner.
#[inline]
pub fn new(src: &'s str) -> Self {
Self { src, index: 0 }
Self { src, index: 0, column_offset: 0 }
}
/// Create a new char scanner with an offset for the first line indent.
#[inline]
pub fn with_indent_offset(src: &'s str, column_offset: usize) -> Self {
Self { src, index: 0, column_offset }
}
/// Whether the end of the string is reached.
@ -173,13 +181,6 @@ impl<'s> Scanner<'s> {
/// The column index of a given index in the source string.
#[inline]
pub fn column(&self, index: usize) -> usize {
self.column_offset(index, 0)
}
/// The column index of a given index in the source string when an offset is
/// applied to the first line of the string.
#[inline]
pub fn column_offset(&self, index: usize, offset: usize) -> usize {
let mut apply_offset = false;
let res = self.src[.. index]
.char_indices()
@ -192,7 +193,13 @@ impl<'s> Scanner<'s> {
})
.count();
if apply_offset { res + offset } else { res }
// The loop is never executed if the slice is empty, but we are of
// course still at the start of the first line.
if self.src[.. index].len() == 0 {
apply_offset = true;
}
if apply_offset { res + self.column_offset } else { res }
}
}

View File

@ -28,9 +28,9 @@ pub enum TokenMode {
impl<'s> Tokens<'s> {
/// Create a new token iterator with the given mode.
#[inline]
pub fn new(src: &'s str, mode: TokenMode) -> Self {
pub fn new(src: &'s str, mode: TokenMode, offset: usize) -> Self {
Self {
s: Scanner::new(src),
s: Scanner::with_indent_offset(src, offset),
mode,
terminated: true,
}
@ -689,7 +689,7 @@ mod tests {
}};
(@$mode:ident: $src:expr => $($token:expr),*) => {{
let src = $src;
let found = Tokens::new(&src, $mode).collect::<Vec<_>>();
let found = Tokens::new(&src, $mode, 0).collect::<Vec<_>>();
let expected = vec![$($token.clone()),*];
check(&src, found, expected);
}};