add snippet system to helix core

pull/9801/head
Pascal Kuthe 9 months ago
parent 97a35d2812
commit 2cf38ca29c
No known key found for this signature in database
GPG Key ID: D715E8655AE166A6

3
Cargo.lock generated

@ -1301,6 +1301,7 @@ name = "helix-core"
version = "24.7.0"
dependencies = [
"ahash",
"anyhow",
"arc-swap",
"bitflags 2.6.0",
"chrono",
@ -1310,6 +1311,7 @@ dependencies = [
"globset",
"hashbrown 0.14.5",
"helix-loader",
"helix-parsec",
"helix-stdx",
"imara-diff",
"indoc",
@ -1319,6 +1321,7 @@ dependencies = [
"parking_lot",
"quickcheck",
"regex",
"regex-cursor",
"ropey",
"serde",
"serde_json",

@ -18,6 +18,7 @@ integration = []
[dependencies]
helix-stdx = { path = "../helix-stdx" }
helix-loader = { path = "../helix-loader" }
helix-parsec = { path = "../helix-parsec" }
ropey = { version = "1.6.1", default-features = false, features = ["simd"] }
smallvec = "1.13"
@ -37,6 +38,7 @@ dunce = "1.0"
url = "2.5.0"
log = "0.4"
anyhow = "1.0"
serde = { version = "1.0", features = ["derive"] }
serde_json = "1.0"
toml = "0.8"
@ -53,6 +55,7 @@ textwrap = "0.16.1"
nucleo.workspace = true
parking_lot = "0.12"
globset = "0.4.14"
regex-cursor = "0.1.4"
[dev-dependencies]
quickcheck = { version = "1", default-features = false }

@ -0,0 +1,69 @@
use crate::Tendril;
// todo: should this be grapheme aware?
pub fn to_pascal_case(text: impl Iterator<Item = char>) -> Tendril {
let mut res = Tendril::new();
to_pascal_case_with(text, &mut res);
res
}
pub fn to_pascal_case_with(text: impl Iterator<Item = char>, buf: &mut Tendril) {
let mut at_word_start = true;
for c in text {
// we don't count _ as a word char here so case conversions work well
if !c.is_alphanumeric() {
at_word_start = true;
continue;
}
if at_word_start {
at_word_start = false;
buf.extend(c.to_uppercase());
} else {
buf.push(c)
}
}
}
pub fn to_upper_case_with(text: impl Iterator<Item = char>, buf: &mut Tendril) {
for c in text {
for c in c.to_uppercase() {
buf.push(c)
}
}
}
pub fn to_lower_case_with(text: impl Iterator<Item = char>, buf: &mut Tendril) {
for c in text {
for c in c.to_lowercase() {
buf.push(c)
}
}
}
pub fn to_camel_case(text: impl Iterator<Item = char>) -> Tendril {
let mut res = Tendril::new();
to_camel_case_with(text, &mut res);
res
}
pub fn to_camel_case_with(mut text: impl Iterator<Item = char>, buf: &mut Tendril) {
for c in &mut text {
if c.is_alphanumeric() {
buf.extend(c.to_lowercase())
}
}
let mut at_word_start = false;
for c in text {
// we don't count _ as a word char here so case conversions work well
if !c.is_alphanumeric() {
at_word_start = true;
continue;
}
if at_word_start {
at_word_start = false;
buf.extend(c.to_uppercase());
} else {
buf.push(c)
}
}
}

@ -1,4 +1,4 @@
use std::{borrow::Cow, collections::HashMap};
use std::{borrow::Cow, collections::HashMap, iter};
use helix_stdx::rope::RopeSliceExt;
use tree_sitter::{Query, QueryCursor, QueryPredicateArg};
@ -8,7 +8,7 @@ use crate::{
graphemes::{grapheme_width, tab_width_at},
syntax::{IndentationHeuristic, LanguageConfiguration, RopeProvider, Syntax},
tree_sitter::Node,
Position, Rope, RopeGraphemes, RopeSlice,
Position, Rope, RopeGraphemes, RopeSlice, Tendril,
};
/// Enum representing indentation style.
@ -210,6 +210,36 @@ fn whitespace_with_same_width(text: RopeSlice) -> String {
s
}
/// normalizes indentation to tabs/spaces based on user configurtion This
/// function does not change the actual indentaiton width just the character
/// composition.
pub fn normalize_indentation(
prefix: RopeSlice<'_>,
line: RopeSlice<'_>,
dst: &mut Tendril,
indent_style: IndentStyle,
tab_width: usize,
) -> usize {
#[allow(deprecated)]
let off = crate::visual_coords_at_pos(prefix, prefix.len_chars(), tab_width).col;
let mut len = 0;
let mut original_len = 0;
for ch in line.chars() {
match ch {
'\t' => len += tab_width_at(len + off, tab_width as u16),
' ' => len += 1,
_ => break,
}
original_len += 1;
}
if indent_style == IndentStyle::Tabs {
dst.extend(iter::repeat('\t').take(len / tab_width));
len %= tab_width;
}
dst.extend(iter::repeat(' ').take(len));
original_len
}
fn add_indent_level(
mut base_indent: String,
added_indent_level: isize,

@ -1,6 +1,7 @@
pub use encoding_rs as encoding;
pub mod auto_pairs;
pub mod case_conversion;
pub mod chars;
pub mod comment;
pub mod config;
@ -21,6 +22,7 @@ mod position;
pub mod search;
pub mod selection;
pub mod shellwords;
pub mod snippets;
pub mod surround;
pub mod syntax;
pub mod test;

@ -0,0 +1,13 @@
mod active;
mod elaborate;
mod parser;
mod render;
#[derive(PartialEq, Eq, Hash, Debug, PartialOrd, Ord, Clone, Copy)]
pub struct TabstopIdx(usize);
pub const LAST_TABSTOP_IDX: TabstopIdx = TabstopIdx(usize::MAX);
pub use active::ActiveSnippet;
pub use elaborate::{Snippet, SnippetElement, Transform};
pub use render::RenderedSnippet;
pub use render::SnippetRenderCtx;

@ -0,0 +1,255 @@
use std::ops::{Index, IndexMut};
use hashbrown::HashSet;
use helix_stdx::range::{is_exact_subset, is_subset};
use helix_stdx::Range;
use ropey::Rope;
use crate::movement::Direction;
use crate::snippets::render::{RenderedSnippet, Tabstop};
use crate::snippets::TabstopIdx;
use crate::{Assoc, ChangeSet, Selection, Transaction};
pub struct ActiveSnippet {
ranges: Vec<Range>,
active_tabstops: HashSet<TabstopIdx>,
active_tabstop: TabstopIdx,
tabstops: Vec<Tabstop>,
}
impl Index<TabstopIdx> for ActiveSnippet {
type Output = Tabstop;
fn index(&self, index: TabstopIdx) -> &Tabstop {
&self.tabstops[index.0]
}
}
impl IndexMut<TabstopIdx> for ActiveSnippet {
fn index_mut(&mut self, index: TabstopIdx) -> &mut Tabstop {
&mut self.tabstops[index.0]
}
}
impl ActiveSnippet {
pub fn new(snippet: RenderedSnippet) -> Option<Self> {
let snippet = Self {
ranges: snippet.ranges,
tabstops: snippet.tabstops,
active_tabstops: HashSet::new(),
active_tabstop: TabstopIdx(0),
};
(snippet.tabstops.len() != 1).then_some(snippet)
}
pub fn is_valid(&self, new_selection: &Selection) -> bool {
is_subset::<false>(self.ranges.iter().copied(), new_selection.range_bounds())
}
pub fn tabstops(&self) -> impl Iterator<Item = &Tabstop> {
self.tabstops.iter()
}
pub fn delete_placeholder(&self, doc: &Rope) -> Transaction {
Transaction::delete(
doc,
self[self.active_tabstop]
.ranges
.iter()
.map(|range| (range.start, range.end)),
)
}
/// maps the active snippets trough a `ChangeSet` updating all tabstop ranges
pub fn map(&mut self, changes: &ChangeSet) -> bool {
let positions_to_map = self.ranges.iter_mut().flat_map(|range| {
[
(&mut range.start, Assoc::After),
(&mut range.end, Assoc::Before),
]
});
changes.update_positions(positions_to_map);
for (i, tabstop) in self.tabstops.iter_mut().enumerate() {
if self.active_tabstops.contains(&TabstopIdx(i)) {
let positions_to_map = tabstop.ranges.iter_mut().flat_map(|range| {
let end_assoc = if range.start == range.end {
Assoc::Before
} else {
Assoc::After
};
[
(&mut range.start, Assoc::Before),
(&mut range.end, end_assoc),
]
});
changes.update_positions(positions_to_map);
} else {
let positions_to_map = tabstop.ranges.iter_mut().flat_map(|range| {
let end_assoc = if range.start == range.end {
Assoc::After
} else {
Assoc::Before
};
[
(&mut range.start, Assoc::After),
(&mut range.end, end_assoc),
]
});
changes.update_positions(positions_to_map);
}
let mut snippet_ranges = self.ranges.iter();
let mut snippet_range = snippet_ranges.next().unwrap();
let mut tabstop_i = 0;
let mut prev = Range { start: 0, end: 0 };
let num_ranges = tabstop.ranges.len() / self.ranges.len();
tabstop.ranges.retain_mut(|range| {
if tabstop_i == num_ranges {
snippet_range = snippet_ranges.next().unwrap();
tabstop_i = 0;
}
tabstop_i += 1;
let retain = snippet_range.start <= snippet_range.end;
if retain {
range.start = range.start.max(snippet_range.start);
range.end = range.end.max(range.start).min(snippet_range.end);
// garunteed by assoc
debug_assert!(prev.start <= range.start);
debug_assert!(range.start <= range.end);
if prev.end > range.start {
// not really sure what to do in this case. It shouldn't
// really occur in practice% the below just ensures
// our invriants hold
range.start = prev.end;
range.end = range.end.max(range.start)
}
prev = *range;
}
retain
});
}
self.ranges.iter().all(|range| range.end <= range.start)
}
pub fn next_tabstop(&mut self, current_selection: &Selection) -> (Selection, bool) {
let primary_idx = self.primary_idx(current_selection);
while self.active_tabstop.0 + 1 < self.tabstops.len() {
self.active_tabstop.0 += 1;
if self.activate_tabstop() {
let selection = self.tabstop_selection(primary_idx, Direction::Forward);
return (selection, self.active_tabstop.0 + 1 == self.tabstops.len());
}
}
(
self.tabstop_selection(primary_idx, Direction::Forward),
true,
)
}
pub fn prev_tabstop(&mut self, current_selection: &Selection) -> Option<Selection> {
let primary_idx = self.primary_idx(current_selection);
while self.active_tabstop.0 != 0 {
self.active_tabstop.0 -= 1;
if self.activate_tabstop() {
return Some(self.tabstop_selection(primary_idx, Direction::Forward));
}
}
None
}
// computes the primary idx adjust for the number of cursors in the current tabstop
fn primary_idx(&self, current_selection: &Selection) -> usize {
let primary: Range = current_selection.primary().into();
let res = self
.ranges
.iter()
.position(|&range| range.contains(primary));
res.unwrap_or_else(|| {
unreachable!(
"active snippet must be valid {current_selection:?} {:?}",
self.ranges
)
})
}
fn activate_tabstop(&mut self) -> bool {
let tabstop = &self[self.active_tabstop];
if tabstop.has_placeholder() && tabstop.ranges.iter().all(|range| range.is_empty()) {
return false;
}
self.active_tabstops.clear();
self.active_tabstops.insert(self.active_tabstop);
let mut parent = self[self.active_tabstop].parent;
while let Some(tabstop) = parent {
self.active_tabstops.insert(tabstop);
parent = self[tabstop].parent;
}
true
// TODO: if the user removes the seleciton(s) in one snippet (but
// there are still other cursors in other snippets) and jumps to the
// next tabstop the selection in that tabstop is restored (at the
// next tabstop). This could be annoying since its not possible to
// remove a snippet cursor until the snippet is complete. On the other
// hand it may be useful since the user may just have meant to edit
// a subselection (like with s) of the tabstops and so the selection
// removal was just temporary. Potentially this could have some sort of
// seperate keymap
}
pub fn tabstop_selection(&self, primary_idx: usize, direction: Direction) -> Selection {
let tabstop = &self[self.active_tabstop];
tabstop.selection(direction, primary_idx, self.ranges.len())
}
pub fn insert_subsnippet(mut self, snippet: RenderedSnippet) -> Option<Self> {
if snippet.ranges.len() % self.ranges.len() != 0
|| !is_exact_subset(self.ranges.iter().copied(), snippet.ranges.iter().copied())
{
log::warn!("number of subsnippets did not match, discarding outer snippet");
return ActiveSnippet::new(snippet);
}
let mut cnt = 0;
let parent = self[self.active_tabstop].parent;
let tabstops = snippet.tabstops.into_iter().map(|mut tabstop| {
cnt += 1;
if let Some(parent) = &mut tabstop.parent {
parent.0 += self.active_tabstop.0;
} else {
tabstop.parent = parent;
}
tabstop
});
self.tabstops
.splice(self.active_tabstop.0..=self.active_tabstop.0, tabstops);
self.activate_tabstop();
Some(self)
}
}
#[cfg(test)]
mod tests {
use std::iter::{self};
use ropey::Rope;
use crate::snippets::{ActiveSnippet, Snippet, SnippetRenderCtx};
use crate::{Selection, Transaction};
#[test]
fn fully_remove() {
let snippet = Snippet::parse("foo(${1:bar})$0").unwrap();
let mut doc = Rope::from("bar.\n");
let (transaction, _, snippet) = snippet.render(
&doc,
&Selection::point(4),
|_| (4, 4),
&mut SnippetRenderCtx::test_ctx(),
);
assert!(transaction.apply(&mut doc));
assert_eq!(doc, "bar.foo(bar)\n");
let mut snippet = ActiveSnippet::new(snippet).unwrap();
let edit = Transaction::change(&doc, iter::once((4, 12, None)));
assert!(edit.apply(&mut doc));
snippet.map(edit.changes());
assert!(!snippet.is_valid(&Selection::point(4)))
}
}

@ -0,0 +1,378 @@
use std::mem::swap;
use std::ops::Index;
use std::sync::Arc;
use anyhow::{anyhow, Result};
use helix_stdx::rope::RopeSliceExt;
use helix_stdx::Range;
use regex_cursor::engines::meta::Builder as RegexBuilder;
use regex_cursor::engines::meta::Regex;
use regex_cursor::regex_automata::util::syntax::Config as RegexConfig;
use ropey::RopeSlice;
use crate::case_conversion::to_lower_case_with;
use crate::case_conversion::to_upper_case_with;
use crate::case_conversion::{to_camel_case_with, to_pascal_case_with};
use crate::snippets::parser::{self, CaseChange, FormatItem};
use crate::snippets::{TabstopIdx, LAST_TABSTOP_IDX};
use crate::Tendril;
#[derive(Debug)]
pub struct Snippet {
elements: Vec<SnippetElement>,
tabstops: Vec<Tabstop>,
}
impl Snippet {
pub fn parse(snippet: &str) -> Result<Self> {
let parsed_snippet = parser::parse(snippet)
.map_err(|rest| anyhow!("Failed to parse snippet. Remaining input: {}", rest))?;
Ok(Snippet::new(parsed_snippet))
}
pub fn new(elements: Vec<parser::SnippetElement>) -> Snippet {
let mut res = Snippet {
elements: Vec::new(),
tabstops: Vec::new(),
};
res.elements = res.elaborate(elements, None).into();
res.fixup_tabstops();
res.ensure_last_tabstop();
res.renumber_tabstops();
res
}
pub fn elements(&self) -> &[SnippetElement] {
&self.elements
}
pub fn tabstops(&self) -> impl Iterator<Item = &Tabstop> {
self.tabstops.iter()
}
fn renumber_tabstops(&mut self) {
Self::renumber_tabstops_in(&self.tabstops, &mut self.elements);
for i in 0..self.tabstops.len() {
if let Some(parent) = self.tabstops[i].parent {
let parent = self
.tabstops
.binary_search_by_key(&parent, |tabstop| tabstop.idx)
.expect("all tabstops have been resolved");
self.tabstops[i].parent = Some(TabstopIdx(parent));
}
let tabstop = &mut self.tabstops[i];
if let TabstopKind::Placeholder { default } = &tabstop.kind {
let mut default = default.clone();
tabstop.kind = TabstopKind::Empty;
Self::renumber_tabstops_in(&self.tabstops, Arc::get_mut(&mut default).unwrap());
self.tabstops[i].kind = TabstopKind::Placeholder { default };
}
}
}
fn renumber_tabstops_in(tabstops: &[Tabstop], elements: &mut [SnippetElement]) {
for elem in elements {
match elem {
SnippetElement::Tabstop { idx } => {
idx.0 = tabstops
.binary_search_by_key(&*idx, |tabstop| tabstop.idx)
.expect("all tabstops have been resolved")
}
SnippetElement::Variable { default, .. } => {
if let Some(default) = default {
Self::renumber_tabstops_in(tabstops, default);
}
}
SnippetElement::Text(_) => (),
}
}
}
fn fixup_tabstops(&mut self) {
self.tabstops.sort_by_key(|tabstop| tabstop.idx);
self.tabstops.dedup_by(|tabstop1, tabstop2| {
if tabstop1.idx != tabstop2.idx {
return false;
}
// use the first non empty tabstop for all multicursor tabstops
if tabstop2.kind.is_empty() {
swap(tabstop2, tabstop1)
}
true
})
}
fn ensure_last_tabstop(&mut self) {
if matches!(self.tabstops.last(), Some(tabstop) if tabstop.idx == LAST_TABSTOP_IDX) {
return;
}
self.tabstops.push(Tabstop {
idx: LAST_TABSTOP_IDX,
parent: None,
kind: TabstopKind::Empty,
});
self.elements.push(SnippetElement::Tabstop {
idx: LAST_TABSTOP_IDX,
})
}
fn elaborate(
&mut self,
default: Vec<parser::SnippetElement>,
parent: Option<TabstopIdx>,
) -> Box<[SnippetElement]> {
default
.into_iter()
.map(|val| match val {
parser::SnippetElement::Tabstop {
tabstop,
transform: None,
} => SnippetElement::Tabstop {
idx: self.elaborate_placeholder(tabstop, parent, Vec::new()),
},
parser::SnippetElement::Tabstop {
tabstop,
transform: Some(transform),
} => SnippetElement::Tabstop {
idx: self.elaborate_transform(tabstop, parent, transform),
},
parser::SnippetElement::Placeholder { tabstop, value } => SnippetElement::Tabstop {
idx: self.elaborate_placeholder(tabstop, parent, value),
},
parser::SnippetElement::Choice { tabstop, choices } => SnippetElement::Tabstop {
idx: self.elaborate_choice(tabstop, parent, choices),
},
parser::SnippetElement::Variable {
name,
default,
transform,
} => SnippetElement::Variable {
name,
default: default.map(|default| self.elaborate(default, parent)),
// TODO: error for invalid transforms
transform: transform.and_then(Transform::new).map(Box::new),
},
parser::SnippetElement::Text(text) => SnippetElement::Text(text),
})
.collect()
}
fn elaborate_choice(
&mut self,
idx: usize,
parent: Option<TabstopIdx>,
choices: Vec<Tendril>,
) -> TabstopIdx {
let idx = TabstopIdx::elaborate(idx);
self.tabstops.push(Tabstop {
idx,
parent,
kind: TabstopKind::Choice {
choices: choices.into(),
},
});
idx
}
fn elaborate_placeholder(
&mut self,
idx: usize,
parent: Option<TabstopIdx>,
default: Vec<parser::SnippetElement>,
) -> TabstopIdx {
let idx = TabstopIdx::elaborate(idx);
let default = self.elaborate(default, Some(idx));
self.tabstops.push(Tabstop {
idx,
parent,
kind: TabstopKind::Placeholder {
default: default.into(),
},
});
idx
}
fn elaborate_transform(
&mut self,
idx: usize,
parent: Option<TabstopIdx>,
transform: parser::Transform,
) -> TabstopIdx {
let idx = TabstopIdx::elaborate(idx);
if let Some(transform) = Transform::new(transform) {
self.tabstops.push(Tabstop {
idx,
parent,
kind: TabstopKind::Transform(Arc::new(transform)),
})
} else {
// TODO: proper error
self.tabstops.push(Tabstop {
idx,
parent,
kind: TabstopKind::Empty,
})
}
idx
}
}
impl Index<TabstopIdx> for Snippet {
type Output = Tabstop;
fn index(&self, index: TabstopIdx) -> &Tabstop {
&self.tabstops[index.0]
}
}
#[derive(Debug)]
pub enum SnippetElement {
Tabstop {
idx: TabstopIdx,
},
Variable {
name: Tendril,
default: Option<Box<[SnippetElement]>>,
transform: Option<Box<Transform>>,
},
Text(Tendril),
}
#[derive(Debug)]
pub struct Tabstop {
idx: TabstopIdx,
pub parent: Option<TabstopIdx>,
pub kind: TabstopKind,
}
#[derive(Debug)]
pub enum TabstopKind {
Choice { choices: Arc<[Tendril]> },
Placeholder { default: Arc<[SnippetElement]> },
Empty,
Transform(Arc<Transform>),
}
impl TabstopKind {
pub fn is_empty(&self) -> bool {
matches!(self, TabstopKind::Empty)
}
}
#[derive(Debug)]
pub struct Transform {
regex: Regex,
regex_str: Box<str>,
global: bool,
replacement: Box<[FormatItem]>,
}
impl PartialEq for Transform {
fn eq(&self, other: &Self) -> bool {
self.replacement == other.replacement
&& self.global == other.global
// doens't compare m and i setting but close enough
&& self.regex_str == other.regex_str
}
}
impl Transform {
fn new(transform: parser::Transform) -> Option<Transform> {
let mut config = RegexConfig::new();
let mut global = false;
let mut invalid_config = false;
for c in transform.options.chars() {
match c {
'i' => {
config = config.case_insensitive(true);
}
'm' => {
config = config.multi_line(true);
}
'g' => {
global = true;
}
// we ignore 'u' since we always want to
// do unicode aware matching
_ => invalid_config = true,
}
}
if invalid_config {
log::error!("invalid transform configuration characters {transform:?}");
}
let regex = match RegexBuilder::new().syntax(config).build(&transform.regex) {
Ok(regex) => regex,
Err(err) => {
log::error!("invalid transform {err} {transform:?}");
return None;
}
};
Some(Transform {
regex,
regex_str: transform.regex.as_str().into(),
global,
replacement: transform.replacement.into(),
})
}
pub fn apply(&self, mut doc: RopeSlice<'_>, range: Range) -> Tendril {
let mut buf = Tendril::new();
let it = self
.regex
.captures_iter(doc.regex_input_at(range))
.enumerate();
doc = doc.slice(range);
let mut last_match = 0;
for (_, cap) in it {
// unwrap on 0 is OK because captures only reports matches
let m = cap.get_group(0).unwrap();
buf.extend(doc.byte_slice(last_match..m.start).chunks());
last_match = m.end;
for fmt in &*self.replacement {
match *fmt {
FormatItem::Text(ref text) => {
buf.push_str(text);
}
FormatItem::Capture(i) => {
if let Some(cap) = cap.get_group(i) {
buf.extend(doc.byte_slice(cap.range()).chunks());
}
}
FormatItem::CaseChange(i, change) => {
if let Some(cap) = cap.get_group(i).filter(|i| !i.is_empty()) {
let mut chars = doc.byte_slice(cap.range()).chars();
match change {
CaseChange::Upcase => to_upper_case_with(chars, &mut buf),
CaseChange::Downcase => to_lower_case_with(chars, &mut buf),
CaseChange::Capitalize => {
let first_char = chars.next().unwrap();
buf.extend(first_char.to_uppercase());
buf.extend(chars);
}
CaseChange::PascalCase => to_pascal_case_with(chars, &mut buf),
CaseChange::CamelCase => to_camel_case_with(chars, &mut buf),
}
}
}
FormatItem::Conditional(i, ref if_, ref else_) => {
if cap.get_group(i).map_or(true, |mat| mat.is_empty()) {
buf.push_str(else_)
} else {
buf.push_str(if_)
}
}
}
}
if !self.global {
break;
}
}
buf.extend(doc.byte_slice(last_match..).chunks());
buf
}
}
impl TabstopIdx {
fn elaborate(idx: usize) -> Self {
TabstopIdx(idx.wrapping_sub(1))
}
}

@ -0,0 +1,922 @@
/*!
A parser for LSP/VSCode style snippet syntax see
<https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#snippet_syntax>
``` text
any ::= tabstop | placeholder | choice | variable | text
tabstop ::= '$' int | '${' int '}'
placeholder ::= '${' int ':' any '}'
choice ::= '${' int '|' text (',' text)* '|}'
variable ::= '$' var | '${' var }'
| '${' var ':' any '}'
| '${' var '/' regex '/' (format | text)+ '/' options '}'
format ::= '$' int | '${' int '}'
| '${' int ':' '/upcase' | '/downcase' | '/capitalize' '}'
| '${' int ':+' if '}'
| '${' int ':?' if ':' else '}'
| '${' int ':-' else '}' | '${' int ':' else '}'
regex ::= Regular Expression value (ctor-string)
options ::= Regular Expression option (ctor-options)
var ::= [_a-zA-Z] [_a-zA-Z0-9]*
int ::= [0-9]+
text ::= .*
if ::= text
else ::= text
```
*/
use crate::Tendril;
use helix_parsec::*;
#[derive(Debug, PartialEq, Eq, Clone, Copy)]
pub enum CaseChange {
Upcase,
Downcase,
Capitalize,
PascalCase,
CamelCase,
}
#[derive(Debug, PartialEq, Eq)]
pub enum FormatItem {
Text(Tendril),
Capture(usize),
CaseChange(usize, CaseChange),
Conditional(usize, Tendril, Tendril),
}
#[derive(Debug, PartialEq, Eq)]
pub struct Transform {
pub regex: Tendril,
pub replacement: Vec<FormatItem>,
pub options: Tendril,
}
#[derive(Debug, PartialEq, Eq)]
pub enum SnippetElement {
Tabstop {
tabstop: usize,
transform: Option<Transform>,
},
Placeholder {
tabstop: usize,
value: Vec<SnippetElement>,
},
Choice {
tabstop: usize,
choices: Vec<Tendril>,
},
Variable {
name: Tendril,
default: Option<Vec<SnippetElement>>,
transform: Option<Transform>,
},
Text(Tendril),
}
pub fn parse(s: &str) -> Result<Vec<SnippetElement>, &str> {
snippet().parse(s).and_then(|(remainder, snippet)| {
if remainder.is_empty() {
Ok(snippet)
} else {
Err(remainder)
}
})
}
fn var<'a>() -> impl Parser<'a, Output = &'a str> {
// var = [_a-zA-Z][_a-zA-Z0-9]*
move |input: &'a str| {
input
.char_indices()
.take_while(|(p, c)| {
*c == '_'
|| if *p == 0 {
c.is_ascii_alphabetic()
} else {
c.is_ascii_alphanumeric()
}
})
.last()
.map(|(index, c)| {
let index = index + c.len_utf8();
(&input[index..], &input[0..index])
})
.ok_or(input)
}
}
const TEXT_ESCAPE_CHARS: &[char] = &['\\', '}', '$'];
const CHOICE_TEXT_ESCAPE_CHARS: &[char] = &['\\', '|', ','];
fn text<'a>(
escape_chars: &'static [char],
term_chars: &'static [char],
) -> impl Parser<'a, Output = Tendril> {
move |input: &'a str| {
let mut chars = input.char_indices().peekable();
let mut res = Tendril::new();
while let Some((i, c)) = chars.next() {
match c {
'\\' => {
if let Some(&(_, c)) = chars.peek() {
if escape_chars.contains(&c) {
chars.next();
res.push(c);
continue;
}
}
res.push('\\');
}
c if term_chars.contains(&c) => return Ok((&input[i..], res)),
c => res.push(c),
}
}
Ok(("", res))
}
}
fn digit<'a>() -> impl Parser<'a, Output = usize> {
filter_map(take_while(|c| c.is_ascii_digit()), |s| s.parse().ok())
}
fn case_change<'a>() -> impl Parser<'a, Output = CaseChange> {
use CaseChange::*;
choice!(
map("upcase", |_| Upcase),
map("downcase", |_| Downcase),
map("capitalize", |_| Capitalize),
map("pascalcase", |_| PascalCase),
map("camelcase", |_| CamelCase),
)
}
fn format<'a>() -> impl Parser<'a, Output = FormatItem> {
use FormatItem::*;
choice!(
// '$' int
map(right("$", digit()), Capture),
// '${' int '}'
map(seq!("${", digit(), "}"), |seq| Capture(seq.1)),
// '${' int ':' '/upcase' | '/downcase' | '/capitalize' '}'
map(seq!("${", digit(), ":/", case_change(), "}"), |seq| {
CaseChange(seq.1, seq.3)
}),
// '${' int ':+' if '}'
map(
seq!("${", digit(), ":+", text(TEXT_ESCAPE_CHARS, &['}']), "}"),
|seq| { Conditional(seq.1, seq.3, Tendril::new()) }
),
// '${' int ':?' if ':' else '}'
map(
seq!(
"${",
digit(),
":?",
text(TEXT_ESCAPE_CHARS, &[':']),
":",
text(TEXT_ESCAPE_CHARS, &['}']),
"}"
),
|seq| { Conditional(seq.1, seq.3, seq.5) }
),
// '${' int ':-' else '}' | '${' int ':' else '}'
map(
seq!(
"${",
digit(),
":",
optional("-"),
text(TEXT_ESCAPE_CHARS, &['}']),
"}"
),
|seq| { Conditional(seq.1, Tendril::new(), seq.4) }
),
)
}
fn regex<'a>() -> impl Parser<'a, Output = Transform> {
map(
seq!(
"/",
// TODO parse as ECMAScript and convert to rust regex
text(&['/'], &['/']),
"/",
zero_or_more(choice!(
format(),
// text doesn't parse $, if format fails we just accept the $ as text
map("$", |_| FormatItem::Text("$".into())),
map(text(&['\\', '/'], &['/', '$']), FormatItem::Text),
)),
"/",
// vscode really doesn't allow escaping } here
// so it's impossible to write a regex escape containing a }
// we can consider deviating here and allowing the escape
text(&[], &['}']),
),
|(_, value, _, replacement, _, options)| Transform {
regex: value,
replacement,
options,
},
)
}
fn tabstop<'a>() -> impl Parser<'a, Output = SnippetElement> {
map(
or(
map(right("$", digit()), |i| (i, None)),
map(
seq!("${", digit(), optional(regex()), "}"),
|(_, i, transform, _)| (i, transform),
),
),
|(tabstop, transform)| SnippetElement::Tabstop { tabstop, transform },
)
}
fn placeholder<'a>() -> impl Parser<'a, Output = SnippetElement> {
map(
seq!(
"${",
digit(),
":",
// according to the grammar there is just a single anything here.
// However in the prose it is explained that placeholders can be nested.
// The example there contains both a placeholder text and a nested placeholder
// which indicates a list. Looking at the VSCode sourcecode, the placeholder
// is indeed parsed as zero_or_more so the grammar is simply incorrect here
zero_or_more(anything(TEXT_ESCAPE_CHARS, true)),
"}"
),
|seq| SnippetElement::Placeholder {
tabstop: seq.1,
value: seq.3,
},
)
}
fn choice<'a>() -> impl Parser<'a, Output = SnippetElement> {
map(
seq!(
"${",
digit(),
"|",
sep(text(CHOICE_TEXT_ESCAPE_CHARS, &['|', ',']), ","),
"|}",
),
|seq| SnippetElement::Choice {
tabstop: seq.1,
choices: seq.3,
},
)
}
fn variable<'a>() -> impl Parser<'a, Output = SnippetElement> {
choice!(
// $var
map(right("$", var()), |name| SnippetElement::Variable {
name: name.into(),
default: None,
transform: None,
}),
// ${var}
map(seq!("${", var(), "}",), |values| SnippetElement::Variable {
name: values.1.into(),
default: None,
transform: None,
}),
// ${var:default}
map(
seq!(
"${",
var(),
":",
zero_or_more(anything(TEXT_ESCAPE_CHARS, true)),
"}",
),
|values| SnippetElement::Variable {
name: values.1.into(),
default: Some(values.3),
transform: None,
}
),
// ${var/value/format/options}
map(seq!("${", var(), regex(), "}"), |values| {
SnippetElement::Variable {
name: values.1.into(),
default: None,
transform: Some(values.2),
}
}),
)
}
fn anything<'a>(
escape_chars: &'static [char],
end_at_brace: bool,
) -> impl Parser<'a, Output = SnippetElement> {
let term_chars: &[_] = if end_at_brace { &['$', '}'] } else { &['$'] };
move |input: &'a str| {
let parser = choice!(
tabstop(),
placeholder(),
choice(),
variable(),
map("$", |_| SnippetElement::Text("$".into())),
map(text(escape_chars, term_chars), SnippetElement::Text),
);
parser.parse(input)
}
}
fn snippet<'a>() -> impl Parser<'a, Output = Vec<SnippetElement>> {
one_or_more(anything(TEXT_ESCAPE_CHARS, false))
}
#[cfg(test)]
mod test {
use crate::snippets::{Snippet, SnippetRenderCtx};
use super::SnippetElement::*;
use super::*;
#[test]
fn empty_string_is_error() {
assert_eq!(Err(""), parse(""));
}
#[test]
fn parse_placeholders_in_function_call() {
assert_eq!(
Ok(vec![
Text("match(".into()),
Placeholder {
tabstop: 1,
value: vec![Text("Arg1".into())],
},
Text(")".into()),
]),
parse("match(${1:Arg1})")
)
}
#[test]
fn unterminated_placeholder() {
assert_eq!(
Ok(vec![
Text("match(".into()),
Text("$".into()),
Text("{1:)".into())
]),
parse("match(${1:)")
)
}
#[test]
fn parse_empty_placeholder() {
assert_eq!(
Ok(vec![
Text("match(".into()),
Placeholder {
tabstop: 1,
value: vec![],
},
Text(")".into()),
]),
parse("match(${1:})")
)
}
#[test]
fn parse_placeholders_in_statement() {
assert_eq!(
Ok(vec![
Text("local ".into()),
Placeholder {
tabstop: 1,
value: vec![Text("var".into())],
},
Text(" = ".into()),
Placeholder {
tabstop: 1,
value: vec![Text("value".into())],
},
]),
parse("local ${1:var} = ${1:value}")
)
}
#[test]
fn parse_tabstop_nested_in_placeholder() {
assert_eq!(
Ok(vec![Placeholder {
tabstop: 1,
value: vec![
Text("var, ".into()),
Tabstop {
tabstop: 2,
transform: None
}
],
}]),
parse("${1:var, $2}")
)
}
#[test]
fn parse_placeholder_nested_in_placeholder() {
assert_eq!(
Ok({
vec![Placeholder {
tabstop: 1,
value: vec![
Text("foo ".into()),
Placeholder {
tabstop: 2,
value: vec![Text("bar".into())],
},
],
}]
}),
parse("${1:foo ${2:bar}}")
)
}
#[test]
fn parse_all() {
assert_eq!(
Ok(vec![
Text("hello ".into()),
Tabstop {
tabstop: 1,
transform: None
},
Tabstop {
tabstop: 2,
transform: None
},
Text(" ".into()),
Choice {
tabstop: 1,
choices: vec!["one".into(), "two".into(), "three".into()],
},
Text(" ".into()),
Variable {
name: "name".into(),
default: Some(vec![Text("foo".into())]),
transform: None,
},
Text(" ".into()),
Variable {
name: "var".into(),
default: None,
transform: None,
},
Text(" ".into()),
Variable {
name: "TM".into(),
default: None,
transform: None,
},
]),
parse("hello $1${2} ${1|one,two,three|} ${name:foo} $var $TM")
);
}
#[test]
fn regex_capture_replace() {
assert_eq!(
Ok({
vec![Variable {
name: "TM_FILENAME".into(),
default: None,
transform: Some(Transform {
regex: "(.*).+$".into(),
replacement: vec![FormatItem::Capture(1), FormatItem::Text("$".into())],
options: Tendril::new(),
}),
}]
}),
parse("${TM_FILENAME/(.*).+$/$1$/}")
);
}
#[test]
fn rust_macro() {
assert_eq!(
Ok({
vec![
Text("macro_rules! ".into()),
Tabstop {
tabstop: 1,
transform: None,
},
Text(" {\n (".into()),
Tabstop {
tabstop: 2,
transform: None,
},
Text(") => {\n ".into()),
Tabstop {
tabstop: 0,
transform: None,
},
Text("\n };\n}".into()),
]
}),
parse("macro_rules! $1 {\n ($2) => {\n $0\n };\n}")
);
}
fn assert_text(snippet: &str, parsed_text: &str) {
let snippet = Snippet::parse(snippet).unwrap();
let mut rendered_snippet = snippet.prepare_render();
let rendered_text = snippet
.render_at(
&mut rendered_snippet,
"".into(),
false,
&mut SnippetRenderCtx::test_ctx(),
0,
)
.0;
assert_eq!(rendered_text, parsed_text)
}
#[test]
fn robust_parsing() {
assert_text("$", "$");
assert_text("\\\\$", "\\$");
assert_text("{", "{");
assert_text("\\}", "}");
assert_text("\\abc", "\\abc");
assert_text("foo${f:\\}}bar", "foo}bar");
assert_text("\\{", "\\{");
assert_text("I need \\\\\\$", "I need \\$");
assert_text("\\", "\\");
assert_text("\\{{", "\\{{");
assert_text("{{", "{{");
assert_text("{{dd", "{{dd");
assert_text("}}", "}}");
assert_text("ff}}", "ff}}");
assert_text("farboo", "farboo");
assert_text("far{{}}boo", "far{{}}boo");
assert_text("far{{123}}boo", "far{{123}}boo");
assert_text("far\\{{123}}boo", "far\\{{123}}boo");
assert_text("far{{id:bern}}boo", "far{{id:bern}}boo");
assert_text("far{{id:bern {{basel}}}}boo", "far{{id:bern {{basel}}}}boo");
assert_text(
"far{{id:bern {{id:basel}}}}boo",
"far{{id:bern {{id:basel}}}}boo",
);
assert_text(
"far{{id:bern {{id2:basel}}}}boo",
"far{{id:bern {{id2:basel}}}}boo",
);
assert_text("${}$\\a\\$\\}\\\\", "${}$\\a$}\\");
assert_text("farboo", "farboo");
assert_text("far{{}}boo", "far{{}}boo");
assert_text("far{{123}}boo", "far{{123}}boo");
assert_text("far\\{{123}}boo", "far\\{{123}}boo");
assert_text("far`123`boo", "far`123`boo");
assert_text("far\\`123\\`boo", "far\\`123\\`boo");
assert_text("\\$far-boo", "$far-boo");
}
fn assert_snippet(snippet: &str, expect: &[SnippetElement]) {
let elements = parse(snippet).unwrap();
assert_eq!(elements, expect.to_owned())
}
#[test]
fn parse_variable() {
use SnippetElement::*;
assert_snippet(
"$far-boo",
&[
Variable {
name: "far".into(),
default: None,
transform: None,
},
Text("-boo".into()),
],
);
assert_snippet(
"far$farboo",
&[
Text("far".into()),
Variable {
name: "farboo".into(),
transform: None,
default: None,
},
],
);
assert_snippet(
"far${farboo}",
&[
Text("far".into()),
Variable {
name: "farboo".into(),
transform: None,
default: None,
},
],
);
assert_snippet(
"$123",
&[Tabstop {
tabstop: 123,
transform: None,
}],
);
assert_snippet(
"$farboo",
&[Variable {
name: "farboo".into(),
transform: None,
default: None,
}],
);
assert_snippet(
"$far12boo",
&[Variable {
name: "far12boo".into(),
transform: None,
default: None,
}],
);
assert_snippet(
"000_${far}_000",
&[
Text("000_".into()),
Variable {
name: "far".into(),
transform: None,
default: None,
},
Text("_000".into()),
],
);
}
#[test]
fn parse_variable_transform() {
assert_snippet(
"${foo///}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: Tendril::new(),
replacement: Vec::new(),
options: Tendril::new(),
}),
default: None,
}],
);
assert_snippet(
"${foo/regex/format/gmi}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: "regex".into(),
replacement: vec![FormatItem::Text("format".into())],
options: "gmi".into(),
}),
default: None,
}],
);
assert_snippet(
"${foo/([A-Z][a-z])/format/}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: "([A-Z][a-z])".into(),
replacement: vec![FormatItem::Text("format".into())],
options: Tendril::new(),
}),
default: None,
}],
);
// invalid regex TODO: reneable tests once we actually parse this regex flavour
// assert_text(
// "${foo/([A-Z][a-z])/format/GMI}",
// "${foo/([A-Z][a-z])/format/GMI}",
// );
// assert_text(
// "${foo/([A-Z][a-z])/format/funky}",
// "${foo/([A-Z][a-z])/format/funky}",
// );
// assert_text("${foo/([A-Z][a-z]/format/}", "${foo/([A-Z][a-z]/format/}");
assert_text(
"${foo/regex\\/format/options}",
"${foo/regex\\/format/options}",
);
// tricky regex
assert_snippet(
"${foo/m\\/atch/$1/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: "m/atch".into(),
replacement: vec![FormatItem::Capture(1)],
options: "i".into(),
}),
default: None,
}],
);
// incomplete
assert_text("${foo///", "${foo///");
assert_text("${foo/regex/format/options", "${foo/regex/format/options");
// format string
assert_snippet(
"${foo/.*/${0:fooo}/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: ".*".into(),
replacement: vec![FormatItem::Conditional(0, Tendril::new(), "fooo".into())],
options: "i".into(),
}),
default: None,
}],
);
assert_snippet(
"${foo/.*/${1}/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: ".*".into(),
replacement: vec![FormatItem::Capture(1)],
options: "i".into(),
}),
default: None,
}],
);
assert_snippet(
"${foo/.*/$1/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: ".*".into(),
replacement: vec![FormatItem::Capture(1)],
options: "i".into(),
}),
default: None,
}],
);
assert_snippet(
"${foo/.*/This-$1-encloses/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: ".*".into(),
replacement: vec![
FormatItem::Text("This-".into()),
FormatItem::Capture(1),
FormatItem::Text("-encloses".into()),
],
options: "i".into(),
}),
default: None,
}],
);
assert_snippet(
"${foo/.*/complex${1:else}/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: ".*".into(),
replacement: vec![
FormatItem::Text("complex".into()),
FormatItem::Conditional(1, Tendril::new(), "else".into()),
],
options: "i".into(),
}),
default: None,
}],
);
assert_snippet(
"${foo/.*/complex${1:-else}/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: ".*".into(),
replacement: vec![
FormatItem::Text("complex".into()),
FormatItem::Conditional(1, Tendril::new(), "else".into()),
],
options: "i".into(),
}),
default: None,
}],
);
assert_snippet(
"${foo/.*/complex${1:+if}/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: ".*".into(),
replacement: vec![
FormatItem::Text("complex".into()),
FormatItem::Conditional(1, "if".into(), Tendril::new()),
],
options: "i".into(),
}),
default: None,
}],
);
assert_snippet(
"${foo/.*/complex${1:?if:else}/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: ".*".into(),
replacement: vec![
FormatItem::Text("complex".into()),
FormatItem::Conditional(1, "if".into(), "else".into()),
],
options: "i".into(),
}),
default: None,
}],
);
assert_snippet(
"${foo/.*/complex${1:/upcase}/i}",
&[Variable {
name: "foo".into(),
transform: Some(Transform {
regex: ".*".into(),
replacement: vec![
FormatItem::Text("complex".into()),
FormatItem::CaseChange(1, CaseChange::Upcase),
],
options: "i".into(),
}),
default: None,
}],
);
assert_snippet(
"${TM_DIRECTORY/src\\//$1/}",
&[Variable {
name: "TM_DIRECTORY".into(),
transform: Some(Transform {
regex: "src/".into(),
replacement: vec![FormatItem::Capture(1)],
options: Tendril::new(),
}),
default: None,
}],
);
assert_snippet(
"${TM_SELECTED_TEXT/a/\\/$1/g}",
&[Variable {
name: "TM_SELECTED_TEXT".into(),
transform: Some(Transform {
regex: "a".into(),
replacement: vec![FormatItem::Text("/".into()), FormatItem::Capture(1)],
options: "g".into(),
}),
default: None,
}],
);
assert_snippet(
"${TM_SELECTED_TEXT/a/in\\/$1ner/g}",
&[Variable {
name: "TM_SELECTED_TEXT".into(),
transform: Some(Transform {
regex: "a".into(),
replacement: vec![
FormatItem::Text("in/".into()),
FormatItem::Capture(1),
FormatItem::Text("ner".into()),
],
options: "g".into(),
}),
default: None,
}],
);
assert_snippet(
"${TM_SELECTED_TEXT/a/end\\//g}",
&[Variable {
name: "TM_SELECTED_TEXT".into(),
transform: Some(Transform {
regex: "a".into(),
replacement: vec![FormatItem::Text("end/".into())],
options: "g".into(),
}),
default: None,
}],
);
}
// TODO port more tests from https://github.com/microsoft/vscode/blob/dce493cb6e36346ef2714e82c42ce14fc461b15c/src/vs/editor/contrib/snippet/test/browser/snippetParser.test.ts
}

@ -0,0 +1,354 @@
use std::borrow::Cow;
use std::ops::{Index, IndexMut};
use std::sync::Arc;
use helix_stdx::Range;
use ropey::{Rope, RopeSlice};
use smallvec::SmallVec;
use crate::indent::{normalize_indentation, IndentStyle};
use crate::movement::Direction;
use crate::snippets::elaborate;
use crate::snippets::TabstopIdx;
use crate::snippets::{Snippet, SnippetElement, Transform};
use crate::{selection, Selection, Tendril, Transaction};
#[derive(Debug, Clone, PartialEq)]
pub enum TabstopKind {
Choice { choices: Arc<[Tendril]> },
Placeholder,
Empty,
Transform(Arc<Transform>),
}
#[derive(Debug, PartialEq)]
pub struct Tabstop {
pub ranges: SmallVec<[Range; 1]>,
pub parent: Option<TabstopIdx>,
pub kind: TabstopKind,
}
impl Tabstop {
pub fn has_placeholder(&self) -> bool {
matches!(
self.kind,
TabstopKind::Choice { .. } | TabstopKind::Placeholder
)
}
pub fn selection(
&self,
direction: Direction,
primary_idx: usize,
snippet_ranges: usize,
) -> Selection {
Selection::new(
self.ranges
.iter()
.map(|&range| {
let mut range = selection::Range::new(range.start, range.end);
if direction == Direction::Backward {
range = range.flip()
}
range
})
.collect(),
primary_idx * (self.ranges.len() / snippet_ranges),
)
}
}
#[derive(Debug, Default, PartialEq)]
pub struct RenderedSnippet {
pub tabstops: Vec<Tabstop>,
pub ranges: Vec<Range>,
}
impl RenderedSnippet {
pub fn first_selection(&self, direction: Direction, primary_idx: usize) -> Selection {
self.tabstops[0].selection(direction, primary_idx, self.ranges.len())
}
}
impl Index<TabstopIdx> for RenderedSnippet {
type Output = Tabstop;
fn index(&self, index: TabstopIdx) -> &Tabstop {
&self.tabstops[index.0]
}
}
impl IndexMut<TabstopIdx> for RenderedSnippet {
fn index_mut(&mut self, index: TabstopIdx) -> &mut Tabstop {
&mut self.tabstops[index.0]
}
}
impl Snippet {
pub fn prepare_render(&self) -> RenderedSnippet {
let tabstops =
self.tabstops()
.map(|tabstop| Tabstop {
ranges: SmallVec::new(),
parent: tabstop.parent,
kind: match &tabstop.kind {
elaborate::TabstopKind::Choice { choices } => TabstopKind::Choice {
choices: choices.clone(),
},
// start out as empty the first non-empty placeholder will change this to a aplaceholder automatically
elaborate::TabstopKind::Empty
| elaborate::TabstopKind::Placeholder { .. } => TabstopKind::Empty,
elaborate::TabstopKind::Transform(transform) => {
TabstopKind::Transform(transform.clone())
}
},
})
.collect();
RenderedSnippet {
tabstops,
ranges: Vec::new(),
}
}
pub fn render_at(
&self,
snippet: &mut RenderedSnippet,
indent: RopeSlice<'_>,
at_newline: bool,
ctx: &mut SnippetRenderCtx,
pos: usize,
) -> (Tendril, usize) {
let mut ctx = SnippetRender {
dst: snippet,
src: self,
indent,
text: Tendril::new(),
off: pos,
ctx,
at_newline,
};
ctx.render_elements(self.elements());
let end = ctx.off;
let text = ctx.text;
snippet.ranges.push(Range { start: pos, end });
(text, end - pos)
}
pub fn render(
&self,
doc: &Rope,
selection: &Selection,
change_range: impl FnMut(&selection::Range) -> (usize, usize),
ctx: &mut SnippetRenderCtx,
) -> (Transaction, Selection, RenderedSnippet) {
let mut snippet = self.prepare_render();
let mut off = 0;
let (transaction, selection) = Transaction::change_by_selection_ignore_overlapping(
doc,
selection,
change_range,
|replacement_start, replacement_end| {
let line_idx = doc.char_to_line(replacement_start);
let line_start = doc.line_to_char(line_idx);
let prefix = doc.slice(line_start..replacement_start);
let indent_len = prefix.chars().take_while(|c| c.is_whitespace()).count();
let indent = prefix.slice(..indent_len);
let at_newline = indent_len == replacement_start - line_start;
let (replacement, replacement_len) = self.render_at(
&mut snippet,
indent,
at_newline,
ctx,
(replacement_start as i128 + off) as usize,
);
off +=
replacement_start as i128 - replacement_end as i128 + replacement_len as i128;
Some(replacement)
},
);
(transaction, selection, snippet)
}
}
pub type VariableResolver = dyn FnMut(&str) -> Option<Cow<str>>;
pub struct SnippetRenderCtx {
pub resolve_var: Box<VariableResolver>,
pub tab_width: usize,
pub indent_style: IndentStyle,
pub line_ending: &'static str,
}
impl SnippetRenderCtx {
#[cfg(test)]
pub(super) fn test_ctx() -> SnippetRenderCtx {
SnippetRenderCtx {
resolve_var: Box::new(|_| None),
tab_width: 4,
indent_style: IndentStyle::Spaces(4),
line_ending: "\n",
}
}
}
struct SnippetRender<'a> {
ctx: &'a mut SnippetRenderCtx,
dst: &'a mut RenderedSnippet,
src: &'a Snippet,
indent: RopeSlice<'a>,
text: Tendril,
off: usize,
at_newline: bool,
}
impl SnippetRender<'_> {
fn render_elements(&mut self, elements: &[SnippetElement]) {
for element in elements {
self.render_element(element)
}
}
fn render_element(&mut self, element: &SnippetElement) {
match *element {
SnippetElement::Tabstop { idx } => self.render_tabstop(idx),
SnippetElement::Variable {
ref name,
ref default,
ref transform,
} => {
// TODO: allow resolve_var access to the doc and make it return rope slice
// so we can access selections and other document content without allocating
if let Some(val) = (self.ctx.resolve_var)(name) {
if let Some(transform) = transform {
self.push_multiline_str(&transform.apply(
(&*val).into(),
Range {
start: 0,
end: val.chars().count(),
},
));
} else {
self.push_multiline_str(&val)
}
} else if let Some(default) = default {
self.render_elements(default)
}
}
SnippetElement::Text(ref text) => self.push_multiline_str(text),
}
}
fn push_multiline_str(&mut self, text: &str) {
let mut lines = text
.split('\n')
.map(|line| line.strip_suffix('\r').unwrap_or(line));
let first_line = lines.next().unwrap();
self.push_str(first_line, self.at_newline);
for line in lines {
self.push_newline();
self.push_str(line, true);
}
}
fn push_str(&mut self, mut text: &str, at_newline: bool) {
if at_newline {
let old_len = self.text.len();
let old_indent_len = normalize_indentation(
self.indent,
text.into(),
&mut self.text,
self.ctx.indent_style,
self.ctx.tab_width,
);
// this is ok because indentation can only be ascii chars (' ' and '\t')
self.off += self.text.len() - old_len;
text = &text[old_indent_len..];
if text.is_empty() {
self.at_newline = true;
return;
}
}
self.text.push_str(text);
self.off += text.chars().count();
}
fn push_newline(&mut self) {
self.off += self.ctx.line_ending.chars().count() + self.indent.len_chars();
self.text.push_str(self.ctx.line_ending);
self.text.extend(self.indent.chunks());
}
fn render_tabstop(&mut self, tabstop: TabstopIdx) {
let start = self.off;
let end = match &self.src[tabstop].kind {
elaborate::TabstopKind::Placeholder { default } if !default.is_empty() => {
self.render_elements(default);
self.dst[tabstop].kind = TabstopKind::Placeholder;
self.off
}
_ => start,
};
self.dst[tabstop].ranges.push(Range { start, end });
}
}
#[cfg(test)]
mod tests {
use helix_stdx::Range;
use crate::snippets::render::Tabstop;
use crate::snippets::{Snippet, SnippetRenderCtx};
use super::TabstopKind;
fn assert_snippet(snippet: &str, expect: &str, tabstops: &[Tabstop]) {
let snippet = Snippet::parse(snippet).unwrap();
let mut rendered_snippet = snippet.prepare_render();
let rendered_text = snippet
.render_at(
&mut rendered_snippet,
"\t".into(),
false,
&mut SnippetRenderCtx::test_ctx(),
0,
)
.0;
assert_eq!(rendered_text, expect);
assert_eq!(&rendered_snippet.tabstops, tabstops);
assert_eq!(
rendered_snippet.ranges.last().unwrap().end,
rendered_text.chars().count()
);
assert_eq!(rendered_snippet.ranges.last().unwrap().start, 0)
}
#[test]
fn rust_macro() {
assert_snippet(
"macro_rules! ${1:name} {\n\t($3) => {\n\t\t$2\n\t};\n}",
"macro_rules! name {\n\t () => {\n\t \n\t };\n\t}",
&[
Tabstop {
ranges: vec![Range { start: 13, end: 17 }].into(),
parent: None,
kind: TabstopKind::Placeholder,
},
Tabstop {
ranges: vec![Range { start: 42, end: 42 }].into(),
parent: None,
kind: TabstopKind::Empty,
},
Tabstop {
ranges: vec![Range { start: 26, end: 26 }].into(),
parent: None,
kind: TabstopKind::Empty,
},
Tabstop {
ranges: vec![Range { start: 53, end: 53 }].into(),
parent: None,
kind: TabstopKind::Empty,
},
],
);
}
}
Loading…
Cancel
Save