Move indent-style code into `helix_core::indent`.

pull/509/head^2
Nathan Vegdahl 3 years ago committed by Blaž Hrastnik
parent e191a75e33
commit f88d4c1e20

@ -1,10 +1,177 @@
use crate::{ use crate::{
chars::{char_is_line_ending, char_is_whitespace},
find_first_non_whitespace_char, find_first_non_whitespace_char,
syntax::{IndentQuery, LanguageConfiguration, Syntax}, syntax::{IndentQuery, LanguageConfiguration, Syntax},
tree_sitter::Node, tree_sitter::Node,
RopeSlice, Rope, RopeSlice,
}; };
/// Enum representing indentation style.
///
/// Only values 1-8 are valid for the `Spaces` variant.
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub enum IndentStyle {
Tabs,
Spaces(u8),
}
impl IndentStyle {
/// Creates an `IndentStyle` from an indentation string.
///
/// For example, passing `" "` (four spaces) will create `IndentStyle::Spaces(4)`.
#[allow(clippy::should_implement_trait)]
#[inline]
pub fn from_str(indent: &str) -> Self {
// XXX: do we care about validating the input more than this? Probably not...?
debug_assert!(!indent.is_empty() && indent.len() <= 8);
if indent.starts_with(' ') {
IndentStyle::Spaces(indent.len() as u8)
} else {
IndentStyle::Tabs
}
}
#[inline]
pub fn as_str(&self) -> &'static str {
match *self {
IndentStyle::Tabs => "\t",
IndentStyle::Spaces(1) => " ",
IndentStyle::Spaces(2) => " ",
IndentStyle::Spaces(3) => " ",
IndentStyle::Spaces(4) => " ",
IndentStyle::Spaces(5) => " ",
IndentStyle::Spaces(6) => " ",
IndentStyle::Spaces(7) => " ",
IndentStyle::Spaces(8) => " ",
// Unsupported indentation style. This should never happen,
// but just in case fall back to two spaces.
IndentStyle::Spaces(n) => {
debug_assert!(n > 0 && n <= 8); // Always triggers. `debug_panic!()` wanted.
" "
}
}
}
}
/// Attempts to detect the indentation style used in a document.
///
/// Returns the indentation style if the auto-detect confidence is
/// reasonably high, otherwise returns `None`.
pub fn auto_detect_indent_style(document_text: &Rope) -> Option<IndentStyle> {
// Build a histogram of the indentation *increases* between
// subsequent lines, ignoring lines that are all whitespace.
//
// Index 0 is for tabs, the rest are 1-8 spaces.
let histogram: [usize; 9] = {
let mut histogram = [0; 9];
let mut prev_line_is_tabs = false;
let mut prev_line_leading_count = 0usize;
// Loop through the lines, checking for and recording indentation
// increases as we go.
'outer: for line in document_text.lines().take(1000) {
let mut c_iter = line.chars();
// Is first character a tab or space?
let is_tabs = match c_iter.next() {
Some('\t') => true,
Some(' ') => false,
// Ignore blank lines.
Some(c) if char_is_line_ending(c) => continue,
_ => {
prev_line_is_tabs = false;
prev_line_leading_count = 0;
continue;
}
};
// Count the line's total leading tab/space characters.
let mut leading_count = 1;
let mut count_is_done = false;
for c in c_iter {
match c {
'\t' if is_tabs && !count_is_done => leading_count += 1,
' ' if !is_tabs && !count_is_done => leading_count += 1,
// We stop counting if we hit whitespace that doesn't
// qualify as indent or doesn't match the leading
// whitespace, but we don't exit the loop yet because
// we still want to determine if the line is blank.
c if char_is_whitespace(c) => count_is_done = true,
// Ignore blank lines.
c if char_is_line_ending(c) => continue 'outer,
_ => break,
}
// Bound the worst-case execution time for weird text files.
if leading_count > 256 {
continue 'outer;
}
}
// If there was an increase in indentation over the previous
// line, update the histogram with that increase.
if (prev_line_is_tabs == is_tabs || prev_line_leading_count == 0)
&& prev_line_leading_count < leading_count
{
if is_tabs {
histogram[0] += 1;
} else {
let amount = leading_count - prev_line_leading_count;
if amount <= 8 {
histogram[amount] += 1;
}
}
}
// Store this line's leading whitespace info for use with
// the next line.
prev_line_is_tabs = is_tabs;
prev_line_leading_count = leading_count;
}
// Give more weight to tabs, because their presence is a very
// strong indicator.
histogram[0] *= 2;
histogram
};
// Find the most frequent indent, its frequency, and the frequency of
// the next-most frequent indent.
let indent = histogram
.iter()
.enumerate()
.max_by_key(|kv| kv.1)
.unwrap()
.0;
let indent_freq = histogram[indent];
let indent_freq_2 = *histogram
.iter()
.enumerate()
.filter(|kv| kv.0 != indent)
.map(|kv| kv.1)
.max()
.unwrap();
// Return the the auto-detected result if we're confident enough in its
// accuracy, based on some heuristics.
if indent_freq >= 1 && (indent_freq_2 as f64 / indent_freq as f64) < 0.66 {
Some(match indent {
0 => IndentStyle::Tabs,
_ => IndentStyle::Spaces(indent as u8),
})
} else {
None
}
}
/// To determine indentation of a newly inserted line, figure out the indentation at the last col /// To determine indentation of a newly inserted line, figure out the indentation at the last col
/// of the previous line. /// of the previous line.
#[allow(dead_code)] #[allow(dead_code)]

@ -1,5 +1,6 @@
use helix_core::{ use helix_core::{
comment, coords_at_pos, find_first_non_whitespace_char, find_root, graphemes, indent, comment, coords_at_pos, find_first_non_whitespace_char, find_root, graphemes, indent,
indent::IndentStyle,
line_ending::{get_line_ending_of_str, line_end_char_index, str_is_line_ending}, line_ending::{get_line_ending_of_str, line_end_char_index, str_is_line_ending},
match_brackets, match_brackets,
movement::{self, Direction}, movement::{self, Direction},
@ -11,7 +12,7 @@ use helix_core::{
}; };
use helix_view::{ use helix_view::{
document::{IndentStyle, Mode}, document::Mode,
editor::Action, editor::Action,
input::KeyEvent, input::KeyEvent,
keyboard::KeyCode, keyboard::KeyCode,

@ -9,8 +9,8 @@ use std::str::FromStr;
use std::sync::Arc; use std::sync::Arc;
use helix_core::{ use helix_core::{
chars::{char_is_line_ending, char_is_whitespace},
history::History, history::History,
indent::{auto_detect_indent_style, IndentStyle},
line_ending::auto_detect_line_ending, line_ending::auto_detect_line_ending,
syntax::{self, LanguageConfiguration}, syntax::{self, LanguageConfiguration},
ChangeSet, Diagnostic, LineEnding, Rope, RopeBuilder, Selection, State, Syntax, Transaction, ChangeSet, Diagnostic, LineEnding, Rope, RopeBuilder, Selection, State, Syntax, Transaction,
@ -63,12 +63,6 @@ impl<'de> Deserialize<'de> for Mode {
} }
} }
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
pub enum IndentStyle {
Tabs,
Spaces(u8),
}
pub struct Document { pub struct Document {
pub(crate) id: DocumentId, pub(crate) id: DocumentId,
text: Rope, text: Rope,
@ -460,9 +454,7 @@ impl Document {
doc.detect_language(theme, loader); doc.detect_language(theme, loader);
} }
// Detect indentation style and line ending. doc.detect_indent_and_line_ending();
doc.detect_indent_style();
doc.line_ending = auto_detect_line_ending(&doc.text).unwrap_or(DEFAULT_LINE_ENDING);
Ok(doc) Ok(doc)
} }
@ -580,6 +572,18 @@ impl Document {
} }
} }
pub fn detect_indent_and_line_ending(&mut self) {
self.indent_style = auto_detect_indent_style(&self.text).unwrap_or_else(|| {
IndentStyle::from_str(
self.language
.as_ref()
.and_then(|config| config.indent.as_ref())
.map_or(" ", |config| config.unit.as_str()), // Fallback to 2 spaces.
)
});
self.line_ending = auto_detect_line_ending(&self.text).unwrap_or(DEFAULT_LINE_ENDING);
}
/// Reload the document from its path. /// Reload the document from its path.
pub fn reload(&mut self, view_id: ViewId) -> Result<(), Error> { pub fn reload(&mut self, view_id: ViewId) -> Result<(), Error> {
let encoding = &self.encoding; let encoding = &self.encoding;
@ -598,9 +602,7 @@ impl Document {
self.append_changes_to_history(view_id); self.append_changes_to_history(view_id);
self.reset_modified(); self.reset_modified();
// Detect indentation style and line ending. self.detect_indent_and_line_ending();
self.detect_indent_style();
self.line_ending = auto_detect_line_ending(&self.text).unwrap_or(DEFAULT_LINE_ENDING);
Ok(()) Ok(())
} }
@ -619,132 +621,6 @@ impl Document {
self.encoding self.encoding
} }
fn detect_indent_style(&mut self) {
// Build a histogram of the indentation *increases* between
// subsequent lines, ignoring lines that are all whitespace.
//
// Index 0 is for tabs, the rest are 1-8 spaces.
let histogram: [usize; 9] = {
let mut histogram = [0; 9];
let mut prev_line_is_tabs = false;
let mut prev_line_leading_count = 0usize;
// Loop through the lines, checking for and recording indentation
// increases as we go.
'outer: for line in self.text.lines().take(1000) {
let mut c_iter = line.chars();
// Is first character a tab or space?
let is_tabs = match c_iter.next() {
Some('\t') => true,
Some(' ') => false,
// Ignore blank lines.
Some(c) if char_is_line_ending(c) => continue,
_ => {
prev_line_is_tabs = false;
prev_line_leading_count = 0;
continue;
}
};
// Count the line's total leading tab/space characters.
let mut leading_count = 1;
let mut count_is_done = false;
for c in c_iter {
match c {
'\t' if is_tabs && !count_is_done => leading_count += 1,
' ' if !is_tabs && !count_is_done => leading_count += 1,
// We stop counting if we hit whitespace that doesn't
// qualify as indent or doesn't match the leading
// whitespace, but we don't exit the loop yet because
// we still want to determine if the line is blank.
c if char_is_whitespace(c) => count_is_done = true,
// Ignore blank lines.
c if char_is_line_ending(c) => continue 'outer,
_ => break,
}
// Bound the worst-case execution time for weird text files.
if leading_count > 256 {
continue 'outer;
}
}
// If there was an increase in indentation over the previous
// line, update the histogram with that increase.
if (prev_line_is_tabs == is_tabs || prev_line_leading_count == 0)
&& prev_line_leading_count < leading_count
{
if is_tabs {
histogram[0] += 1;
} else {
let amount = leading_count - prev_line_leading_count;
if amount <= 8 {
histogram[amount] += 1;
}
}
}
// Store this line's leading whitespace info for use with
// the next line.
prev_line_is_tabs = is_tabs;
prev_line_leading_count = leading_count;
}
// Give more weight to tabs, because their presence is a very
// strong indicator.
histogram[0] *= 2;
histogram
};
// Find the most frequent indent, its frequency, and the frequency of
// the next-most frequent indent.
let indent = histogram
.iter()
.enumerate()
.max_by_key(|kv| kv.1)
.unwrap()
.0;
let indent_freq = histogram[indent];
let indent_freq_2 = *histogram
.iter()
.enumerate()
.filter(|kv| kv.0 != indent)
.map(|kv| kv.1)
.max()
.unwrap();
// Use the auto-detected result if we're confident enough in its
// accuracy, based on some heuristics. Otherwise fall back to
// the language-based setting.
if indent_freq >= 1 && (indent_freq_2 as f64 / indent_freq as f64) < 0.66 {
// Use the auto-detected setting.
self.indent_style = match indent {
0 => IndentStyle::Tabs,
_ => IndentStyle::Spaces(indent as u8),
};
} else {
// Fall back to language-based setting.
let indent = self
.language
.as_ref()
.and_then(|config| config.indent.as_ref())
.map_or(" ", |config| config.unit.as_str()); // fallback to 2 spaces
self.indent_style = if indent.starts_with(' ') {
IndentStyle::Spaces(indent.len() as u8)
} else {
IndentStyle::Tabs
};
}
}
pub fn set_path(&mut self, path: &Path) -> Result<(), std::io::Error> { pub fn set_path(&mut self, path: &Path) -> Result<(), std::io::Error> {
let path = canonicalize_path(path)?; let path = canonicalize_path(path)?;
@ -1002,21 +878,7 @@ impl Document {
/// TODO: we might not need this function anymore, since the information /// TODO: we might not need this function anymore, since the information
/// is conveniently available in `Document::indent_style` now. /// is conveniently available in `Document::indent_style` now.
pub fn indent_unit(&self) -> &'static str { pub fn indent_unit(&self) -> &'static str {
match self.indent_style { self.indent_style.as_str()
IndentStyle::Tabs => "\t",
IndentStyle::Spaces(1) => " ",
IndentStyle::Spaces(2) => " ",
IndentStyle::Spaces(3) => " ",
IndentStyle::Spaces(4) => " ",
IndentStyle::Spaces(5) => " ",
IndentStyle::Spaces(6) => " ",
IndentStyle::Spaces(7) => " ",
IndentStyle::Spaces(8) => " ",
// Unsupported indentation style. This should never happen,
// but just in case fall back to two spaces.
_ => " ",
}
} }
#[inline] #[inline]

Loading…
Cancel
Save