@ -4,6 +4,7 @@ use tree_sitter::{Query, QueryCursor, QueryPredicateArg};
use crate ::{
chars ::{ char_is_line_ending , char_is_whitespace } ,
find_first_non_whitespace_char ,
graphemes ::{ grapheme_width , tab_width_at } ,
syntax ::{ LanguageConfiguration , RopeProvider , Syntax } ,
tree_sitter ::Node ,
@ -196,6 +197,19 @@ pub fn indent_level_for_line(line: RopeSlice, tab_width: usize, indent_width: us
len / indent_width
}
/// Create a string of tabs & spaces that has the same visual width as the given RopeSlice (independent of the tab width).
fn whitespace_with_same_width ( text : RopeSlice ) -> String {
let mut s = String ::new ( ) ;
for grapheme in RopeGraphemes ::new ( text ) {
if grapheme = = "\t" {
s . push ( '\t' ) ;
} else {
s . extend ( std ::iter ::repeat ( ' ' ) . take ( grapheme_width ( & Cow ::from ( grapheme ) ) ) ) ;
}
}
s
}
/// Computes for node and all ancestors whether they are the first node on their line.
/// The first entry in the return value represents the root node, the last one the node itself
fn get_first_in_line ( mut node : Node , new_line_byte_pos : Option < usize > ) -> Vec < bool > {
@ -241,21 +255,21 @@ fn get_first_in_line(mut node: Node, new_line_byte_pos: Option<usize>) -> Vec<bo
/// - max(0, indent - outdent) tabs, if tabs are used for indentation
/// - max(0, indent - outdent)*indent_width spaces, if spaces are used for indentation
#[ derive(Default, Debug, PartialEq, Eq, Clone) ]
pub struct Indentation {
pub struct Indentation < ' a > {
indent : usize ,
indent_always : usize ,
outdent : usize ,
outdent_always : usize ,
/// The alignment, as a string containing only tabs & spaces. Storing this as a string instead of e.g.
/// the (visual) width ensures that the alignment is preserved even if the tab width changes.
align : Option < String > ,
align : Option < RopeSlice < ' a > > ,
}
impl Indentation {
impl < ' a > Indentation < ' a > {
/// Add some other [Indentation] to this.
/// The added indent should be the total added indent from one line.
/// Indent should always be added starting from the bottom (or equivalently, the innermost tree-sitter node).
fn add_line ( & mut self , added : Indentation ) {
fn add_line ( & mut self , added : Indentation < ' a > ) {
// Align overrides the indent from outer scopes.
if self . align . is_some ( ) {
return ;
@ -274,7 +288,7 @@ impl Indentation {
/// Only captures that apply to the same line should be added together in this way (otherwise use `add_line`)
/// and the captures should be added starting from the innermost tree-sitter node (currently this only matters
/// if multiple `@align` patterns occur on the same line).
fn add_capture ( & mut self , added : IndentCaptureType ) {
fn add_capture ( & mut self , added : IndentCaptureType < ' a > ) {
match added {
IndentCaptureType ::Indent = > {
if self . indent_always = = 0 {
@ -303,7 +317,60 @@ impl Indentation {
}
}
}
fn into_string ( self , indent_style : & IndentStyle ) -> String {
fn net_indent ( & self ) -> isize {
( self . indent + self . indent_always ) as isize
- ( ( self . outdent + self . outdent_always ) as isize )
}
/// Convert `self` into a string, taking into account the computed and actual indentation of some other line.
fn relative_indent (
& self ,
other_computed_indent : & Self ,
other_leading_whitespace : RopeSlice ,
indent_style : & IndentStyle ,
tab_width : usize ,
) -> Option < String > {
if self . align = = other_computed_indent . align {
// If self and baseline are either not aligned to anything or both aligned the same way,
// we can simply take `other_leading_whitespace` and add some indent / outdent to it (in the second
// case, the alignment should already be accounted for in `other_leading_whitespace`).
let indent_diff = self . net_indent ( ) - other_computed_indent . net_indent ( ) ;
if indent_diff > = 0 {
let mut indent = other_leading_whitespace . to_string ( ) ;
indent . push_str ( & indent_style . as_str ( ) . repeat ( indent_diff as usize ) ) ;
Some ( indent )
} else {
// It's not entirely clear how to subtract a given indent level from the other line if its indentation is
// complex (e.g. a weird alignment or a mixture of tabs and spaces). Therefore, we only consider the indent level
// of `baseline_leading_whitespace`, add `indent_diff` to it and convert this indent level back to a string. If we ever encounter
// cases where some other behavior is expected, the behavior for strings that don't exactly correspond to some indent
// level could be re-evaluated.
let actual_baseline_indent_level = indent_level_for_line (
other_leading_whitespace ,
tab_width ,
indent_style . indent_width ( tab_width ) ,
) ;
let total_indent = actual_baseline_indent_level as isize + indent_diff ;
if total_indent < 0 {
log ::warn ! (
"Computed negative indent during a relative indent computation (actual baseline indent: {}, computed baseline indent: {}, computed line indent: {})" ,
actual_baseline_indent_level ,
other_computed_indent . net_indent ( ) ,
self . net_indent ( ) ,
) ;
Some ( String ::new ( ) )
} else {
Some ( indent_style . as_str ( ) . repeat ( total_indent as usize ) )
}
}
} else if self . align . is_some ( ) {
Some ( self . to_string ( indent_style ) )
} else {
// If the other line has some alignment and `self` does not, there is no reasonable way to take
// into account `other_leading_whitespace`.
None
}
}
pub fn to_string ( & self , indent_style : & IndentStyle ) -> String {
let indent = self . indent_always + self . indent ;
let outdent = self . outdent_always + self . outdent ;
@ -314,7 +381,7 @@ impl Indentation {
0
} ;
let mut indent_string = if let Some ( align ) = self . align {
whitespace_with_same_width( align)
} else {
String ::new ( )
} ;
@ -325,21 +392,21 @@ impl Indentation {
/// An indent definition which corresponds to a capture from the indent query
#[ derive(Debug) ]
struct IndentCapture {
capture_type : IndentCaptureType ,
struct IndentCapture < ' a > {
capture_type : IndentCaptureType < ' a > ,
scope : IndentScope ,
}
#[ derive(Debug, Clone, PartialEq) ]
enum IndentCaptureType {
enum IndentCaptureType < ' a > {
Indent ,
IndentAlways ,
Outdent ,
OutdentAlways ,
/// Alignment given as a string of whitespace
Align ( String ) ,
Align ( RopeSlice < ' a > ) ,
}
impl IndentCaptureType {
impl < ' a > IndentCaptureType < ' a > {
fn default_scope ( & self ) -> IndentScope {
match self {
IndentCaptureType ::Indent | IndentCaptureType ::IndentAlways = > IndentScope ::Tail ,
@ -371,8 +438,8 @@ enum ExtendCapture {
/// each node (identified by its ID) the relevant captures (already filtered
/// by predicates).
#[ derive(Debug) ]
struct IndentQueryResult {
indent_captures : HashMap < usize , Vec < IndentCapture > ,
struct IndentQueryResult < ' a > {
indent_captures : HashMap < usize , Vec < IndentCapture <' a > >> ,
extend_captures : HashMap < usize , Vec < ExtendCapture > > ,
}
@ -393,14 +460,14 @@ fn get_node_end_line(node: Node, new_line_byte_pos: Option<usize>) -> usize {
node_line
}
fn query_indents (
fn query_indents < ' a > (
query : & Query ,
syntax : & Syntax ,
cursor : & mut QueryCursor ,
text : RopeSlice ,
text : RopeSlice < ' a > ,
range : std ::ops ::Range < usize > ,
new_line_byte_pos : Option < usize > ,
) -> IndentQueryResult {
) -> IndentQueryResult < ' a > {
let mut indent_captures : HashMap < usize , Vec < IndentCapture > > = HashMap ::new ( ) ;
let mut extend_captures : HashMap < usize , Vec < ExtendCapture > > = HashMap ::new ( ) ;
cursor . set_byte_range ( range ) ;
@ -488,7 +555,7 @@ fn query_indents(
"outdent" = > IndentCaptureType ::Outdent ,
"outdent.always" = > IndentCaptureType ::OutdentAlways ,
// The alignment will be updated to the correct value at the end, when the anchor is known.
"align" = > IndentCaptureType ::Align ( String from ( "" ) ) ,
"align" = > IndentCaptureType ::Align ( RopeSlice from ( "" ) ) ,
"anchor" = > {
if anchor . is_some ( ) {
log ::error ! ( "Invalid indent query: Encountered more than one @anchor in the same match." )
@ -560,22 +627,10 @@ fn query_indents(
}
Some ( anchor ) = > anchor ,
} ;
// Create a string of tabs & spaces that should have the same width
// as the string that precedes the anchor (independent of the tab width).
let mut align = String ::new ( ) ;
for grapheme in RopeGraphemes ::new (
capture . capture_type = IndentCaptureType ::Align (
text . line ( anchor . start_position ( ) . row )
. byte_slice ( 0 .. anchor . start_position ( ) . column ) ,
) {
if grapheme = = "\t" {
align . push ( '\t' ) ;
} else {
align . extend (
std ::iter ::repeat ( ' ' ) . take ( grapheme_width ( & Cow ::from ( grapheme ) ) ) ,
) ;
}
}
capture . capture_type = IndentCaptureType ::Align ( align ) ;
) ;
}
indent_captures
. entry ( node_id )
@ -661,56 +716,20 @@ fn extend_nodes<'a>(
}
}
/// Use the syntax tree to determine the indentation for a given position.
/// This can be used in 2 ways:
///
/// - To get the correct indentation for an existing line (new_line=false), not necessarily equal to the current indentation.
/// - In this case, pos should be inside the first tree-sitter node on that line.
/// In most cases, this can just be the first non-whitespace on that line.
/// - To get the indentation for a new line (new_line=true). This behaves like the first usecase if the part of the current line
/// after pos were moved to a new line.
///
/// The indentation is determined by traversing all the tree-sitter nodes containing the position.
/// Each of these nodes produces some [Indentation] for:
///
/// - The line of the (beginning of the) node. This is defined by the scope `all` if this is the first node on its line.
/// - The line after the node. This is defined by:
/// - The scope `tail`.
/// - The scope `all` if this node is not the first node on its line.
/// Intuitively, `all` applies to everything contained in this node while `tail` applies to everything except for the first line of the node.
/// The indents from different nodes for the same line are then combined.
/// The result [Indentation] is simply the sum of the [Indentation] for all lines.
///
/// Specifying which line exactly an [Indentation] applies to is important because indents on the same line combine differently than indents on different lines:
/// ```ignore
/// some_function(|| {
/// // Both the function parameters as well as the contained block should be indented.
/// // Because they are on the same line, this only yields one indent level
/// });
/// ```
///
/// ```ignore
/// some_function(
/// param1,
/// || {
/// // Here we get 2 indent levels because the 'parameters' and the 'block' node begin on different lines
/// },
/// );
/// ```
/// Prepare an indent query by computing:
/// - The node from which to start the query (this is non-trivial due to `@extend` captures)
/// - The indent captures for all relevant nodes.
#[ allow(clippy::too_many_arguments) ]
pub fn treesitter_indent_for_pos (
fn init_indent_query < ' a , ' b > (
query : & Query ,
syntax : & Syntax ,
indent_style: & IndentStyle ,
syntax : & ' a Syntax ,
text : RopeSlice < ' b > ,
tab_width : usize ,
indent_width : usize ,
text : RopeSlice ,
line : usize ,
pos : usize ,
new_line : bool ,
) -> Option < String > {
let byte_pos = text . char_to_byte ( pos ) ;
let new_line_byte_pos = new_line . then_some ( byte_pos ) ;
byte_pos : usize ,
new_line_byte_pos : Option < usize > ,
) -> Option < ( Node < ' a > , HashMap < usize , Vec < IndentCapture < ' b > > > ) > {
// The innermost tree-sitter node which is considered for the indent
// computation. It may change if some predeceding node is extended
let mut node = syntax
@ -754,7 +773,6 @@ pub fn treesitter_indent_for_pos(
( query_result , deepest_preceding )
} )
} ;
let mut indent_captures = query_result . indent_captures ;
let extend_captures = query_result . extend_captures ;
// Check for extend captures, potentially changing the node that the indent calculation starts with
@ -769,6 +787,68 @@ pub fn treesitter_indent_for_pos(
indent_width ,
) ;
}
Some ( ( node , query_result . indent_captures ) )
}
/// Use the syntax tree to determine the indentation for a given position.
/// This can be used in 2 ways:
///
/// - To get the correct indentation for an existing line (new_line=false), not necessarily equal to the current indentation.
/// - In this case, pos should be inside the first tree-sitter node on that line.
/// In most cases, this can just be the first non-whitespace on that line.
/// - To get the indentation for a new line (new_line=true). This behaves like the first usecase if the part of the current line
/// after pos were moved to a new line.
///
/// The indentation is determined by traversing all the tree-sitter nodes containing the position.
/// Each of these nodes produces some [Indentation] for:
///
/// - The line of the (beginning of the) node. This is defined by the scope `all` if this is the first node on its line.
/// - The line after the node. This is defined by:
/// - The scope `tail`.
/// - The scope `all` if this node is not the first node on its line.
/// Intuitively, `all` applies to everything contained in this node while `tail` applies to everything except for the first line of the node.
/// The indents from different nodes for the same line are then combined.
/// The result [Indentation] is simply the sum of the [Indentation] for all lines.
///
/// Specifying which line exactly an [Indentation] applies to is important because indents on the same line combine differently than indents on different lines:
/// ```ignore
/// some_function(|| {
/// // Both the function parameters as well as the contained block should be indented.
/// // Because they are on the same line, this only yields one indent level
/// });
/// ```
///
/// ```ignore
/// some_function(
/// param1,
/// || {
/// // Here we get 2 indent levels because the 'parameters' and the 'block' node begin on different lines
/// },
/// );
/// ```
#[ allow(clippy::too_many_arguments) ]
pub fn treesitter_indent_for_pos < ' a > (
query : & Query ,
syntax : & Syntax ,
tab_width : usize ,
indent_width : usize ,
text : RopeSlice < ' a > ,
line : usize ,
pos : usize ,
new_line : bool ,
) -> Option < Indentation < ' a > > {
let byte_pos = text . char_to_byte ( pos ) ;
let new_line_byte_pos = new_line . then_some ( byte_pos ) ;
let ( mut node , mut indent_captures ) = init_indent_query (
query ,
syntax ,
text ,
tab_width ,
indent_width ,
line ,
byte_pos ,
new_line_byte_pos ,
) ? ;
let mut first_in_line = get_first_in_line ( node , new_line . then_some ( byte_pos ) ) ;
let mut result = Indentation ::default ( ) ;
@ -836,7 +916,7 @@ pub fn treesitter_indent_for_pos(
break ;
}
}
Some ( result .into_string ( indent_style ) )
Some ( result
}
/// Returns the indentation for a new line.
@ -860,7 +940,6 @@ pub fn indent_for_newline(
if let Some ( indent ) = treesitter_indent_for_pos (
query ,
syntax ,
indent_style ,
tab_width ,
indent_width ,
text ,
@ -868,9 +947,55 @@ pub fn indent_for_newline(
line_before_end_pos ,
true ,
) {
return indent ;
// We want to compute the indentation not only based on the
// syntax tree but also on the actual indentation of a previous
// line. This makes indentation computation more resilient to
// incomplete queries, incomplete source code & differing indentation
// styles for the same language.
// However, using the indent of a previous line as a baseline may not
// make sense, e.g. if it has a different alignment than the new line.
// In order to prevent edge cases with long running times, we only try
// a constant number of (non-empty) lines.
const MAX_ATTEMPTS : usize = 2 ;
let mut num_attempts = 0 ;
for line_idx in ( 0 ..= line_before ) . rev ( ) {
let line = text . line ( line_idx ) ;
let first_non_whitespace_char = match find_first_non_whitespace_char ( line ) {
Some ( i ) = > i ,
None = > {
continue ;
}
} ;
if let Some ( indent ) = ( | | {
let computed_indent = treesitter_indent_for_pos (
query ,
syntax ,
tab_width ,
indent_width ,
text ,
line_idx ,
text . line_to_char ( line_idx ) + first_non_whitespace_char ,
false ,
) ? ;
let leading_whitespace = line . slice ( 0 .. first_non_whitespace_char ) ;
indent . relative_indent (
& computed_indent ,
leading_whitespace ,
indent_style ,
tab_width ,
)
} ) ( ) {
return indent ;
}
num_attempts + = 1 ;
if num_attempts = = MAX_ATTEMPTS {
break ;
}
}
return indent . to_string ( indent_style ) ;
} ;
}
// Fallback in case we either don't have indent queries or they failed for some reason
let indent_level = indent_level_for_line ( text . line ( current_line ) , tab_width , indent_width ) ;
indent_style . as_str ( ) . repeat ( indent_level )
}
@ -962,10 +1087,13 @@ mod test {
.. Default ::default ( )
} ;
let add_capture = | mut indent : Indentation , capture | {
fn add_capture < ' a > (
mut indent : Indentation < ' a > ,
capture : IndentCaptureType < ' a > ,
) -> Indentation < ' a > {
indent . add_capture ( capture ) ;
indent
} ;
}
// adding an indent to no indent makes an indent
assert_eq! (
Daniel Ebert
1 year ago
committed by
Blaž Hrastnik