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fix: Place Node/Text capture effects on entry to prevent matched_node clobbering #307

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Merged
zharinov merged 1 commit into from
Jan 7, 2026
Merged

fix: Place Node/Text capture effects on entry to prevent matched_node clobbering #307

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44 changes: 28 additions & 16 deletions crates/plotnik-lib/src/compile/expressions.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -17,8 +17,7 @@ use crate::parser::ast::{self, Expr};
use super::Compiler;
use super::capture::CaptureEffects;
use super::navigation::{
check_trailing_anchor, inner_creates_scope, is_skippable_quantifier,
is_star_or_plus_quantifier, is_truly_empty_scope,
check_trailing_anchor, inner_creates_scope, is_star_or_plus_quantifier, is_truly_empty_scope,
};

impl Compiler<'_> {
Expand Down Expand Up @@ -73,39 +72,52 @@ impl Compiler<'_> {
);
}

// Check if first item is skippable - its skip path should bypass the Up.
// When a zero-match quantifier (? or *) is the first child with Down navigation,
// the skip path never descends, so executing Up would ascend too far.
let first_is_skippable = items
.first()
.and_then(|i| i.as_expr())
.is_some_and(is_skippable_quantifier);
// Split capture.post: Node/Text effects (and their Set) go on entry (need matched_node
// right after match), other effects go on final_exit (after children processing).
// Node/Text capture effects use matched_node which is only valid immediately after the match,
// before descending into children (which may clobber matched_node via backtracking).
use crate::bytecode::EffectOpcode;

// Find Node/Text effects and their following Set effects (they come in pairs: Node Set)
let mut entry_effects = Vec::new();
let mut exit_effects = Vec::new();
let mut iter = capture.post.into_iter().peekable();
while let Some(eff) = iter.next() {
if matches!(eff.opcode, EffectOpcode::Node | EffectOpcode::Text) {
entry_effects.push(eff);
// Take the following Set if present (Node/Text are always followed by Set)
if iter.peek().is_some_and(|e| e.opcode == EffectOpcode::Set) {
entry_effects.push(iter.next().unwrap());
}
} else {
exit_effects.push(eff);
}
}

// With items: nav → items → Up → [post_effects] → exit
// If first item is skippable: skip path → exit (bypass Up), match path → Up → exit
let final_exit = self.emit_post_effects_exit(exit, capture.post);
// With items: nav[entry_effects] → items → Up → [exit_effects] → exit
let final_exit = self.emit_post_effects_exit(exit, exit_effects);

let up_label = self.fresh_label();
let skip_exit = first_is_skippable.then_some(exit);
let items_entry = self.compile_seq_items_inner(
&items,
up_label,
true,
None,
CaptureEffects::default(),
skip_exit,
None, // No skip_exit bypass - all paths need Up
);

self.instructions
.push(MatchIR::epsilon(up_label, final_exit).nav(up_nav).into());

// Emit entry instruction into the node (only pre_effects here)
// Emit entry instruction with node_effects on post (executes right after match)
self.emit_match_with_cascade(
MatchIR::epsilon(entry, items_entry)
.nav(nav)
.node_type(node_type)
.neg_fields(neg_fields)
.pre_effects(capture.pre),
.pre_effects(capture.pre)
.post_effects(entry_effects),
);

entry
Expand Down
31 changes: 15 additions & 16 deletions ...nik-lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__alternations_in_quantifier.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -53,23 +53,22 @@ Test:
06 ε 07
07 ! (object) 08
08 ε [Arr] 10
10 ε 39, 20
10 ε 37, 12
12 ε [EndArr Set(M5)] 14
14 △ _ 19
15 ε [EndObj Push] 17
17 ε 45, 12
17 ε 43, 12
19 ▶
20 ε [EndArr Set(M5)] 19
22 ε [Set(M4)] 15
24 ! [Enum(M2)] (pair) [Node Set(M0) EndEnum] 22
27 ! [Enum(M3)] (shorthand_property_identifier) [Node Set(M1) EndEnum] 22
30 ε 24, 27
32 ε [Obj] 30
34 ▷ _ 37
35 ε 34, 20
37 ε 32, 35
39 ▽ _ 37
40 ▷ _ 43
41 ε 40, 12
43 ε 32, 41
45 ▷ _ 43
20 ε [Set(M4)] 15
22 ! [Enum(M2)] (pair) [Node Set(M0) EndEnum] 20
25 ! [Enum(M3)] (shorthand_property_identifier) [Node Set(M1) EndEnum] 20
28 ε 22, 25
30 ε [Obj] 28
32 ▷ _ 35
33 ε 32, 12
35 ε 30, 33
37 ▽ _ 35
38 ▷ _ 41
39 ε 38, 12
41 ε 30, 39
43 ▷ _ 41
17 changes: 7 additions & 10 deletions ...plotnik-lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__captures_deeply_nested.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -48,14 +48,11 @@ _ObjWrap:

Test:
06 ε 07
07 ! (a) 08
08 ▽ (b) 09
09 ▽ (c) 10
10 ▽ (d) [Node Set(M3)] 12
12 △ _ 13
13 ε [Node Set(M2)] 15
07 ! (a) [Node Set(M0)] 09
09 ▽ (b) [Node Set(M1)] 11
11 ▽ (c) [Node Set(M2)] 13
13 ▽ (d) [Node Set(M3)] 15
15 △ _ 16
16 ε [Node Set(M1)] 18
18 △ _ 19
19 ε [Node Set(M0)] 21
21 ▶
16 △ _ 17
17 △ _ 18
18 ▶
12 changes: 5 additions & 7 deletions ...s/plotnik-lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__captures_nested_flat.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -42,11 +42,9 @@ _ObjWrap:

Test:
06 ε 07
07 ! (a) 08
08 ▽ (b) 09
09 ▽ (c) [Node Set(M2)] 11
11 △ _ 12
12 ε [Node Set(M1)] 14
07 ! (a) [Node Set(M0)] 09
09 ▽ (b) [Node Set(M1)] 11
11 ▽ (c) [Node Set(M2)] 13
13 △ _ 14
14 △ _ 15
15 ε [Node Set(M0)] 17
17 ▶
15 ▶
31 changes: 15 additions & 16 deletions ...nik-lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__definitions_nested_capture.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -56,23 +56,22 @@ Outer:
12 ε 13
13 ! (parent) 14
14 ε [Arr] 16
16 ε 42, 26
16 ε 40, 18
18 ε [EndArr Set(M2)] 20
20 △ _ 25
21 ε [EndObj Push] 23
23 ε 48, 18
23 ε 46, 18
25 ▶
26 ε [EndArr Set(M2)] 25
28 ε [Set(M1)] 21
30 ε [EndObj] 28
32 ! (Inner) 06 : 30
33 ε [Obj] 32
35 ε [Obj] 33
37 ▷ _ 40
38 ε 37, 26
40 ε 35, 38
42 ▽ _ 40
43 ▷ _ 46
44 ε 43, 18
46 ε 35, 44
48 ▷ _ 46
26 ε [Set(M1)] 21
28 ε [EndObj] 26
30 ! (Inner) 06 : 28
31 ε [Obj] 30
33 ε [Obj] 31
35 ▷ _ 38
36 ε 35, 18
38 ε 33, 36
40 ▽ _ 38
41 ▷ _ 44
42 ε 41, 18
44 ε 33, 42
46 ▷ _ 44
18 changes: 9 additions & 9 deletions ...lotnik-lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__optional_null_injection.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -37,12 +37,12 @@ _ObjWrap:
Test:
06 ε 07
07 ! (function_declaration) 08
08 ε 21, 14
10 ! (decorator) [Node Set(M0)] 12
12 △ _ 13
13 ▶
14 ε [Null Set(M0)] 13
16 ▷ _ 19
17 ε 16, 14
19 ε 10, 17
21 ▽ _ 19
08 ε 20, 13
10 ▶
11 ! (decorator) [Node Set(M0)] 21
13 ε [Null Set(M0)] 21
15 ▷ _ 18
16 ε 15, 13
18 ε 11, 16
20 ▽ _ 18
21 △ _ 10
18 changes: 9 additions & 9 deletions ...s/plotnik-lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__quantifiers_optional.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -37,12 +37,12 @@ _ObjWrap:
Test:
06 ε 07
07 ! (function_declaration) 08
08 ε 21, 14
10 ! (decorator) [Node Set(M0)] 12
12 △ _ 13
13 ▶
14 ε [Null Set(M0)] 13
16 ▷ _ 19
17 ε 16, 14
19 ε 10, 17
21 ▽ _ 19
08 ε 20, 13
10 ▶
11 ! (decorator) [Node Set(M0)] 21
13 ε [Null Set(M0)] 21
15 ▷ _ 18
16 ε 15, 13
18 ε 11, 16
20 ▽ _ 18
21 △ _ 10
18 changes: 9 additions & 9 deletions ...lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__quantifiers_optional_nongreedy.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -37,12 +37,12 @@ _ObjWrap:
Test:
06 ε 07
07 ! (function_declaration) 08
08 ε 14, 21
10 ! (decorator) [Node Set(M0)] 12
12 △ _ 13
13 ▶
14 ε [Null Set(M0)] 13
16 ▷ _ 19
17 ε 14, 16
19 ε 17, 10
21 ▽ _ 19
08 ε 13, 20
10 ▶
11 ! (decorator) [Node Set(M0)] 21
13 ε [Null Set(M0)] 21
15 ▷ _ 18
16 ε 13, 15
18 ε 16, 11
20 ▽ _ 18
21 △ _ 10
21 changes: 10 additions & 11 deletions ...-lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__quantifiers_repeat_navigation.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -38,18 +38,17 @@ Test:
06 ε 07
07 ! (function_declaration) 08
08 ε [Arr] 10
10 ε 27, 20
10 ε 25, 12
12 ε [EndArr Set(M0)] 14
14 △ _ 19
15 ! (decorator) [Node Push] 17
17 ε 33, 12
17 ε 31, 12
19 ▶
20 ε [EndArr Set(M0)] 19
22 ▷ _ 25
23 ε 22, 20
25 ε 15, 23
27 ▽ _ 25
28 ▷ _ 31
29 ε 28, 12
31 ε 15, 29
33 ▷ _ 31
20 ▷ _ 23
21 ε 20, 12
23 ε 15, 21
25 ▽ _ 23
26 ▷ _ 29
27 ε 26, 12
29 ε 15, 27
31 ▷ _ 29
27 changes: 13 additions & 14 deletions ...otnik-lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__quantifiers_struct_array.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -48,21 +48,20 @@ Test:
06 ε 07
07 ! (array) 08
08 ε [Arr] 10
10 ε 33, 20
10 ε 31, 12
12 ε [EndArr Set(M2)] 14
14 △ _ 19
15 ε [EndObj Push] 17
17 ε 39, 12
17 ε 37, 12
19 ▶
20 ε [EndArr Set(M2)] 19
22 ▷ (number) [Node Set(M1)] 15
24 ! (identifier) [Node Set(M0)] 22
26 ε [Obj] 24
28 ▷ _ 31
29 ε 28, 20
31 ε 26, 29
33 ▽ _ 31
34 ▷ _ 37
35 ε 34, 12
37 ε 26, 35
39 ▷ _ 37
20 ▷ (number) [Node Set(M1)] 15
22 ! (identifier) [Node Set(M0)] 20
24 ε [Obj] 22
26 ▷ _ 29
27 ε 26, 12
29 ε 24, 27
31 ▽ _ 29
32 ▷ _ 35
33 ε 32, 12
35 ε 24, 33
37 ▷ _ 35
23 changes: 11 additions & 12 deletions ...lotnik-lib/src/emit/snapshots/plotnik_lib__emit__emit_tests__sequences_in_quantifier.snap
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Original file line number Diff line number Diff line change
Expand Up @@ -39,19 +39,18 @@ Test:
06 ε 07
07 ! (parent) 08
08 ε [Arr] 10
10 ε 28, 20
10 ε 26, 12
12 ε [EndArr Set(M0)] 14
14 △ _ 19
15 ▷ (b) [Node Push] 17
17 ε 34, 12
17 ε 32, 12
19 ▶
20 ε [EndArr Set(M0)] 19
22 ! (a) 15
23 ▷ _ 26
24 ε 23, 20
26 ε 22, 24
28 ▽ _ 26
29 ▷ _ 32
30 ε 29, 12
32 ε 22, 30
34 ▷ _ 32
20 ! (a) 15
21 ▷ _ 24
22 ε 21, 12
24 ε 20, 22
26 ▽ _ 24
27 ▷ _ 30
28 ε 27, 12
30 ε 20, 28
32 ▷ _ 30
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