Enum DiagnosticKind 

pub enum DiagnosticKind {
    UnclosedTree,
    UnclosedSequence,
    UnclosedAlternation,
    UnclosedRegex,
    ExpectedExpression,
    ExpectedTypeName,
    ExpectedCaptureName,
    ExpectedFieldName,
    ExpectedSubtype,
    ExpectedPredicateValue,
    EmptyTree,
    EmptyAnonymousNode,
    EmptySequence,
    EmptyAlternation,
    BareIdentifier,
    InvalidSeparator,
    AnchorInAlternation,
    InvalidFieldEquals,
    InvalidSupertypeSyntax,
    InvalidTypeAnnotationSyntax,
    ErrorTakesNoArguments,
    RefCannotHaveChildren,
    ErrorMissingOutsideParens,
    UnsupportedPredicate,
    UnexpectedToken,
    CaptureWithoutTarget,
    LowercaseBranchLabel,
    CaptureNameHasDots,
    CaptureNameHasHyphens,
    CaptureNameUppercase,
    DefNameLowercase,
    DefNameHasSeparators,
    BranchLabelHasSeparators,
    FieldNameHasDots,
    FieldNameHasHyphens,
    FieldNameUppercase,
    TypeNameInvalidChars,
    TreeSitterSequenceSyntax,
    NegationSyntaxDeprecated,
    DuplicateDefinition,
    UndefinedReference,
    MixedAltBranches,
    RecursionNoEscape,
    DirectRecursion,
    FieldSequenceValue,
    AnchorWithoutContext,
    IncompatibleTypes,
    MultiCaptureQuantifierNoName,
    UnusedBranchLabels,
    StrictDimensionalityViolation,
    MultiElementScalarCapture,
    UncapturedOutputWithCaptures,
    AmbiguousUncapturedOutputs,
    DuplicateCaptureInScope,
    IncompatibleCaptureTypes,
    IncompatibleStructShapes,
    PredicateOnNonLeaf,
    EmptyRegex,
    RegexBackreference,
    RegexLookaround,
    RegexNamedCapture,
    RegexSyntaxError,
    UnknownNodeType,
    UnknownField,
    FieldNotOnNodeType,
    InvalidFieldChildType,
    InvalidChildType,
    UnnamedDef,
}

Diagnostic kinds ordered by priority (highest priority first).

When two diagnostics have overlapping spans, the higher-priority one suppresses the lower-priority one. This prevents cascading error noise.

Priority rationale:

• Unclosed delimiters cause massive cascading errors downstream
• Expected token errors are root causes the user should fix first
• Invalid syntax usage is a specific mistake at a location
• Naming validation errors are convention violations
• Semantic errors assume valid syntax
• Structural observations are often consequences of earlier errors

Variants

UnclosedTree

UnclosedSequence

UnclosedAlternation

UnclosedRegex

ExpectedExpression

ExpectedTypeName

ExpectedCaptureName

ExpectedFieldName

ExpectedSubtype

ExpectedPredicateValue

EmptyTree

EmptyAnonymousNode

EmptySequence

EmptyAlternation

BareIdentifier

InvalidSeparator

AnchorInAlternation

InvalidFieldEquals

InvalidSupertypeSyntax

InvalidTypeAnnotationSyntax

ErrorTakesNoArguments

RefCannotHaveChildren

ErrorMissingOutsideParens

UnsupportedPredicate

UnexpectedToken

CaptureWithoutTarget

LowercaseBranchLabel

CaptureNameHasDots

CaptureNameHasHyphens

CaptureNameUppercase

DefNameLowercase

DefNameHasSeparators

BranchLabelHasSeparators

FieldNameHasDots

FieldNameHasHyphens

FieldNameUppercase

TypeNameInvalidChars

TreeSitterSequenceSyntax

NegationSyntaxDeprecated

DuplicateDefinition

UndefinedReference

MixedAltBranches

RecursionNoEscape

DirectRecursion

FieldSequenceValue

AnchorWithoutContext

IncompatibleTypes

MultiCaptureQuantifierNoName

UnusedBranchLabels

StrictDimensionalityViolation

MultiElementScalarCapture

UncapturedOutputWithCaptures

AmbiguousUncapturedOutputs

DuplicateCaptureInScope

IncompatibleCaptureTypes

IncompatibleStructShapes

PredicateOnNonLeaf

EmptyRegex

RegexBackreference

RegexLookaround

RegexNamedCapture

RegexSyntaxError

UnknownNodeType

UnknownField

FieldNotOnNodeType

InvalidFieldChildType

InvalidChildType

UnnamedDef

Implementations

impl DiagnosticKind

pub fn default_severity(&self) -> Severity

Default severity for this kind. Can be overridden by policy.

pub fn suppresses(&self, other: &DiagnosticKind) -> bool

Whether this kind suppresses other when spans overlap.

Uses enum discriminant ordering: lower position = higher priority. A higher-priority diagnostic suppresses lower-priority ones in the same span.

pub fn is_structural_error(&self) -> bool

Structural errors are Unclosed* - they cause cascading errors but should be suppressed by root-cause errors at the same position.

pub fn is_root_cause_error(&self) -> bool

Root cause errors - user omitted something required. These suppress structural errors at the same position.

pub fn is_consequence_error(&self) -> bool

Consequence errors - often caused by earlier parse errors. These get suppressed when any root-cause or structural error exists.

pub fn default_hint(&self) -> Option<&'static str>

Default hint for this kind, automatically included in diagnostics. Call sites can add additional hints for context-specific information.

pub fn fallback_message(&self) -> &'static str

Base message for this diagnostic kind, used when no custom message is provided.

pub fn custom_message(&self) -> String

Template for custom messages. Contains {} placeholder for caller-provided detail.

pub fn message(&self, msg: Option<&str>) -> String

Render the final message.

• None → returns fallback_message()
• Some(detail) → returns custom_message() with {} replaced by detail

Trait Implementations

impl Clone for DiagnosticKind

fn clone(&self) -> DiagnosticKind

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DiagnosticKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for DiagnosticKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for DiagnosticKind

fn cmp(&self, other: &DiagnosticKind) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for DiagnosticKind

fn eq(&self, other: &DiagnosticKind) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for DiagnosticKind

fn partial_cmp(&self, other: &DiagnosticKind) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for DiagnosticKind

impl Eq for DiagnosticKind

impl StructuralPartialEq for DiagnosticKind