Enum EmbeddingError 

pub enum EmbeddingError {
    Parse {
        source: String,
        message: String,
        position: Option<usize>,
    },
    UnresolvedPlaceholder {
        name: String,
        source: String,
    },
    LifecycleMismatch {
        source: String,
        dynamic_inputs: Vec<String>,
    },
    UnknownNode {
        name: String,
        source: String,
        suggestion: Option<String>,
    },
    TypeMismatch {
        from_node: String,
        from_type: PortType,
        to_node: String,
        to_type: PortType,
        source: String,
    },
    NodeEvalPanic {
        node_name: String,
        message: String,
        source: String,
    },
    ResultMissing {
        output_name: String,
        source: String,
    },
    NonePropagated {
        accessor: &'static str,
        source: String,
    },
    Timeout {
        source: String,
        elapsed_ms: u64,
        deadline_ms: u64,
    },
    RegistryNotInitialised {
        missing: Vec<String>,
        source: String,
    },
}

Typed error ontology for the embedded-evaluation surface.

Per expression_engine.md §6 Error Ontology (under crates/polydat/docs/design/), every failure mode the embedding surface can produce maps to one of these variants. Hosts pattern-match on the variant to drive UX, recovery, or logging without parsing message strings.

The embedding surfaces (eval_const_expr*, the typed surfaces, interpolate_via_kernel) return this type; the compile_polydat* entry points return String errors, and From<EmbeddingError> for String bridges the two.

Variants

Parse

Text could not be parsed as polydat expression source. The lexer or parser rejected the input before any semantic analysis.

Fields

source: String

The source text.

message: String

The lexer’s or parser’s message.

position: Option<usize>

The byte offset of the error, when known.

UnresolvedPlaceholder

A {name} placeholder in the text had no matching binding in the kernel chain. Produced by interpolate_via_kernel only.

Fields

name: String

The placeholder’s name.

source: String

The source text.

LifecycleMismatch

The expression’s upstream cone reaches a dynamic input, but the requested evaluation surface requires effectively-const lifecycle. Produced by eval_const_expr (directly or via the two-step composition).

Fields

source: String

The source text.

dynamic_inputs: Vec<String>

The dynamic inputs the cone reaches.

UnknownNode

A node mentioned in the expression is not registered in the runtime. Includes a suggested alternative when the name is close to a known node.

Fields

name: String

The unknown node’s name.

source: String

The source text.

suggestion: Option<String>

A registered name close to it, if any.

TypeMismatch

The expression’s wire chain has a type mismatch that auto-adapters cannot heal. Produced by the assembly pass during compilation.

Fields

from_node: String

The producing node.

from_type: PortType

Its output type.

to_node: String

The consuming node.

to_type: PortType

The type its port requires.

source: String

The source text.

NodeEvalPanic

A node’s eval panicked during scope-init evaluation. The kernel’s catch_unwind boundary captured the panic; the message is the panic payload’s human-readable form.

Fields

node_name: String

The node that panicked.

message: String

The panic’s message.

source: String

The source text.

ResultMissing

Compilation succeeded but the requested output name could not be resolved in the resulting kernel. Indicates an internal compiler issue or a mismatch between the wrapper template and the compiler’s output naming.

Fields

output_name: String

The output the caller asked for.

source: String

The source text.

NonePropagated

A Value::None propagated to the expression’s output where a concrete value was required. Produced by a HostType::from_value conversion that meets Value::None, or by a host’s own strict accessor (as_bool on Value::None, etc.). See SRD-74.

Fields

accessor: &'static str

The accessor the host called.

source: String

The source text.

Timeout

Evaluation exceeded a host-specified time budget. Currently produced only by deadline-accepting surfaces (reserved for the bulk-evaluation surface γ-9 and adapter-specific embedding paths).

Fields

source: String

The source text.

elapsed_ms: u64

Milliseconds spent.

deadline_ms: u64

The budget, in milliseconds.

RegistryNotInitialised

A node the expression references is absent from the link-time node registry. Carries the node names that could not be resolved. Not produced by any current surface.

Fields

missing: Vec<String>

The node names that could not be resolved.

source: String

The source text.

Trait Implementations

impl Clone for EmbeddingError

fn clone(&self) -> EmbeddingError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EmbeddingError

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

Formats the value using the given formatter.

impl Display for EmbeddingError

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

Formats the value using the given formatter.

impl Error for EmbeddingError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<EmbeddingError> for String

Renders the error as its message for callers on the Result<_, String> entry points.

fn from(e: EmbeddingError) -> String

Converts to this type from the input type.