Trait hcl::eval::Evaluate

pub trait Evaluate: Sealed {
    type Output;

    fn evaluate(&self, ctx: &Context<'_>) -> EvalResult<Self::Output>;
}

A trait for evaluating the HCL template and expression sub-languages.

The types implementing this trait must recursively evaluate all HCL templates and expressions in their fields.

This trait is sealed to prevent implementation outside of this crate.

Required Associated Types

type Output

The type that is returned by evaluate on success.

Required Methods

fn evaluate(&self, ctx: &Context<'_>) -> EvalResult<Self::Output>

Recursively evaluates all HCL templates and expressions in the implementing type using the variables and functions declared in the Context.

See the module-level documentation for usage examples.

Errors

This function fails with an error if:

• an expression evaluates to a value that is not allowed in a given context, e.g. a string occures where a boolean value is expected.
• an operation is performed on values that it’s not applicable to.
• an undefined variable or function is encountered.
• a defined function is called with unexpected arguments.

Implementations on Foreign Types

impl<T> Evaluate for Vec<T>where
    T: Evaluate,

type Output = Vec<<T as Evaluate>::Output, Global>

fn evaluate(&self, ctx: &Context<'_>) -> EvalResult<Self::Output>

Implementors

impl Evaluate for Expression

type Output = Value

impl Evaluate for ObjectKey

type Output = String

impl Evaluate for Structure

type Output = Structure

impl Evaluate for Operation

type Output = Value

impl Evaluate for TemplateExpr

type Output = Value

impl Evaluate for BinaryOp

type Output = Value

impl Evaluate for Conditional

type Output = Value

impl Evaluate for ForExpr

type Output = Value

impl Evaluate for FuncCall

type Output = Value

impl Evaluate for Traversal

type Output = Value

impl Evaluate for UnaryOp

type Output = Value

impl Evaluate for Template

type Output = String

impl Evaluate for Attribute

type Output = Attribute

impl Evaluate for Block

type Output = Block

impl Evaluate for Body

type Output = Body

impl<K, V> Evaluate for Object<K, V>where
    K: Evaluate,
    K::Output: Hash + Eq,
    V: Evaluate,

type Output = IndexMap<<K as Evaluate>::Output, <V as Evaluate>::Output, RandomState>