Evaluator Engine

The evaluator performs static extraction of resource declarations from TypeScript AST nodes. It converts new ResourceType({...}) expressions into structured data that lexicon serializers can consume.

How It Works

The evaluator walks top-level statements in each source file, looking for exported variable declarations with new Type({...}) initializers. For each resource found, it recursively evaluates the property object into a value tree.

The evaluator never executes TypeScript. It reads the AST as data, resolving only what can be determined statically.

Supported Expressions

• Literals: strings, numbers, booleans, null, arrays, object literals
• Identifiers: references to const bindings (traced to their initializer)
• Property access: obj.key on known objects
• Spread: {...defaults, name: "x"} from const sources
• Ternary: cond ? a : b
• Binary expressions: arithmetic, string concatenation
• Nullish coalescing: left ?? right
• Tagged templates: lexicon-registered intrinsic tags

Expressions that cannot be statically resolved are rejected by lint rules before the evaluator runs.

Output

Each extracted resource produces an evaluated resource with:

• LogicalName — derived from the export binding name
• ResourceType — provider type string from the resource registry
• Props — ordered map of evaluated property values

Composite Support

The evaluator detects Composite({...}) definitions and stores them in a composite registry. When a composite is instantiated, the evaluator expands its resource map, resolving siblings references between member resources.