tryResolveType() — react Function Reference

Architecture documentation for the tryResolveType() function in InferTypes.ts from the react codebase.

Function typescript MIRInfrastructure HIR calls 3 called by 1

Entity Profile

MIRInfrastructure→ HIR→ tryResolveType() — react Function Reference

Dependency Diagram

graph TD
  3586dd2f_f748_328e_8e11_2899a16d4f45["tryResolveType()"]
  e91596b5_bd35_ace7_a141_7dbab722b96d["Unifier"]
  3586dd2f_f748_328e_8e11_2899a16d4f45 -->|defined in| e91596b5_bd35_ace7_a141_7dbab722b96d
  6938eece_f870_22b1_d136_01eb0a26f7b9["bindVariableTo()"]
  6938eece_f870_22b1_d136_01eb0a26f7b9 -->|calls| 3586dd2f_f748_328e_8e11_2899a16d4f45
  f0603215_bdb0_88a0_8649_8c18b423f04f["get()"]
  3586dd2f_f748_328e_8e11_2899a16d4f45 -->|calls| f0603215_bdb0_88a0_8649_8c18b423f04f
  073c81a5_c389_d108_5b8f_4d6dc6eece83["push()"]
  3586dd2f_f748_328e_8e11_2899a16d4f45 -->|calls| 073c81a5_c389_d108_5b8f_4d6dc6eece83
  d7fde76c_4fd9_feb3_299b_798689f05bc6["assertExhaustive()"]
  3586dd2f_f748_328e_8e11_2899a16d4f45 -->|calls| d7fde76c_4fd9_feb3_299b_798689f05bc6
  style 3586dd2f_f748_328e_8e11_2899a16d4f45 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

compiler/packages/babel-plugin-react-compiler/src/TypeInference/InferTypes.ts lines 700–792

  tryResolveType(v: TypeVar, type: Type): Type | null {
    switch (type.kind) {
      case 'Phi': {
        /**
         * Resolve the type of the phi by recursively removing `v` as an operand.
         * For example we can end up with types like this:
         *
         * v = Phi [
         *   T1
         *   T2
         *   Phi [
         *     T3
         *     Phi [
         *       T4
         *       v <-- cycle!
         *     ]
         *   ]
         * ]
         *
         * By recursively removing `v`, we end up with:
         *
         * v = Phi [
         *   T1
         *   T2
         *   Phi [
         *     T3
         *     Phi [
         *       T4
         *     ]
         *   ]
         * ]
         *
         * Which avoids the cycle
         */
        const operands = [];
        for (const operand of type.operands) {
          if (operand.kind === 'Type' && operand.id === v.id) {
            continue;
          }
          const resolved = this.tryResolveType(v, operand);
          if (resolved === null) {
            return null;
          }
          operands.push(resolved);
        }
        return {kind: 'Phi', operands};
      }
      case 'Type': {
        const substitution = this.get(type);
        if (substitution !== type) {
          const resolved = this.tryResolveType(v, substitution);
          if (resolved !== null) {
            this.substitutions.set(type.id, resolved);
          }
          return resolved;
        }
        return type;
      }
      case 'Property': {
        const objectType = this.tryResolveType(v, this.get(type.objectType));
        if (objectType === null) {
          return null;
        }
        return {
          kind: 'Property',
          objectName: type.objectName,
          objectType,
          propertyName: type.propertyName,
        };
      }
      case 'Function': {
        const returnType = this.tryResolveType(v, this.get(type.return));
        if (returnType === null) {
          return null;
        }
        return {
          kind: 'Function',
          return: returnType,
          shapeId: type.shapeId,
          isConstructor: type.isConstructor,
        };