Method readField

javascript/packages/core/lib/gen/struct.ts:587–658

(fieldName: string, fieldTypeInfo: TypeInfo, assignStmt: (expr: string) => string, embedGenerator: SerializerGenerator)

  }

  readField(fieldName: string, fieldTypeInfo: TypeInfo, assignStmt: (expr: string) => string, embedGenerator: SerializerGenerator) {
    const { nullable = false, dynamic, trackingRef } = fieldTypeInfo;
    const refMode = toRefMode(trackingRef, nullable);
    const assignCompatible = (expr: string) => assignStmt(compatibleReadTargetExpr(fieldTypeInfo, expr));
    if (shouldSkipCompatibleRead(fieldTypeInfo)) {
      const discard = (expr: string) => `${expr};`;
      if (this.builder.resolver.isMonomorphic(fieldTypeInfo, dynamic)) {
        if (refMode == RefMode.TRACKING || refMode === RefMode.NULL_ONLY) {
          return embedGenerator.readRefWithoutTypeInfo(discard);
        }
        if (isDepthFreeField(fieldTypeInfo)) {
          return embedGenerator.read(discard, "false");
        }
        return embedGenerator.readWithDepth(discard, "false");
      }
      if (refMode == RefMode.TRACKING || refMode === RefMode.NULL_ONLY) {
        return embedGenerator.readRef(discard);
      }
      return embedGenerator.readNoRef(discard, "false");
    }
    const scalarAction = getCompatibleScalarReadAction(fieldTypeInfo);
    if (scalarAction) {
      const readValue = compatibleScalarFieldReadExpr(
        scalarAction.remoteTypeId,
        scalarAction.localTypeId,
        this.builder,
      );
      if (readValue === null) {
        throw new Error(
          `Unsupported compatible scalar conversion from ${scalarAction.remoteTypeId} to ${scalarAction.localTypeId}`,
        );
      }
      if (scalarAction.remoteNullable !== true) {
        return assignStmt(readValue);
      }
      const refFlag = this.scope.uniqueName("refFlag");
      return `
        const ${refFlag} = ${this.builder.reader.readInt8()};
        switch (${refFlag}) {
          case ${RefFlags.NotNullValueFlag}:
            ${assignStmt(readValue)}
            break;
          case ${RefFlags.NullFlag}:
            ${assignStmt("null")}
            break;
          default:
            throw new Error("Invalid reference flag for compatible scalar field ${CodecBuilder.replaceBackslashAndQuote(fieldName)}");
        }
      `;
    }
    let stmt = "";
    // polymorphic type
    if (this.builder.resolver.isMonomorphic(fieldTypeInfo, dynamic)) {
      if (refMode == RefMode.TRACKING || refMode === RefMode.NULL_ONLY) {
        stmt = `
          ${embedGenerator.readRefWithoutTypeInfo(assignCompatible)}
        `;
      } else if (isDepthFreeField(fieldTypeInfo)) {