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import { Evaluator } from '../evaluator.ts';import { TypeBase } from './datatype-base.ts';import { DataType, nil, QueryError } from '../interfaces.ts';import {_IRelation, _ISchema, _IType, _Transaction} from '../interfaces-private.ts';
export function asEnum(o: _IRelation | null): CustomEnumType  {    if (o && o.type === 'type' && o instanceof CustomEnumType) {        return o;    }    throw new QueryError(`"${o?.name}" is not a enum`);}export class CustomEnumType extends TypeBase<string> {
    get primary(): DataType {        return this.name as any;    }
    get name(): string {        return this._name;    }
    constructor(readonly schema: _ISchema        , private readonly _name: string        , readonly values: string[]) {        super();    }
    install() {        this.schema._registerType(this);    }
    doCanCast(to: _IType) {        return to.primary === DataType.text;    }
    doCast(value: Evaluator<string>, to: _IType<string>): Evaluator<any> | nil {        return value;    }
    prefer(type: _IType<any>): _IType | nil {        return this;    }
    doCanBuildFrom(from: _IType): boolean | nil {        return from.primary === DataType.text;    }
    doBuildFrom(value: Evaluator<string>, from: _IType<string>): Evaluator<string> | nil {        return value            .setConversion((raw: string) => {                if (!this.values.includes(raw)) {                    throw new QueryError(`invalid input value for enum ${this.name}: "${raw}"`);                }                return raw;            }                , conv => ({ conv, toCenum: this.name }))    }

    drop(t: _Transaction): void {        this.schema._unregisterType(this);    }}