@helios-lang/compiler/src/expressions/PathExpr.js

Helios is a Domain Specific Language that compiles to Plutus-Core (i.e. Cardano on-chain validator scripts). Helios is a non-Haskell alternative to Plutus. With this library you can compile Helios scripts and build Cardano transactions, all you need to bu

import { makeReferenceError, mergeSites } from "@helios-lang/compiler-utils"
import { $ } from "@helios-lang/ir"
import { ToIRContext } from "../codegen/index.js"
import { Scope } from "../scopes/index.js"
import { Expr } from "./Expr.js"
import { AllType, AnyType, DataEntity } from "../typecheck/common.js"

/**
 * @import { Site, Word } from "@helios-lang/compiler-utils"
 * @import { SourceMappedStringI } from "@helios-lang/ir"
 * @import { TypeCheckContext } from "../index.js"
 * @typedef {import("../typecheck/index.js").EvalEntity} EvalEntity
 */

/**
 * Name::Member expression
 */
export class PathExpr extends Expr {
    /**
     * @private
     * @readonly
     * @type {Expr}
     */
    _baseExpr

    /**
     * @private
     * @readonly
     * @type {Word}
     */
    _memberName

    /**
     * @param {Site} site
     * @param {Expr} baseExpr
     * @param {Word} memberName
     */
    constructor(site, baseExpr, memberName) {
        super(site)
        this._baseExpr = baseExpr
        this._memberName = memberName
    }

    /**
     * @type {Expr}
     */
    get baseExpr() {
        return this._baseExpr
    }

    /**
     * @param {TypeCheckContext} ctx
     * @param {Scope} scope
     * @param {boolean} [preferType]
     * @returns {EvalEntity}
     */
    evalInternal(ctx, scope, preferType = true) {
        const base = this._baseExpr.eval(ctx, scope)

        /**
         * @type {null | EvalEntity}
         */
        let member = null

        if (base.asNamespace) {
            member = base.asNamespace.namespaceMembers[this._memberName.value]
        } else if (base.asType) {
            const typeMembers = base.asType.typeMembers

            member = typeMembers[this._memberName.value]
        }

        if (!member) {
            ctx.errors.reference(
                mergeSites(this._baseExpr.site, this._memberName.site),
                `${base.toString()}::${this._memberName.value} undefined`
            )

            if (preferType) {
                return new AllType()
            } else {
                return new DataEntity(new AllType())
            }
        }

        if (member.asType?.toTyped().asFunc) {
            return member.asType.toTyped()
        } else {
            return member
        }
    }

    /**
     * @param {ToIRContext} ctx
     * @returns {SourceMappedStringI}
     */
    toIR(ctx) {
        const v = this.cache

        if (v?.asNamed) {
            return $(`${v.asNamed.path}`, this.site)
        } else if (this._baseExpr.cache?.asNamed) {
            return $(
                `${this._baseExpr.cache.asNamed.path}__${this._memberName.value}`,
                this.site
            )
        } else {
            throw new Error(`expected named value, ${v?.toString()}`)
        }
    }

    /**
     * @returns {string}
     */
    toString() {
        return `${this._baseExpr.toString()}::${this._memberName.toString()}`
    }
}