84 lines
2.3 KiB
TypeScript
84 lines
2.3 KiB
TypeScript
import { UnknownSymbolError, InvalidType, type TracingLogger } from '@/utils';
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import { matchSignature, type Denotable } from '.';
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export class Environment {
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private scope: Map<string, Denotable>;
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private parent: Environment | null;
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private logger: TracingLogger;
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constructor(logger: TracingLogger, parent: Environment | null = null) {
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this.logger = logger;
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this.parent = parent;
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this.scope = new Map();
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}
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public set(name: string, value: Denotable) {
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this.scope.set(name, value);
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}
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public get(name: string): Denotable {
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if (this.scope.has(name)) {
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this.logger.debug(`Found Name=(${name}) in current scope`);
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return this.scope.get(name)!;
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}
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if (this.parent) {
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this.logger.debug(`Looking for Name=(${name}) in parent scope`);
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return this.parent.get(name);
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}
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throw new UnknownSymbolError(`Undefined variable: ${name}`);
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}
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public has(name: string): boolean {
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if (this.scope.has(name)) {
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this.logger.debug(`Found Name=(${name}) in current scope`);
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return true;
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}
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if (this.parent) {
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this.logger.debug(`Found Name=(${name}) in current scope`);
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return this.parent.has(name);
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}
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this.logger.debug(`Name=(${name}) not found in any scope`);
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return false;
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}
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public createChild(): Environment {
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return new Environment(this.logger.createChild('Env'), this);
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}
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public apply(name: string, args: Denotable[]): Denotable {
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const fn = this.get(name);
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if (typeof fn.value !== 'object' || !fn.value || !('body' in fn.value)) {
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throw new InvalidType(name + ' is not a valid function');
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}
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const argTypes = args.map(arg => {
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const { type, value } = arg;
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const isFunction =
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type === 'function' &&
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typeof value === 'object' &&
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value &&
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'signatures' in value;
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if (isFunction) {
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return value.signatures;
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}
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return type;
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});
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const appliedSignature = matchSignature(argTypes, fn.value.signatures);
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if (!appliedSignature) {
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throw new InvalidType(`No matching signature for ${name}`);
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}
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this.logger.debug(
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`Applying Function=(${name}) with Args=(${JSON.stringify(args)}) with Signature=(${JSON.stringify(appliedSignature)})`,
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);
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const value = fn.value.body.apply(this, args);
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return { type: appliedSignature.return, value };
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}
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}
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