Skip to content

[expressions] Add getValue API to lookup property value #13

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
brsanthu wants to merge 1 commit into
base: main
Choose a base branch
from
Open

[expressions] Add getValue API to lookup property value #13

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 5 additions & 0 deletions packages/expressions/src/lib/ast_factory.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,6 +7,7 @@ import * as ast from './ast.js';

export interface AstFactory<E extends ast.Expression> {
empty(): E;
getValue(receiver: Record<string, any>, name: string): any;
literal(value: ast.LiteralValue): E;
id(name: string): E;
unary(operator: string, expression: E): E;
Expand All @@ -30,6 +31,10 @@ export class DefaultAstFactory implements AstFactory<ast.Expression> {
return {type: 'Empty'};
}

getValue(receiver: Record<string, any>, name: string) {
return receiver?.[name];
}

// TODO(justinfagnani): just use a JS literal?
literal(value: ast.LiteralValue): ast.Literal {
return {
Expand Down
15 changes: 12 additions & 3 deletions packages/expressions/src/lib/eval.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -130,6 +130,10 @@ export class EvalAstFactory implements AstFactory<Expression> {
};
}

getValue(receiver: Record<string, any>, name: string) {
return receiver?.[name];
}

// TODO(justinfagnani): just use a JS literal?
literal(v: string): Literal {
return {
Expand All @@ -145,13 +149,14 @@ export class EvalAstFactory implements AstFactory<Expression> {
}

id(v: string): ID {
const astFactoryInstance = this;
return {
type: 'ID',
value: v,
evaluate(scope) {
// TODO(justinfagnani): this prevents access to properties named 'this'
if (this.value === 'this') return scope;
return scope?.[this.value];
return astFactoryInstance.getValue(scope, this.value);
},
getIds(idents) {
idents.push(this.value);
Expand Down Expand Up @@ -220,12 +225,14 @@ export class EvalAstFactory implements AstFactory<Expression> {
}

getter(g: Expression, n: string): Getter {
const astFactoryInstance = this;

return {
type: 'Getter',
receiver: g,
name: n,
evaluate(scope) {
return this.receiver.evaluate(scope)?.[this.name];
return astFactoryInstance.getValue(this.receiver.evaluate(scope), this.name);
},
getIds(idents) {
this.receiver.getIds(idents);
Expand Down Expand Up @@ -267,12 +274,14 @@ export class EvalAstFactory implements AstFactory<Expression> {
}

index(e: Expression, a: Expression): Index {
const astFactoryInstance = this;

return {
type: 'Index',
receiver: e,
argument: a,
evaluate(scope) {
return this.receiver.evaluate(scope)?.[this.argument.evaluate(scope)];
return astFactoryInstance.getValue(this.receiver.evaluate(scope), this.argument.evaluate(scope));
},
getIds(idents) {
this.receiver.getIds(idents);
Expand Down