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4a288a7 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 | // @flow
import type {Type} from '../types';
import type {Expression} from '../expression';
import type ParsingContext from '../parsing_context';
import type EvaluationContext from '../evaluation_context';
class Var implements Expression {
type: Type;
name: string;
boundExpression: Expression;
constructor(name: string, boundExpression: Expression) {
this.type = boundExpression.type;
this.name = name;
this.boundExpression = boundExpression;
}
static parse(args: $ReadOnlyArray<mixed>, context: ParsingContext) {
if (args.length !== 2 || typeof args[1] !== 'string')
return context.error(`'var' expression requires exactly one string literal argument.`);
const name = args[1];
if (!context.scope.has(name)) {
return context.error(`Unknown variable "${name}". Make sure "${name}" has been bound in an enclosing "let" expression before using it.`, 1);
}
return new Var(name, context.scope.get(name));
}
evaluate(ctx: EvaluationContext) {
return this.boundExpression.evaluate(ctx);
}
eachChild() {}
outputDefined() {
return false;
}
serialize() {
return ["var", this.name];
}
}
export default Var;
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