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// @flow
import {ResolvedImageType, StringType} from '../types.js';
import ResolvedImage from '../types/resolved_image.js';
import type {Expression, SerializedExpression} from '../expression.js';
import type EvaluationContext from '../evaluation_context.js';
import type ParsingContext from '../parsing_context.js';
import type {Type} from '../types.js';
export default class ImageExpression implements Expression {
type: Type;
input: Expression;
constructor(input: Expression) {
this.type = ResolvedImageType;
this.input = input;
}
static parse(args: $ReadOnlyArray<mixed>, context: ParsingContext): ?Expression {
if (args.length !== 2) {
return context.error(`Expected two arguments.`);
}
const name = context.parse(args[1], 1, StringType);
if (!name) return context.error(`No image name provided.`);
return new ImageExpression(name);
}
evaluate(ctx: EvaluationContext): null | ResolvedImage {
const evaluatedImageName = this.input.evaluate(ctx);
const value = ResolvedImage.fromString(evaluatedImageName);
if (value && ctx.availableImages) value.available = ctx.availableImages.indexOf(evaluatedImageName) > -1;
return value;
}
eachChild(fn: (_: Expression) => void) {
fn(this.input);
}
outputDefined(): boolean {
// The output of image is determined by the list of available images in the evaluation context
return false;
}
serialize(): SerializedExpression {
return ["image", this.input.serialize()];
}
}