import { CaretInfixParselet, CharToken, TokensTag } from "@caret-js/core";
import { CaretNode, CaretParser } from "@caret-js/core";
import { EquationNode } from "../nodes/equation";
import { FunctionDefinitionNode } from "../nodes/functionDefinition";

export class EquationParselet extends CaretInfixParselet {
  public readonly associativity = "left";

  parse(
    parser: CaretParser,
    left: CaretNode
  ): EquationNode | FunctionDefinitionNode {
    const token = parser.consume();
    this.assert(
      token instanceof CharToken && token.char === "=",
      "Expected '=' token"
    );

    const right = parser.parseMinBP(this);
    return EquationNode.from([left, right]).addTag(new TokensTag([token]));
  }
}