VarStatement.java

package calculator.interpreter.ast.vars;

import java.util.LinkedList;
import calculator.interpreter.AnnotationValue;
import calculator.interpreter.Cell;
import calculator.interpreter.Environment;
import calculator.interpreter.Variable;
import calculator.interpreter.ast.Expression;
import calculator.interpreter.ast.Statement;
import calculator.interpreter.ast.meta.Annotation;
import calculator.interpreter.ast.meta.DocumentationLine;

/**
 * The variable definition statement
 */
public class VarStatement extends Statement {
  /** the type of the statement ("var" or "let") */
  public String type;
  /** the definition name */
  public Name name;
  /** the statement value (optional) */
  public Expression value;

  @Override
  public Environment eval(Environment env, Cell result) {
    env.checkFree(location, name.name());
    boolean isVar = "var".equals(type);
    String docs;
    if (!this.documentation.isEmpty()) {
      StringBuilder b = new StringBuilder();
      for (DocumentationLine l : this.documentation) {
        b.append(l.text).append('\n');
      }
      docs = b.toString();
    } else {
      docs = null;
    }
    LinkedList<AnnotationValue> evaluatedAnnotations = new LinkedList<AnnotationValue>();
    for (Annotation a : this.annotations) {
      evaluatedAnnotations.add(a.eval(env));
    }
    Variable var = new Variable(name.name(), isVar, location, docs,
        evaluatedAnnotations);
    Environment rc = new Environment(env, var);
    for (AnnotationValue a1 : var.annotations) {
      a1.process(rc, var);
    }
    if (value != null) {
      var.bind(this.location, value.eval(env));
    }
    if (var.isBound && result != null) {
      result.value = var.value;
    }
    return rc;
  }
}