/// <summary>
/// Initializes a new instance of the Environment class.
/// This is used to create the global environment.
/// When we refer to "parent" we mean the enclosing lexical environment.
/// </summary>
/// <param name="interp">The interpreter.</param>
/// <param name="lexicalParent">The lexical parent environment.</param>
public Environment(Interpreter interp, Environment lexicalParent)
{
this.interp = interp;
this.lexicalParent = lexicalParent;
this.symbolTable = new SymbolTable(0);
if (interp != nullInterp)
{
interp.IncrementCounter(this.GetType().Name + ":ctor");
}
}
/// <summary>
/// Open a file for input.
/// </summary>
/// <param name="filename">The filename of the file to open.</param>
/// <param name="interp">The interpreter.</param>
/// <returns>The input port, used for reading.</returns>
internal static InputPort OpenInputFile(SchemeObject filename, Interpreter interp)
{
try
{
return InputPort.New(new StreamReader(filename.ToString(false)), interp);
}
catch (FileNotFoundException)
{
return (InputPort)ErrorHandlers.IoError("No such file: " + filename.ToString(true));
}
catch (IOException ex)
{
return (InputPort)ErrorHandlers.IoError("IOException: " + ex.Message);
}
}
/// <summary>
/// Initializes a new instance of the OutputPort class.
/// </summary>
/// <param name="outp">The TextWriter to write output to.</param>
/// <param name="interp">The interpreter.</param>
/// <returns>A new output port</returns>
public static OutputPort New(TextWriter outp, Interpreter interp)
{
return new OutputPort(outp, interp);
}
/// <summary>
/// Initializes a new instance of the OutputPort class.
/// </summary>
/// <param name="outp">The TextWriter to write output to.</param>
/// <param name="interp">The interpreter.</param>
private OutputPort(TextWriter outp, Interpreter interp)
{
this.outp = outp;
this.transcript = interp.Transcript;
}
/// <summary>
/// Initializes a new instance of the Environment class.
/// Start out with a set of variable bindings and a lexical parent environment.
/// The initial variable bindings are the formal parameters and the corresponding argument values.
/// </summary>
/// <param name="formals">A list of variable names.</param>
/// <param name="vals">The values for these variables.</param>
/// <param name="lexicalParent">The lexical parent environment.</param>
public Environment(SchemeObject formals, SchemeObject vals, Environment lexicalParent)
{
this.interp = lexicalParent.Interp;
this.lexicalParent = lexicalParent;
this.symbolTable = new SymbolTable(formals, vals);
}
/// <summary>
/// Initializes a new instance of the TranscriptLogger class.
/// </summary>
/// <param name="interp">The interpreter using the logger.</param>
internal TranscriptLogger(Interpreter interp)
{
this.interp = interp;
}