step1_read_print.vb

Imports System
Imports System.IO
Imports Mal
Imports MalVal = Mal.types.MalVal

Namespace Mal
    Class step1_read_print
        ' read
        Shared Function READ(str As String) As MalVal
            Return reader.read_str(str)
        End Function

        ' eval
        Shared Function EVAL(ast As MalVal, env As String) As MalVal
            Return ast
        End Function
        
        ' print
        Shared Function PRINT(exp As MalVal) As String
            return printer._pr_str(exp, TRUE)
        End Function

        ' repl
        Shared Function REP(str As String) As String
            Return PRINT(EVAL(READ(str), ""))
        End Function

        Shared Function Main As Integer
            Dim args As String() = Environment.GetCommandLineArgs()

            If args.Length > 1 AndAlso args(1) = "--raw" Then
                Mal.readline.SetMode(Mal.readline.Modes.Raw)
            End If

            ' repl loop
            Dim line As String
            Do
                Try
                    line = Mal.readline.Readline("user> ")
                    If line is Nothing Then
                        Exit Do
                    End If
                    If line = "" Then
                        Continue Do
                    End If
                Catch e As IOException
                    Console.WriteLine("IOException: " & e.Message)
                End Try
                Try
                    Console.WriteLine(REP(line))
                Catch e as Exception
                    Console.WriteLine("Error: " & e.Message)
                    Console.WriteLine(e.StackTrace)
                    Continue Do
                End Try
            Loop While True
        End function
    End Class
End Namespace