F# Interactiveの改造

console.fs

#light 

namespace Microsoft.FSharp.Compiler.Interactive

open System
open System.IO
open System.Text
open System.Collections.Generic

type ReadLineConsole(complete: (string option * string -> seq<string>)) as this =
    let history = new List<string>()
    let log = Path.Combine(Directory.GetCurrentDirectory(), "log.fsx")
    let mutable complete = complete
    
    do
        if File.Exists(log) then this.AppendLog("")
        this.AppendLog("// " + DateTime.Now.ToString())
    
    member x.Complete with set(v) = (complete <- v)
    member x.Prompt = "> "
    
    member x.ReadLine() =
        let count(s : string, ch : char) =
            let mutable ret = 0
            for c in s do if c = ch then ret <- ret + 1
            ret
            
        let getWords(s : string) =
            let ret = new List<string>()
            let rec getWords(p1, p2) =
                if p2 >= s.Length || not (Char.IsLetterOrDigit(s.[p2])) then
                    if p1 < p2 then ret.Add(s.Substring(p1, p2 - p1))
                    if p2 < s.Length then getWords(p2 + 1, p2 + 1)
                else
                    getWords(p1, p2 + 1)
            getWords(0, 0)
            ret

        let lines = ref 0
        let p1 = ref 0
        let p2 = ref 0
        let sb = new StringBuilder()

        let rec readLine(indent : string) =
            if indent <> "" || !lines > 0 then
                Console.Write(indent + "- ")
            let line = Console.ReadLine().Trim()
            if indent = "" && line = "#h" then
                for cmd in history do Console.WriteLine(cmd)
                Console.Write(x.Prompt)
                readLine(indent)
            else if indent = "" && line.StartsWith("#cd ") then
                Directory.SetCurrentDirectory(line.Substring(4));
                Console.Write(x.Prompt)
                readLine(indent)
            else if indent = "" && line = "#pwd" then
                Console.WriteLine(Directory.GetCurrentDirectory())
                Console.Write(x.Prompt)
                readLine(indent)
            else if indent = "" && line = "#dir" then
                let di = new DirectoryInfo(Directory.GetCurrentDirectory())
                Console.WriteLine(di.FullName)
                for di in di.GetDirectories() do
                    Console.WriteLine("{0}/", di)
                for fi in di.GetFiles() do
                    Console.WriteLine(fi)
                Console.Write(x.Prompt)
                readLine(indent)
            else if String.IsNullOrEmpty(line) then
                ()
            else
                if sb.Length > 0 then sb.AppendLine() |> ignore
                sb.Append(indent + line) |> ignore
                lines := !lines + 1
                if line.StartsWith("//") then
                    readLine(indent)
                else
                    let d1 = count(line, '(') - count(line, ')')
                    let d2 = count(line, '[') - count(line, ']')
                    p1 := !p1 + d1
                    p2 := !p2 + d2
                    let words = getWords(line)
                    let w1 = if words.Count > 0 then words.[words.Count - 1] else ""
                    if (!p1 <> 0 && d1 <> 0) || (!p2 <> 0 && d2 <> 0)
                        || line.EndsWith("=") || line.EndsWith("->")
                        || w1 = "in" || w1 = "do" || w1 = "then" || w1 = "else"
                    then
                        readLine(indent + "    ")
                    let w2 = if words.Count > 0 then words.[0] else ""
                    if !p1 <> 0 || !p2 <> 0 || indent <> ""
                        || (line.EndsWith(";") && not(line.EndsWith(";;")))
                        || (w2 = "if" && not(words.Contains("then") && words.Contains("else")))
                        || w2 = "match"
                    then
                        readLine(indent)
        
        readLine("")
        let ret = sb.ToString()
        history.Add(ret)
        x.AppendLog(ret)
        if ret.EndsWith(";;") then
            ret
        else
            if !lines = 1 then
                ret + ";;"
            else
                ret + Environment.NewLine + ";;"
    
    member x.AppendLog(cmd : string) =
        use fs = new FileStream(log, FileMode.Append)
        use sw = new StreamWriter(fs)
        sw.WriteLine(cmd)