string.n

/*
 * Copyright (c) 2003-2008 The University of Wroclaw.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *    1. Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *    2. Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *    3. The name of the University may not be used to endorse or promote
 *       products derived from this software without specific prior
 *       written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
 * NO EVENT SHALL THE UNIVERSITY BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#if DEBUG_StringTemplate
using StringTemplate2;
#else
using StringTemplate;
#endif

using Nemerle.Collections;
using Nemerle.Compiler.NemerleModifiers;
using Nemerle.Compiler.Parsetree;
using Nemerle.Compiler;
using Nemerle.Imperative;
using Nemerle.Utility;
using Nemerle; 
using System.Diagnostics.Trace;
using System.Reflection;
using System.Text;
using System;

using BF = System.Reflection.BindingFlags;
using Debug = System.Diagnostics.Debug;
using PT = Nemerle.Compiler.Parsetree;
using SB = Nemerle.Utility.NStringBuilderExtensions;
using SCG = System.Collections.Generic;
using TExpr = Nemerle.Compiler.Typedtree.TExpr;
using TT = Nemerle.Compiler.Typedtree;
using NC = Nemerle.Compiler;


#if DEBUG_StringTemplate
namespace StringTemplate2
#else
namespace StringTemplate
#endif
{
#if DEBUG_StringTemplate
  using StringTemplate2.Helper;
#else
  using StringTemplate.Helper;
#endif

  public enum StringType { | Error | C | Monkey | Recursive }

  macro @s(str)
  syntax ("s", str)
  {
    Helper.SprintImpl(str, true, expr => expr, Macros.ImplicitCTX().Env)
  }

  [MacroUsage(MacroPhase.BeforeInheritance, MacroTargets.Class, Inherited = true)]
#if DEBUG_StringTemplate
  macro StringTemplateGroupDebug(tb : TypeBuilder)
#else
  macro StringTemplateGroup(tb : TypeBuilder)
#endif
  {
    Helper2.StringTemplateGroupBeforeInheritance(tb, Nemerle.Macros.ImplicitCTX());
  }

  [MacroUsage(MacroPhase.BeforeTypedMembers, MacroTargets.Class, Inherited = true)]
#if DEBUG_StringTemplate
  macro StringTemplateGroupDebug(tb : TypeBuilder)
#else
  macro StringTemplateGroup(tb : TypeBuilder)
#endif
  {
    Helper2.StringTemplateGroupBeforeTypedMembers(tb, Nemerle.Macros.ImplicitCTX());
  }

  [MacroUsage(MacroPhase.WithTypedMembers, MacroTargets.Class, Inherited = true)]
#if DEBUG_StringTemplate
  macro StringTemplateGroupDebug(tb : TypeBuilder)
#else
  macro StringTemplateGroup(tb : TypeBuilder)
#endif
  {
    Helper2.StringTemplateGroupWithTypedMembers(tb, Nemerle.Macros.ImplicitCTX());
  }

  internal module Helper2
  {
    StSuffix = "__StImpl";
    mutable _inherMap : Set[NC.TypeInfo] = Set();
    _sync : object = object();

    internal StringTemplateGroupBeforeInheritance(tb : TypeBuilder, _ctx : Typer) : void
    {
      lock (_sync)
        _inherMap = _inherMap.Replace(tb);
    }

    internal StringTemplateGroupBeforeTypedMembers(tb : TypeBuilder, ctx : Typer) : void
    {
      def isDerived = _inherMap.Contains(tb.BaseType);
      //TODO: Добавить распознование StringTemplateGroup-классов из внешних сборок.
      ctx.Manager.MacroColors.PushUseSiteColor();
      try
      {
        if (tb.IsAbstract) _ = tb.DefineWithSource(<[ decl: 
          public abstract CreateInstance() : object; ]>);
        else if (isDerived) _ = tb.DefineWithSource(<[ decl: 
            public override CreateInstance() : object { $(tb.ParsedTypeName)() } ]>);
        else if (tb.IsSealed) _ = tb.DefineWithSource(<[ decl: 
            public CreateInstance() : object { $(tb.ParsedTypeName)() } ]>);
        else _ = tb.DefineWithSource(<[ decl: 
            public virtual  CreateInstance() : object { $(tb.ParsedTypeName)() } ]>);

        // Add <MethodName>__StImpl method into STG.
        
        def members1 = tb.GetParsedMembers(true);
        def testAbstract(m) { m.Attributes %&& Abstract && m.Name != "CreateInstance" }
        def ideTest      = m => testAbstract(m) || m.Tokens != null // BUG in compiler! Workaround!
          && m.Tokens is Token.BracesGroup(Token.LooseGroup(Token.StringLiteral(_, _)), _);
        def compilerTest = m => testAbstract(m) || m.Body is PExpr.Sequence([PExpr.Literal(Literal.String(_))]);
        def test = if (ctx.Manager.IsIntelliSenseMode) ideTest else compilerTest;
        def members2 = members1.Filter(_ => { | m is ClassMember.Function when test(m) => true | _ => false});
        
        foreach (method is ClassMember.Function in members2)
        {
          def mods               = method.modifiers;
          def attrs              = mods.Attributes;
          def newMods            = AttributesAndModifiers(Public | (attrs & (Virtual | Override | Abstract)), //Protected
                                   mods.GetCustomAttributes());
          def h                  = method.header;
          def workMethParsedName = MakeWorkMethParsedName(method);
          def newMethodAst = <[ decl:
             ..$newMods $(workMethParsedName : name)[..$(h.TypeParameters.tyvars)] (..$(h.Parameters)) : void
              where ..$(h.TypeParameters.constraints)
            {
            }]>;
          _ = tb.DefineWithSource(newMethodAst);
          method.UserData = newMethodAst;
          method.Attributes = method.Attributes %| Public; // & ~(Virtual %| Override) %| Static  %| New
        }
      }
      finally { ctx.Manager.MacroColors.PopColor(); }
    }

    internal StringTemplateGroupWithTypedMembers(tb : TypeBuilder, ctx : Typer) : void
    {
      def isDerived = _inherMap.Contains(tb.BaseType);

      ctx.Manager.MacroColors.PushUseSiteColor();
      try
      {
        unless (isDerived)
        {
          tb.Define(<[ decl: protected         _builder : StringBuilder = StringBuilder(1024); ]>);
          tb.Define(<[ decl: protected mutable _indent : string = "\n"; ]>);
          tb.Define(<[ decl: protected         _indentLenStack : Stack[int] = Stack(); ]>);
          def isTypeString(ty : FixedType)
          {
            | FixedType.Class(ty, []) => ty.Equals(ctx.Manager.InternalType.String_tc)
            | _ => false
          }
          def isToStringExists = tb.GetMethods().Exists(fun(m) {
                 m.Name == "ToString" 
              && m.GetParameters().Length == 1 
              && m.GetParameters().Head.ty is FixedType.StaticTypeVarRef
              && isTypeString(m.ReturnType.Fix()) 
            });

          unless (isToStringExists)
          {
            def t = Macros.NewSymbol("T");
            def ts = [Splicable.Name(t)];
            if (tb.IsSealed)
              _ = tb.DefineWithSource(<[ decl: public ToString[..$ts](value : $(t : name)) : string { value.ToString() } ]>);
            else
              _ = tb.DefineWithSource(<[ decl: public virtual ToString[..$ts](value : $(t : name)) : string { value.ToString() } ]>);
          }
          
          _ = tb.DefineWithSource(<[ decl: 
            protected AddIndent(indent : string) : void
            {
              _indentLenStack.Add(indent.Length);
              _indent += indent;
            }
           ]>);
          _ = tb.DefineWithSource(<[ decl: 
            protected RemoveLastIndent() : void
            {
              _indent = _indent.Substring(0, _indent.Length - _indentLenStack.Pop());
            }
           ]>);
          _ = tb.DefineWithSource(<[ decl: 
            protected PrintNewLineAndIndent() : void
            {
              _ = _builder.Append(_indent);
            }
           ]>);
          _ = tb.DefineWithSource(<[ decl: 
            public override ToString() : string
            {
              _builder.ToString()
            }
           ]>);
        }

        def beforeBodyTypingHandler(mb : MethodBuilder, pBody) : PExpr
        {
          def pBody = pBody;
          
          match (pBody)
          {
            | PExpr.Sequence([PExpr.Literal(Literal.String) as lit]) =>
            
              // 1. Сгенерировать и подставить тело для х__StImpl-метода.
              // 2. В тело данного метода подставить код вызова этого метода.
              
              def findCorrespondMethod()
              {
                def stAst = mb.Ast.UserData;
                def stMethods = tb.GetMethods(BF.DeclaredOnly | BF.Instance | BF.Public).FindAll(
                  _ => { | m is MethodBuilder when m.Ast == stAst => true | _ => false });
                  
                match (stMethods)
                {
                  | [m is MethodBuilder] => m
                  | _ => Util.ice($"Found to many correspond 'string template' methods: ..$stMethods");
                }
              }
              
              def expr         = MakeStringTemplateExpr(mb, lit.val.RawString, lit.Location, ctx);
              def m            = findCorrespondMethod();
              
              m.Body = expr;
              mb.Related = RefTo.Method(m);
              
              def h                  = mb.Ast.header;
              def workMethParsedName = MakeWorkMethParsedName(mb);
              <[  def instance = CreateInstance() :> $(tb.ParsedTypeName);
                  //Console.WriteLine(instance.GetType().FullName);
                  instance.$(workMethParsedName : name)(..$(h.ParametersReferences));
                  instance._builder.ToString() ]>

            | _ => pBody
          }
        }

        foreach (mb is MethodBuilder in tb.GetMethods(BF.DeclaredOnly | BF.Public | BF.Instance))
          when (mb.Ast.UserData is ClassMember.Function && !(mb.Attributes %&& Abstract))
            mb.AddBeforeBodyTypingHandler(beforeBodyTypingHandler);
      }
      finally { ctx.Manager.MacroColors.PopColor(); }
    }
    
    MakeStringTemplateExpr(mb : MethodBuilder, templateRawStr : string, location : Location, ctx : Typer) : PExpr
    {
      def (template1, loc1, strType) = ExtractStringBody(templateRawStr, location);
      def (template, loc, offset) = Helper.SquareString(template1, loc1);
      def makeEllipsisSplaceExpr(env : GlobalEnv, expr : string, isComplexExpr : bool, startLoc : Location) : PT.PExpr
      {
        Util.locate(startLoc,
          if (isComplexExpr || env.Manager.IsCompletionInProgress)
          {
            def pExpr = MainParser.ParseExpr(env, expr, startLoc);
            match (pExpr)
            {
              | <[ $seqExpr; $sep; $cnvFuncExpr; ]> =>
                // If cnvFuncExpr is a StrinTemplete reference,
                // replace it by <methodName>__StImpl-method.

                def mb = mb;
                // Find __StImpl-method corresponding to mb.
                def corespStImplMethod = (mb.Ast.UserData :> ClassMember.Function).Builder;
                // Type fake expression to determinate what is cnvFuncExpr (it type).
                def expr = <[ NCollectionsExtensions.MapLazy($seqExpr, $cnvFuncExpr) ]>;
                def typer = Typer(corespStImplMethod);
                  
                _ = typer.TypeExpr(expr);

                match (cnvFuncExpr.TypedObject)
                {
                  | TExpr.StaticRef(_, m is MethodBuilder, _) 
                    when m.DeclaringType.Equals(mb.DeclaringType) =>
                    match (m.Ast.UserData) 
                    {
                      | workMeth is ClassMember.Function =>
                        def cnvFunc = <[ this.$(workMeth.PName : name) ]>;
                        cnvFunc.member.Location = cnvFuncExpr.Location;
                        <[ SB.AppendSeqByConvert(_builder, $seqExpr, $sep, _indent, $cnvFunc); ]>
                      | _ => <[ SB.AppendSeq(_builder, $seqExpr, $sep, _indent, $cnvFuncExpr); ]>
                    }
                  | _ => <[ SB.AppendSeq(_builder, $seqExpr, $sep, _indent, $cnvFuncExpr); ]>
                }
                
              | <[ $seqExpr; $sep; ]> 
              | _ with (sep = <[ ", " ]>, seqExpr = pExpr) => 
                <[ SB.AppendSeq(_builder, $seqExpr, $sep, _indent, ToString); ]>
            }
          }
          else 
          {
            def pExpr = if (expr == "this") <[ this ]> else <[ $(expr : usesite) ]>;
            pExpr.Location = startLoc; // Mark expression as parsed (remove IsGenerated flag).
            <[ SB.AppendSeq(_builder, $pExpr, ", ", _indent, ToString); ]>
          })
      }
      def makeSplaceExpr(env : GlobalEnv, expr : string, isComplexExpr : bool, startLoc : Location) : PT.PExpr
      {
        def makeExpr(pExpr)
        {
          assert2(startLoc.Contains(pExpr.Location)); // Generated flag is ignored
          pExpr.Location = startLoc; // Mark expression as parsed (remove IsGenerated flag if it set).
          <[ 
              if (_indent.Length > 1)
              {
                def pos = _builder.Length;
                _ = _builder.Append(ToString($pExpr));
                _ = _builder.Replace("\n", _indent, pos, _builder.Length - pos);
              }
              else
                _ = _builder.Append(ToString($pExpr));
          ]>
        }
        Util.locate(startLoc,
          if (isComplexExpr || env.Manager.IsCompletionInProgress)
          {
            env.Manager.MacroColors.PushUseSiteColor ();
            try
            {
              def _builder = StringBuilder();
              def pExpr = MainParser.ParseExpr(env, expr, startLoc);
              makeExpr(pExpr);
            }
            finally { env.Manager.MacroColors.PopColor (); }
          } 
          else if (expr == "this") makeExpr(<[ this ]>);
          else                     makeExpr(<[ $(expr : usesite) ]>))
      }

      def exprs = Helper.make_splice_distribution2(template, loc, strType, 
        ctx.Env, makeSplaceExpr, makeEllipsisSplaceExpr);
        
      when (loc1 != loc)
      {
        def relInf = RelocationInfo(loc.FileIndex, TextPoint(loc.Line + 1, 1), TextPoint(loc.Line + 1, 1), TextPoint(loc.Line + 1, 1 + offset));
        
        foreach (part in exprs)
        {
          | Expr(pExpr) | IndentedExpr(_, pExpr) => 
            (pExpr : ISupportRelocation).RelocateImpl(relInf);
            
          | Lit | NewLine => ()
        }
      }
        
      //def isNeedOptimize(_ : list[StrPart])
      //{
        //| Lit(_) :: Lit(_) :: _    => true
        //| _                :: tail => isNeedOptimize(tail)
        //| []                       => false
      //}
      //def optimize(_ : list[StrPart])
      //{
        //| Lit(s1) :: Lit(s2) :: tail => optimize(StrPart.Lit(s2 + s1) :: tail)
        //| x                  :: tail => x :: optimize(tail)
        //| []                         => []
      //}
      //def exprs = if (isNeedOptimize(exprs)) optimize(exprs) else exprs;
      def res = exprs.RevMap(e => 
        match (e : StrPart)
        {
          | Lit(str)    => <[ _ = _builder.Append($(str : string)); ]>
          | NewLine     => <[ _ = PrintNewLineAndIndent(); ]>
          | Expr(expr)  => expr
          | IndentedExpr(indent, expr) => <[ 
            def indent = $(indent : string);
            _ = _builder.Append(indent);
            AddIndent(indent);
            try { $expr; } 
            finally { RemoveLastIndent() } ]>
        });
      
      <[ { ..$res } ]>
    }
    
    MakeWorkMethParsedName(ast : PT.ClassMember) : PT.Name
    {
      def workMethName            = ast.Name + StSuffix;
      def workMethParsedName      = Macros.UseSiteSymbol(workMethName);
      workMethParsedName.Location = ast.PName.Location; // this allow rename refactoring
      workMethParsedName
    }

    MakeWorkMethParsedName(mb : MethodBuilder) : PT.Name
    {
      MakeWorkMethParsedName(mb.Ast)
    }
  }

  public variant StrPart
  {
    | Lit           { str    : string; }
    | Expr          { expr   : PT.PExpr; }
    | NewLine
    | IndentedExpr  { indent : string; expr : PT.PExpr; }
    
    public override ToString() : string
    {
      match (this)
      {
        | Lit(str)                   => $"Lit: '$str'"
        | Expr(expr)                 => $"Expr: $expr"
        | NewLine                    => "<\n>"
        | IndentedExpr(indent, expr) => $"IndentedExpr: '$expr' ('$indent')"
      }
    }
  }

  public module Helper
  {
    public SprintImpl (
      @string : PT.PExpr, 
      warnIfFormatStrIsEmpty : bool, 
      envelopExpr : PT.PExpr -> PT.PExpr, 
      env : GlobalEnv
    )
      : PT.PExpr
    {
      def (str, loc, strType) = match (@string)
      {
        | Literal(Literal.String(_)) as lit => ExtractStringBody(lit)
        | _ => 
          Message.Error(@string.Location, "The $ or sprint macro expect string literal.");
          (null, @string.Location, StringType.Error)
      }

      if (string.IsNullOrEmpty (str))
      {
        when (strType != StringType.Error)
          Message.Warning ("empty spliced string");
          
        envelopExpr(<[ $(@string.ToString() : string) ]>)
      }
      else
      {
        def seq = make_splice_distribution (str, loc, strType, env).Rev();

        match (seq)
        {
          | [StrPart.Lit(val)] =>
            when (warnIfFormatStrIsEmpty)
              Message.Warning ($"spliced string without splices: '$str'");
            envelopExpr(<[ $(val : string) ]>);

          | _ => 
            //def indentPresent = seq.Exists(_ is StrPart.IndentedExpr);
            //def seq = if (indentPresent) StrPart.Expr(<[ def ident = ""; ]>) :: seq;
            //mutable curIndent = "";
            def seq = seq;
            
            def res = seq.Map(e => 
              match (e : StrPart)
              {
                | Lit(str)    => <[ $(str : string) ]>
                | NewLine     =>   <[ Environment.NewLine ]>
                | Expr(expr)  => expr
                | IndentedExpr(indent, expr) => // TODO: Try add support of identation.
                  <[ def indent = $(indent : string);
                     indent + (System.Convert.ToString($expr) : string) ]>
              });
              
            envelopExpr(<[ string.Concat (..$res) ]>);
        }
      }
    }
    
    public ExtractStringBody(literal : PExpr.Literal) : string * Location * StringType
    {
      assert2(literal.val is Nemerle.Compiler.Literal.String);
      // TODO: VladD2: Add filing of RawString in string literal embeded in quasi-quotation extressins.
      if (literal.val.RawString == null)
        ((literal.val :> Nemerle.Compiler.Literal.String).val, literal.Location, StringType.Monkey)
      else
        ExtractStringBody(literal.val.RawString, literal.Location)
    }
    
    public ExtractStringBody(rawString : string, location : Location) 
      : string * Location * StringType
    {
      /// Calc string value and location from raw literal data
      def calcStrBounds(firstLen, lastLen, strType)
      {
        def x = location;
        def quotasLen = firstLen + lastLen;
        (rawString.Substring(firstLen, rawString.Length - quotasLen), 
         Location(x.FileIndex, x.Line,    x.Column + firstLen,
                               x.EndLine, x.EndColumn - lastLen),
         strType)
      }
      
      match (rawString[0])
      {
        | '<' => assert(rawString[1] == '#'); calcStrBounds(2, 2, StringType.Recursive)
        | '@' => assert(rawString[1] == '"'); calcStrBounds(2, 1, StringType.Monkey)
        | n   => assert(n == '"');            calcStrBounds(1, 1, StringType.C)
      }
    }

    /// If we have string like this
    ///     &lt;#
    ///   SomeText1
    ///   SomeText2
    ///   #&gt;
    /// this function convert it to
    /// "SomeText1\nSomeText2"   
    /// string - convertrd string
    /// Location - changed location
    /// int - indent (in chars) from begin of line which was deleted.
    public SquareString(str : string, loc : Location) : string * Location * int
    {
      match (str.LastIndexOfAny(array['\r', '\n']))
      {
        | -1 => (str, Location(loc.FileIndex, loc.Line,    loc.Column,
                                              loc.EndLine, loc.EndColumn), 0)
        | _ => 
          def rows = str.Split(array["\r\n", "\n", "\r"], StringSplitOptions.None);
          when (rows.Length <= 2)
              Message.Error(loc, "The multiline String Template should contain 3 and more row. "
                                 "(First and last line in multiline String Template ignored.)");
          def prefix = rows.NLast ();
          def prefixLen = prefix.NCount ();
          def firstIndex = if (rows[0].ForAll(char.IsWhiteSpace)) 1 else 0;
          def sb = StringBuilder(str.Length - prefixLen 
                                 - if (firstIndex == 1) rows[0].Length else 0);
          def len = rows.Length - 1;
          mutable isIndentMismatch = false;
          for (mutable i = firstIndex; i < len; i++)
          {
            def row = rows[i];
            if (row.StartsWith(prefix, StringComparison.InvariantCulture))
              _ = sb.AppendLine(row.Substring(prefixLen, row.Length - prefixLen));
            else
            {
              Message.Error(Location(loc, loc.Line + i, 1, loc.Line + i, row.Length + 1),
                "Mismatch of the string template strBuilder characters.");
              isIndentMismatch = true;
              _ = sb.AppendLine(row);
            }
          }
          
          when (sb.Length > Environment.NewLine.Length)
            sb.Length -= Environment.NewLine.Length;

          when (isIndentMismatch)
            Message.Hint(Location(loc, loc.EndLine, 1, loc.EndLine, loc.EndColumn),
              "Please, make sure that all of the strBuilder characters of your "
              "string template match the last line indentation.");
            // TODO: Локейшон вычисляется неверно. Переделать.
          (sb.ToString(), Location(loc.FileIndex, 
            loc.Line    + firstIndex, prefixLen + 1,
            loc.EndLine - firstIndex, rows[len - 1].Length + 1),  // + 1 => Location coordinates 1 bound
            prefixLen);
      }
    }

    public make_splice_distribution (
      str     : string,
      loc     : Location,
      strType : StringType,
      env     : GlobalEnv
    ) 
      : list [StrPart]
    {
      def makeEllipsisSplaceExpr(env : GlobalEnv, expr : string, isComplexExpr : bool, startLoc : Location) : PT.PExpr
      {
        // TODO: Find a real bug
        // Force create function in .Net, otherwise we get error
        // Possibly it is realated to the bug that
        // _ -> string doesn't use the right type but uses always object.
        def convertToString = <[ x => System.Convert.ToString(x) ]>;
      
        Util.locate(startLoc,
          if (isComplexExpr || env.Manager.IsCompletionInProgress)
          {
            env.Manager.MacroColors.PushUseSiteColor ();
            try
            {
              def pExpr = MainParser.ParseExpr (env, expr);
              def makeSeqExpr(seqExpr, sepExpr, cnvFuncExpr)
              {
                <[ string.Join($sepExpr, NCollectionsExtensions.MapToArray.[_, string]($seqExpr : SCG.IEnumerable[_], $cnvFuncExpr)) ]>
              }
              match (pExpr)
              {
                | <[ $seqExpr; $sepExpr; $cnvFuncExpr; ]> => makeSeqExpr(seqExpr, sepExpr, cnvFuncExpr)
                | <[ $seqExpr; $sepExpr; ]> => makeSeqExpr(seqExpr, sepExpr, convertToString)
                | _ => makeSeqExpr(pExpr, <[ ", " ]>, convertToString)
              }
            }
            finally { env.Manager.MacroColors.PopColor (); }
          }
          else 
          {
            def pExpr = if (expr == "this") <[ this ]> else <[ $(expr : usesite) ]>;
            pExpr.Location = startLoc; // Mark expression as parsed (remove IsGenerated flag).
            <[ string.Join(", ", NCollectionsExtensions.MapToArray.[_, string]($pExpr : SCG.IEnumerable[_], $convertToString)) ]>
          })
      }
      
      def makeSplaceExpr(env : GlobalEnv, expr : string, isComplexExpr : bool, startLoc : Location) : PT.PExpr
      {
        Util.locate(startLoc, {
          def pExpr = if (isComplexExpr || env.Manager.IsCompletionInProgress)
          {
            env.Manager.MacroColors.PushUseSiteColor();
            try { MainParser.ParseExpr(env, expr) }
            finally { env.Manager.MacroColors.PopColor(); }
          }
          else 
          {
            def pExpr = if (expr == "this") <[ this ]> else <[ $(expr : usesite) ]>;
            pExpr.Location = startLoc; // Mark expression as parsed (remove IsGenerated flag).
            pExpr
          }
          <[ Convert.ToString($pExpr) : string ]>})
      }
      
      make_splice_distribution2(str, loc, strType, env, makeSplaceExpr, makeEllipsisSplaceExpr)
    }


    /** for $(...) and ..$(...) expressions:
        - first evaluate expressions
        - store intermediate results in variables
        - return list of evaluators and reference variables in reverse order
     */
    public make_splice_distribution2 (
      @string                : string,
      loc                    : Location,
      strType                : StringType,
      env                    : GlobalEnv,
      makeSplaceExpr         : GlobalEnv * string * bool * Location -> PT.PExpr, // env * strExpr * isComplexExpr
      makeEllipsisSplaceExpr : GlobalEnv * string * bool * Location -> PT.PExpr  // env * strExpr * isComplexExpr
    )
      : list [StrPart]
    {
      def str = @string;
      mutable index     = -1;
      mutable curCol    = loc.Column;
      mutable curLine   = loc.Line;
      mutable ch = if (str.Length > 0) str[0] else '\0';
      def strBuilder = StringBuilder();
      def peekN(n) { def next = index + n; if (next < str.Length) str[next] else '\0' }
      def peek() { peekN(1) }
      def next()
      {
        ch = peek();
        index++;
        
        if (ch == '\n')
        {
          curLine++;
          curCol = 1;
        }
        else curCol++;
        
        ch
      }
      def error = Message.Error (loc, _); //TODO: Вычислять локешон более точно
      def getEscapeValue : char -> char = LexerBase.EscapeValue(_, null,
        LexerBase.GetCharFromHex(_, _, peek, next, error), error);
      def getStrFromBuilder() { def res = strBuilder.ToString(); strBuilder.Length = 0; res }
      def appendToBuilder(chr) { _ = strBuilder.Append(chr) }
      def tryUnescape(ch)
      {
        def p = peek();
        _ = p;
        if (ch == '\\' && strType == StringType.C)
          getEscapeValue(next())
        else if (ch == '"' && strType == StringType.Monkey && peek() == '"')
          next()
        else ch;
      }
      def currLoc(exprStr) //TODO: Надо учитывать концы строк в многострочных строках.
      { // Данная реализация некуда не годится. Видимо надо завести "текущий локешон".
        def loc = loc;
        Location(loc, curLine, curCol - exprStr.Length, curLine, curCol)
      }
      /// ~~~Parse expression based on nested brackets.
      /// Разбирает строку производя поиск закрывающей скобки.
      /// Вложенные скобки игнорируются. В итоге получается строка содержащая
      /// выражение заключенное в скбоки (которое так же может содержать вложенные скобки)
      /// и булево значение говорящее, содержится ли в строке простой идентификатор или варажение.
      /// Returns pare of (exprStr * isIdentifier)
      def parseExpressionStr() : string * bool * Location
      {
        Assert(strBuilder.Length == 0, "strBuilder.Length == 0");
        Assert(ch == '(', "ch == '('");
        def startCol  = curCol;
        def startLine = curLine;
        /// exprStr * allIsAlphNum
        def loop(balance, allIsAlphNum) : string * bool
        {
          def ch2 = tryUnescape(next()); //TODO: Скорее всего строку для парсера Unescape-ить не надо!
          match (ch2)
          {
            // TODO: Обработать ситуацию когда скобка не закрыта! См. файл:
            // C:\MyProjects\Nemerle\nemerle\ncc\testsuite\negative\tyenf.n
            | '\0'
            | ')' when balance == 1 => (getStrFromBuilder(), allIsAlphNum)
            | ')'                   => appendToBuilder(ch2); loop(balance - 1, false)
            | '('                   => appendToBuilder(ch2); loop(balance + 1, false)
            | curCh                 =>
              appendToBuilder(ch2);
              loop(balance, allIsAlphNum && (char.IsLetterOrDigit(curCh) || curCh == '_'))
          }
        }
        
        def (expr, allIsAlphNum) = loop(1, true);
        (expr, 
         allIsAlphNum && expr.Length != 0 && expr != "_" && char.IsLetter(expr[0]),
         Location(loc, startLine, startCol, curLine, curCol - 1))
      }
      def parseIdentifier()
      {
        Assert(strBuilder.Length == 0, "strBuilder.Length == 0");

        def loop()
        {
          def curCh = peek();
          match (curCh)
          {
            | '_'
            | _ when char.IsLetterOrDigit(curCh) => appendToBuilder(next()); loop()
            | _ => getStrFromBuilder()
          }
        }
        
        if (ch == '_' || char.IsLetter(ch)) 
        {
          appendToBuilder(ch);
          loop()
        }
        else ""
      }

      def loop (res : list[StrPart]) : list[StrPart]
      {
        // Завершает акомуляцию сиволов литерала и создает соотвествующую 
        // лексему добавляя ее к началу списка лексем
        def endLiteral()
        {
          if (strBuilder.Length == 0)
            res
          else
            StrPart.Lit(getStrFromBuilder()) :: res
        }
        def isNextDollar(n)
        {
          def ch1 = peekN(n);
          if (char.IsWhiteSpace(ch1)) isNextDollar(n + 1)
          else ch1 == '$' && peekN(n + 1) != '$'
        }
        def isElipse() { peek() == '.' && isNextDollar(2) }
        def processNewLine() { loop (StrPart.NewLine() :: endLiteral()) }
        def isNextNewLine()
        {
          if (strType == StringType.C)
            peek() == '\\' && peekN(2) == 'n'
          else
            peek() == '\n'
        }
 
        def ch2 = tryUnescape(next());
        match (ch2)
        {
          | '\0'                      => endLiteral()
          | '$' when peek() == '$'    => _ = next(); appendToBuilder('$'); loop(res) // $$ => $
          | '$'                       => parceSpliceEx(endLiteral(), true)
          | '.'  when isElipse()      => while (next() != '$') { } // '..$'
                                         parceSpliceEx(endLiteral(), false);
          | '\r' when isNextNewLine() => _ = tryUnescape(next()); processNewLine()
          | '\n' | '\r'               =>                          processNewLine()
          | x                         => appendToBuilder(x); loop(res)
        }
      }
      and parceSpliceEx(res, isSimple)
      {
        when (next() == '\0')
        {
          //Diagnostics.Trace.Assert(false);
          Message.Error ("lone `$' at the end of the format string");
          return [StrPart.Lit("$")];
        }
        
        def rtyIndent(res : list[StrPart], expr)
        {
          match (res)
          {
            | Lit(str) :: NewLine :: tail when str.ForAll(char.IsWhiteSpace) => 
              StrPart.IndentedExpr(str, expr)  :: StrPart.NewLine() :: tail
            | _ => StrPart.Expr(expr) :: res
          }
        }
        
        def str = str; _ = str;
        
        if (ch == '(')
        {
          def (exprStr, isIdentifier, exprLoc) = parseExpressionStr();
          
          if (ch == '\0') // скобка не закрыта
          {
            def exprStr = "(" + exprStr;
            Message.Error($"no closing bracket found in `$(exprStr)' "
                           "(the closing bracket in format string is probably missing)");
          }
          else when (exprStr.Trim().Length == 0)
            Message.Error("expression without content");

          def expr = if (isSimple) makeSplaceExpr(env, exprStr, !isIdentifier, exprLoc) 
                     else  makeEllipsisSplaceExpr(env, exprStr, !isIdentifier, exprLoc);
          loop (rtyIndent(res, expr))
        }
        else if (ch == '$')
          loop (StrPart.Lit("$") :: res)
        else
        {
          def variableName = parseIdentifier();
          def startLoc = currLoc(variableName);
          def index3 = index; _ = index3;
          
          if (variableName == "")
          {
            appendToBuilder(ch);
            Message.Warning ("expected variable name or expression enclosed with (..) after $ in splice string");
            loop (StrPart.Lit("$") :: res)
          }
          else
          {
            def expr = if (isSimple) makeSplaceExpr(env, variableName, false, startLoc) 
                       else  makeEllipsisSplaceExpr(env, variableName, false, startLoc);
            //def index1 = index; _ = index1;
            loop (rtyIndent(res, expr))
          }
        }
      }

      loop ([])
    }
  }
}