// This switch follows more or less a DEA to this EBNF
// COMMAND-EBNF := COMMAND
// COMMAND := (!ARGUMENT \s+ (ARGUMENT|\s)*)
// ARGUMENT := COMMAND|FREESTRING|QUOTESTRING
// FREESTRING := [^)]+
// QUOTESTRING := "[<anything but ", \" is ok>]+"
public static ASTNode ParseCommandRequest(string request)
{
ASTCommand root = null;
var comAst = new Stack<ASTCommand>();
BuildStatus build = BuildStatus.ParseCommand;
var strb = new StringBuilder();
var strPtr = new StringPtr(request);
while (!strPtr.End)
{
ASTCommand buildCom;
switch (build)
{
case BuildStatus.ParseCommand:
// Got a command
buildCom = new ASTCommand();
// Consume CommandChar if left over
if (strPtr.Char == CommandChar)
strPtr.Next(CommandChar);
if (root == null) root = buildCom;
else comAst.Peek().Parameter.Add(buildCom);
comAst.Push(buildCom);
build = BuildStatus.SelectParam;
break;
case BuildStatus.SelectParam:
strPtr.SkipSpace();
if (strPtr.End)
build = BuildStatus.End;
else
{
switch (strPtr.Char)
{
case '"':
build = BuildStatus.ParseQuotedString;
break;
case '(':
if (!strPtr.HasNext)
build = BuildStatus.ParseFreeString;
else if (strPtr.IsNext(CommandChar))
{
strPtr.Next('(');
build = BuildStatus.ParseCommand;
}
else
build = BuildStatus.ParseFreeString;
break;
case ')':
if (!comAst.Any())
build = BuildStatus.End;
else
{
comAst.Pop();
if (!comAst.Any())
build = BuildStatus.End;
}
strPtr.Next();
break;
default:
build = BuildStatus.ParseFreeString;
break;
}
}
break;
case BuildStatus.ParseFreeString:
strb.Clear();
var valFreeAst = new ASTValue();
using (strPtr.TrackNode(valFreeAst))
{
for (; !strPtr.End; strPtr.Next())
{
if ((strPtr.Char == '(' && strPtr.HasNext && strPtr.IsNext(CommandChar))
|| strPtr.Char == ')'
|| char.IsWhiteSpace(strPtr.Char))
break;
strb.Append(strPtr.Char);
}
}
valFreeAst.Value = strb.ToString();
buildCom = comAst.Peek();
buildCom.Parameter.Add(valFreeAst);
build = BuildStatus.SelectParam;
break;
case BuildStatus.ParseQuotedString:
strb.Clear();
strPtr.Next('"');
var valQuoAst = new ASTValue();
using (strPtr.TrackNode(valQuoAst))
{
bool escaped = false;
for (; !strPtr.End; strPtr.Next())
{
if (strPtr.Char == '\\') escaped = true;
else if (strPtr.Char == '"')
{
if (escaped) strb.Length--;
else { strPtr.Next(); break; }
escaped = false;
}
else escaped = false;
strb.Append(strPtr.Char);
}
}
valQuoAst.Value = strb.ToString();
buildCom = comAst.Peek();
buildCom.Parameter.Add(valQuoAst);
build = BuildStatus.SelectParam;
break;
case BuildStatus.End:
strPtr.JumpToEnd();
break;
default: throw new InvalidOperationException();
}
}
return root;
}
// This switch follows more or less a DEA to this EBNF
// COMMAND-EBNF := COMMAND
// COMMAND := (!ARGUMENT \s+ (ARGUMENT|\s)*)
// ARGUMENT := COMMAND|FREESTRING|QUOTESTRING
// FREESTRING := [^)]+
// QUOTESTRING := "[<anything but ", \" is ok>]+"
public static ASTNode ParseCommandRequest(string request, char commandChar = DefaultCommandChar, char delimeterChar = DefaultDelimeterChar)
{
ASTCommand root = null;
var comAst = new Stack <ASTCommand>();
BuildStatus build = BuildStatus.ParseCommand;
var strb = new StringBuilder();
var strPtr = new StringPtr(request);
while (!strPtr.End)
{
ASTCommand buildCom;
switch (build)
{
case BuildStatus.ParseCommand:
// Got a command
buildCom = new ASTCommand();
// Consume CommandChar if left over
if (strPtr.Char == commandChar)
{
strPtr.Next(commandChar);
}
if (root == null)
{
root = buildCom;
}
else
{
comAst.Peek().Parameter.Add(buildCom);
}
comAst.Push(buildCom);
build = BuildStatus.SelectParam;
break;
case BuildStatus.SelectParam:
strPtr.SkipChar(delimeterChar);
if (strPtr.End)
{
build = BuildStatus.End;
}
else
{
switch (strPtr.Char)
{
case '"':
build = BuildStatus.ParseQuotedString;
//goto case BuildStatus.ParseQuotedString;
break;
case '(':
if (!strPtr.HasNext)
{
build = BuildStatus.ParseFreeString;
}
else if (strPtr.IsNext(commandChar))
{
strPtr.Next('(');
build = BuildStatus.ParseCommand;
}
else
{
build = BuildStatus.ParseFreeString;
}
break;
case ')':
if (!comAst.Any())
{
build = BuildStatus.End;
}
else
{
comAst.Pop();
if (!comAst.Any())
{
build = BuildStatus.End;
}
}
strPtr.Next();
break;
default:
build = BuildStatus.ParseFreeString;
break;
}
}
break;
case BuildStatus.ParseFreeString:
strb.Clear();
var valFreeAst = new ASTValue();
using (strPtr.TrackNode(valFreeAst))
{
for (; !strPtr.End; strPtr.Next())
{
if ((strPtr.Char == '(' && strPtr.HasNext && strPtr.IsNext(commandChar)) ||
strPtr.Char == ')' ||
strPtr.Char == delimeterChar)
{
break;
}
strb.Append(strPtr.Char);
}
}
valFreeAst.Value = strb.ToString();
buildCom = comAst.Peek();
buildCom.Parameter.Add(valFreeAst);
build = BuildStatus.SelectParam;
break;
case BuildStatus.ParseQuotedString:
strb.Clear();
strPtr.Next('"');
var valQuoAst = new ASTValue();
using (strPtr.TrackNode(valQuoAst))
{
bool escaped = false;
for (; !strPtr.End; strPtr.Next())
{
if (strPtr.Char == '\\')
{
escaped = true;
}
else if (strPtr.Char == '"')
{
if (escaped)
{
strb.Length--;
}
else
{
strPtr.Next(); break;
}
escaped = false;
}
else
{
escaped = false;
}
strb.Append(strPtr.Char);
}
}
valQuoAst.Value = strb.ToString();
buildCom = comAst.Peek();
buildCom.Parameter.Add(valQuoAst);
build = BuildStatus.SelectParam;
break;
case BuildStatus.End:
strPtr.JumpToEnd();
break;
default: throw new InvalidOperationException();
}
}
return(root);
}
