internal static Inst Parse(LexContext input)
{
Inst result = new Inst();
_SkipCommentsAndWhiteSpace(input);
var l = input.Line;
var c = input.Column;
var p = input.Position;
result.Line = l;
var id = _ParseIdentifier(input);
switch (id)
{
case "regex":
_SkipWhiteSpace(input);
result.Opcode = Regex;
input.Expecting('(');
input.Advance();
result.Expr = Ast.Parse(input);
input.Expecting(')');
input.Advance();
_SkipToNextInstruction(input);
break;
case "match":
_SkipWhiteSpace(input);
var ll = input.CaptureBuffer.Length;
var neg = false;
if ('-' == input.Current)
{
neg = true;
input.Advance();
}
if (!input.TryReadDigits())
{
throw new ExpectingException("Illegal operand in match instruction. Expecting integer", input.Line, input.Column, input.Position, input.FileOrUrl, "integer");
}
var i = int.Parse(input.GetCapture(ll));
if (neg)
{
i = -i;
}
result.Opcode = Match;
result.Value = i;
_SkipToNextInstruction(input);
break;
/*case "jmp":
* _SkipWhiteSpace(input);
* var lbl = _ParseIdentifier(input);
* result.Opcode = Jmp;
* result.Name = lbl;
* _SkipToNextInstruction(input);
* break;*/
case "jmp":
_SkipWhiteSpace(input);
result.Opcode = Jmp;
result.Labels = _ParseLabels(input);
_SkipToNextInstruction(input);
break;
case "switch":
_SkipWhiteSpace(input);
result.Opcode = Switch;
_ParseCases(result, input);
_SkipToNextInstruction(input);
break;
case "any":
result.Opcode = Any;
_SkipToNextInstruction(input);
break;
case "char":
_SkipWhiteSpace(input);
result.Opcode = Char;
result.Value = _ParseChar(input);
_SkipToNextInstruction(input);
break;
case "set":
_SkipWhiteSpace(input);
result.Opcode = Set;
result.Ranges = _ParseRanges(input);
_SkipToNextInstruction(input);
break;
case "nset":
_SkipWhiteSpace(input);
result.Opcode = NSet;
result.Ranges = _ParseRanges(input);
_SkipToNextInstruction(input);
break;
case "ucode":
_SkipWhiteSpace(input);
ll = input.CaptureBuffer.Length;
if (!input.TryReadDigits())
{
throw new ExpectingException("Illegal operand in ucode instruction. Expecting integer", input.Line, input.Column, input.Position, input.FileOrUrl, "integer");
}
i = int.Parse(input.GetCapture(ll));
result.Opcode = UCode;
result.Value = i;
_SkipToNextInstruction(input);
break;
case "nucode":
_SkipWhiteSpace(input);
ll = input.CaptureBuffer.Length;
if (!input.TryReadDigits())
{
throw new ExpectingException("Illegal operand in nucode instruction. Expecting integer", input.Line, input.Column, input.Position, input.FileOrUrl, "integer");
}
i = int.Parse(input.GetCapture(ll));
result.Opcode = NUCode;
result.Value = i;
_SkipToNextInstruction(input);
break;
case "save":
_SkipWhiteSpace(input);
ll = input.CaptureBuffer.Length;
if (!input.TryReadDigits())
{
throw new ExpectingException("Illegal operand in save instruction. Expecting integer", input.Line, input.Column, input.Position, input.FileOrUrl, "integer");
}
i = int.Parse(input.GetCapture(ll));
result.Opcode = Save;
result.Value = i;
_SkipToNextInstruction(input);
break;
default:
if (':' != input.Current)
{
throw new ExpectingException("Expecting instruction or label", l, c, p, input.FileOrUrl, "match", "jmp", "jmp", "any", "char", "set", "nset", "ucode", "nucode", "save", "label");
}
input.Advance();
result.Opcode = Label;
result.Name = id;
break;
}
_SkipCommentsAndWhiteSpace(input);
return(result);
}
