ExpSyntaxTree ParseMainExp()
{
ExpSyntaxTree exp;
switch (LookAhead().m_type)
{
case (int)TokenType.NIL:
case (int)TokenType.FALSE:
case (int)TokenType.TRUE:
case (int)TokenType.NUMBER:
case (int)TokenType.STRING:
case (int)TokenType.DOTS:
case (int)TokenType.NAME:
exp = new Terminator(NextToken());
break;
case (int)TokenType.STRING_BEGIN:
exp = ParseComplexString();
break;
case (int)TokenType.FUNCTION:
exp = ParseFunctionDef();
break;
case (int)'(':
NextToken();
exp = ParseExp();
if (NextToken().m_type != (int)')')
{
throw NewParserException("expect ')' to match Main Exp's head '('", _current);
}
break;
case (int)'{':
exp = ParseTableConstructor();
break;
// unop exp priority is 90 less then ^
case (int)'-':
case (int)TokenType.NOT:
var unexp = new UnaryExpression(LookAhead().m_line);
unexp.op = NextToken();
unexp.exp = ParseExp(90);
exp = unexp;
break;
default:
throw NewParserException("unexpect token for main exp", _look_ahead);
}
return(ParseTailExp(exp));
}
private ComplexString ParseComplexString()
{
var head = NextToken();
var next = LookAhead();
var exp = new ComplexString(_current.m_line);
if (head.m_string_type >= StringBlockType.InverseQuotation)
{
exp.is_shell = true;
if (next.Match(TokenType.STRING) &&
next.m_string.Length > 3 &&
head.m_string_type == StringBlockType.InverseThreeQuotation)
{
int idx = 0;
var str = next.m_string;
while (idx < str.Length && char.IsLetter(str[idx]))
{
idx++;
}
if (idx < str.Length && str[idx] == ' ')
{
exp.shell_name = str.Substring(0, idx);
next.m_string = str.Substring(idx + 1);
}
}
}
do
{
next = NextToken();
if (next.Match(TokenType.STRING) || next.Match(TokenType.NAME))
{
var term = new Terminator(next);
exp.list.Add(term);
}
else if (next.Match('{'))
{
var term = ParseComplexItem();
exp.list.Add(term);
}
else
{
throw NewParserException("expect string,name,'{' in complex-string", next);
}
} while (next.IsStringEnded == false);
return(exp);
}