void HandleAssignStatement(AssignStatement tree)
{
HandleExpList(tree.exp_list, tree.var_list.Count);
// var list
int register = GetNextRegisterId();
ResetRegisterId(register + tree.var_list.Count);
for (int i = 0; i < tree.var_list.Count; ++i)
{
HandleVarWrite(tree.var_list[i], register + i);
}
ResetRegisterId(register);
}
SyntaxTree ParseOtherStatement()
{
// lua做了限制，其他语句只有两种，assign statement and func call
// SS还增加几个语法支持，+=，-=，++，--
SyntaxTree exp;
if (LookAhead().m_type == (int)TokenType.NAME)
{
exp = ParsePrefixExp();
if (IsVar(exp))
{
if (LookAhead().m_type == (int)TokenType.ADD_ONE)
{
// ++
NextToken();
var special_statement = new SpecialAssginStatement(_current.m_line);
special_statement.var = exp;
special_statement.is_add_op = true;
return(special_statement);
}
else if (LookAhead().m_type == (int)TokenType.ADD_SELF)
{
// +=
NextToken();
var special_statement = new SpecialAssginStatement(_current.m_line);
special_statement.var = exp;
special_statement.exp = ParseExp();
special_statement.is_add_op = true;
return(special_statement);
}
else if (LookAhead().m_type == (int)TokenType.DEC_ONE)
{
// --
NextToken();
var special_statement = new SpecialAssginStatement(_current.m_line);
special_statement.var = exp;
special_statement.is_add_op = false;
return(special_statement);
}
else if (LookAhead().m_type == (int)TokenType.DEC_SELF)
{
// -=
NextToken();
var special_statement = new SpecialAssginStatement(_current.m_line);
special_statement.var = exp;
special_statement.exp = ParseExp();
special_statement.is_add_op = false;
return(special_statement);
}
// assign statement
var assign_statement = new AssignStatement(LookAhead().m_line);
assign_statement.var_list.Add(exp);
while (LookAhead().m_type != (int)'=')
{
if (NextToken().m_type != (int)',')
{
throw NewParserException("expect ',' to split var-list", _current);
}
if (LookAhead().m_type != (int)TokenType.NAME)
{
throw NewParserException("expect 'id' to start var", _look_ahead);
}
exp = ParsePrefixExp();
if (!IsVar(exp))
{
throw NewParserException("expect var here", _current);
}
assign_statement.var_list.Add(exp);
}
NextToken();// skip '='
assign_statement.exp_list = ParseExpList();
return(assign_statement);
}
else
{
Debug.Assert(exp is FuncCall);
return(exp);
}
}
else
{
if (IsMainExp())
{
throw NewParserException("unsupport statement", _look_ahead);
}
return(null);
}
}