%namespace NewLanguage

%token <symbol> SYMBOL

%nonassoc '<' '>' '='
%left '-' '+'
%left '*' '/'

%YYSTYPE ParseNode
%YYLTYPE SourceLocation

%type <declaration> decl
%type <expr> expr
%type <typespec> typespec
%type <exprlist> typeconstraint
%%
/* currently we only allow one line.  Later we
   need to extend this to separate statements. */
start: /* empty */
        | decl { this.AtTopLevel($1); }
        | expr { this.AtTopLevel($1); }
        ;

decl : typespec SYMBOL
        {        
                //Console.WriteLine("Decl \"{0}\"", $1);
                $$ = new DeclarationNode($1, $2);
        }
        ;

typespec : SYMBOL       { $$ = new TypeSpecNode($1); }
        | SYMBOL '[' typeconstraint ']'       
                        { $$ = new TypeSpecNode($1, $3); }
        ;

typeconstraint : expr   { $$ = new ExprListNode(); $$.Add($1); }
        | typeconstraint ',' expr
                        { $1.Add($3); }
        ;

expr : SYMBOL { $$ = new SymbolRefNode($1); }
        | expr '+' expr { $$ = new OperatorNode($2.str, $1, $3); }
        | expr '-' expr { $$ = new OperatorNode($2.str, $1, $3); }
        | expr '*' expr { $$ = new OperatorNode($2.str, $1, $3); }
        | expr '/' expr { $$ = new OperatorNode($2.str, $1, $3); }
        | expr '<' expr { $$ = new OperatorNode($2.str, $1, $3); }
        | expr '>' expr { $$ = new OperatorNode($2.str, $1, $3); }
        | expr '=' expr { $$ = new OperatorNode($2.str, $1, $3); }
        ;

%%
private List<NodeBase> _topLevel = new List<NodeBase>();
public IEnumerable<NodeBase> TopLevel
{
        get {
                return _topLevel.AsReadOnly();
        }
}
private void AtTopLevel(NodeBase node)
{
        _topLevel.Add(node);
}
public readonly ErrorHandler handler = new ErrorHandler();