List <ImportStmt> ParseImportStmt( )
{
var importList = new List <ImportStmt>();
while (CurrTokenType == TokenType.Import &&
CurrTokenType != TokenType.EOF)
{
var defpos = CurrTokenPos;
Expect(TokenType.Import);
var tk = Expect(TokenType.QuotedString);
var pkgName = new BasicLit(tk.Value, (TokenType)tk.MatcherID, tk.Pos);
var n = new ImportStmt(pkgName, defpos);
importList.Add(n);
ScopeManager.Declare(n, ScopeMgr.PackageScope, tk.Value, defpos, SymbolUsage.Package);
// 如果包存在, 就不会在定义
var pkg = Exe.GetPackageByName(tk.Value);
if (pkg == null)
{
Compiler.Import(_exe, _loader, tk.Value, tk.Value, ImportMode.Directory);
}
}
return(importList);
}
void ResolveSelectorElement(Expr x, Ident sel, TokenPos dotpos)
{
var xident = x as Ident;
if (xident == null)
{
return;
}
if (xident.Symbol == null)
{
throw new CompileException(string.Format("{0} not defined", xident.Name), dotpos);
}
switch (xident.Symbol.Usage)
{
// 包.函数名
case SymbolUsage.Package:
{
var pkg = Exe.GetPackageByName(xident.Name);
if (pkg == null)
{
throw new CompileException("package not found: " + xident.Name, dotpos);
}
// 包必须有一个顶级作用域
if (pkg.TopScope == null)
{
throw new CompileException("package should have a scope: " + xident.Name, dotpos);
}
ScopeMgr.Resolve(sel, pkg.TopScope);
}
break;
// 实例.函数名
case SymbolUsage.Variable:
case SymbolUsage.Parameter:
case SymbolUsage.SelfParameter:
{
}
break;
default:
throw new CompileException("unknown usage", dotpos);
}
}