simarg.hh

一个mips虚拟机非常好代码,使用C++来编写的,希望大家多学学,

#ifndef simarg_hh_included
#define simarg_hh_included

#include <tcl.h>
#include "error.hh"
#include "object.hh"


// The Tcl interpreter.
extern Tcl_Interp *sulima_tcl;


// A script error as stored in the Tcl interpreter result.

class ScriptError : public Error {
private:
    Tcl_Obj *obj;
public:
    ScriptError()
	: obj(Tcl_GetObjResult(sulima_tcl)) { Tcl_IncrRefCount(obj); }
    ~ScriptError();
    const char *what() const;
};


// This file defines a simple wrapper around the Tcl function arguments.  It
// is here both for convinience and to hide details of the scripting engine.


// A single argument to a callback function (and its return value.)

class SimArg
    : public Object
{
    friend class SimArgs;

private:

    Tcl_Obj *obj;

    // Construct a SimArg from a constant Tcl object.
    SimArg(Tcl_Obj *o)
	: obj(o) { Tcl_IncrRefCount(obj); }

public:

    // Constructors, etc.
    SimArg(const SimArg &a)
	: obj(a.obj) { Tcl_IncrRefCount(obj); }
    ~SimArg()
	  { Tcl_DecrRefCount(obj); }
    SimArg& operator=(const SimArg &a)
	{
	    Tcl_DecrRefCount(obj);
	    obj = a.obj;
	    Tcl_IncrRefCount(obj);
	    return *this;
	}
    SimArg(int x = 0)
	: obj(Tcl_NewIntObj(x))
	{
	    if (!obj)
		throw OutOfMemory();
	    Tcl_IncrRefCount(obj);
	}
    SimArg(long x)
	: obj(Tcl_NewLongObj(x))
	{
	    if (!obj)
		throw OutOfMemory();
	    Tcl_IncrRefCount(obj);
	}
    SimArg(bool x)
	: obj(Tcl_NewBooleanObj(x))
	{
	    if (!obj)
		throw OutOfMemory();
	    Tcl_IncrRefCount(obj);
	}
    SimArg(const char *s)
	: obj(Tcl_NewStringObj((char *)s, -1))
	{
	    if (!obj)
		throw OutOfMemory();
	    Tcl_IncrRefCount(obj);
	}

    // Return the internal object representation.
    Tcl_Obj *get_obj() const
	{ return obj; }

    // Finaly, implicit conversions to strings, integers and booleans.
    operator int() const
	{
	    int x;
	    if (Tcl_GetIntFromObj(sulima_tcl, obj, &x) != TCL_OK)
		throw ScriptError();
	    return x;
	}
    operator long() const
	{
	    long x;
	    if (Tcl_GetLongFromObj(sulima_tcl, obj, &x) != TCL_OK)
		throw ScriptError();
	    return x;
	}
    operator bool() const
	{
	    int x;
	    if (Tcl_GetBooleanFromObj(sulima_tcl, obj, &x) != TCL_OK)
		throw ScriptError();
	    return x;
	}
    operator const char *() const
	{
	    char *s = Tcl_GetStringFromObj(obj, NULL);
	    if (!s)
		throw OutOfMemory();
	    return s;
	}

};


// A list of arguments to a callback function.

class SimArgs {

private:

    // Internal representation.
    int objc;
    Tcl_Obj *const *objv;

public:

    // Constructors, etc.
    SimArgs()
	: objc(0), objv(0) { }
    SimArgs(int c, Tcl_Obj *const v[])
	: objc(c), objv(v) { }

    // Return the array size.
    int length() const
	{ return objc; }
    int size() const
	{ return objc; }

    // Index the array.
    SimArg operator[](int i) const
	{
	    if (i >= objc)
		throw Error("At least %d arguments expected.", i + 1);
	    return SimArg(objv[i]);
	}

};


#endif // simarg_hh_included