代码生成

pbni-rs可以非常方便地将Rust对象或函数与PowerBuilder建立映射，全部由pbni-rs生成代码，省去手写繁琐的样板代码的同时保证了类型安全。

映射PowerBuilder全局函数

• PowerBuilder

global type gf_bit_or from function_object native "pbrs.dll"
end type

forward prototypes
global function long gf_bit_or (readonly long a,readonly long b)
end prototypes

• C++

#include <pbext.h>

PBXRESULT bit_or(PBCallInfo *ci)
{
    pblong a = ci->pArgs->GetAt(0)->GetLong();
    pblong b = ci->pArgs->GetAt(1)->GetLong();
    return ci->returnValue->SetLong(a|b);
}
PBXRESULT PBXCALL PBX_InvokeGlobalFunction(
    IPB_Session *pbsession,
    LPCWSTR functionName,
    PBCallInfo *ci)
{
    if(::wcscmp(functionName,L"gf_bit_or") == 0)
        return bit_or(ci);
    return PBX_E_NO_REGISTER_FUNCTION;
}

• Rust(pbni-rs)

use pbni::*;

#[global_function(name="gf_bit_or")]
fn bit_or(a: pblong, b: pblong) -> pblong {
    a | b
}

映射PowerBuilder对象

• PowerBuilder

forward
global type n_pbni from nonvisualobject
end type
end forward

global type n_pbni from nonvisualobject native "pbrs.dll"
public function string of_hello (string world)
end type
global n_pbni n_pbni

on n_pbni.create
call super::create
TriggerEvent( this, "constructor" )
end on

on n_pbni.destroy
TriggerEvent( this, "destructor" )
call super::destroy
end on

• C++

#include <pbext.h>

class CppObject: public IPBX_NonVisualObject
{
    IPB_Session *session;
    pbobject ctx;

    PBXRESULT handle_hello(PBCallInfo *ci)
    {
        LPCWSTR lpcsWorld = this->session->GetString(ci->pArgs->GetAt(0)->GetString());
        std::wostringstream ss;
        ss << L"hello " << lpcsWorld << L"!";
        return ci->returnValue->SetString(ss.str().c_str());
    }

public:
    CppObject(IPB_Session *pbsession,pbobject pbobj)
    :session(pbsession),
    ctx(pbobj)
    {}
    virtual ~CppObject() override {};

    virtual void Destroy() override { delete this; }

    virtual PBXRESULT Invoke(
        IPB_Session *session,
        pbobject obj,
        pbmethodID mid,
        PBCallInfo *ci) override
   {
        if(mid == 0)
            return this->handle_hello(ci);
        return PBX_E_NO_REGISTER_FUNCTION;
   }
};

PBXRESULT PBXCALL PBX_CreateNonVisualObject(
    IPB_Session *pbsession,
    pbobject pbobj,
    LPCWSTR className,
    IPBX_NonVisualObject **obj)
{
    if(::wcscmp(className,L"n_pbni") == 0)
    {
        *obj = new CppObject(pbsession,pbobj);
        return PBX_OK;
    }
    return PBX_E_NO_SUCH_CLASS;
}

• Rust(pbni-rs)

use pbni::*;

struct RustObject {
    session: Session,
    ctx: ContextObject
}

#[nonvisualobject(name = "n_pbni")]
impl RustObject {
    #[constructor]
    fn new(session: Session, ctx: ContextObject) -> RustObject {
        RustObject {
            session,
            ctx
        }
    }
    #[method(name="of_Hello")]
    fn hello(&self, world: String) -> String {
        format!("hello {}!",world)
    }
}

参数提取

pbni-rs代码生成宏会自动提取PB参数为Rust映射的数据类型，参数的提取顺序与PB端定义的顺序保持一致。其中有几个特殊的参数：Session，CallInfoRef，ArgumentsRef，这几个参数对位置没有要求并且数量任意。

use pbni::*;

#[global_function(name="gf_bit_or")]
fn bit_or(session: Session,a: pblong, b: pblong) -> pblong {
    a | b
}

//等同于

#[global_function(name="gf_bit_or")]
fn bit_or(session: Session,args: ArgumentsRef,a: pblong) -> pblong {
    a | args.get(1).get_long().unwrap()
}

global type gf_test from function_object native "pbrs.dll"
end type

forward prototypes
global function long gf_test (readonly long a,readonly long b)
global function long gf_test (readonly long a,readonly long b,readonly long c)
global function long gf_test (readonly long a,readonly long b,readonly long c,readonly long d)
end prototypes

use pbni::*;

#[global_function(name="gf_test")]
fn test(a: pblong, b: pblong, c: Option<long>, d: Option<long>) -> pblong {
    a | b
}