search - Emacs Lisp 向后搜索

Question

序言

在 C++ 中使用 VTK 库，我经常不得不这样写:

vtkInteractorStyleRubberBandZoom *isrbz = vtkInteractorStyleRubberBandZoom::New();

此外，每次我需要在我的程序中使用一个新的 VTK 类时，我都必须在源文件的某个地方添加#include "vtkInteractorStyleRubberBandZoom.h"

我如何实现自动化，这样我就必须将每个长得难以忍受的类名输入一次而不是三个？

我试着为它写一个 Emacs 次要模式。可能已经有现成的解决方案(YaSnippet？)，但我认为自己编写它也是一个很好的练习。

代码

;vtk-mode.el
;add to .emacs:
;(load  "vtk-mode")
;(global-set-key [(control =)] 'expand-vtk)

(defun expand-vtk ()
  (interactive)
  (setq now (point))
  (setq vtkstart (search-backward "vtk"))
  (setq vtkend (- (search-forward " ") 1))
  (setq vtkname (buffer-substring vtkstart vtkend))

  ;check for #include "vtkBlah.h"
  (setq includename (format "#include \"%s.h\"\n" vtkname))
  (search-backward includename nil (append-include-vtk includename))
  (goto-char (+ now (length includename)))

  (insert (format "= %s::New();" vtkname)))

(defun append-include-vtk (incname)
  (goto-char 0)
  (insert incname))

问题

基本上，它可以工作，除了搜索包含名称总是失败，例如。例如:

vtkSomething *smth /*press C-= here, it looks backward for 
#include "vtkSomething.h", can't find it and 
calls append-include-vtk, adding it to the beginning 
of the file, then comes back here and expands this line into: */

vtkSomething *smth = vtkSomething::New();

//and let's add another instance of vtkSomething...
vtkSomething *smth2 /*press C-= again, it looks backward for 
#include "vtkSomething", and fails, despite the fact 
that it was added by the previous command. So it adds it again."*/

我在这里使用向后搜索做错了什么？

(代码中还有另一个(至少一个)错误，如果向后搜索成功，我不应该添加 (length includename)，但现在我更感兴趣的是如何让它成功，首先)

Answer 1

好的，我知道了。不知何故，我知道 search-backward (noerror) 的第三个参数是回调，但事实并非如此。因此每次都会对其进行评估，而不仅仅是在搜索失败时。它应该是这样的:

(defun expand-vtk ()
  (interactive)
  (setq now (point))
  (setq vtkstart (search-backward "vtk"))
  (setq vtkend (- (search-forward " ") 1))
  (setq vtkname (buffer-substring vtkstart vtkend))

  ;check for #include "vtkBlah.h"
  (setq includename (format "#include \"%s.h\"\n" vtkname))
  (if (search-backward includename nil t) 
      (goto-char now) 
      (progn (append-include-vtk includename) 
             (goto-char (+ now (length includename)))))  

  (insert (format "= %s::New();" vtkname)))

(defun append-include-vtk (incname)
  (goto-char 0)
  (insert incname))