带有前缀参数和用户输入作为可选参数的 ELISP 交互函数
ELISP interactive function with both prefix argument and user input as optional arguments
在 ELISP 中,interactive
codes 的文档提到:
P -- Prefix arg in raw form. Does not do I/O.
...
s -- Arbitrary text, read in the minibuffer and returned as a string ... Prompt.
我假设我可以编写一个带有可选前缀参数的函数,如:
(defun some-function (&optional prefix)
(interactive "P")
...
)
或带有用户输入的函数,如:
(defun some-function (user-argument)
(interactive "sProvide an argument: ")
...
)
但不是两者。然后我找到了 Org-mode 函数 org-match-sparse-tree
,我可以用 C-u C-c \
调用它,其中前缀参数限制匹配打开 org-mode 标题,我仍然提示匹配.源代码在下面,我找不到变量 match
是如何赋值的:
(defun org-match-sparse-tree (&optional todo-only match)
"..."
(interactive "P")
(org-agenda-prepare-buffers (list (current-buffer)))
(let ((org--matcher-tags-todo-only todo-only))
(org-scan-tags 'sparse-tree (cdr (org-make-tags-matcher match))
org--matcher-tags-todo-only)))
此函数如何同时接受前缀参数和用户输入?
How does this function [interactively] take both prefix argument and user input?
它不是 -- match
参数未获得,因此是 nil
。您看到的是随后以 nil
值作为参数调用 (org-make-tags-matcher match)
的效果:
(defun org-make-tags-matcher (match)
"..."
(unless match
;; Get a new match request, with completion against the global
;; tags table and the local tags in current buffer.
(let ((org-last-tags-completion-table
(org-tag-add-to-alist
(org-get-buffer-tags)
(org-global-tags-completion-table))))
(setq match
(completing-read
"Match: "
'org-tags-completion-function nil nil nil 'org-tags-history))))
...)
函数可以接受多个interactive
参数。
参见C-hf interactive
To pass several arguments to the command, concatenate the individual strings, separating them by newline characters.
该帮助中的第一个示例说明了这一点:
(defun foo (arg buf) "Doc string" (interactive "P\nbbuffer: ") .... )
这在 (elisp)Using Interactive
中进行了详细说明 -- 您链接到的文档中的上一级:
It may be a string; its contents are a sequence of elements
separated by newlines, one for each argument(1). Each element
consists of a code character (*note Interactive Codes::) optionally
followed by a prompt (which some code characters use and some
ignore). Here is an example:
(interactive "P\nbFrobnicate buffer: ")
The code letter ‘P’ sets the command’s first argument to the raw
command prefix (*note Prefix Command Arguments::). ‘bFrobnicate
buffer: ’ prompts the user with ‘Frobnicate buffer: ’ to enter the
name of an existing buffer, which becomes the second and final
argument.
不过,您应该完整阅读该文档——您可以做更复杂的事情,包括编写任意 elisp 来生成交互式参数(这可能涉及也可能不涉及提示用户)。
在 ELISP 中,interactive
codes 的文档提到:
P -- Prefix arg in raw form. Does not do I/O. ... s -- Arbitrary text, read in the minibuffer and returned as a string ... Prompt.
我假设我可以编写一个带有可选前缀参数的函数,如:
(defun some-function (&optional prefix)
(interactive "P")
...
)
或带有用户输入的函数,如:
(defun some-function (user-argument)
(interactive "sProvide an argument: ")
...
)
但不是两者。然后我找到了 Org-mode 函数 org-match-sparse-tree
,我可以用 C-u C-c \
调用它,其中前缀参数限制匹配打开 org-mode 标题,我仍然提示匹配.源代码在下面,我找不到变量 match
是如何赋值的:
(defun org-match-sparse-tree (&optional todo-only match)
"..."
(interactive "P")
(org-agenda-prepare-buffers (list (current-buffer)))
(let ((org--matcher-tags-todo-only todo-only))
(org-scan-tags 'sparse-tree (cdr (org-make-tags-matcher match))
org--matcher-tags-todo-only)))
此函数如何同时接受前缀参数和用户输入?
How does this function [interactively] take both prefix argument and user input?
它不是 -- match
参数未获得,因此是 nil
。您看到的是随后以 nil
值作为参数调用 (org-make-tags-matcher match)
的效果:
(defun org-make-tags-matcher (match)
"..."
(unless match
;; Get a new match request, with completion against the global
;; tags table and the local tags in current buffer.
(let ((org-last-tags-completion-table
(org-tag-add-to-alist
(org-get-buffer-tags)
(org-global-tags-completion-table))))
(setq match
(completing-read
"Match: "
'org-tags-completion-function nil nil nil 'org-tags-history))))
...)
函数可以接受多个interactive
参数。
参见C-hf interactive
To pass several arguments to the command, concatenate the individual strings, separating them by newline characters.
该帮助中的第一个示例说明了这一点:
(defun foo (arg buf) "Doc string" (interactive "P\nbbuffer: ") .... )
这在 (elisp)Using Interactive
中进行了详细说明 -- 您链接到的文档中的上一级:
It may be a string; its contents are a sequence of elements
separated by newlines, one for each argument(1). Each element
consists of a code character (*note Interactive Codes::) optionally
followed by a prompt (which some code characters use and some
ignore). Here is an example:
(interactive "P\nbFrobnicate buffer: ")
The code letter ‘P’ sets the command’s first argument to the raw
command prefix (*note Prefix Command Arguments::). ‘bFrobnicate
buffer: ’ prompts the user with ‘Frobnicate buffer: ’ to enter the
name of an existing buffer, which becomes the second and final
argument.
不过,您应该完整阅读该文档——您可以做更复杂的事情,包括编写任意 elisp 来生成交互式参数(这可能涉及也可能不涉及提示用户)。