diff options
Diffstat (limited to 'helpful.el')
| -rw-r--r-- | helpful.el | 124 |
1 files changed, 101 insertions, 23 deletions
@@ -2535,22 +2535,26 @@ escapes that are used by `substitute-command-keys'." (documentation-property sym 'variable-documentation t))) docstring)) -(defun helpful--read-symbol (prompt predicate) - (let* ((sym-here (symbol-at-point)) - (default-val - (when (funcall predicate sym-here) - (symbol-name sym-here)))) - (when default-val - ;; TODO: Only modify the prompt when we don't have ido/ivy/helm, - ;; because the default is obvious for them. - (setq prompt - (replace-regexp-in-string - (rx ": " eos) - (format " (default: %s): " default-val) - prompt))) - (intern (completing-read prompt obarray - predicate t nil nil - default-val)))) +(defun helpful--read-symbol (prompt default-val predicate) + "Read a symbol from the minibuffer, with completion. +Returns the symbol." + (when (and default-val + (not (funcall predicate default-val))) + (setq default-val nil)) + (when default-val + ;; `completing-read' expects a string. + (setq default-val (symbol-name default-val)) + + ;; TODO: Only modify the prompt when we don't have ido/ivy/helm, + ;; because the default is obvious for them. + (setq prompt + (replace-regexp-in-string + (rx ": " eos) + (format " (default: %s): " default-val) + prompt))) + (intern (completing-read prompt obarray + predicate t nil nil + default-val))) ;;;###autoload (defun helpful-function (symbol) @@ -2558,7 +2562,10 @@ escapes that are used by `substitute-command-keys'." See also `helpful-macro', `helpful-command' and `helpful-callable'." (interactive - (list (helpful--read-symbol "Function: " #'functionp))) + (list (helpful--read-symbol + "Function: " + (helpful--callable-at-point) + #'functionp))) (funcall helpful-switch-buffer-function (helpful--buffer symbol t)) (helpful-update)) @@ -2568,7 +2575,10 @@ See also `helpful-macro', `helpful-command' and `helpful-callable'." See also `helpful-function'." (interactive - (list (helpful--read-symbol "Command: " #'commandp))) + (list (helpful--read-symbol + "Command: " + (helpful--callable-at-point) + #'commandp))) (funcall helpful-switch-buffer-function (helpful--buffer symbol t)) (helpful-update)) @@ -2594,7 +2604,10 @@ See also `helpful-function'." (defun helpful-macro (symbol) "Show help for macro named SYMBOL." (interactive - (list (helpful--read-symbol "Macro: " #'macrop))) + (list (helpful--read-symbol + "Macro: " + (helpful--callable-at-point) + #'macrop))) (funcall helpful-switch-buffer-function (helpful--buffer symbol t)) (helpful-update)) @@ -2604,7 +2617,10 @@ See also `helpful-function'." See also `helpful-macro', `helpful-function' and `helpful-command'." (interactive - (list (helpful--read-symbol "Callable: " #'fboundp))) + (list (helpful--read-symbol + "Callable: " + (helpful--callable-at-point) + #'fboundp))) (funcall helpful-switch-buffer-function (helpful--buffer symbol t)) (helpful-update)) @@ -2663,7 +2679,10 @@ nil if SYMBOL doesn't begin with \"F\" or \"V\"." See also `helpful-callable' and `helpful-variable'." (interactive - (list (helpful--read-symbol "Symbol: " #'helpful--bound-p))) + (list (helpful--read-symbol + "Symbol: " + (helpful--symbol-at-point) + #'helpful--bound-p))) (let ((c-var-sym (helpful--convert-c-name symbol t)) (c-fn-sym (helpful--convert-c-name symbol nil))) (cond @@ -2688,15 +2707,74 @@ See also `helpful-callable' and `helpful-variable'." (defun helpful-variable (symbol) "Show help for variable named SYMBOL." (interactive - (list (helpful--read-symbol "Variable: " #'helpful--variable-p))) + (list (helpful--read-symbol + "Variable: " + (helpful--variable-at-point) + #'helpful--variable-p))) (funcall helpful-switch-buffer-function (helpful--buffer symbol nil)) (helpful-update)) +(defun helpful--variable-at-point-exactly () + "Return the symbol at point, if it's a bound variable." + (let ((var (variable-at-point))) + ;; `variable-at-point' uses 0 rather than nil to signify no symbol + ;; at point (presumably because 'nil is a symbol). + (unless (symbolp var) + (setq var nil)) + (when (helpful--variable-p var) + var))) + +(defun helpful--variable-defined-at-point () + "Return the variable defined in the form enclosing point." + ;; TODO: do the same thing if point is just before a top-level form. + (save-excursion + (save-restriction + (widen) + (let* ((ppss (syntax-ppss)) + (sexp-start (nth 1 ppss)) + sexp) + (when sexp-start + (goto-char sexp-start) + (setq sexp (read (current-buffer))) + (when (memq (car-safe sexp) + (list 'defvar 'defvar-local 'defcustom 'defconst)) + (nth 1 sexp))))))) + +(defun helpful--variable-at-point () + "Return the variable exactly under point, or defined at point." + (let ((var (helpful--variable-at-point-exactly))) + (if var + var + (let ((var (helpful--variable-defined-at-point))) + (when (helpful--variable-p var) + var))))) + +(defun helpful--callable-at-point () + (let ((sym (symbol-at-point)) + (enclosing-sym (function-called-at-point))) + (if (fboundp sym) + sym + enclosing-sym))) + +(defun helpful--symbol-at-point-exactly () + "Return the symbol at point, if it's bound." + (let ((sym (symbol-at-point))) + (when (helpful--bound-p sym) + sym))) + +(defun helpful--symbol-at-point () + "Find the most relevant symbol at or around point. +Returns nil if nothing found." + (or + (helpful--symbol-at-point-exactly) + (helpful--callable-at-point) + (helpful--variable-at-point))) + ;;;###autoload (defun helpful-at-point () "Show help for the symbol at point." (interactive) - (-if-let (symbol (symbol-at-point)) + (-if-let (symbol (helpful--symbol-at-point)) (helpful-symbol symbol) (user-error "There is no symbol at point."))) |