src/main.lisp @ 145f327b5678

Fix group help text not showing up in help
author Steve Losh <steve@stevelosh.com>
date Sat, 18 May 2019 13:35:43 -0400
parents 7f0abaf11050
children c0e14a25c572
(in-package :adopt)

;;;; Utils --------------------------------------------------------------------
(defun flip (function)
  "Return a function of two arguments X and Y that calls `function` with Y and X.

  Useful for wrapping existing functions that expect their arguments in the
  opposite order.

  Examples:

    (funcall #'cons 1 2)        ; => (1 . 2)
    (funcall (flip #'cons) 1 2) ; => (2 . 1)
    (reduce (flip #'cons) '(1 2 3) :initial-value nil)
    ; => (3 2 1)

  "
  (lambda (x y)
    (funcall function y x)))

(defun collect (list el)
  "Append element `el` to the end of `list`.

  It is useful as a `:reduce` function when you want to collect all values given
  for an option.

  This is implemented as `(append list (list el))`.  It is not particularly
  fast.  If you can live with reversed output consider `(flip #'cons)`  instead.

  "
  (append list (list el)))

(defun last (old new)
  "Return `new`.

  It is useful as a `:reduce` function when you want to just keep the last-given
  value for an option.

  "
  (declare (ignore old))
  new)

(defun first (old new)
  "Return `new` if `old` is `nil`, otherwise return `old`.

  It is useful as a `:reduce` function when you want to just keep the
  first-given value for an option.

  "
  (if (null old)
    new
    old))


(defun argv ()
  "Return a list of the program name and command line arguments.

  This is not implemented for every Common Lisp implementation.  You can always
  pass your own values to `parse-options` and `print-help` if it's not
  implemented for your particular Lisp.

  "
  #+sbcl sb-ext:*posix-argv*
  #+ccl (destructuring-bind (program-name &rest arguments)
            ccl:*command-line-argument-list*
            (cons program-name (rest (member "--" arguments :test #'string=))))
  #-(or sbcl ccl) (error "ARGV is not supported on this implementation."))

(defun exit (&optional (code 0))
  #+sbcl (sb-ext:exit :code code)
  #+ccl (ccl:quit code)
  #-(or sbcl ccl) (error "EXIT is not supported on this implementation."))


(defun funcall% (value function)
  (funcall function value))

(define-modify-macro funcallf (function) funcall%)


(defmacro define-string (var string &rest args)
  "Convenience macro for `(defparameter ,var (format nil ,string ,@args))`."
  `(defparameter ,var (format nil ,string ,@args)))


(defmacro defclass* (name &rest slots)
  `(defclass ,name ()
     ,(loop :for slot :in slots
            :for initarg = (intern (symbol-name slot) :keyword)
            :collect `(,slot :initarg ,initarg :accessor ,slot))))


;;;; Definition ---------------------------------------------------------------
(defclass* option
  name
  result-key
  help
  manual
  short
  long
  parameter
  initial-value
  key
  finally
  reduce)

(defmethod print-object ((o option) stream)
  (print-unreadable-object (o stream :type t)
    (format stream "~A ~A/~A" (name o) (short o) (long o))))

(defun make-option (name &key
                    long
                    short
                    help
                    manual
                    parameter
                    reduce
                    (result-key name)
                    (initial-value nil initial-value?)
                    (key #'identity)
                    (finally #'identity))
  (when (and (null long) (null short))
    (error "Option ~A requires at least one of :long/:short." name))
  (when (null reduce)
    (error "Option ~A is missing required argument :reduce." name))
  (when (null help)
    (error "Option ~A is missing required argument :help" name))
  (when (and (member reduce (list 'collect #'collect
                                  'first #'first
                                  'last #'last))
             (null parameter))
    (error "Option ~A has reduce function ~A, which requires a :parameter."
           name reduce))
  (apply #'make-instance 'option
         :name name
         :result-key result-key
         :help help
         :manual manual
         :long long
         :short short
         :parameter parameter
         :reduce reduce
         :key key
         :finally finally
         (when initial-value?
           (list :initial-value initial-value))))

(defun optionp (object)
  (typep object 'option))


(defclass* group
  name title help manual options)

(defmethod print-object ((g group) stream)
  (print-unreadable-object (g stream :type t)
    (format stream "~A (~D options)" (name g) (length (options g)))))

(defun make-group (name &key title help manual options)
  (make-instance 'group
    :name name
    :title title
    :help help
    :manual manual
    :options options))

(defun make-default-group (options)
  (make-instance 'group
    :name nil
    :title nil
    :help nil
    :manual nil
    :options options))

(defun groupp (object)
  (typep object 'group))


(defclass* interface
  name
  summary
  examples
  options
  groups
  short-options
  long-options
  usage
  help
  manual)

(defmethod print-object ((i interface) stream)
  (print-unreadable-object (i stream :type t)
    (format stream "~A (~D options in ~D groups)"
            (name i)
            (length (options i))
            (length (groups i)))))

(defun make-interface (&key name summary usage help manual examples contents)
  (let* ((ungrouped-options (remove-if-not #'optionp contents))
         (groups (cons (make-default-group ungrouped-options)
                       (remove-if-not #'groupp contents)))
         (options (loop :for g :in groups :append (options g)))
         (interface (make-instance 'interface
                      :name name
                      :usage usage
                      :summary summary
                      :help help
                      :manual manual
                      :examples examples
                      :groups groups
                      :options options
                      :short-options (make-hash-table)
                      :long-options (make-hash-table :test #'equal))))
    (flet ((add-option (option)
             (let ((short (short option))
                   (long (long option)))
               (when short
                 (setf (gethash short (short-options interface)) option))
               (when long
                 (setf (gethash long (long-options interface)) option)))))
      (dolist (g groups)
        (map nil #'add-option (options g))))
    interface))


;;;; Parsing ------------------------------------------------------------------
(defun shortp (arg)
  (and (> (length arg) 1)
       (char= #\- (aref arg 0))
       (char/= #\- (aref arg 1))))

(defun longp (arg)
  (and (> (length arg) 2)
       (char= #\- (aref arg 0))
       (char= #\- (aref arg 1))))

(defun terminatorp (arg)
  (string= "--" arg))


(define-condition unrecognized-option (error)
  ((problematic-option :accessor problematic-option :initarg :problematic-option))
  (:report (lambda (condition stream)
             (format stream "No such option ~S." (problematic-option condition)))))

(defun unrecognized-option-p (value)
  (typep value 'unrecognized-option))


(defun parse-long (interface results arg remaining)
  (let* ((= (position #\= arg))
         (long-name (subseq arg 2 =))
         (option (gethash long-name (long-options interface))))
    (when (null option)
      (error 'unrecognized-option :problematic-option (format nil "--~A" long-name)))
    (let* ((k (result-key option))
           (current (gethash k results)))
      (setf (gethash k results)
            (if (parameter option)
              (let ((param (funcall (key option)
                                    (if =
                                      (subseq arg (1+ =))
                                      (pop remaining)))))
                (funcall (reduce option) current param))
              (funcall (reduce option) current)))))
  remaining)

(defun parse-short (interface results arg remaining)
  (let* ((short-name (aref arg 1))
         (option (gethash short-name (short-options interface))))
    (when (null option)
      (error 'unrecognized-option :problematic-option (format nil "-~A" short-name)))
    (let* ((k (result-key option))
           (current (gethash k results)))
      (setf (gethash k results)
            (if (parameter option)
              (let ((param (funcall (key option)
                                    (if (> (length arg) 2)
                                      (subseq arg 2) ; -xfoo
                                      (pop remaining))))); -x foo
                (funcall (reduce option) current param))
              (prog1 (funcall (reduce option) current)
                (if (> (length arg) 2)
                  (push (format nil "-~A" (subseq arg 2)) remaining)))))))
  remaining)


(defun initialize-results (interface results)
  (dolist (option (options interface))
    (when (slot-boundp option 'initial-value)
      (setf (gethash (result-key option) results)
            (initial-value option))))
  results)

(defun finalize-results (interface results)
  (dolist (option (options interface))
    (funcallf (gethash (result-key option) results)
              (finally option)))
  results)


(defun discard-option (condition)
  "Invoke the `discard-option` restart properly.

  Example:

    (handler-bind ((unrecognized-option 'discard-option))
      (multiple-value-bind (arguments options) (parse-options *ui*)
        (run arguments options)))

  "
  (invoke-restart (find-restart 'discard-option condition)))

(defun treat-as-argument (condition)
  "Invoke the `treat-as-argument` restart properly.

  Example:

    (handler-bind ((unrecognized-option 'treat-as-argument))
      (multiple-value-bind (arguments options) (parse-options *ui*)
        (run arguments options)))

  "
  (invoke-restart (find-restart 'treat-as-argument condition)))

(defun supply-new-value (condition value)
  "Invoke the `supply-new-value` restart properly.

  Example:

    (handler-bind
        ((unrecognized-option (alexandria:rcurry 'supply-new-value \"--foo\"))
      (multiple-value-bind (arguments options) (parse-options *ui*)
        (run arguments options)))

  "
  (invoke-restart (find-restart 'supply-new-value condition) value))


(defun parse-options (interface &optional (arguments (rest (argv))))
  "Parse `arguments` according to `interface`.

  Two values are returned:

  1. A fresh list of top-level, unaccounted-for arguments that don't correspond
     to any options defined in `interface`.
  2. An `EQL` hash table of option keys to values.

  See the full documentation for more information.

  "
  (let ((toplevel nil)
        (results (make-hash-table)))
    (initialize-results interface results)
    (labels
        ((recur (arguments)
           (if (null arguments)
             (values (nreverse toplevel)
                     (finalize-results interface results))
             (destructuring-bind (arg . remaining) arguments
               (recur
                 (restart-case
                     (cond
                       ((terminatorp arg) (dolist (r remaining) (push r toplevel)))
                       ((shortp arg) (parse-short interface results arg remaining))
                       ((longp arg) (parse-long interface results arg remaining))
                       (t (push arg toplevel) remaining))
                   (discard-option ()
                     :test unrecognized-option-p
                     :report "Discard the unrecognized option."
                     remaining)
                   (treat-as-argument ()
                     :test unrecognized-option-p
                     :report "Treat the unrecognized option as a plain argument."
                     (push arg toplevel)
                     remaining)
                   (supply-new-value (v)
                     :test unrecognized-option-p
                     :report "Supply a new value to parse."
                     :interactive (lambda () (list (read-line)))
                     (cons v remaining))))))))
      (recur arguments))))


;;;; Help ---------------------------------------------------------------------
(defun option-string (option)
  (let* ((long (long option))
         (short (short option))
         (parameter (parameter option))
         (parameter-string (if parameter
                             (format nil " ~A" parameter)
                             "")))
    (format nil "~{~A~^, ~}"
            (remove nil
                    (list (when short
                            (format nil "-~A~A" short parameter-string))
                          (when long
                            (format nil "--~A~A" long parameter-string)))))))

(defun print-option-help (stream option option-column doc-column doc-width)
  "Print `option`'s help to `stream`, indented/wrapped properly.

  Assumes the last thing printed to `stream` was a newline.

  The option string will start at `option-column`.  The help will start at
  `doc-column` and be line-wrapped to `doc-width`.

  "
  (let ((option-string (option-string option))
        (lines (bobbin:wrap (split-sequence:split-sequence
                              #\newline (help option))
                            doc-width))
        (col 0))
    (flet ((print-at (c string &optional newline)
             "Print `string` starting at column `c`, adding padding/newline if needed."
             (when (>= col c)
               (terpri stream)
               (setf col 0))
             (format stream "~vA~A" (- c col) #\space string)
             (if newline
               (progn (terpri stream)
                      (setf col 0))
               (setf col (+ c (length string))))))
      (print-at option-column option-string)
      (dolist (line lines)
        (print-at doc-column line t)))))

(defun print-help (interface &key
                   (stream *standard-output*)
                   (program-name (car (argv)))
                   (width 80)
                   (option-width 20)
                   (include-examples t))
  "Print a pretty help document for `interface` to `stream`.

  `width` should be the total width (in characters) for line-wrapping purposes.
  Care will be taken to ensure lines are no longer than this, though some edge
  cases (extremely long short/long option names and parameters) may slip
  through.

  `option-width` should be the width of the column of short/long options (in
  characters).  If the short/long option help is shorter than this, the option's
  help string will start on the same line.  Otherwise the option's help string
  will start on the next line.

  The result will look something like:

    (print-help *program-interface* :width 60 :option-width 15)
    ; =>
    ; foo - do some things and meow
    ;
    ; USAGE: /bin/foo [options] FILES
    ;
    ; Foo is a program to frobulate some files, meowing as it
    ; happens.
    ;
    ; Options:
    ;   -v, --verbose    Output extra information.
    ;   -q, --quiet      Shut up.
    ;   --ignore FILE    Ignore FILE.  May be specified multiple
    ;                    times.
    ;   -n NAME, --name NAME
    ;                    Your name.  May be specified many times,
    ;                    last one wins.
    ;   -m, --meow       Meow.
    ;   0.........1.... option-width
    ; 0........1.........2.........3.........4.........5.........6

  "
  (assert (> width (+ 2 option-width 2)) (width option-width)
    "WIDTH (~D) must be at least 4 greater than OPTION-WIDTH (~D)"
    width option-width)
  (format stream "~A - ~A~2%" (name interface) (summary interface))
  (format stream "USAGE: ~A ~A~2%" program-name (usage interface))
  (format stream (bobbin:wrap (help interface) width))
  (format stream "~%")
  (dolist (group (groups interface))
    (when (options group)
      (format stream "~%~A:~%" (or (title group) (name group) "Options"))
      (let* ((help (help group))
             (help-column 2)
             (help-width (- width help-column))
             (option-column 2)
             (option-padding 2)
             (doc-column (+ option-column option-width option-padding))
             (doc-width (- width doc-column)))
        (when help
          (format stream "~%~{  ~A~^~%~}~2%"
                  (bobbin:wrap (list help) help-width)))
        (dolist (option (options group))
          (print-option-help stream option option-column doc-column doc-width)))))
  (let* ((examples (examples interface))
         (example-column 2)
         (example-width (- width example-column)))
    (when (and examples include-examples)
      (format stream "~%Examples:~%")
      (loop :for (prose . command) :in examples :do
            (format stream "~%~{  ~A~^~%~}~2%      ~A~%"
                    (bobbin:wrap (list prose) example-width)
                    command)))))

(defun print-help-and-exit
    (interface &key
     (stream *standard-output*)
     (program-name (car (argv)))
     (width 80)
     (option-width 20)
     (include-examples t)
     (exit-code 0))
  "Print a pretty help document for `interface` to `stream` and exit.

  Handy for easily providing --help:

    (multiple-value-bind (arguments options) (parse-options *ui*)
      (when (gethash 'help options)
        (print-help-and-exit *ui*))
      (run arguments options))
  "
  (print-help interface
               :stream stream
               :program-name program-name
               :width width
               :option-width option-width
               :include-examples include-examples)
  (exit exit-code))

(defun print-error-and-exit (error &key
                             (stream *error-output*)
                             (exit-code 1)
                             (prefix "error: "))
  "Print `prefix` and `error` to `stream` and exit.

  Example:

    (handler-case
        (multiple-value-bind (arguments options) (parse-options *ui*)
          (run arguments options))
      (unrecognized-option (c)
        (print-error-and-exit c)))

  "
  (format stream "~A~A~%" (or prefix "") error)
  (exit exit-code))


;;;; Man ----------------------------------------------------------------------
(defun escape (string)
  (if (zerop (length string))
    ""
    (with-output-to-string (s)
      (when (char= #\. (aref string 0)) ;; is this some kind of joke, troff?
        (write-string "\\[char46]" s)
        (setf string (subseq string 1)))
      (loop :for char :across string :do
            (when (find char "\\-")
              (write-char #\\ s))
            (write-char char s)))))

(defun split-paragraphs (string &key (delimiter ".PP") (escape t))
  (let ((lines (split-sequence:split-sequence #\newline string)))
    (when escape
      (setf lines (mapcar #'escape lines)))
    (substitute delimiter "" lines :test #'string=)))

(defun option-troff (option)
  (let ((short (short option))
        (long (long option))
        (parameter (parameter option)))
    (labels
        ((short-option ()
           (when short
             (if parameter
               (format nil "\\-~A \" \" \\fI~A\\fR" short parameter)
               (format nil "\\-~A" short))))
         (long-option ()
           (when long
             (if parameter
               (format nil "\\-\\-~A=\\fI~A\\fR" long parameter)
               (format nil "\\-\\-~A" long)))))
      (format nil ".BR ~{~A~^ \", \"~}"
              (remove nil (list (short-option) (long-option)))))))


(defun print-manual (interface &key
                     (stream *standard-output*)
                     (manual-section 1))
  (check-type manual-section (integer 1))
  (labels
      ((f (&rest args)
         (apply #'format stream args)
         (terpri stream))
       (fa (string-or-list)
         (if (listp string-or-list)
           (map nil #'fa string-or-list)
           (f "~A" string-or-list)))
       (print-header ()
         (f ".TH ~:@(~A~) ~D" (escape (name interface)) manual-section))
       (print-name ()
         (f ".SH NAME")
         (f "~A \\- ~A" (escape (name interface)) (escape (summary interface))))
       (print-synopsis ()
         (f ".SH SYNOPSIS")
         (f ".B ~A" (escape (name interface)))
         (unless (string= "" (usage interface))
           (f ".R ~A" (escape (usage interface)))))
       (print-description ()
         (f ".SH DESCRIPTION")
         (fa (split-paragraphs (or (manual interface)
                                   (help interface)))))
       (print-option (option)
         (f ".TP")
         (fa (option-troff option))
         (fa (split-paragraphs
               (or (manual option) (help option))
               :delimiter ".IP")))
       (print-group (group)
         (if (title group)
           (f ".SS ~A" (escape (title group)))
           (f ".SH OPTIONS"))
         (let ((desc (or (manual group)
                         (help group))))
           (when desc
             (fa (split-paragraphs desc))))
         (map nil #'print-option (options group)))
       (print-groups ()
         (map nil #'print-group (groups interface)))
       (print-example (prose command prefix)
         (f prefix)
         (fa (escape prose))
         (f ".PP")
         (f ".nf")
         (f ".RS")
         (fa command)
         (f ".RE")
         (f ".fi"))
       (print-examples ()
         (let ((examples (examples interface)))
           (loop :for prefix = ".SH EXAMPLES" :then ".PP"
                 :for (prose . command) :in examples
                 :do (print-example prose command prefix)))))
    (print-header)
    (print-name)
    (print-synopsis)
    (print-description)
    (print-groups)
    (print-examples)))