branch: elpa/llama
commit 392b89ba544039633a271d384ff6a776923826e5
Author: Jonas Bernoulli <[email protected]>
Commit: Jonas Bernoulli <[email protected]>
Improve documentation
---
README.org | 62 +++++++++++++++++-----------------
llama.el | 111 ++++++++++++++++++++++++++++++-------------------------------
2 files changed, 85 insertions(+), 88 deletions(-)
diff --git a/README.org b/README.org
index 43411a0f73..e9a56b31bb 100644
--- a/README.org
+++ b/README.org
@@ -1,28 +1,30 @@
* Llama — Compact syntax for short lambda
-This package implements the macro ~##~, which provides compact
-syntax for short ~lambda~, without actually being new syntax,
-which would be difficult to get merged into Emacs. Past attempts
-to add syntax were met with determined pushback and the use of a
-macro was suggested as an alternative.
-
-The ~##~ macro, whose signature is ~(## FN &rest BODY)~, expands
-to a ~lambda~ expression, which wraps around these arguments.
-
-This ~lambda~ expression calls the function FN with arguments
-BODY and returns its value. Its own arguments are derived from
-symbols found in BODY.
-
-Each symbol from ~%1~ through ~%9~, which appears in BODY,
-specifies a mandatory argument. Each symbol from ~&1~ through
-~&9~, which appears in BODY, specifies an optional argument.
-All arguments following an optional argument have to be optional
-as well, thus their names have to begin with ~&~. Symbol ~&*~
-specifies extra (~&rest~) arguments.
-
-The shorter symbol ~%~ can be used instead of ~%1~, but using both
-in the same expression is not allowed. Likewise ~&~ can be used
-instead of ~&1~.
+This package implements a macro named ~##~, which provides a compact way
+to write short ~lambda~ expressions.
+
+The signature of the macro is ~(## FN &rest BODY)~ and it expands to a
+~lambda~ expression, which calls the function ~FN~ with the arguments ~BODY~
+and returns the value of that. The arguments of the ~lambda~ expression
+are derived from symbols found in ~BODY~.
+
+Each symbol from ~%1~ through ~%9~, which appears in an unquoted part
+of ~BODY~, specifies a mandatory argument. Each symbol from ~&1~ through
+~&9~, which appears in an unquoted part of ~BODY~, specifies an optional
+argument. The symbol ~&*~ specifies extra (~&rest~) arguments.
+
+The shorter symbol ~%~ can be used instead of ~%1~, but using both in
+the same expression is not allowed. Likewise ~&~ can be used instead
+of ~&1~. These shorthands are not recognized in function position.
+
+To support binding forms that use a vector as ~VARLIST~ (such as ~-let~
+from the ~dash~ package), argument symbols are also detected inside of
+vectors.
+
+The space between ~##~ and ~FN~ can be omitted because ~##~ is read-syntax
+for the symbol whose name is the empty string. If you prefer you can
+place a space there anyway, and if you prefer to not use this somewhat
+magical symbol at all, you can instead use the alternative name ~llama~.
Instead of:
@@ -44,8 +46,8 @@ which expands to:
(foo %1 (bar &3) &*))
#+end_src
-Unused trailing arguments and mandatory unused arguments at the
-border between mandatory and optional arguments are also supported:
+Unused trailing arguments and mandatory unused arguments at the border
+between mandatory and optional arguments are also supported:
#+begin_src emacs-lisp
(##list %1 _%3 &5 _&6)
@@ -58,10 +60,6 @@ becomes:
(list %1 &5))
#+end_src
-Note how ~_%3~ and ~_&6~ are removed from the body, because their
-names begin with an underscore. Also note that ~_&4~ is optional,
-unlike the explicitly specified ~_%3~.
-
-The name ~##~ was chosen because that allows (optionally)
-omitting the whitespace between it and the following symbol.
-It also looks similar to ~#'function~.
+Note how ~_%3~ and ~_&6~ are removed from the body, because their names
+begin with an underscore. Also note that ~_&4~ is optional, unlike the
+explicitly specified ~_%3~.
diff --git a/llama.el b/llama.el
index 1928da3586..b5545fef98 100644
--- a/llama.el
+++ b/llama.el
@@ -25,29 +25,31 @@
;;; Commentary:
-;; This package implements the macro `##', which provides compact
-;; syntax for short `lambda', without actually being new syntax,
-;; which would be difficult to get merged into Emacs. Past attempts
-;; to add syntax were met with determined pushback and the use of a
-;; macro was suggested as an alternative.
-
-;; The `##' macro, whose signature is (## FN &rest BODY), expands
-;; to a `lambda' expression, which wraps around these arguments.
-
-;; This `lambda' expression calls the function FN with arguments
-;; BODY and returns its value. Its own arguments are derived from
-;; symbols found in ARGS.
-
-;; Each symbol from `%1' through `%9', which appears in BODY,
-;; specifies a mandatory argument. Each symbol from `&1' through
-;; `&9', which appears in BODY, specifies an optional argument.
-;; All arguments following an optional argument have to be optional
-;; as well, thus their names have to begin with `&'. Symbol `&*'
-;; specifies extra (`&rest') arguments.
-
-;; The shorter symbol `%' can be used instead of `%1', but using both
-;; in the same expression is not allowed. Likewise `&' can be used
-;; instead of `&1'.
+;; This package implements a macro named `##', which provides a compact way
+;; to write short `lambda' expressions.
+
+;; The signature of the macro is (## FN &rest BODY) and it expands to a
+;; `lambda' expression, which calls the function FN with the arguments BODY
+;; and returns the value of that. The arguments of the `lambda' expression
+;; are derived from symbols found in BODY.
+
+;; Each symbol from `%1' through `%9', which appears in an unquoted part
+;; of BODY, specifies a mandatory argument. Each symbol from `&1' through
+;; `&9', which appears in an unquoted part of BODY, specifies an optional
+;; argument. The symbol `&*' specifies extra (`&rest') arguments.
+
+;; The shorter symbol `%' can be used instead of `%1', but using both in
+;; the same expression is not allowed. Likewise `&' can be used instead
+;; of `&1'. These shorthands are not recognized in function position.
+
+;; To support binding forms that use a vector as VARLIST (such as `-let'
+;; from the `dash' package), argument symbols are also detected inside of
+;; vectors.
+
+;; The space between `##' and FN can be omitted because `##' is read-syntax
+;; for the symbol whose name is the empty string. If you prefer you can
+;; place a space there anyway, and if you prefer to not use this somewhat
+;; magical symbol at all, you can instead use the alternative name `llama'.
;; Instead of:
;;
@@ -63,8 +65,8 @@
;; (lambda (%1 &optional _&2 &3 &rest &*)
;; (foo %1 (bar &3) &*))
-;; Unused trailing arguments and mandatory unused arguments at the
-;; border between mandatory and optional arguments are also supported:
+;; Unused trailing arguments and mandatory unused arguments at the border
+;; between mandatory and optional arguments are also supported:
;;
;; (##list %1 _%3 &5 _&6)
;;
@@ -73,13 +75,9 @@
;; (lambda (%1 _%2 _%3 &optional _&4 &5 _&6)
;; (list %1 &5))
;;
-;; Note how `_%3' and `_&6' are removed from the body, because their
-;; names begin with an underscore. Also note that `_&4' is optional,
-;; unlike the explicitly specified `_%3'.
-
-;; The name `##' was chosen because that allows (optionally)
-;; omitting the whitespace between it and the following symbol.
-;; It also looks similar to #'function.
+;; Note how `_%3' and `_&6' are removed from the body, because their names
+;; begin with an underscore. Also note that `_&4' is optional, unlike the
+;; explicitly specified `_%3'.
;;; Code:
@@ -87,20 +85,28 @@
(defmacro llama (fn &rest body)
"Expand to a `lambda' expression that wraps around FN and BODY.
-This `lambda' expression calls the function FN with arguments
-BODY and returns its value. Its own arguments are derived from
-symbols found in BODY.
+This macro provides a compact way to write short `lambda' expressions.
+It expands to a `lambda' expression, which calls the function FN with
+arguments BODY and returns its value. The arguments of the `lambda'
+expression are derived from symbols found in BODY.
+
+Each symbol from `%1' through `%9', which appears in an unquoted part
+of BODY, specifies a mandatory argument. Each symbol from `&1' through
+`&9', which appears in an unquoted part of BODY, specifies an optional
+argument. The symbol `&*' specifies extra (`&rest') arguments.
-Each symbol from `%1' through `%9', which appears in BODY,
-specifies a mandatory argument. Each symbol from `&1' through
-`&9', which appears in BODY, specifies an optional argument.
-All arguments following an optional argument have to be optional
-as well, thus their names have to begin with `&'. Symbol `&*'
-specifies extra (`&rest') arguments.
+The shorter symbol `%' can be used instead of `%1', but using both in
+the same expression is not allowed. Likewise `&' can be used instead
+of `&1'. These shorthands are not recognized in function position.
-The shorter symbol `%' can be used instead of `%1', but using both
-in the same expression is not allowed. Likewise `&' can be used
-instead of `&1'.
+To support binding forms that use a vector as VARLIST (such as `-let'
+from the `dash' package), argument symbols are also detected inside of
+vectors.
+
+The space between `##' and FN can be omitted because `##' is read-syntax
+for the symbol whose name is the empty string. If you prefer you can
+place a space there anyway, and if you prefer to not use this somewhat
+magical symbol at all, you can instead use the alternative name `llama'.
Instead of:
@@ -116,8 +122,8 @@ which expands to:
(lambda (%1 &optional _&2 &3 &rest &*)
(foo %1 (bar &3) &*))
-Unused trailing arguments and mandatory unused arguments at the
-border between mandatory and optional arguments are also supported:
+Unused trailing arguments and mandatory unused arguments at the border
+between mandatory and optional arguments are also supported:
(##list %1 _%3 &5 _&6)
@@ -126,16 +132,9 @@ becomes:
(lambda (%1 _%2 _%3 &optional _&4 &5 _&6)
(list %1 &5))
-Note how `_%3' and `_&6' are removed from the body, because their
-names begin with an underscore. Also note that `_&4' is optional,
-unlike the explicitly specified `_%3'.
-
-The name `##' was chosen because that allows (optionally) omitting
-the whitespace between it and the following symbol. If you dislike
-this trickery, you can alternatively use this macro under the name
-`llama'. (It is also available under the name `\\#\\#', but the sole
-purpose of that is to allow using \"M-x describe-function RET ## RET\"
-to view this docstring.)"
+Note how `_%3' and `_&6' are removed from the body, because their names
+begin with an underscore. Also note that `_&4' is optional, unlike the
+explicitly specified `_%3'."
(cond ((symbolp fn))
((and (eq (car-safe fn) backquote-backquote-symbol)
(not body))
