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Diffstat (limited to 'third_party/lisp/npg/examples/python.lisp')
| -rw-r--r-- | third_party/lisp/npg/examples/python.lisp | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/third_party/lisp/npg/examples/python.lisp b/third_party/lisp/npg/examples/python.lisp new file mode 100644 index 0000000000..a45ac614f7 --- /dev/null +++ b/third_party/lisp/npg/examples/python.lisp @@ -0,0 +1,336 @@ +;;; python.lisp --- sample grammar definition for the Python language + +;;; Copyright (C) 2003 by Walter C. Pelissero + +;;; Author: Walter C. Pelissero <walter@pelissero.de> +;;; Project: NPG a Naive Parser Generator +;;; $Id: F-C1A8CD5961889C584B22F05E8B956006.lisp,v 1.3 2004/03/09 10:33:06 wcp Exp $ + +;;; This library is free software; you can redistribute it and/or +;;; modify it under the terms of the GNU Lesser General Public License +;;; as published by the Free Software Foundation; either version 2.1 +;;; of the License, or (at your option) any later version. +;;; This library is distributed in the hope that it will be useful, +;;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +;;; Lesser General Public License for more details. +;;; You should have received a copy of the GNU Lesser General Public +;;; License along with this library; if not, write to the Free +;;; Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA +;;; 02111-1307 USA + +;;; Commentary: +;;; +;;; This is far from being a complete Python grammar. Actually I +;;; haven't even read a Python book before starting to write this +;;; stuff, so the code below comes mostly from wild guessing while +;;; reading a Python source file. +;;; +;;; It's a design decision to avoid writing any transformation in this +;;; module; only tagging is done at this level. This improves the +;;; separation between parsing and transformation, making the grammar +;;; reusable for other purposes. + + +#+cmu (ext:file-comment "$Id: F-C1A8CD5961889C584B22F05E8B956006.lisp,v 1.3 2004/03/09 10:33:06 wcp Exp $") + +(in-package :grammar) + +(deflazy define-grammar + (let ((*package* #.*package*) + (*compile-print* (and parser::*debug* t))) + (reset-grammar) + (format t "~&creating Python grammar...~%") + (populate-grammar) + (let ((grammar (parser:generate-grammar))) + (reset-grammar) + (parser:print-grammar-figures grammar) + grammar))) + +(defun populate-grammar () + +(defrule program + := comment-string? statement+) + +(defrule comment-string + := string eol + :reduce string) + +;;; BOB = Beginning Of Block, EOB = End Of Block. It's lexical +;;; analyzer's task to find out where a statement or block starts/ends. + +(defrule suite + := statement-list eol + :reduce statement-list + := statement-block) + +(defrule commentable-suite + := statement-list eol + :reduce statement-list + := commented-statement-block) + +(defrule statement-block + := bob statement+ eob + :reduce $2) + +(defrule commented-statement-block + := bob comment-string? statement* eob + :reduce (cons comment-string statement)) + +(defrule statement-list + := (+ simple-statement ";") + :reduce (if (cdr $1) + (cons :statement-list $1) + (car $1))) + +(defrule statement + := statement-list eol + :reduce statement-list + := compound-statement) + +(defrule simple-statement + := import-statement + := raise-statement + := assignment + := function-call + := return-statement + := assert-statement + := pass-statement + := break-statement + := continue-statement) + +(defrule compound-statement + := class-definition + := method-definition + := try-statement + := if-statement + := while-statement + := for-statement) + +(defrule import-statement + := "import" (+ package-name ",") + :tag :import + := "from" package-name "import" (+ symbol-name ",") + :tag :import-from) + +(defrule package-name := identifier) + +(defrule symbol-name + := identifier + := "*") + +(defrule try-statement + := "try" ":" suite try-except-part* try-finally-part? + :tag :try) + +(defrule try-except-part + := "except" exception-subject? ":" suite) + +(defrule try-finally-part + := "finally" ":" suite) + +(defrule exception-subject + := exception-name exception-variable?) + +(defrule exception-variable + := "," identifier) + +(defrule exception-name := class-name) + +(defrule class-name := identifier) + +(defrule raise-statement + := "raise" + :tag :raise-same + := "raise" exception-name + :tag :raise + := "raise" exception-name "," expression + :tag :raise + := "raise" exception-name "(" expression ")" + :tag :raise) + +(defrule assignment + := (+ variable-with-optional-subscript ",") "=" more-assignment + :tag :set) + +(defrule more-assignment + := expression + := assignment) + +(defrule variable-with-optional-subscript + := variable-name subscript + :tag :subscript + := variable-name) + +(defrule variable-name + := (+ identifier ".") + :tag :varef) + +(defrule expression + := expression "or" expression1 + :tag :or + := expression1) + +(defrule expression1 + := expression1 "and" expression2 + :tag :and + := expression2) + +(defrule expression2 + := expression2 "==" expression3 + :tag :equal + := expression2 ">=" expression3 + :tag :more-equal + := expression2 "<=" expression3 + :tag :less-equal + := expression2 "!=" expression3 + :tag :not-equal + := expression2 ">" expression3 + :tag :more + := expression2 "<" expression3 + :tag :less + := expression2 "is" expression3 + :tag :equal + := expression2 "is" "not" expression3 + :tag :not-equal + := expression3) + +(defrule expression3 + := expression3 "+" expression4 + :tag :plus + := expression3 "-" expression4 + :tag :minus + := expression3 "|" expression4 + :tag :bit-or + := expression4) + +;; high priority expression +(defrule expression4 + := expression4 "*" expression5 + :tag :mult + := expression4 "/" expression5 + :tag :div + := expression4 "%" expression5 + :tag :modulo + := expression4 "&" expression5 + :tag :bit-and + := expression4 "in" expression5 + :tag :in + := expression5) + +(defrule expression5 + := "~" expression5 + :tag :bit-not + := "not" expression5 + :tag :not + := "(" expression ")" + := expression6) + +(defrule expression6 + := simple-expression subscript + :tag :subscript + := simple-expression) + +(defrule simple-expression + := function-call + := variable-name + := constant + := string-conversion + := list-constructor) + +(defrule subscript + := "[" expression "]" + := "[" expression ":" expression "]" + := "[" expression ":" "]" + :reduce (list expression nil) + := "[" ":" expression "]" + :reduce (list nil expression)) + +(defrule string-conversion + := "`" expression "`" + :tag :to-string) + +(defrule constant + := number + := string + := lambda-expression) + +(defrule number + := float + := integer) + +(defrule list-constructor + := "[" (* expression ",") "]" + :tag :make-list) + +(defrule class-definition + := "class" class-name superclasses? ":" commentable-suite + :tag :defclass) + +(defrule superclasses + := "(" class-name+ ")") + +(defrule method-definition + := "def" method-name "(" method-arguments ")" ":" commentable-suite + :tag :defmethod) + +(defrule method-arguments + := (* method-argument ",")) + +(defrule method-argument + := identifier argument-default?) + +(defrule argument-default + := "=" expression) + +(defrule method-name := identifier) + +(defrule if-statement + := "if" expression ":" suite elif-part* else-part? + :tag :if) + +(defrule else-part + := "else" ":" suite) + +(defrule elif-part + := "elif" expression ":" suite) + +(defrule lambda-expression + := "lambda" method-arguments ":" expression + :tag :lambda) + +(defrule function-call + := (+ identifier ".") "(" (* expression ",") ")" + :tag :funcall) + +(defrule for-statement + := "for" identifier "in" expression ":" suite + :tag :do-list + := "for" identifier "in" "range" "(" expression "," expression ")" ":" suite + :tag :do-range) + +(defrule while-statement + := "while" expression ":" suite + :tag :while) + +(defrule return-statement + := "return" expression? + :tag :return) + +(defrule assert-statement + := "assert" expression "," string + :tag :assert) + +(defrule pass-statement + := "pass" + :tag :pass) + +(defrule break-statement + := "break" + :tag :break) + +(defrule continue-statement + := "continue" + :tag :continue) + +) ; end of POPULATE-GRAMMAR |