;;;; -*- Mode: LISP; Syntax: ANSI-Common-Lisp; Base: 10 -*-
-;;;; ======================================================================
-;;;; File: package.lisp
-;;;; Updated: <04/04/2004 12:05:16 marcusp>
-;;;; ======================================================================
+;;;; *************************************************************************
;;;;
-;;;; Description ==========================================================
-;;;; ======================================================================
+;;;; $Id$
;;;;
-;;;; CLSQL-USQL square bracket symbolic query syntax. Functions for
+;;;; CLSQL square bracket symbolic query syntax. Functions for
;;;; enabling and disabling the syntax and for building SQL
;;;; expressions using the syntax.
;;;;
-;;;; ======================================================================
+;;;; This file is part of CLSQL.
+;;;;
+;;;; CLSQL users are granted the rights to distribute and use this software
+;;;; as governed by the terms of the Lisp Lesser GNU Public License
+;;;; (http://opensource.franz.com/preamble.html), also known as the LLGPL.
+;;;; *************************************************************************
(in-package #:clsql-sys)
-(defvar *original-reader-enter* nil)
-
-(defvar *original-reader-exit* nil)
+(defvar *original-readtable* nil)
(defvar *sql-macro-open-char* #\[)
;; Exported functions for disabling SQL syntax.
(defmacro disable-sql-reader-syntax ()
- "Turn off SQL square bracket syntax changing syntax state. Set state
-such that RESTORE-SQL-READER-SYNTAX-STATE will make the syntax
-disabled if it is consequently locally enabled."
+ "Turns off the SQL reader syntax setting the syntax state such
+that if the syntax is subsequently enabled,
+RESTORE-SQL-READER-SYNTAX-STATE will disable it again."
'(eval-when (:compile-toplevel :load-toplevel :execute)
- (setf *restore-sql-reader-syntax* nil)
- (%disable-sql-reader-syntax)))
+ (setf *restore-sql-reader-syntax* nil)
+ (%disable-sql-reader-syntax)))
(defmacro locally-disable-sql-reader-syntax ()
- "Turn off SQL square bracket syntax and do not change syntax state."
+ "Turns off the SQL reader syntax without changing the syntax
+state such that RESTORE-SQL-READER-SYNTAX-STATE will re-establish
+the current syntax state."
'(eval-when (:compile-toplevel :load-toplevel :execute)
(%disable-sql-reader-syntax)))
(defun %disable-sql-reader-syntax ()
- (when *original-reader-enter*
- (set-macro-character *sql-macro-open-char* *original-reader-enter*))
- (setf *original-reader-enter* nil)
+ (when *original-readtable*
+ (setf *readtable* *original-readtable*
+ *original-readtable* nil))
(values))
;; Exported functions for enabling SQL syntax.
(defmacro enable-sql-reader-syntax ()
- "Turn on SQL square bracket syntax changing syntax state. Set state
-such that RESTORE-SQL-READER-SYNTAX-STATE will make the syntax enabled
-if it is consequently locally disabled."
+ "Turns on the SQL reader syntax setting the syntax state such
+that if the syntax is subsequently disabled,
+RESTORE-SQL-READER-SYNTAX-STATE will enable it again."
'(eval-when (:compile-toplevel :load-toplevel :execute)
- (setf *restore-sql-reader-syntax* t)
- (%enable-sql-reader-syntax)))
+ (setf *restore-sql-reader-syntax* t)
+ (%enable-sql-reader-syntax)))
(defmacro locally-enable-sql-reader-syntax ()
- "Turn on SQL square bracket syntax and do not change syntax state."
+ "Turns on the SQL reader syntax without changing the syntax
+state such that RESTORE-SQL-READER-SYNTAX-STATE will re-establish
+the current syntax state."
'(eval-when (:compile-toplevel :load-toplevel :execute)
- (%enable-sql-reader-syntax)))
+ (%enable-sql-reader-syntax)))
(defun %enable-sql-reader-syntax ()
- (unless *original-reader-enter*
- (setf *original-reader-enter* (get-macro-character *sql-macro-open-char*)))
- (set-macro-character *sql-macro-open-char* #'sql-reader-open)
- (enable-sql-close-syntax)
+ (unless *original-readtable*
+ (setf *original-readtable* *readtable*
+ *readtable* (copy-readtable))
+ (set-macro-character *sql-macro-open-char* #'sql-reader-open)
+ (set-macro-character *sql-macro-close-char* (get-macro-character #\))))
(values))
(defmacro restore-sql-reader-syntax-state ()
- "Sets the enable/disable square bracket syntax state to reflect the
-last call to either DISABLE-SQL-READER-SYNTAX or
-ENABLE-SQL-READER-SYNTAX. The default state of the square bracket
-syntax is disabled."
+ "Enables the SQL reader syntax if ENABLE-SQL-READER-SYNTAX has
+been called more recently than DISABLE-SQL-READER-SYNTAX and
+otherwise disables the SQL reader syntax. By default, the SQL
+reader syntax is disabled."
'(eval-when (:compile-toplevel :load-toplevel :execute)
(if *restore-sql-reader-syntax*
(%enable-sql-reader-syntax)
(defun sql-reader-open (stream char)
(declare (ignore char))
(let ((sqllist (read-delimited-list #\] stream t)))
- (if (sql-operator (car sqllist))
- (cons (sql-operator (car sqllist)) (cdr sqllist))
- (apply #'generate-sql-reference sqllist))))
-
-;; Internal function that disables the close syntax when leaving sql context.
-(defun disable-sql-close-syntax ()
- (set-macro-character *sql-macro-close-char* *original-reader-exit*)
- (setf *original-reader-exit* nil))
-
-;; Internal function that enables close syntax when entering SQL context.
-(defun enable-sql-close-syntax ()
- (setf *original-reader-exit* (get-macro-character *sql-macro-close-char*))
- (set-macro-character *sql-macro-close-char* (get-macro-character #\))))
+ (unless *read-suppress*
+ (handler-case
+ (cond ((string= (write-to-string (car sqllist)) "||")
+ (cons (sql-operator 'concat-op) (cdr sqllist)))
+ ((and (= (length sqllist) 1) (eql (car sqllist) '*))
+ (apply #'generate-sql-reference sqllist))
+ ((sql-operator (car sqllist))
+ (cons (sql-operator (car sqllist)) (cdr sqllist)))
+ (t (apply #'generate-sql-reference sqllist)))
+ (sql-user-error (c)
+ (error 'sql-user-error
+ :message (format nil "Error ~A occured while attempting to parse '~A' at file position ~A"
+ (sql-user-error-message c) sqllist (file-position stream))))))))
(defun generate-sql-reference (&rest arglist)
- (cond ((= (length arglist) 1) ; string, table or attribute
- (if (stringp (car arglist))
- (sql-expression :string (car arglist))
- (sql-expression :attribute (car arglist))))
- ((<= 2 (length arglist))
- (let ((sqltype (if (keywordp (caddr arglist))
- (caddr arglist) nil))
- (sqlparam (if (keywordp (caddr arglist))
- (caddr arglist))))
- (cond
- ((stringp (cadr arglist))
- (sql-expression :table (car arglist)
- :alias (cadr arglist)
- :type sqltype))
- ((keywordp (cadr arglist))
- (sql-expression :attribute (car arglist)
- :type (cadr arglist)
- :params sqlparam))
- (t
- (sql-expression :attribute (cadr arglist)
- :table (car arglist)
- :params sqlparam
- :type sqltype)))))
- (t
- (error 'clsql-sql-syntax-error :reason "bad expression syntax"))))
-
-
-;; Exported functions for dealing with SQL syntax
+ (cond ((= (length arglist) 1) ; string, table or attribute
+ (if (stringp (car arglist))
+ (sql-expression :string (car arglist))
+ (sql-expression :attribute (car arglist))))
+ ((<= 2 (length arglist))
+ (let ((sqltype (when (keywordp (caddr arglist)) (caddr arglist) nil)))
+ (cond
+ ((stringp (cadr arglist))
+ (sql-expression :table (car arglist)
+ :alias (cadr arglist)
+ :type sqltype))
+ ((keywordp (cadr arglist))
+ (sql-expression :attribute (car arglist)
+ :type (cadr arglist)))
+ (t
+ (sql-expression :attribute (cadr arglist)
+ :table (car arglist)
+ :type sqltype)))))
+ (t
+ (error 'sql-user-error :message "bad expression syntax"))))
+
+
+;; Exported functions for dealing with SQL syntax
(defun sql (&rest args)
- "Generates SQL from a set of expressions given by ARGS. Each
-argument is translated into SQL and then the args are concatenated
-with a single space between each pair."
+ "Returns an SQL string generated from the expressions ARGS. The
+expressions are translated into SQL strings and then concatenated
+with a single space delimiting each expression. An error of type
+SQL-USER-ERROR is signalled if any element in ARGS is not of the
+supported types (a symbol, string, number or symbolic SQL
+expression) or a list or vector containing only these supported
+types."
(format nil "~{~A~^ ~}" (mapcar #'sql-output args)))
-(defun sql-expression (&key string table alias attribute type params)
- "Generates an SQL expression from the given keywords. Valid
-combinations of the arguments are: string; table; table and alias;
-table and attribute; table, attribute, and type; table or alias, and
-attribute; table or alias, and attribute and type; attribute; and
-attribute and type."
+(defun sql-expression (&key string table alias attribute type)
+ "Returns an SQL expression constructed from the supplied
+arguments which may be combined as follows: ATTRIBUTE and TYPE;
+ATTRIBUTE; ALIAS or TABLE and ATTRIBUTE and TYPE; ALIAS or TABLE
+and ATTRIBUTE; TABLE, ATTRIBUTE and TYPE; TABLE and ATTRIBUTE;
+TABLE and ALIAS; TABLE; and STRING. An error of type
+SQL-USER-ERROR is signalled if an unsupported combination of
+keyword arguments is specified."
(cond
(string
(make-instance 'sql :string string))
(attribute
(make-instance 'sql-ident-attribute :name attribute
:qualifier (or table alias)
- :type type
- :params params))
+ :type type))
((and table (not attribute))
(make-instance 'sql-ident-table :name table
:table-alias alias))))
-(defun sql-operator (operation)
- "Takes an SQL operator as an argument and returns the Lisp symbol
-for the operator."
- (typecase operation
+(defun sql-operator (operator)
+ "Returns the Lisp symbol corresponding to the SQL operator
+ represented by the symbol OPERATOR. If OPERATOR does not
+ represent a supported SQL operator or is not a symbol, nil is
+ returned."
+ (typecase operator
(string nil)
- (symbol (gethash (string-upcase (symbol-name operation))
- *sql-op-table*))))
-
-(defun sql-operation (operation &rest rest)
- "Generates an SQL statement from an operator and arguments."
- (if (sql-operator operation)
- (apply (symbol-function (sql-operator operation)) rest)
- (error "~A is not a recognized SQL operator." operation)))
+ (symbol (values (gethash (symbol-name-default-case (symbol-name operator))
+ *sql-op-table*)))))
+
+(defun sql-operation (operator &rest args)
+ "Returns an SQL expression constructed from the supplied symbol
+OPERATOR representing an SQL operator or function and its
+arguments ARGS. An error of type SQL-USER-ERROR is signalled if
+OPERATOR is not a symbol representing a supported SQL
+operator. If OPERATOR is passed the symbol FUNCTION then the
+first value in ARGS must be a string representing a valid SQL
+function and the remaining values in ARGS its arguments as
+strings."
+ (if (sql-operator operator)
+ (apply (symbol-function (sql-operator operator)) args)
+ (error 'sql-user-error
+ :message
+ (format nil "~A is not a recognized SQL operator." operator))))