# bibliography:
#   I.lex&yacc programming, ASCII, ISBN4-7561-0297-2
#  II.MySQL&mSQL, O'REILLY Japan, ISBN4-87311-011-4
# III.Ruby Pocket Reference, O'REILLY Japan, ISBN4-87311-023-8

class MSQLParser

	prechigh
		left '='
		left '<>' '<' '>' '<=' '>='
		left AND OR
	preclow

rule

	mSQL	:
					sql_list

	sql_list	:
					sql ';'
				| sql_list sql ';'

	sql	:
					create_statement
				| delete_statement
				| drop_statement
				| insert_statement
				| select_statement
				| update_statement


#CREATE statement

	create_statement	:
					create_table_statement
				| create_sequence_statement
				| create_index_statement

	create_table_statement	:
					CREATE TABLE table '(' field_def_list ')'

	field_def_list	:
					field_def
				| field_def_list ',' field_def

	field_def	:
					column data_type optional_attribute

	optional_attribute	:
					/* empty */
				| NOT NULL

	create_sequence_statement	:
					CREATE SEQUENCE ON table optional_step optional_value

	optional_step	:
					/* empty */
				| STEP FIXNUM

	optional_value	:
					/* empty */
				| VALUE FIXNUM

	create_index_statement	:
					CREATE INDEX index ON table '(' column_list ')'


#DELETE statement

	delete_statement	:
					DELETE FROM table optional_where_clause


#DROP statement

	drop_statement	:
					DROP INDEX index
				| DROP TABLE table
				| DROP SEQUENCE FROM table


#INSERT statement

	insert_statement	:
					INSERT INTO table optional_column_list VALUES '(' values ')'

	optional_column_list	:
					/* empty */
				| '(' column_list ')'

	values	:
					 atom_list


#SELECT statement

	select_statement	:
					SELECT optional_distinct_keyword column_list FROM table optional_order_by_clause optional_where_clause

	optional_distinct_keyword	:
					/* empty */
				| DISTINCT

	optional_order_by_clause	:
					/* empty */
				| ORDER BY ordering_list

	ordering_list	:
					ordering
				| ordering_list ',' ordering

	ordering	:
					column optional_desc

	optional_desc	:
						/* empty */
					| DESC


#UPDATE statement

	update_statement	:
					UPDATE table SET modify_expression_list optional_where_clause

	assignment_list	:
					assignment_expression
				| assignment_list ',' assignment_expression

	assignment_expression	:
					column '=' value

	value	:
					atom

#list

	atom_list	:
					atom
				| atom_list ',' atom

	column_list	:
					column_ref
				| column_list ',' column_ref


#WHERE clause

	optional_where_clause :
					/* empty */
				| where_clause

	where_clause	:
					WHERE condition

	condition	:
					condition AND condition
				| condition OR condition
				| '(' condition ')'
				| predicate

	predicate	:
					comparison_predicate
				| like_predicate

	comparison_predicate	:
					scalar_expression '=' scalar_expression
				| scalar_expression '<>' scalar_expression
				| scalar_expression '<=' scalar_expression
				| scalar_expression '<' scalar_expression
				| scalar_expression '>=' scalar_expression
				| scalar_expression '>' scalar_expression

	like_predicate	:
					scalar_expression LIKE scalar_expression
				| scalar_expression RLIKE scalar_expression
				| scalar_expression CLIKE scalar_expression

	scalar_expression	:
					atom
				| column_ref
				| '(' scalar_expression ')'

#data type

	data_type	:
					CHAR '(' length ')'
				| DATE
				| INT
				| MONEY
				| REAL
				| TEXT '(' length ')'
				| TIME
				| UINT

	length	:
					FIXNUM


#element

	atom	:
					FIXNUM
				| LITERAL

	column	:
					NAME

	column_ref	:
					NAME
				| NAME '.' NAME

	index	:
					NAME

	table	:
					NAME

end


---- header ----
#
# msql.rb : generated by racc
#

---- inner ----

	RESERVED = ['AND',   'BY',     'CHAR',  'CLIKE',  'CREATE',
							'DATE',  'DELETE', 'DESC',  'DROP',   'FROM',
							'INDEX', 'INSERT', 'INT',   'INTO',   'LIKE',
							'MONEY', 'NOT',    'NULL',  'ON',     'OR',
							'ORDER', 'REAL',   'RLIKE', 'SELECT', 'SEQUENCE',
							'SET',   'STEP',   'TABLE', 'TEXT',   'TIME',
							'UINT',  'UPDATE', 'VALUE', 'VALUES', 'WHERE']

	def parse( str )
		@q = []

		return nil if /\A\n/ =~ str

		while str.size > 0 do
			case str
			when /\A\s+/, /\A\n/
			when /\A\d+/
				@q.push [:FIXNUM, $&.to_i]
			when /\A\'.*\'/
				s = $&
				@q.push [:LITERAL, s]
			when /\A\w+/
				s = $&
				if RESERVED.include?(s.upcase)
					@q.push [eval(":#{s.upcase}"), s]
				else
					@q.push [:NAME, s]
				end
			when /\A./
				s = $&
				@q.push [s, s]
			end
			str = $'
		end
		@q.push [false, '$']

		do_parse
	end

	def next_token
		@q.shift
	end

	def on_error( err_tok, err_val, _values ) 
		p err_tok, err_val, _values
	end

---- footer ----

parser = MSQLParser.new

while line = ARGF.gets
	begin
		p parser.parse(line)
	rescue Racc::ParseError
		p $!
	end
end