# sql grammar, partial, based on ODBC 2.0 programmer's ref

## someday add subquery precedence to allow more general selects.

sqlrules = """

statement_list ::

@R stat1 :: statement_list >> statement
@R statn :: statement_list >> statement ; statement_list

@R dropindexstat :: statement >> drop_index_statement

@R createindexstat :: statement >> create_index_statement

@R selstat :: statement >> select_statement

@R insstat :: statement >> insert_statement

@R createtablestat :: statement >> create_table_statement

@R droptablestat :: statement >> drop_table_statement

@R delstat :: statement >> delete_statement_searched

@R updatestat :: statement >> update_statement_searched

@R createviewstat :: statement >> create_view_statement

@R dropviewstat :: statement >> drop_view_statement

## drop view statement
@R dropview :: drop_view_statement >> DROP VIEW user_defined_name

## create view statement
@R createview :: create_view_statement >> 
    CREATE VIEW user_defined_name optnamelist AS select_statement
@R optnamelist0 :: optnamelist >>
@R optnamelistn :: optnamelist >> ( namelist )
    
## drop index statement
@R dropindex :: drop_index_statement >> DROP INDEX user_defined_name

## create index statement
@R createindex :: create_index_statement >>
     CREATE INDEX user_defined_name
     ON user_defined_name
     ( namelist )
     
@R createuniqueindex :: create_index_statement >>
     CREATE UNIQUE INDEX user_defined_name
     ON user_defined_name
     ( namelist )
     
@R names1 :: namelist >> user_defined_name
@R namesn :: namelist >> namelist , user_defined_name

## update statement
@R update :: update_statement_searched >>
     UPDATE user_defined_name
     SET assns
     optwhere
     
@R assn1 :: assns >> assn
@R assnn :: assns >> assns , assn
@R assn :: assn >> column_identifier = expression

#####

## delete statement
@R deletefrom :: delete_statement_searched >> DELETE FROM user_defined_name optwhere

## drop table
@R droptable :: drop_table_statement >> DROP TABLE user_defined_name

## create table statement ( restricted )
@R createtable :: create_table_statement >>
    CREATE TABLE user_defined_name ( colelts )
@R colelts1 :: colelts >> colelt
@R coleltsn :: colelts >> colelts , colelt
@R coleltid :: colelt >> column_definition
@R coleltconstraint :: colelt >> column_constraint_definition
## column constraints deferred
@R coldef :: column_definition >> 
    column_identifier data_type optdefault optcolconstraints
## optdefault deferred
@R optdef0 :: optdefault >>
## optcolconstraint deferred
@R optcolconstr0 :: optcolconstraints >>
@R stringtype :: data_type >> character_string_type
@R exnumtype :: data_type >> exact_numeric_type
@R appnumtype :: data_type >> approximate_numeric_type
@R integer :: exact_numeric_type >> INTEGER
@R float :: approximate_numeric_type >> FLOAT
@R varchar :: character_string_type >> VARCHAR
@R varcharn :: character_string_type >> VARCHAR ( numeric_literal )

## insert statement

@R insert1 :: insert_statement >>
    INSERT INTO table_name optcolids insert_spec
@R optcolids0 :: optcolids >>
@R optcolids1 :: optcolids >> ( colids )
@R colids1 :: colids >> column_identifier
@R colidsn :: colids >> colids , column_identifier
@R insert_values :: insert_spec >> VALUES ( litlist )
@R insert_query :: insert_spec >> sub_query
@R litlist1 :: litlist >> sliteral
@R litlistn :: litlist >> litlist , sliteral
@R sliteral0 :: sliteral >> literal
@R sliteralp :: sliteral >> + literal

## hack to permit complexes

@R sliterals :: sliteral >> sliteral + literal
@R sliterald :: sliteral >> sliteral - literal
@R sliteralm :: sliteral >> - literal

## select statement

@R subselect :: sub_query >>
     SELECT alldistinct select_list
     FROM table_reference_list
     optwhere optgroup opthaving optunion
     
## @R psubselect :: sub_query >> ( sub_query ) 
     
@R selectx :: select_statement >>
     sub_query
     optorder_by
@R ad0 :: alldistinct >>
@R adall :: alldistinct >> ALL
@R addistinct :: alldistinct >> DISTINCT
@R where0 :: optwhere >>
@R where1 :: optwhere >> WHERE search_condition
@R group0 :: optgroup >> 
@R group1 :: optgroup >> GROUP BY colnamelist
@R colnames1 :: colnamelist >> column_name
@R colnamesn :: colnamelist >> colnamelist , column_name
@R having0 :: opthaving >>
@R having1 :: opthaving >> HAVING search_condition
@R union0 :: optunion >>
@R union1 :: optunion >> UNION alldistinct sub_query
@R except1 :: optunion >> EXCEPT sub_query
@R intersect1 :: optunion >> INTERSECT sub_query
@R order0 :: optorder_by >>
@R order1 :: optorder_by >> ORDER BY sortspeclist
##@R orderby :: order_by_clause >> ORDER BY sortspeclist
@R sortspec1 :: sortspeclist >> sort_specification
@R sortspecn :: sortspeclist >> sortspeclist , sort_specification
## really, should be unsigned int
@R sortint :: sort_specification >> numeric_literal opt_ord
@R sortcol :: sort_specification >> column_name opt_ord
@R optord0 :: opt_ord >>
@R optordasc :: opt_ord >> ASC
@R optorddesc :: opt_ord >> DESC

## table reference list (nasty hack alert)
@R trl1 :: table_reference_list >> user_defined_name
@R trln :: table_reference_list >> user_defined_name , table_reference_list
@R trl1a :: table_reference_list >> user_defined_name user_defined_name
@R trlna :: table_reference_list >> user_defined_name user_defined_name , table_reference_list
@R trl1as :: table_reference_list >> user_defined_name AS user_defined_name
@R trlnas :: table_reference_list >> user_defined_name AS user_defined_name , table_reference_list

## select list 
@R selectstar :: select_list >> *
@R selectsome :: select_list >> selectsubs
@R select1 :: selectsubs >> select_sublist
@R selectn :: selectsubs >> selectsubs , select_sublist
@R selectit :: select_sublist >> expression
@R selectname :: select_sublist >> expression AS column_alias
@R colalias :: column_alias >> user_defined_name

## search condition
@R search1 :: search_condition >> boolean_term
@R searchn :: search_condition >> boolean_term OR search_condition
@R bool1 :: boolean_term >> boolean_factor
@R booln :: boolean_term >> boolean_factor AND boolean_term
@R bf1 :: boolean_factor >> boolean_primary
@R notbf :: boolean_factor >> NOT boolean_primary
@R bp1 :: boolean_primary >> predicate
@R bps :: boolean_primary >> ( search_condition )

## predicate (simple for now!!!)
@R predicate1 :: predicate >> comparison_predicate

## comparison predicate (simple for now!!!)
@R predicateeq :: comparison_predicate >> expression = expression
@R predicatelt :: comparison_predicate >> expression < expression
@R predicategt :: comparison_predicate >> expression > expression
@R predicatele :: comparison_predicate >> expression < = expression
@R predicatege :: comparison_predicate >> expression > = expression
@R predicatene :: comparison_predicate >> expression < > expression
@R predbetween :: comparison_predicate >> expression BETWEEN expression AND expression
@R prednotbetween :: comparison_predicate >> 
     expression NOT BETWEEN expression AND expression

## exists predicate
@R predexists :: predicate >> exists_predicate
@R exists :: exists_predicate >> EXISTS ( sub_query )

## quantified predicate
@R predqeq :: predicate >> expression = allany ( sub_query )
@R predqne :: predicate >> expression < > allany ( sub_query )
@R predqlt :: predicate >> expression < allany ( sub_query )
@R predqgt :: predicate >> expression > allany ( sub_query )
@R predqle :: predicate >> expression < = allany ( sub_query )
@R predqge :: predicate >> expression > = allany ( sub_query )
@R nnall :: allany >> ALL
@R nnany :: allany >> ANY

## in predicate
@R predin :: predicate >> expression IN ( sub_query )
@R prednotin :: predicate >> expression NOT IN ( sub_query )
@R predinlits :: predicate >> expression IN ( litlist )
@R prednotinlits :: predicate >> expression NOT IN ( litlist )

## subquery expression
@R subqexpr :: expression >> ( sub_query )

## expression (simple for now!!!)
@R exp1 :: expression >> term
@R expplus :: expression >> expression + term
@R expminus :: expression >> expression - term
@R term1 :: term >> factor
@R termtimes :: term >> term * factor
@R termdiv :: term >> term / factor
@R factor1 :: factor >> primary
@R plusfactor :: factor >> + factor
@R minusfactor :: factor >> - factor
@R primary1 :: primary >> column_name
@R primarylit :: primary >> literal
@R primaryexp :: primary >> ( expression )
@R primaryset :: primary >> set_function_reference
@R stringlit :: literal >> character_string_literal
@R stringstring :: literal >> literal character_string_literal
@R numlit :: literal >> numeric_literal

## set functions (nasty hack!)
@R countstar :: set_function_reference >> COUNT ( * )
@R distinctcount :: set_function_reference >> COUNT ( DISTINCT expression )
@R allcount :: set_function_reference >> COUNT ( expression )
@R distinctset :: set_function_reference >> aggregate ( DISTINCT expression )
@R allset :: set_function_reference >> aggregate ( expression )
@R average :: aggregate >> AVG
##@R count :: aggregate >> COUNT
@R maximum :: aggregate >> MAX
@R minimum :: aggregate >> MIN
@R summation :: aggregate >> SUM
@R median :: aggregate >> MEDIAN

## dynamic parameter (varies quite a bit from ODBC spec)
@R dynamic :: literal >> ?

## column name
@R columnname1 :: column_name >> column_identifier
@R columnname2 :: column_name >> table_name . column_identifier
@R tablename1 :: table_name >> user_defined_name
@R columnid1 :: column_identifier >> user_defined_name
"""

nonterms = """
sliteral
exists_predicate set_function_reference aggregate
sortspeclist sort_specification opt_ord
drop_table_statement delete_statement_searched update_statement_searched
assns assn
insert_statement litlist colelt optcolconstraints optdefault
optcolids insert_spec create_table_statement
colids colelts column_constraint_definition
column_definition data_type character_string_type
exact_numeric_type approximate_numeric_type
expression term factor primary literal
comparison_predicate column_alias column_identifier table_name
boolean_term boolean_factor boolean_primary predicate
selectsubs expression alias sub_query
statement_list statement select_statement alldistinct subselect
select_list table_reference_list optwhere optgroup opthaving
order_by_clause select_sublist
optunion optorder_by search_condition colnamelist column_name
table_reference table_name create_index_statement namelist
drop_index_statement allany create_view_statement drop_view_statement
optnamelist
"""

keywords = """
INDEX ON ANY IN VIEW AS
EXCEPT INTERSECT
EXISTS AVG COUNT MAX MIN SUM MEDIAN
UPDATE DROP DELETE FROM SET
INSERT INTO VALUES CREATE TABLE INTEGER FLOAT VARCHAR
AND OR NOT
SELECT FROM WHERE HAVING GROUP BY UNION ALL DISTINCT AS ORDER
ASC DESC BETWEEN UNIQUE
"""

puncts = """.,*;=<>{}()?+-/"""

# terminals user_defined_name, character_string_literal,
#    numeric_literal