| // Copyright 2015 The Vanadium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // Package query_parser is a parser to parse a simplified select statement (a la SQL) for the |
| // Vanadium key value store (a.k.a., syncbase). |
| // |
| // The select is of the form: |
| // |
| // <query_specification> ::= |
| // <select_clause> <from_clause> [<where_clause>] [<limit_offset_clause>] |
| // |
| // <select_clause> ::= SELECT <selector> [{<comma><selector>}...] |
| // |
| // <from_clause> ::= FROM <table> |
| // |
| // <where_clause> ::= WHERE <expression> |
| // |
| // <limit_offset_clause> ::= |
| // LIMIT <int_literal> [OFFSET <int_literal>] |
| // | OFFSET <int_literal> [LIMIT <int_literal>] |
| // |
| // <selector> ::= <column> [AS <string_literal>] |
| // |
| // <column> ::= |
| // k |
| // | v[<period><field>] |
| // | <function> |
| // |
| // <field> ::= <segment>[{<period><segment>}...] |
| // |
| // <segment> ::= <identifier>[<keys>] |
| // |
| // <keys> ::= <key>... |
| // |
| // <key> ::= <left_bracket> <operand> <right_bracket> |
| // |
| // <function> ::= <identifier><left_paren>[<operand>[{<comma><operand>}...]<right_paren> |
| // |
| // <table> ::= <identifier> |
| // |
| // <expression> ::= |
| // <left_paren> <expression> <right_paren> |
| // | <logical_expression> |
| // | <binary_expression> |
| // |
| // <logical_expression> ::= |
| // <expression> <logical_op> <expression> |
| // |
| // <logical_op> ::= |
| // AND |
| // | OR |
| // |
| // <binary_expression> ::= |
| // <operand> <binary_op> <operand> |
| // | v[<period><field>] IS [NOT] NIL |
| // |
| // <operand> ::= |
| // k |
| // | v[<period><field>] |
| // | <literal> |
| // | <function> |
| // |
| // <binary_op> ::= |
| // = |
| // | EQUAL |
| // | <> |
| // | NOT EQUAL |
| // | LIKE |
| // | NOT LIKE |
| // | < |
| // | <= |
| // | >= |
| // | > |
| // |
| // <literal> ::= |
| // <string_literal> |
| // | <bool_literal> |
| // | <int_literal> |
| // | <float_literal> |
| // |
| // Example: |
| // select v.Foo.Far, v.Baz[2] from Foobarbaz where Type(v) like "%.Customer" and (v.Foo = 42 and v.Bar not like "abc%) or (k >= "100" and k < "200") |
| package query_parser |
