1 #pragma once
2 
3 #include "filter_expr_parser_ast.hpp"
4 
5 #include <boost/spirit/home/x3.hpp>
6 
7 namespace redfish::filter_grammar
8 {
9 
10 // The below rules very intentionally use the same naming as section 7.3.4 of
11 // the redfish specification and are declared in the order of the precedence
12 // that the standard requires.
13 
14 namespace details
15 {
16 using boost::spirit::x3::char_;
17 using boost::spirit::x3::int64;
18 using boost::spirit::x3::lexeme;
19 using boost::spirit::x3::lit;
20 using boost::spirit::x3::real_parser;
21 using boost::spirit::x3::rule;
22 using boost::spirit::x3::strict_real_policies;
23 using boost::spirit::x3::symbols;
24 
25 using filter_ast::BooleanOp;
26 using filter_ast::Comparison;
27 using filter_ast::ComparisonOpEnum;
28 using filter_ast::LogicalAnd;
29 using filter_ast::LogicalNot;
30 using filter_ast::LogicalOr;
31 using filter_ast::QuotedString;
32 using filter_ast::UnquotedString;
33 
34 // Clang format makes a mess of these rules and makes them hard to read
35 // clang-format on
36 
37 // Basic argument types
38 const rule<class QuotedStringId, QuotedString> quotedString("QuotedString");
39 const rule<class UnquotedStrId, UnquotedString> unquotedString("UnquotedStr");
40 
41 // Value comparisons -> boolean (value eq value) (value lt number)
42 const rule<class BooleanOpId, BooleanOp> booleanOp("BooleanOp");
43 const rule<class ComparisonId, Comparison> comparison("Comparison");
44 
45 // Logical Comparisons (bool eq bool)
46 const rule<class LogicalAndId, LogicalAnd> logicalAnd("LogicalAnd");
47 const rule<class LogicalOrId, LogicalOr> logicalOr("LogicalOr");
48 const rule<class LogicalNotId, LogicalNot> logicalNot("LogicalNot");
49 
50 ///// BEGIN GRAMMAR
51 
52 // Two types of strings.
53 const auto quotedString_def =
54     '\'' >> lexeme[*('\\' >> char_ | ~char_('\''))] >> '\'';
55 const auto unquotedString_def = char_("a-zA-Z") >> *(char_("a-zA-Z0-9[]/"));
56 
57 // Make sure we only parse true floating points as doubles
58 // This requires we have a "." which causes 1 to parse as int64, and 1.0 to
59 // parse as double
60 constexpr const real_parser<double, strict_real_policies<double>> strictDouble;
61 
62 // Argument
63 const auto arg = strictDouble | int64 | unquotedString | quotedString;
64 
65 // Greater Than/Less Than/Equals
66 const symbols<ComparisonOpEnum> compare{
67     {"gt", ComparisonOpEnum::GreaterThan},
68     {"ge", ComparisonOpEnum::GreaterThanOrEqual},
69     {"lt", ComparisonOpEnum::LessThan},
70     {"le", ComparisonOpEnum::LessThanOrEqual},
71     {"ne", ComparisonOpEnum::NotEquals},
72     {"eq", ComparisonOpEnum::Equals}};
73 
74 // Note, unlike most other comparisons, spaces are required here (one or more)
75 // to differentiate keys from values (ex Fooeq eq foo)
76 const auto comparison_def =
77     lexeme[arg >> +lit(' ') >> compare >> +lit(' ') >> arg];
78 
79 // Parenthesis
80 const auto parens = lit('(') >> logicalAnd >> lit(')');
81 
82 // Logical values
83 const auto booleanOp_def = comparison | parens;
84 
85 // Not
86 const auto logicalNot_def = -(char_('n') >> lit("ot")) >> booleanOp;
87 
88 // Or
89 const auto logicalOr_def = logicalNot >> *(lit("or") >> logicalNot);
90 
91 // And
92 const auto logicalAnd_def = logicalOr >> *(lit("and") >> logicalOr);
93 
94 BOOST_SPIRIT_DEFINE(booleanOp, logicalAnd, logicalNot, logicalOr, quotedString,
95                     comparison, unquotedString);
96 ///// END GRAMMAR
97 
98 // Make the grammar and AST available outside of the system
99 static constexpr auto& grammar = logicalAnd;
100 using program = filter_ast::LogicalAnd;
101 
102 } // namespace details
103 
104 using details::grammar;
105 using details::program;
106 
107 } // namespace redfish::filter_grammar
108