risinglight 0.2.0

An OLAP database system for educational purpose
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

// Copyright 2022 RisingLight Project Authors. Licensed under Apache-2.0.

use super::expression::*;
use crate::types::DataValue;

pub trait ExprVisitor {
    fn visit_expr(&mut self, expr: &BoundExpr) {
        match expr {
            BoundExpr::Constant(v) => self.visit_constant(v),
            BoundExpr::ColumnRef(expr) => self.visit_column_ref(expr),
            BoundExpr::InputRef(expr) => self.visit_input_ref(expr),
            BoundExpr::BinaryOp(expr) => self.visit_binary_op(expr),
            BoundExpr::UnaryOp(expr) => self.visit_unary_op(expr),
            BoundExpr::TypeCast(expr) => self.visit_type_cast(expr),
            BoundExpr::AggCall(expr) => self.visit_agg_call(expr),
            BoundExpr::IsNull(expr) => self.visit_is_null(expr),
            BoundExpr::ExprWithAlias(expr) => self.visit_expr_with_alias(expr),
            BoundExpr::Alias(expr) => self.visit_alias(expr),
        }
    }

    fn visit_constant(&mut self, _: &DataValue) {}

    fn visit_column_ref(&mut self, _: &BoundColumnRef) {}

    fn visit_input_ref(&mut self, _: &BoundInputRef) {}

    fn visit_binary_op(&mut self, expr: &BoundBinaryOp) {
        self.visit_expr(expr.left_expr.as_ref());
        self.visit_expr(expr.right_expr.as_ref());
    }

    fn visit_unary_op(&mut self, expr: &BoundUnaryOp) {
        self.visit_expr(expr.expr.as_ref());
    }

    fn visit_type_cast(&mut self, expr: &BoundTypeCast) {
        self.visit_expr(expr.expr.as_ref());
    }

    fn visit_agg_call(&mut self, agg: &BoundAggCall) {
        for arg in &agg.args {
            self.visit_expr(arg);
        }
    }

    fn visit_is_null(&mut self, expr: &BoundIsNull) {
        self.visit_expr(expr.expr.as_ref());
    }

    fn visit_expr_with_alias(&mut self, expr: &BoundExprWithAlias) {
        self.visit_expr(expr.expr.as_ref());
    }

    fn visit_alias(&mut self, _: &BoundAlias) {}
}

pub trait ExprRewriter {
    fn rewrite_expr(&self, expr: &mut BoundExpr) {
        match expr {
            BoundExpr::Constant(_) => self.rewrite_constant(expr),
            BoundExpr::ColumnRef(_) => self.rewrite_column_ref(expr),
            BoundExpr::InputRef(_) => self.rewrite_input_ref(expr),
            BoundExpr::BinaryOp(_) => self.rewrite_binary_op(expr),
            BoundExpr::UnaryOp(_) => self.rewrite_unary_op(expr),
            BoundExpr::TypeCast(_) => self.rewrite_type_cast(expr),
            BoundExpr::AggCall(_) => self.rewrite_agg_call(expr),
            BoundExpr::IsNull(_) => self.rewrite_is_null(expr),
            BoundExpr::ExprWithAlias(_) => self.rewrite_expr_with_alias(expr),
            BoundExpr::Alias(_) => self.rewrite_alias(expr),
        }
    }

    fn rewrite_constant(&self, _: &mut BoundExpr) {}

    fn rewrite_column_ref(&self, _: &mut BoundExpr) {}

    fn rewrite_input_ref(&self, _: &mut BoundExpr) {}

    fn rewrite_binary_op(&self, expr: &mut BoundExpr) {
        match expr {
            BoundExpr::BinaryOp(expr) => {
                self.rewrite_expr(expr.left_expr.as_mut());
                self.rewrite_expr(expr.right_expr.as_mut());
            }
            _ => unreachable!(),
        }
    }

    fn rewrite_unary_op(&self, expr: &mut BoundExpr) {
        match expr {
            BoundExpr::UnaryOp(expr) => self.rewrite_expr(expr.expr.as_mut()),
            _ => unreachable!(),
        }
    }

    fn rewrite_type_cast(&self, expr: &mut BoundExpr) {
        match expr {
            BoundExpr::TypeCast(expr) => self.rewrite_expr(expr.expr.as_mut()),
            _ => unreachable!(),
        }
    }

    fn rewrite_agg_call(&self, agg: &mut BoundExpr) {
        match agg {
            BoundExpr::AggCall(agg) => {
                for arg in &mut agg.args {
                    self.rewrite_expr(arg);
                }
            }
            _ => unreachable!(),
        }
    }

    fn rewrite_is_null(&self, expr: &mut BoundExpr) {
        match expr {
            BoundExpr::IsNull(expr) => self.rewrite_expr(expr.expr.as_mut()),
            _ => unreachable!(),
        }
    }

    fn rewrite_expr_with_alias(&self, expr: &mut BoundExpr) {
        match expr {
            BoundExpr::ExprWithAlias(expr) => self.rewrite_expr(expr.expr.as_mut()),
            _ => unreachable!(),
        }
    }

    fn rewrite_alias(&self, _: &mut BoundExpr) {}
}