linkrs-query 0.1.0

Query engine, parser, and executor for Linkrs
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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146

use crate::executor::expression::ExpressionError;
use linkrs_core::value::{DateTimeValue, DateValue, NullType};
use linkrs_core::Value;

pub(crate) fn execute_date_trunc(args: &[Value]) -> Result<Value, ExpressionError> {
    let precision = match &args[1] {
        Value::String(s) => s.as_str(),
        Value::Null(_) => return Ok(Value::Null(NullType::Null)),
        _ => {
            return Err(ExpressionError::type_error(
                "date_trunc precision must be a string",
            ))
        }
    };
    match &args[0] {
        Value::Date(d) => match precision {
            "year" => Ok(Value::Date(DateValue {
                year: d.year,
                month: 1,
                day: 1,
            })),
            "month" => Ok(Value::Date(DateValue {
                year: d.year,
                month: d.month,
                day: 1,
            })),
            "day" => Ok(Value::Date(DateValue {
                year: d.year,
                month: d.month,
                day: d.day,
            })),
            _ => Err(ExpressionError::type_error(format!(
                "Invalid date_trunc precision: {}",
                precision
            ))),
        },
        Value::DateTime(dt) => match precision {
            "year" => Ok(Value::DateTime(DateTimeValue {
                year: dt.year,
                month: 1,
                day: 1,
                hour: 0,
                minute: 0,
                sec: 0,
                microsec: 0,
            })),
            "month" => Ok(Value::DateTime(DateTimeValue {
                year: dt.year,
                month: dt.month,
                day: 1,
                hour: 0,
                minute: 0,
                sec: 0,
                microsec: 0,
            })),
            "day" => Ok(Value::DateTime(DateTimeValue {
                year: dt.year,
                month: dt.month,
                day: dt.day,
                hour: 0,
                minute: 0,
                sec: 0,
                microsec: 0,
            })),
            "hour" => Ok(Value::DateTime(DateTimeValue {
                year: dt.year,
                month: dt.month,
                day: dt.day,
                hour: dt.hour,
                minute: 0,
                sec: 0,
                microsec: 0,
            })),
            "minute" => Ok(Value::DateTime(DateTimeValue {
                year: dt.year,
                month: dt.month,
                day: dt.day,
                hour: dt.hour,
                minute: dt.minute,
                sec: 0,
                microsec: 0,
            })),
            "second" => Ok(Value::DateTime(DateTimeValue {
                year: dt.year,
                month: dt.month,
                day: dt.day,
                hour: dt.hour,
                minute: dt.minute,
                sec: dt.sec,
                microsec: 0,
            })),
            _ => Err(ExpressionError::type_error(format!(
                "Invalid date_trunc precision: {}",
                precision
            ))),
        },
        Value::Null(_) => Ok(Value::Null(NullType::Null)),
        _ => Err(ExpressionError::type_error(
            "date_trunc requires a date or datetime as first argument",
        )),
    }
}

pub(crate) fn execute_last_day(args: &[Value]) -> Result<Value, ExpressionError> {
    match &args[0] {
        Value::Date(d) => {
            let last_day = get_last_day(d.year, d.month);
            Ok(Value::Date(DateValue {
                year: d.year,
                month: d.month,
                day: last_day,
            }))
        }
        Value::DateTime(dt) => {
            let last_day = get_last_day(dt.year, dt.month);
            Ok(Value::DateTime(DateTimeValue {
                year: dt.year,
                month: dt.month,
                day: last_day,
                hour: dt.hour,
                minute: dt.minute,
                sec: dt.sec,
                microsec: dt.microsec,
            }))
        }
        Value::Null(_) => Ok(Value::Null(NullType::Null)),
        _ => Err(ExpressionError::type_error(
            "last_day requires a date or datetime argument",
        )),
    }
}

fn get_last_day(year: i32, month: u32) -> u32 {
    match month {
        1 | 3 | 5 | 7 | 8 | 10 | 12 => 31,
        4 | 6 | 9 | 11 => 30,
        2 => {
            if (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0) {
                29
            } else {
                28
            }
        }
        _ => 30,
    }
}