vrl 0.32.0

Vector Remap Language
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

use crate::compiler::prelude::*;

#[derive(Clone, Copy, Debug)]
pub struct StripWhitespace;

impl Function for StripWhitespace {
    fn identifier(&self) -> &'static str {
        "strip_whitespace"
    }

    fn usage(&self) -> &'static str {
        "Strips whitespace from the start and end of `value`, where whitespace is defined by the [Unicode `White_Space` property](https://en.wikipedia.org/wiki/Unicode_character_property#Whitespace)."
    }

    fn category(&self) -> &'static str {
        Category::String.as_ref()
    }

    fn return_kind(&self) -> u16 {
        kind::BYTES
    }

    fn parameters(&self) -> &'static [Parameter] {
        const PARAMETERS: &[Parameter] = &[Parameter::required(
            "value",
            kind::BYTES,
            "The string to trim.",
        )];
        PARAMETERS
    }

    fn examples(&self) -> &'static [Example] {
        &[
            example! {
                title: "Strip whitespace",
                source: r#"strip_whitespace("  A sentence.  ")"#,
                result: Ok("A sentence."),
            },
            example! {
                title: "Start whitespace",
                source: r#"strip_whitespace("  foobar")"#,
                result: Ok("foobar"),
            },
            example! {
                title: "End whitespace",
                source: r#"strip_whitespace("foo bar  ")"#,
                result: Ok("foo bar"),
            },
            example! {
                title: "Newlines",
                source: r#"strip_whitespace("\n\nfoo bar\n  ")"#,
                result: Ok("foo bar"),
            },
        ]
    }

    fn compile(
        &self,
        _state: &state::TypeState,
        _ctx: &mut FunctionCompileContext,
        arguments: ArgumentList,
    ) -> Compiled {
        let value = arguments.required("value");

        Ok(StripWhitespaceFn { value }.as_expr())
    }
}

#[derive(Debug, Clone)]
struct StripWhitespaceFn {
    value: Box<dyn Expression>,
}

impl FunctionExpression for StripWhitespaceFn {
    fn resolve(&self, ctx: &mut Context) -> Resolved {
        let value = self.value.resolve(ctx)?;

        Ok(value.try_bytes_utf8_lossy()?.trim().into())
    }

    fn type_def(&self, _: &state::TypeState) -> TypeDef {
        TypeDef::bytes().infallible()
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    test_function![
        strip_whitespace => StripWhitespace;

        empty {
            args: func_args![value: ""],
            want: Ok(""),
            tdef: TypeDef::bytes().infallible(),
        }

        just_spaces {
            args: func_args![value: "      "],
            want: Ok(""),
            tdef: TypeDef::bytes().infallible(),
        }

        no_spaces {
            args: func_args![value: "hi there"],
            want: Ok("hi there"),
            tdef: TypeDef::bytes().infallible(),
        }

        spaces {
            args: func_args![value: "           hi there        "],
            want: Ok("hi there"),
            tdef: TypeDef::bytes().infallible(),
        }

        unicode_whitespace {
            args: func_args![value: " \u{3000}\u{205F}\u{202F}\u{A0}\u{9} ❤❤ hi there ❤❤  \u{9}\u{A0}\u{202F}\u{205F}\u{3000} "],
            want: Ok("❤❤ hi there ❤❤"),
            tdef: TypeDef::bytes().infallible(),
        }
    ];
}