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

use nu_engine::CallExt;
use nu_protocol::ast::Call;
use nu_protocol::engine::{Command, EngineState, Stack};
use nu_protocol::{
    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Span, SyntaxShape,
    Type, Value,
};

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

impl Command for BytesCollect {
    fn name(&self) -> &str {
        "bytes collect"
    }

    fn signature(&self) -> Signature {
        Signature::build("bytes collect")
            .input_output_types(vec![(Type::List(Box::new(Type::Binary)), Type::Binary)])
            .optional(
                "separator",
                SyntaxShape::Binary,
                "optional separator to use when creating binary",
            )
            .category(Category::Bytes)
    }

    fn usage(&self) -> &str {
        "Concatenate multiple binary into a single binary, with an optional separator between each."
    }

    fn search_terms(&self) -> Vec<&str> {
        vec!["join", "concatenate"]
    }

    fn run(
        &self,
        engine_state: &EngineState,
        stack: &mut Stack,
        call: &Call,
        input: PipelineData,
    ) -> Result<PipelineData, ShellError> {
        let separator: Option<Vec<u8>> = call.opt(engine_state, stack, 0)?;
        // input should be a list of binary data.
        let mut output_binary = vec![];
        for value in input {
            match value {
                Value::Binary { mut val, .. } => {
                    output_binary.append(&mut val);
                    // manually concat
                    // TODO: make use of std::slice::Join when it's available in stable.
                    if let Some(sep) = &separator {
                        let mut work_sep = sep.clone();
                        output_binary.append(&mut work_sep)
                    }
                }
                // Explicitly propagate errors instead of dropping them.
                Value::Error { error } => return Err(*error),
                other => {
                    return Err(ShellError::OnlySupportsThisInputType {
                        exp_input_type: "binary".into(),
                        wrong_type: other.get_type().to_string(),
                        dst_span: call.head,
                        src_span: other.expect_span(),
                    });
                }
            }
        }

        match separator {
            None => Ok(Value::Binary {
                val: output_binary,
                span: call.head,
            }
            .into_pipeline_data()),
            Some(sep) => {
                if output_binary.is_empty() {
                    Ok(Value::Binary {
                        val: output_binary,
                        span: call.head,
                    }
                    .into_pipeline_data())
                } else {
                    // have push one extra separator in previous step, pop them out.
                    for _ in sep {
                        let _ = output_binary.pop();
                    }
                    Ok(Value::Binary {
                        val: output_binary,
                        span: call.head,
                    }
                    .into_pipeline_data())
                }
            }
        }
    }

    fn examples(&self) -> Vec<Example> {
        vec![
            Example {
                description: "Create a byte array from input",
                example: "[0x[11] 0x[13 15]] | bytes collect",
                result: Some(Value::Binary {
                    val: vec![0x11, 0x13, 0x15],
                    span: Span::test_data(),
                }),
            },
            Example {
                description: "Create a byte array from input with a separator",
                example: "[0x[11] 0x[33] 0x[44]] | bytes collect 0x[01]",
                result: Some(Value::Binary {
                    val: vec![0x11, 0x01, 0x33, 0x01, 0x44],
                    span: Span::test_data(),
                }),
            },
        ]
    }
}

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

        test_examples(BytesCollect {})
    }
}