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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
use nu_engine::command_prelude::*;
#[derive(Clone)]
pub struct Compact;
impl Command for Compact {
fn name(&self) -> &str {
"compact"
}
fn signature(&self) -> Signature {
Signature::build("compact")
.input_output_types(vec![(
Type::List(Box::new(Type::Any)),
Type::List(Box::new(Type::Any)),
)])
.switch(
"empty",
"also compact empty items like \"\", {}, and []",
Some('e'),
)
.rest(
"columns",
SyntaxShape::Any,
"The columns to compact from the table.",
)
.category(Category::Filters)
}
fn description(&self) -> &str {
"Creates a table with non-empty rows."
}
fn search_terms(&self) -> Vec<&str> {
vec!["empty", "remove"]
}
fn run(
&self,
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
) -> Result<PipelineData, ShellError> {
let empty = call.has_flag(engine_state, stack, "empty")?;
compact(engine_state, stack, call, input, empty)
}
fn examples(&self) -> Vec<Example> {
vec![
Example {
description: "Filter out all records where 'Hello' is null",
example: r#"[["Hello" "World"]; [null 3]] | compact Hello"#,
result: Some(Value::test_list(vec![])),
},
Example {
description: "Filter out all records where 'World' is null",
example: r#"[["Hello" "World"]; [null 3]] | compact World"#,
result: Some(Value::test_list(vec![Value::test_record(record! {
"Hello" => Value::nothing(Span::test_data()),
"World" => Value::test_int(3),
})])),
},
Example {
description: "Filter out all instances of null from a list",
example: r#"[1, null, 2] | compact"#,
result: Some(Value::test_list(vec![
Value::test_int(1),
Value::test_int(2),
])),
},
Example {
description: "Filter out all instances of null and empty items from a list",
example: r#"[1, null, 2, "", 3, [], 4, {}, 5] | compact --empty"#,
result: Some(Value::test_list(vec![
Value::test_int(1),
Value::test_int(2),
Value::test_int(3),
Value::test_int(4),
Value::test_int(5),
])),
},
]
}
}
pub fn compact(
engine_state: &EngineState,
stack: &mut Stack,
call: &Call,
input: PipelineData,
compact_empties: bool,
) -> Result<PipelineData, ShellError> {
let columns: Vec<String> = call.rest(engine_state, stack, 0)?;
let metadata = input.metadata();
input
.filter(
move |item| {
match item {
// Nothing is filtered out
Value::Nothing { .. } => false,
Value::Record { val, .. } => {
for column in columns.iter() {
match val.get(column) {
None => return false,
Some(x) => {
if let Value::Nothing { .. } = x {
return false;
}
if compact_empties {
// check if the value is one of the empty value
if match x {
Value::String { val, .. } => val.is_empty(),
Value::Record { val, .. } => val.is_empty(),
Value::List { vals, .. } => vals.is_empty(),
_ => false,
} {
// one of the empty value found so skip now
return false;
}
}
}
}
}
if compact_empties && val.is_empty() {
return false;
}
// No defined columns contained Nothing
true
}
Value::List { vals, .. } => {
if compact_empties && vals.is_empty() {
return false;
}
true
}
Value::String { val, .. } => {
if compact_empties && val.is_empty() {
return false;
}
true
}
// Any non-Nothing, non-record should be kept
_ => true,
}
},
engine_state.signals(),
)
.map(|m| m.set_metadata(metadata))
}
#[cfg(test)]
mod tests {
use super::Compact;
#[test]
fn examples_work_as_expected() {
use crate::test_examples;
test_examples(Compact {})
}
}