hl7_parser/message/
subcomponent.rs

1use super::Separators;
2use crate::display::SubcomponentDisplay;
3use std::ops::Range;
4
5/// A subcomponent is the smallest unit of data in an HL7 message.
6/// It is a string that may contain escape sequences to encode the separators.
7/// It is the only type that does not have a separator character.
8/// It is always contained within a component.
9///
10/// For parsing performance reasons, the subcomponent does not decode the escape
11/// sequences when it is parsed. Instead, the escape sequences are decoded when
12/// the subcomponent is displayed. This allows the subcomponent to be parsed
13/// without allocating a new string for the decoded value.
14#[derive(Debug, Clone, PartialEq, Eq)]
15#[cfg_attr(feature = "serde", derive(serde::Serialize))]
16pub struct Subcomponent<'m> {
17    /// The raw value of the subcomponent, including escape sequences
18    pub value: &'m str,
19    /// The range of the subcomponent in the original message
20    pub range: Range<usize>,
21}
22
23impl<'m> Subcomponent<'m> {
24    pub(crate) fn new_single(source: &'m str, range: Range<usize>) -> Self {
25        Subcomponent {
26            value: source,
27            range,
28        }
29    }
30
31    #[inline]
32    /// Display the subcomponent value, using the separators to decode escape sequences
33    /// by default. Note: if you want to display the raw value without decoding escape
34    /// sequences, use the `#` flag, e.g. `format!("{:#}", subcomponent.display(separators))`
35    ///
36    /// # Examples
37    ///
38    /// ```
39    /// use hl7_parser::message::{Separators, Subcomponent};
40    /// let separators = Separators::default();
41    ///
42    /// let subcomponent = Subcomponent {
43    ///     value: r"foo\F\bar",
44    ///     range: 0..1, // ignore
45    /// };
46    ///
47    /// assert_eq!(format!("{}", subcomponent.display(&separators)), "foo|bar");
48    /// assert_eq!(format!("{:#}", subcomponent.display(&separators)), r"foo\F\bar");
49    /// ```
50    pub fn display(&'m self, separators: &'m Separators) -> SubcomponentDisplay<'m> {
51        SubcomponentDisplay {
52            value: self.value,
53            separators,
54        }
55    }
56
57    #[inline]
58    /// Get the raw value of the subcomponent. This is the value as it appears in the message,
59    /// without any decoding of escape sequences.
60    pub fn raw_value(&self) -> &'m str {
61        self.value
62    }
63}
64
65#[cfg(test)]
66mod tests {
67    use super::*;
68
69    #[test]
70    fn subcomponents_can_display_raw() {
71        let separators = Separators::default();
72
73        let subcomponent = Subcomponent {
74            value: r"foo\F\bar",
75            range: 0..1, // ignore
76        };
77
78        assert_eq!(
79            format!("{:#}", subcomponent.display(&separators)),
80            r"foo\F\bar"
81        );
82    }
83
84    #[test]
85    fn subcomponents_can_display_decoded() {
86        let separators = Separators::default();
87
88        let subcomponent = Subcomponent {
89            value: r"foo\F\bar",
90            range: 0..1, // ignore
91        };
92
93        assert_eq!(format!("{}", subcomponent.display(&separators)), "foo|bar");
94    }
95}
hl7_parser/message/subcomponent.rs

hl7_parser/message/
subcomponent.rs
