organic/src/util/elisp/util.rs

76 lines
2.7 KiB
Rust
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use super::Token;
pub(crate) fn maybe_token_to_usize(
token: Option<&Token<'_>>,
) -> Result<Option<usize>, Box<dyn std::error::Error>> {
Ok(token
.map(|token| token.as_atom())
.map_or(Ok(None), |r| r.map(Some))?
.and_then(|val| {
if val == "nil" {
None
} else {
Some(val.parse::<usize>())
}
})
.map_or(Ok(None), |r| r.map(Some))?)
}
pub(crate) struct EmacsStandardProperties {
pub(crate) begin: Option<usize>,
#[allow(dead_code)]
pub(crate) post_affiliated: Option<usize>,
#[allow(dead_code)]
pub(crate) contents_begin: Option<usize>,
#[allow(dead_code)]
pub(crate) contents_end: Option<usize>,
pub(crate) end: Option<usize>,
#[allow(dead_code)]
pub(crate) post_blank: Option<usize>,
}
pub(crate) fn get_emacs_standard_properties(
emacs: &Token<'_>,
) -> Result<EmacsStandardProperties, Box<dyn std::error::Error>> {
let children = emacs.as_list()?;
let attributes_child = children.get(1).ok_or("Should have an attributes child.")?;
let attributes_map = attributes_child.as_map()?;
let standard_properties = attributes_map.get(":standard-properties");
Ok(if standard_properties.is_some() {
let mut std_props = standard_properties
.expect("if statement proves its Some")
.as_vector()?
.iter();
let begin = maybe_token_to_usize(std_props.next())?;
let post_affiliated = maybe_token_to_usize(std_props.next())?;
let contents_begin = maybe_token_to_usize(std_props.next())?;
let contents_end = maybe_token_to_usize(std_props.next())?;
let end = maybe_token_to_usize(std_props.next())?;
let post_blank = maybe_token_to_usize(std_props.next())?;
EmacsStandardProperties {
begin,
post_affiliated,
contents_begin,
contents_end,
end,
post_blank,
}
} else {
let begin = maybe_token_to_usize(attributes_map.get(":begin").copied())?;
let end = maybe_token_to_usize(attributes_map.get(":end").copied())?;
let contents_begin = maybe_token_to_usize(attributes_map.get(":contents-begin").copied())?;
let contents_end = maybe_token_to_usize(attributes_map.get(":contents-end").copied())?;
let post_blank = maybe_token_to_usize(attributes_map.get(":post-blank").copied())?;
let post_affiliated =
maybe_token_to_usize(attributes_map.get(":post-affiliated").copied())?;
EmacsStandardProperties {
begin,
post_affiliated,
contents_begin,
contents_end,
end,
post_blank,
}
})
}