aimx/inference/
key.rs

1//! Parsing of UPPERCASE inference keys used in AIM prompts and responses.
2//!
3//! Keys are UCIDs (`[A-Z_][A-Z0-9_]*`) with one of three suffix patterns:
4//! - `key_colon_eol`: `UCID ':'` optional whitespace, then end-of-line → multi-line body follows.
5//! - `key_eol`: `UCID` optional whitespace, then end-of-line → delimiter/marker line.
6//! - `key_colon`: `UCID ':'` → inline value on same line.
7
8use nom::{
9    IResult, Parser,
10    branch::alt,
11    bytes::complete::take_while,
12    character::complete::{char, multispace0, satisfy},
13    combinator::{map, recognize},
14    error::{Error, ErrorKind},
15    sequence::{pair, preceded},
16};
17use std::sync::Arc;
18
19/// Suffix patterns that follow an inference key.
20///
21/// Used by `parse_key` to describe how subsequent content is terminated.
22#[derive(Debug, PartialEq, Eq, Clone)]
23pub enum Suffix {
24    /// Key followed by colon and end-of-line.
25    /// Indicates a multi-line value on subsequent lines.
26    ColonEol,
27
28    /// Key followed by optional whitespace and end-of-line.
29    /// Used as a delimiter/marker line.
30    Eol,
31
32    /// Key followed by colon.
33    /// Indicates an inline value on the same line.
34    Colon,
35}
36
37/// Parse an uppercase identifier `UCID = [A-Z_][A-Z0-9_]*`.
38pub fn parse_ucid(input: &str) -> IResult<&str, Arc<str>> {
39    let (remain, ucid) = recognize(pair(
40        satisfy(|c: char| c.is_ascii_uppercase() || c == '_'),
41        take_while(|c: char| c.is_ascii_uppercase() || c.is_ascii_digit() || c == '_'),
42    ))
43    .parse(input)?;
44    Ok((remain, Arc::from(ucid)))
45}
46
47/// Check if there is no remaining content (end-of-line/input marker).
48fn check_eol(input: &str) -> IResult<&str, ()> {
49    if input.is_empty() {
50        Ok((input, ()))
51    } else {
52        Err(nom::Err::Error(Error::new(input, ErrorKind::Fail)))
53    }
54}
55
56/// Parse an inference key and classify its suffix.
57///
58/// Leading whitespace is skipped; returns `(key, Suffix)` with remaining input.
59pub fn parse_key(input: &str) -> IResult<&str, (Arc<str>, Suffix)> {
60    let (input, ucid) = preceded(multispace0, parse_ucid).parse(input)?;    
61    alt((
62        // key_colon_eol = UCID ':' S? EOL
63        map(
64            (char(':'), multispace0, check_eol),
65            |_| (ucid.clone(), Suffix::ColonEol)
66        ),
67        // key_eol = UCID S? EOL
68        map(
69            (multispace0, check_eol),
70            |_| (ucid.clone(), Suffix::Eol)
71        ),
72        // key_colon = UCID ':'
73        map(
74            char(':'),
75            |_| (ucid.clone(), Suffix::Colon)
76        ),
77    )).parse(input)
78}
aimx/inference/key.rs

aimx/inference/
key.rs
