khive_query/
language.rs

1//! Query language detection and dispatch.
2
3use crate::ast::GqlQuery;
4use crate::error::QueryError;
5use crate::parsers;
6use crate::parsers::sparql::leading_keyword;
7
8pub(crate) const GQL_WRITE_KEYWORDS: &[&str] = &[
9    "CREATE", "DELETE", "DETACH", "SET", "REMOVE", "MERGE", "INSERT", "UPDATE",
10];
11pub(crate) const SPARQL_WRITE_KEYWORDS: &[&str] = &[
12    "INSERT", "DELETE", "WITH", "LOAD", "CLEAR", "CREATE", "DROP", "COPY", "MOVE", "ADD",
13];
14pub(crate) const DEFAULT_HOP_CAP: usize = 5;
15
16pub(crate) fn read_only_error(constructor: fn(String) -> QueryError) -> QueryError {
17    constructor(
18        "the query verb is read-only; \
19         to mutate the graph use: create, update, link, merge, delete"
20            .into(),
21    )
22}
23
24/// Which query language the input is written in.
25#[derive(Clone, Copy, Debug, PartialEq, Eq)]
26pub enum QueryLanguage {
27    Gql,
28    Sparql,
29}
30
31/// Parses `input` as the selected language into a [`GqlQuery`].
32///
33/// # Errors
34///
35/// Returns [`QueryError`] when syntax is invalid, write-shaped, or unsupported.
36/// See `crates/khive-query/docs/api/parsing.md` for accepted dialect subsets.
37pub fn parse(language: QueryLanguage, input: &str) -> Result<GqlQuery, QueryError> {
38    match language {
39        QueryLanguage::Gql => parsers::gql::parse(input),
40        QueryLanguage::Sparql => parsers::sparql::parse(input),
41    }
42}
43
44/// Auto-detects SPARQL for `SELECT`, GQL for `MATCH`, and otherwise falls back to GQL.
45///
46/// Write-shaped input is rejected before dispatch, including SPARQL prologues.
47///
48/// # Errors
49///
50/// Returns [`QueryError`] when syntax is invalid, write-shaped, or unsupported.
51/// See `crates/khive-query/docs/api/parsing.md` for detection and guard behavior.
52pub fn parse_auto(input: &str) -> Result<GqlQuery, QueryError> {
53    parse_auto_with_language(input).map(|(_, query)| query)
54}
55
56/// Auto-detects and parses `input`, retaining the selected query language.
57///
58/// # Errors
59///
60/// Returns [`QueryError`] when syntax is invalid, write-shaped, or unsupported.
61pub fn parse_auto_with_language(input: &str) -> Result<(QueryLanguage, GqlQuery), QueryError> {
62    let trimmed = input.trim();
63    reject_write(trimmed)?;
64    let language = if trimmed
65        .as_bytes()
66        .get(..6)
67        .is_some_and(|p| p.eq_ignore_ascii_case(b"SELECT"))
68    {
69        QueryLanguage::Sparql
70    } else {
71        QueryLanguage::Gql
72    };
73    parse(language, trimmed).map(|query| (language, query))
74}
75
76/// Rejects GQL/Cypher mutations and SPARQL Update before dialect dispatch.
77fn reject_write(input: &str) -> Result<(), QueryError> {
78    let keyword = leading_keyword(input);
79    if GQL_WRITE_KEYWORDS.contains(&keyword.as_str())
80        || SPARQL_WRITE_KEYWORDS.contains(&keyword.as_str())
81    {
82        Err(read_only_error(QueryError::Unsupported))
83    } else {
84        Ok(())
85    }
86}
87
88#[cfg(test)]
89#[path = "language_tests.rs"]
90mod tests;
khive_query/language.rs

khive_query/
language.rs
