init i guess

crates/lopal_json/src/syntax_kind.rs

@@ -0,0 +1,117 @@
+use logos::Logos;
+
+pub fn lex(src: &str) -> Vec<(SyntaxKind, &str)> {
+    let mut lex = SyntaxKind::lexer(src);
+    let mut r = Vec::new();
+
+    while let Some(tok_res) = lex.next() {
+        r.push((tok_res.unwrap_or(SyntaxKind::LEX_ERR), lex.slice()))
+    }
+
+    r
+}
+
+#[derive(enumset::EnumSetType, Debug, Logos, PartialEq, Eq, Clone, Copy, Hash)]
+#[repr(u16)]
+#[enumset(no_super_impls)]
+#[allow(non_camel_case_types)]
+pub enum SyntaxKind {
+    OBJECT,
+    MEMBER,
+    MEMBER_NAME,
+    MEMBER_VALUE,
+
+    ARRAY,
+    ELEMENT,
+
+    // SyntaxKinds for future json5/etc support
+    TRAILING_COMMA,
+
+    // Tokens
+    // Regexes adapted from [the logos handbook](https://logos.maciej.codes/examples/json_borrowed.html)
+    #[token("true")]
+    #[token("false")]
+    BOOL,
+    #[token("{")]
+    BRACE_OPEN,
+    #[token("}")]
+    BRACE_CLOSE,
+    #[token("[")]
+    BRACKET_OPEN,
+    #[token("]")]
+    BRACKET_CLOSE,
+    #[token(":")]
+    COLON,
+    #[token(",")]
+    COMMA,
+    #[token("null")]
+    NULL,
+    #[regex(r"-?(?:0|[1-9]\d*)(?:\.\d+)?(?:[eE][+-]?\d+)?")]
+    NUMBER,
+    #[regex(r#""([^"\\]|\\["\\bnfrt]|u[a-fA-F0-9]{4})*""#)]
+    STRING,
+
+    // Whitespace tokens
+    #[regex("[ \\t\\f]+")]
+    WHITESPACE,
+    #[token("\n")]
+    NEWLINE,
+
+    // Error SyntaxKinds
+    LEX_ERR,
+    PARSE_ERR,
+
+    // Meta SyntaxKinds
+    ROOT,
+    EOF,
+}
+
+impl lopal_core::parser::SyntaxElement for SyntaxKind {
+    const SYNTAX_EOF: Self = Self::EOF;
+
+    const SYNTAX_ERROR: Self = Self::PARSE_ERR;
+    const SYNTAX_ROOT: Self = Self::ROOT;
+}
+
+impl From<SyntaxKind> for rowan::SyntaxKind {
+    fn from(kind: SyntaxKind) -> Self {
+        Self(kind as u16)
+    }
+}
+
+impl From<rowan::SyntaxKind> for SyntaxKind {
+    fn from(raw: rowan::SyntaxKind) -> Self {
+        assert!(raw.0 <= SyntaxKind::EOF as u16);
+        #[allow(unsafe_code, reason = "The transmute is necessary here")]
+        unsafe {
+            std::mem::transmute::<u16, SyntaxKind>(raw.0)
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::syntax_kind::{lex, SyntaxKind};
+
+    #[test]
+    fn simple_object() {
+        const TEST_DATA: &str = r#"{"hello_world": "meow", "some_num":7.42}"#;
+
+        assert_eq!(
+            dbg!(lex(TEST_DATA)),
+            vec![
+                (SyntaxKind::BRACE_OPEN, "{"),
+                (SyntaxKind::STRING, "\"hello_world\""),
+                (SyntaxKind::COLON, ":"),
+                (SyntaxKind::WHITESPACE, " "),
+                (SyntaxKind::STRING, "\"meow\""),
+                (SyntaxKind::COMMA, ","),
+                (SyntaxKind::WHITESPACE, " "),
+                (SyntaxKind::STRING, "\"some_num\""),
+                (SyntaxKind::COLON, ":"),
+                (SyntaxKind::NUMBER, "7.42"),
+                (SyntaxKind::BRACE_CLOSE, "}")
+            ]
+        );
+    }
+}