{"record":{"id":"9c05b4647150bfbb","repo":"bevyengine/bevy","slug":"expected-an-identifier-got-0-instead","errorCode":null,"errorMessage":"expected an identifier, got '{0}' instead","messagePattern":"expected an identifier, got '(.+?)' instead","errorType":"exception","errorClass":"ParseError","httpStatus":null,"severity":"error","filePath":"crates/bevy_reflect/src/path/parse.rs","lineNumber":21,"sourceCode":"    num::ParseIntError,\n    str::from_utf8_unchecked,\n};\nuse thiserror::Error;\n\nuse super::{Access, ReflectPathError};\n\n/// An error that occurs when parsing reflect path strings.\n#[derive(Debug, PartialEq, Eq, Error)]\n#[error(transparent)]\npub struct ParseError<'a>(Error<'a>);\n\n/// A parse error for a path string.\n#[derive(Debug, PartialEq, Eq, Error)]\nenum Error<'a> {\n    #[error(\"expected an identifier, but reached end of path string\")]\n    NoIdent,\n\n    #[error(\"expected an identifier, got '{0}' instead\")]\n    ExpectedIdent(Token<'a>),\n\n    #[error(\"failed to parse index as integer\")]\n    InvalidIndex(#[from] ParseIntError),\n\n    #[error(\"a '[' wasn't closed, reached end of path string before finding a ']'\")]\n    Unclosed,\n\n    #[error(\"a '[' wasn't closed properly, got '{0}' instead\")]\n    BadClose(Token<'a>),\n\n    #[error(\"a ']' was found before an opening '['\")]\n    CloseBeforeOpen,\n}\n\npub(super) struct PathParser<'a> {\n    path: &'a str,\n    remaining: &'a [u8],","sourceCodeStart":3,"sourceCodeEnd":39,"githubUrl":"https://github.com/bevyengine/bevy/blob/396ca727080776bd313bb892423b7d94e03b81b4/crates/bevy_reflect/src/path/parse.rs#L3-L39","documentation":"This nested ParseError variant ExpectedIdent reports that the parser found a token where an identifier was required: it includes the offending token. It happens when a segment starts with something that is not an identifier — a number, ']', '[', '.', etc. — e.g. accessing tuple/struct elements by '.'-index instead of bracket syntax.","triggerScenarios":"Paths like \"foo.0\" (index written after a dot — must be \"foo[0]\"), \"0.foo\" (leading digit), or tokens like \"foo.]\" where a field name was expected; the message shows the exact bad token.","commonSituations":"Developers used to tuple-access syntax (tuple.0) applying it to reflect paths; concatenating segments that start with digits; copy-paste from JSONPath/JS expressions into reflect path strings.","solutions":["Replace dot-then-index with bracket syntax: \"foo.0\" becomes \"foo[0]\".","Ensure each segment begins with a valid identifier (letter/underscore, then alphanumerics/underscore).","Prefix numeric-named fields if the type genuinely has such names, or index them via brackets when they are tuple elements.","Inspect the token in the error message to see exactly what the parser saw."],"exampleFix":"// before\nlet x = tuple_struct.path::<f32>(\"fields.0\"); // ExpectedIdent: got '0'\n\n// after\nlet x = tuple_struct.path::<f32>(\"fields[0]\");","handlingStrategy":"try-catch","validationCode":"fn starts_with_ident_seg(p: &str) -> bool {\n    p.split('.').all(|seg| seg.chars().next().is_some_and(|c| c.is_alphabetic() || c == '_'))\n}","typeGuard":null,"tryCatchPattern":"match entity.reflect_path(path_str) {\n    Ok(el) => { /* ... */ }\n    Err(ReflectPathError::ParseError { offset, path, error }) => {\n        // error names the offending token, e.g. got '0'\n        warn!(\"'{path}' has a non-name token at {offset}: {error}\");\n    }\n    Err(other) => warn!(\"path failed: {other}\"),\n}","preventionTips":["Use bracket syntax for indices: 'foo[0]', never 'foo.0'.","Start every segment with a letter or underscore; translate JSONPath/JS-style paths before use."],"tags":["rust","bevy","bevy-reflect","reflect-path","parse-error","expected-ident"],"backgroundTag":"invalid-path-syntax","analyzedSha":"396ca727080776bd313bb892423b7d94e03b81b4","analyzedAt":"2026-08-20T16:12:39.808Z","contentChangedAt":"2026-08-20T16:12:39.808Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}