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Diffstat (limited to 'syn/json/src/lib.rs')
| -rw-r--r-- | syn/json/src/lib.rs | 214 |
1 files changed, 0 insertions, 214 deletions
diff --git a/syn/json/src/lib.rs b/syn/json/src/lib.rs deleted file mode 100644 index e3546d9..0000000 --- a/syn/json/src/lib.rs +++ /dev/null @@ -1,214 +0,0 @@ -//! # Data structures that describe Syn's syntax tree. -//! -//! The Syn syntax tree is made up of more than 200 types. Occasionally it can -//! come up that you need to implement some behavior across them all. -//! -//! - For example [the Rust integration for AST Explorer][astexplorer] wants to -//! turn a syntax tree from Syn into a JavaScript value understood by the -//! platform's existing cross-language syntax tree visualization code. -//! -//! [astexplorer]: https://astexplorer.net/#/gist/388150a52f74d45a355d2b5e865ded96/0c6d563f28d900472f699c21a1845ad20ae9927f -//! -//! - As another example from within Syn itself, the traits and implementations -//! of the [`visit`], [`visit_mut`], and [`fold`] modules can be generated -//! programmatically from a description of the syntax tree. -//! -//! [`visit`]: https://docs.rs/syn/1.0/syn/visit/index.html -//! [`visit_mut`]: https://docs.rs/syn/1.0/syn/visit_mut/index.html -//! [`fold`]: https://docs.rs/syn/1.0/syn/fold/index.html -//! -//! To make this type of code as easy as possible to implement in any language, -//! every Syn release comes with a machine-readable description of that version -//! of the syntax tree as a JSON file [syn.json]. This `syn-codegen` crate -//! provides the canonical data structures for parsing and making use of the -//! representation in syn.json from Rust code. -//! -//! [syn.json]: https://raw.githubusercontent.com/dtolnay/syn/master/syn.json -//! -//! ## Example -//! -//! ``` -//! use syn_codegen::Definitions; -//! -//! # const IGNORE: &str = stringify! { -//! const SYN: &str = include_str!("syn.json"); -//! # }; -//! # const SYN: &str = include_str!("../../syn.json"); -//! -//! fn main() { -//! let defs: Definitions = serde_json::from_str(SYN).unwrap(); -//! -//! for node in &defs.types { -//! println!("syn::{}", node.ident); -//! } -//! } -//! ``` - -use indexmap::IndexMap; -use semver::Version; -use serde::{Deserialize, Deserializer, Serialize}; - -use std::collections::{BTreeMap, BTreeSet}; - -/// Top-level content of the syntax tree description. -#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)] -pub struct Definitions { - /// The Syn version whose syntax tree is described by this data. - pub version: Version, - - /// Syntax tree types defined by Syn. - pub types: Vec<Node>, - - /// Token types defined by Syn (keywords as well as punctuation). - /// - /// The keys in the map are the Rust type name for the token. The values in - /// the map are the printed token representation. - /// - /// These tokens are accessible in the Syn public API as `syn::token::#name` - /// or alternatively `syn::Token![#repr]`. - pub tokens: BTreeMap<String, String>, -} - -/// Syntax tree type defined by Syn. -#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)] -pub struct Node { - /// Name of the type. - /// - /// This type is accessible in the Syn public API as `syn::#name`. - pub ident: String, - - /// Features behind which this type is cfg gated. - pub features: Features, - - /// Content of the data structure. - #[serde( - flatten, - skip_serializing_if = "is_private", - deserialize_with = "private_if_absent" - )] - pub data: Data, - - #[serde(skip_serializing_if = "is_true", default = "bool_true")] - pub exhaustive: bool, -} - -/// Content of a syntax tree data structure. -#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)] -pub enum Data { - /// This is an opaque type with no publicy accessible structure. - Private, - - /// This type is a braced struct with named fields. - #[serde(rename = "fields")] - Struct(Fields), - - /// This type is an enum. - #[serde(rename = "variants")] - Enum(Variants), -} - -/// Fields of a braced struct syntax tree node with named fields. -/// -/// The keys in the map are the field names. -pub type Fields = IndexMap<String, Type>; - -/// Variants of an enum syntax tree node. -/// -/// The keys in the map are the variant names. -/// -/// Variants are unit variants if they hold no data and tuple variants -/// otherwise. The Syn syntax tree does not make use of braced variants. -pub type Variants = IndexMap<String, Vec<Type>>; - -/// Type of a struct field or tuple variant field in the syntax tree. -#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)] -#[serde(rename_all = "lowercase")] -pub enum Type { - /// Syntax tree type defined by Syn. - /// - /// This name will match the ident of some `Node`. - Syn(String), - - /// Type defined by the Rust language or standard library. - /// - /// All such types used by Syn are accessible in the Rust prelude and can be - /// used without a qualifying path in most Rust code. - Std(String), - - /// Type defined by proc-macro2. - /// - /// The type is accessible in the proc-macro2 public API as - /// `proc_macro2::#name`. - #[serde(rename = "proc_macro2")] - Ext(String), - - /// Keyword or punctuation token type defined by Syn. - /// - /// This name will match one of the keys in the `tokens` map. - Token(String), - - /// Grouping token defined by Syn. - /// - /// The type is accessible in the Syn public API as `syn::token::#name`. - Group(String), - - /// Punctuated list. - /// - /// This refers to `syn::punctuated::Punctuated<T, P>` with the specified - /// element type and punctuation. - Punctuated(Punctuated), - - /// `std::option::Option` - Option(Box<Type>), - - /// `std::boxed::Box` - Box(Box<Type>), - - /// `std::vec::Vec` - Vec(Box<Type>), - - /// Rust tuple with two or more fields. - Tuple(Vec<Type>), -} - -/// Type of a punctuated list. -/// -/// This refers to `syn::punctuated::Punctuated<#element, #punct>`. -/// -/// The punct string will match one of the keys in the `tokens` map. -#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)] -pub struct Punctuated { - pub element: Box<Type>, - pub punct: String, -} - -/// Features behind which a syntax tree type is cfg gated. -#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize)] -pub struct Features { - /// Type is accessible if at least one of these features is enabled against - /// the Syn dependency. - pub any: BTreeSet<String>, -} - -fn is_private(data: &Data) -> bool { - match data { - Data::Private => true, - Data::Struct(_) | Data::Enum(_) => false, - } -} - -fn private_if_absent<'de, D>(deserializer: D) -> Result<Data, D::Error> -where - D: Deserializer<'de>, -{ - let option = Option::deserialize(deserializer)?; - Ok(option.unwrap_or(Data::Private)) -} - -fn is_true(b: &bool) -> bool { - *b -} - -fn bool_true() -> bool { - true -} |