722 lines
19 KiB
Rust
722 lines
19 KiB
Rust
#![allow(
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clippy::needless_lifetimes,
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clippy::single_element_loop,
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clippy::uninlined_format_args
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)]
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#[macro_use]
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mod macros;
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use proc_macro2::{Delimiter, Group};
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use quote::{quote, ToTokens as _};
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use std::mem;
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use syn::punctuated::Punctuated;
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use syn::visit_mut::{self, VisitMut};
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use syn::{parse_quote, token, Expr, ExprRange, ExprTuple, Stmt, Token};
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#[test]
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fn test_expr_parse() {
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let tokens = quote!(..100u32);
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snapshot!(tokens as Expr, @r#"
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Expr::Range {
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limits: RangeLimits::HalfOpen,
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end: Some(Expr::Lit {
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lit: 100u32,
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}),
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}
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"#);
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let tokens = quote!(..100u32);
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snapshot!(tokens as ExprRange, @r#"
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ExprRange {
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limits: RangeLimits::HalfOpen,
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end: Some(Expr::Lit {
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lit: 100u32,
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}),
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}
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"#);
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}
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#[test]
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fn test_await() {
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// Must not parse as Expr::Field.
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let tokens = quote!(fut.await);
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snapshot!(tokens as Expr, @r#"
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Expr::Await {
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base: Expr::Path {
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path: Path {
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segments: [
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PathSegment {
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ident: "fut",
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},
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],
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},
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},
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}
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"#);
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}
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#[rustfmt::skip]
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#[test]
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fn test_tuple_multi_index() {
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let expected = snapshot!("tuple.0.0" as Expr, @r#"
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Expr::Field {
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base: Expr::Field {
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base: Expr::Path {
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path: Path {
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segments: [
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PathSegment {
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ident: "tuple",
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},
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],
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},
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},
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member: Member::Unnamed(Index {
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index: 0,
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}),
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},
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member: Member::Unnamed(Index {
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index: 0,
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}),
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}
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"#);
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for &input in &[
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"tuple .0.0",
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"tuple. 0.0",
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"tuple.0 .0",
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"tuple.0. 0",
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"tuple . 0 . 0",
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] {
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assert_eq!(expected, syn::parse_str(input).unwrap());
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}
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for tokens in [
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quote!(tuple.0.0),
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quote!(tuple .0.0),
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quote!(tuple. 0.0),
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quote!(tuple.0 .0),
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quote!(tuple.0. 0),
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quote!(tuple . 0 . 0),
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] {
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assert_eq!(expected, syn::parse2(tokens).unwrap());
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}
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}
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#[test]
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fn test_macro_variable_func() {
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// mimics the token stream corresponding to `$fn()`
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let path = Group::new(Delimiter::None, quote!(f));
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let tokens = quote!(#path());
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snapshot!(tokens as Expr, @r#"
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Expr::Call {
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func: Expr::Group {
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expr: Expr::Path {
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path: Path {
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segments: [
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PathSegment {
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ident: "f",
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},
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],
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},
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},
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},
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}
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"#);
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let path = Group::new(Delimiter::None, quote! { #[inside] f });
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let tokens = quote!(#[outside] #path());
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snapshot!(tokens as Expr, @r#"
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Expr::Call {
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attrs: [
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Attribute {
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style: AttrStyle::Outer,
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meta: Meta::Path {
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segments: [
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PathSegment {
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ident: "outside",
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},
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],
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},
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},
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],
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func: Expr::Group {
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expr: Expr::Path {
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attrs: [
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Attribute {
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style: AttrStyle::Outer,
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meta: Meta::Path {
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segments: [
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PathSegment {
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ident: "inside",
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},
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],
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},
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},
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],
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path: Path {
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segments: [
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PathSegment {
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ident: "f",
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},
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],
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},
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},
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},
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}
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"#);
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}
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#[test]
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fn test_macro_variable_macro() {
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// mimics the token stream corresponding to `$macro!()`
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let mac = Group::new(Delimiter::None, quote!(m));
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let tokens = quote!(#mac!());
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snapshot!(tokens as Expr, @r#"
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Expr::Macro {
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mac: Macro {
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path: Path {
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segments: [
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PathSegment {
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ident: "m",
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},
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],
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},
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delimiter: MacroDelimiter::Paren,
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tokens: TokenStream(``),
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},
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}
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"#);
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}
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#[test]
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fn test_macro_variable_struct() {
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// mimics the token stream corresponding to `$struct {}`
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let s = Group::new(Delimiter::None, quote! { S });
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let tokens = quote!(#s {});
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snapshot!(tokens as Expr, @r#"
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Expr::Struct {
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path: Path {
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segments: [
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PathSegment {
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ident: "S",
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},
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],
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},
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}
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"#);
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}
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#[test]
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fn test_macro_variable_unary() {
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// mimics the token stream corresponding to `$expr.method()` where expr is `&self`
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let inner = Group::new(Delimiter::None, quote!(&self));
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let tokens = quote!(#inner.method());
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snapshot!(tokens as Expr, @r#"
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Expr::MethodCall {
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receiver: Expr::Group {
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expr: Expr::Reference {
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expr: Expr::Path {
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path: Path {
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segments: [
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PathSegment {
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ident: "self",
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},
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],
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},
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},
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},
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},
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method: "method",
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}
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"#);
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}
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#[test]
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fn test_macro_variable_match_arm() {
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// mimics the token stream corresponding to `match v { _ => $expr }`
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let expr = Group::new(Delimiter::None, quote! { #[a] () });
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let tokens = quote!(match v { _ => #expr });
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snapshot!(tokens as Expr, @r#"
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Expr::Match {
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expr: Expr::Path {
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path: Path {
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segments: [
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PathSegment {
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ident: "v",
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},
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],
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},
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},
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arms: [
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Arm {
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pat: Pat::Wild,
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body: Expr::Group {
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expr: Expr::Tuple {
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attrs: [
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Attribute {
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style: AttrStyle::Outer,
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meta: Meta::Path {
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segments: [
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PathSegment {
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ident: "a",
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},
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],
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},
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},
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],
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},
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},
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},
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],
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}
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"#);
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let expr = Group::new(Delimiter::None, quote!(loop {} + 1));
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let tokens = quote!(match v { _ => #expr });
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snapshot!(tokens as Expr, @r#"
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Expr::Match {
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expr: Expr::Path {
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path: Path {
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segments: [
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PathSegment {
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ident: "v",
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},
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],
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},
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},
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arms: [
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Arm {
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pat: Pat::Wild,
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body: Expr::Group {
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expr: Expr::Binary {
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left: Expr::Loop {
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body: Block {
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stmts: [],
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},
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},
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op: BinOp::Add,
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right: Expr::Lit {
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lit: 1,
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},
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},
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},
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},
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],
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}
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"#);
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}
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// https://github.com/dtolnay/syn/issues/1019
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#[test]
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fn test_closure_vs_rangefull() {
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#[rustfmt::skip] // rustfmt bug: https://github.com/rust-lang/rustfmt/issues/4808
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let tokens = quote!(|| .. .method());
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snapshot!(tokens as Expr, @r#"
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Expr::MethodCall {
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receiver: Expr::Closure {
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output: ReturnType::Default,
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body: Expr::Range {
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limits: RangeLimits::HalfOpen,
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},
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},
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method: "method",
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}
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"#);
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}
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#[test]
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fn test_postfix_operator_after_cast() {
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syn::parse_str::<Expr>("|| &x as T[0]").unwrap_err();
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syn::parse_str::<Expr>("|| () as ()()").unwrap_err();
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}
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#[test]
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fn test_range_kinds() {
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syn::parse_str::<Expr>("..").unwrap();
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syn::parse_str::<Expr>("..hi").unwrap();
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syn::parse_str::<Expr>("lo..").unwrap();
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syn::parse_str::<Expr>("lo..hi").unwrap();
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syn::parse_str::<Expr>("..=").unwrap_err();
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syn::parse_str::<Expr>("..=hi").unwrap();
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syn::parse_str::<Expr>("lo..=").unwrap_err();
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syn::parse_str::<Expr>("lo..=hi").unwrap();
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syn::parse_str::<Expr>("...").unwrap_err();
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syn::parse_str::<Expr>("...hi").unwrap_err();
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syn::parse_str::<Expr>("lo...").unwrap_err();
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syn::parse_str::<Expr>("lo...hi").unwrap_err();
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}
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#[test]
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fn test_range_precedence() {
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snapshot!(".. .." as Expr, @r#"
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Expr::Range {
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limits: RangeLimits::HalfOpen,
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end: Some(Expr::Range {
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limits: RangeLimits::HalfOpen,
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}),
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}
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"#);
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snapshot!(".. .. ()" as Expr, @r#"
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Expr::Range {
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limits: RangeLimits::HalfOpen,
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end: Some(Expr::Range {
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limits: RangeLimits::HalfOpen,
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end: Some(Expr::Tuple),
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}),
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}
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"#);
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snapshot!("() .. .." as Expr, @r#"
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Expr::Range {
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start: Some(Expr::Tuple),
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limits: RangeLimits::HalfOpen,
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end: Some(Expr::Range {
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limits: RangeLimits::HalfOpen,
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}),
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}
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"#);
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// A range with a lower bound cannot be the upper bound of another range,
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// and a range with an upper bound cannot be the lower bound of another
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// range.
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syn::parse_str::<Expr>(".. x ..").unwrap_err();
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syn::parse_str::<Expr>("x .. x ..").unwrap_err();
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}
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#[test]
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fn test_ambiguous_label() {
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for stmt in [
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quote! {
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return 'label: loop { break 'label 42; };
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},
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quote! {
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break ('label: loop { break 'label 42; });
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},
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quote! {
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break 1 + 'label: loop { break 'label 42; };
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},
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quote! {
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break 'outer 'inner: loop { break 'inner 42; };
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},
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] {
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syn::parse2::<Stmt>(stmt).unwrap();
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}
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for stmt in [
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// Parentheses required. See https://github.com/rust-lang/rust/pull/87026.
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quote! {
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break 'label: loop { break 'label 42; };
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},
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] {
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syn::parse2::<Stmt>(stmt).unwrap_err();
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}
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}
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#[test]
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fn test_extended_interpolated_path() {
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let path = Group::new(Delimiter::None, quote!(a::b));
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let tokens = quote!(if #path {});
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snapshot!(tokens as Expr, @r#"
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Expr::If {
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cond: Expr::Group {
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expr: Expr::Path {
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path: Path {
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segments: [
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PathSegment {
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ident: "a",
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},
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Token![::],
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PathSegment {
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ident: "b",
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},
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],
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},
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},
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},
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then_branch: Block {
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stmts: [],
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},
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}
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"#);
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let tokens = quote!(#path {});
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snapshot!(tokens as Expr, @r#"
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Expr::Struct {
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path: Path {
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segments: [
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PathSegment {
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ident: "a",
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},
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Token![::],
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PathSegment {
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ident: "b",
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},
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],
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},
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}
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"#);
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let tokens = quote!(#path :: c);
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snapshot!(tokens as Expr, @r#"
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Expr::Path {
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path: Path {
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segments: [
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PathSegment {
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ident: "a",
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},
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Token![::],
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PathSegment {
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ident: "b",
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},
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Token![::],
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PathSegment {
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ident: "c",
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},
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],
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},
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}
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"#);
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let nested = Group::new(Delimiter::None, quote!(a::b || true));
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let tokens = quote!(if #nested && false {});
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snapshot!(tokens as Expr, @r#"
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Expr::If {
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cond: Expr::Binary {
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left: Expr::Group {
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expr: Expr::Binary {
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left: Expr::Path {
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path: Path {
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segments: [
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PathSegment {
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ident: "a",
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},
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Token![::],
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PathSegment {
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ident: "b",
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},
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],
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},
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},
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op: BinOp::Or,
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right: Expr::Lit {
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lit: Lit::Bool {
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value: true,
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},
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},
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},
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},
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op: BinOp::And,
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right: Expr::Lit {
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lit: Lit::Bool {
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value: false,
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},
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},
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},
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then_branch: Block {
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stmts: [],
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},
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}
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"#);
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}
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#[test]
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fn test_tuple_comma() {
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let mut expr = ExprTuple {
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attrs: Vec::new(),
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paren_token: token::Paren::default(),
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elems: Punctuated::new(),
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};
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snapshot!(expr.to_token_stream() as Expr, @"Expr::Tuple");
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expr.elems.push_value(parse_quote!(continue));
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// Must not parse to Expr::Paren
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snapshot!(expr.to_token_stream() as Expr, @r#"
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Expr::Tuple {
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elems: [
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Expr::Continue,
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Token![,],
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],
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}
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"#);
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expr.elems.push_punct(<Token![,]>::default());
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snapshot!(expr.to_token_stream() as Expr, @r#"
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Expr::Tuple {
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elems: [
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Expr::Continue,
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Token![,],
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],
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}
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"#);
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expr.elems.push_value(parse_quote!(continue));
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snapshot!(expr.to_token_stream() as Expr, @r#"
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Expr::Tuple {
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elems: [
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Expr::Continue,
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Token![,],
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Expr::Continue,
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],
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}
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"#);
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expr.elems.push_punct(<Token![,]>::default());
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snapshot!(expr.to_token_stream() as Expr, @r#"
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Expr::Tuple {
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elems: [
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Expr::Continue,
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Token![,],
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Expr::Continue,
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Token![,],
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],
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}
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"#);
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}
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|
#[test]
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fn test_binop_associativity() {
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// Left to right.
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snapshot!("() + () + ()" as Expr, @r#"
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Expr::Binary {
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left: Expr::Binary {
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left: Expr::Tuple,
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op: BinOp::Add,
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right: Expr::Tuple,
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},
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op: BinOp::Add,
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right: Expr::Tuple,
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}
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"#);
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// Right to left.
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snapshot!("() += () += ()" as Expr, @r#"
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Expr::Binary {
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left: Expr::Tuple,
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op: BinOp::AddAssign,
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right: Expr::Binary {
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left: Expr::Tuple,
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op: BinOp::AddAssign,
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right: Expr::Tuple,
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},
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}
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"#);
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|
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// Parenthesization is required.
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syn::parse_str::<Expr>("() == () == ()").unwrap_err();
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}
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#[test]
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fn test_assign_range_precedence() {
|
|
// Range has higher precedence as the right-hand of an assignment, but
|
|
// ambiguous precedence as the left-hand of an assignment.
|
|
snapshot!("() = () .. ()" as Expr, @r#"
|
|
Expr::Assign {
|
|
left: Expr::Tuple,
|
|
right: Expr::Range {
|
|
start: Some(Expr::Tuple),
|
|
limits: RangeLimits::HalfOpen,
|
|
end: Some(Expr::Tuple),
|
|
},
|
|
}
|
|
"#);
|
|
|
|
snapshot!("() += () .. ()" as Expr, @r#"
|
|
Expr::Binary {
|
|
left: Expr::Tuple,
|
|
op: BinOp::AddAssign,
|
|
right: Expr::Range {
|
|
start: Some(Expr::Tuple),
|
|
limits: RangeLimits::HalfOpen,
|
|
end: Some(Expr::Tuple),
|
|
},
|
|
}
|
|
"#);
|
|
|
|
syn::parse_str::<Expr>("() .. () = ()").unwrap_err();
|
|
syn::parse_str::<Expr>("() .. () += ()").unwrap_err();
|
|
}
|
|
|
|
#[test]
|
|
fn test_chained_comparison() {
|
|
// https://github.com/dtolnay/syn/issues/1738
|
|
let _ = syn::parse_str::<Expr>("a = a < a <");
|
|
let _ = syn::parse_str::<Expr>("a = a .. a ..");
|
|
let _ = syn::parse_str::<Expr>("a = a .. a +=");
|
|
|
|
let err = syn::parse_str::<Expr>("a < a < a").unwrap_err();
|
|
assert_eq!("comparison operators cannot be chained", err.to_string());
|
|
|
|
let err = syn::parse_str::<Expr>("a .. a .. a").unwrap_err();
|
|
assert_eq!("unexpected token", err.to_string());
|
|
|
|
let err = syn::parse_str::<Expr>("a .. a += a").unwrap_err();
|
|
assert_eq!("unexpected token", err.to_string());
|
|
}
|
|
|
|
#[test]
|
|
fn test_fixup() {
|
|
struct FlattenParens;
|
|
|
|
impl VisitMut for FlattenParens {
|
|
fn visit_expr_mut(&mut self, e: &mut Expr) {
|
|
while let Expr::Paren(paren) = e {
|
|
*e = mem::replace(&mut *paren.expr, Expr::PLACEHOLDER);
|
|
}
|
|
visit_mut::visit_expr_mut(self, e);
|
|
}
|
|
}
|
|
|
|
for tokens in [
|
|
quote! { 2 * (1 + 1) },
|
|
quote! { 0 + (0 + 0) },
|
|
quote! { (a = b) = c },
|
|
quote! { (x as i32) < 0 },
|
|
quote! { 1 + (x as i32) < 0 },
|
|
quote! { (1 + 1).abs() },
|
|
quote! { (lo..hi)[..] },
|
|
quote! { (a..b)..(c..d) },
|
|
quote! { (&mut fut).await },
|
|
quote! { &mut (x as i32) },
|
|
quote! { -(x as i32) },
|
|
quote! { if (S {} == 1) {} },
|
|
quote! { { (m! {}) - 1 } },
|
|
quote! { match m { _ => ({}) - 1 } },
|
|
quote! { if let _ = (a && b) && c {} },
|
|
quote! { if let _ = (S {}) {} },
|
|
quote! { break ('a: loop { break 'a 1 } + 1) },
|
|
quote! { a + (|| b) + c },
|
|
quote! { if let _ = ((break) - 1 || true) {} },
|
|
quote! { if let _ = (break + 1 || true) {} },
|
|
quote! { (break)() },
|
|
quote! { (..) = () },
|
|
quote! { (..) += () },
|
|
quote! { (1 < 2) == (3 < 4) },
|
|
quote! { { (let _ = ()) } },
|
|
] {
|
|
let original: Expr = syn::parse2(tokens).unwrap();
|
|
|
|
let mut flat = original.clone();
|
|
FlattenParens.visit_expr_mut(&mut flat);
|
|
let reconstructed: Expr = match syn::parse2(flat.to_token_stream()) {
|
|
Ok(reconstructed) => reconstructed,
|
|
Err(err) => panic!("failed to parse `{}`: {}", flat.to_token_stream(), err),
|
|
};
|
|
|
|
assert!(
|
|
original == reconstructed,
|
|
"original: {}\nreconstructed: {}",
|
|
original.to_token_stream(),
|
|
reconstructed.to_token_stream(),
|
|
);
|
|
}
|
|
}
|