Add edn::read example showing how to handle reading quoted s-expressi…

…ons.

Run clippy on examples in CI.

.github/workflows/check.yml

@@ -35,7 +35,7 @@ jobs:
  run: |
  cargo test --all-features --no-fail-fast --target ${{ matrix.target }}
  cargo test --features std --no-default-features --no-fail-fast --target ${{ matrix.target }}
- cargo run --example get-nth --target ${{ matrix.target }}
+ cargo test --examples --target ${{ matrix.target }}
 
  build_linux:
  name: Build Linux
@@ -114,7 +114,7 @@ jobs:
  run: |
  cargo test --all-features --no-fail-fast --target ${{ matrix.target }}
  cargo test --features std --no-default-features --no-fail-fast --target ${{ matrix.target }}
- cargo run --example get-nth --target ${{ matrix.target }}
+ cargo test --examples --target ${{ matrix.target }}
 
  build_embedded:
  name: Build Embedded
@@ -158,3 +158,4 @@ jobs:
  toolchain: stable minus 2 releases
  - run: cargo clippy --all-features -- --deny warnings
  - run: cargo clippy --no-default-features -- --deny warnings
+ - run: cargo clippy --examples -- --deny warnings -A clippy::unwrap-used

bb.edn

@@ -1,14 +1,14 @@
 {:tasks
  {:init (do (def code-cov-env
  {"CARGO_INCREMENTAL" "0"
- "RUSTFLAGS" "-Cinstrument-coverage -Copt-level=0 -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off"
+ "RUSTFLAGS"  "-Cinstrument-coverage -Copt-level=0 -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off"
  "LLVM_PROFILE_FILE" "target/coverage/cargo-test-%p-%m.profraw"}))
  :requires ([babashka.fs :as fs])
  clean {:doc "Removes target folder"
  :task (fs/delete-tree "target")}
  test_lib_features (shell "cargo test --all-features --no-fail-fast")
  test_lib_no_default_features (shell "cargo test --features std --no-default-features --no-fail-fast")
- test-examples (do (shell "cargo run --example get-nth"))
+ test-examples (do (shell "cargo test --examples"))
  cargo-test {:doc "Runs all cargo tests"
  :depends [test_lib_features test_lib_no_default_features test-examples]}
  cargo-fmt {:doc "Checks cargo fmt"
@@ -17,6 +17,8 @@
  :task (shell "cargo clippy --all-features -- --deny warnings")}
  cargo-clippy-no-defaults {:doc "Cargo clippy with no default features"
  :task (shell "cargo clippy --no-default-features -- --deny warnings")}
+ cargo-clippy-examples {:doc "Cargo clippy on examples"
+ :task (shell "cargo --examples -- --deny warnings -A clippy::unwrap-used")}
  clippy {:doc "Runs all variations of cargo clippy"
  :depends [cargo-clippy-all-features cargo-clippy-no-defaults]}
  cov-all-features {:doc "Coverage, all features"

examples/get-nth.rs

@@ -18,5 +18,11 @@ fn maybe_forty_two<'a>(edn: &'a Edn<'a>) -> Option<&Edn<'a>> {
 
 fn main() {
  let e = edn::read_string("{:foo {猫 {{:foo :bar} [1 2 42 3]}}}").unwrap();
- println!("{:?}", maybe_forty_two(&e));
+ let edn = maybe_forty_two(&e).unwrap();
+ assert_eq!(edn, &Edn::Int(42));
+}
+
+#[test]
+fn run() {
+ main();
 }

examples/read_quotes.rs

@@ -0,0 +1,62 @@
+use clojure_reader::edn::{self, Edn};
+
+// Recursively traverse the Edn struct.
+// To keep this example short, this only handles lists and literals.
+fn wrap_quote(edn: Edn<'_>) -> Edn<'_> {
+ match edn {
+ Edn::Symbol(s) => s.strip_prefix('\'').map_or(Edn::Symbol(s), |stripped| {
+ Edn::List(vec![Edn::Symbol("quote"), Edn::Symbol(stripped)])
+ }),
+ Edn::List(mut edn) => {
+ edn.reverse();
+ let mut list = vec![];
+
+ while let Some(e) = edn.pop() {
+ if e == Edn::Symbol("'") {
+ list.push(Edn::List(vec![Edn::Symbol("quote"), wrap_quote(edn.pop().unwrap())]));
+ } else {
+ list.push(wrap_quote(e));
+ }
+ }
+
+ return Edn::List(list);
+ }
+ _ => edn,
+ }
+}
+
+// Use `read` to handle the leading ' symbol.
+fn quotify(s: &str) -> Edn<'_> {
+ let (edn, rest) = edn::read(s).unwrap();
+
+ let edn = if edn == Edn::Symbol("'") {
+ Edn::List(vec![Edn::Symbol("quote"), edn::read_string(rest).unwrap()])
+ } else {
+ edn
+ };
+
+ let edn = wrap_quote(edn);
+ edn
+}
+
+fn main() {
+ let quoted = quotify("'(foo (bar '(a 'b)))");
+ assert_eq!(format!("{quoted}"), "(quote (foo (bar (quote (a (quote b))))))");
+
+ let quoted = quotify("(foo '(a))");
+ assert_eq!(format!("{quoted}"), "(foo (quote (a)))");
+
+ let quoted = quotify("'(foo the 'bar)");
+ assert_eq!(format!("{quoted}"), "(quote (foo the (quote bar)))");
+
+ let quoted = quotify("(foo the 'bar)");
+ assert_eq!(format!("{quoted}"), "(foo the (quote bar))");
+
+ let quoted = quotify("(foo the bar)");
+ assert_eq!(format!("{quoted}"), "(foo the bar)");
+}
+
+#[test]
+fn run() {
+ main();
+}

src/edn.rs

@@ -48,11 +48,12 @@ pub fn read_string(edn: &str) -> Result<Edn<'_>, error::Error> {
 ///
 /// # Errors
 ///
+/// Default behavior of Clojure's `read` is to throw an error on EOF, unlike `read_string`.
+/// https://clojure.github.io/tools.reader/#clojure.tools.reader.edn/read
+///
 /// See [`crate::error::Error`].
 pub fn read(edn: &str) -> Result<(Edn<'_>, &str), error::Error> {
  let r = parse::parse(edn)?;
- // Default behavior of Clojure's `read` is to throw an error on EOF, unlike `read_string`
- // https://clojure.github.io/tools.reader/#clojure.tools.reader.edn/read
  if r.0 == Edn::Nil && r.1.is_empty() {
  return Err(error::Error {
  code: error::Code::UnexpectedEOF,