build(ariadne): vendor clap

third_party/crates/anstream-1.0.0/src/fmt.rs

@@ -0,0 +1,54 @@
+/// A shim which allows a [`std::io::Write`] to be implemented in terms of a [`std::fmt::Write`]
+///
+/// This saves off I/O errors. instead of discarding them
+pub(crate) struct Adapter<W>
+where
+    W: FnMut(&[u8]) -> std::io::Result<()>,
+{
+    writer: W,
+    error: std::io::Result<()>,
+}
+
+impl<W> Adapter<W>
+where
+    W: FnMut(&[u8]) -> std::io::Result<()>,
+{
+    pub(crate) fn new(writer: W) -> Self {
+        Adapter {
+            writer,
+            error: Ok(()),
+        }
+    }
+
+    pub(crate) fn write_fmt(mut self, fmt: std::fmt::Arguments<'_>) -> std::io::Result<()> {
+        match std::fmt::write(&mut self, fmt) {
+            Ok(()) => Ok(()),
+            Err(..) => {
+                // check if the error came from the underlying `Write` or not
+                if self.error.is_err() {
+                    self.error
+                } else {
+                    Err(std::io::Error::new(
+                        std::io::ErrorKind::Other,
+                        "formatter error",
+                    ))
+                }
+            }
+        }
+    }
+}
+
+impl<W> std::fmt::Write for Adapter<W>
+where
+    W: FnMut(&[u8]) -> std::io::Result<()>,
+{
+    fn write_str(&mut self, s: &str) -> std::fmt::Result {
+        match (self.writer)(s.as_bytes()) {
+            Ok(()) => Ok(()),
+            Err(e) => {
+                self.error = Err(e);
+                Err(std::fmt::Error)
+            }
+        }
+    }
+}