chore: remove unneeded dependencies

Signed-off-by: Henry Gressmann <mail@henrygressmann.de>

2 files changed, 19 insertions, 10 deletions

diff --git a/crates/tinywasm/Cargo.toml b/crates/tinywasm/Cargo.toml
index 807a19f..02ea1f5 100644
--- a/crates/tinywasm/Cargo.toml
+++ b/crates/tinywasm/Cargo.toml
@@ -7,11 +7,11 @@ edition="2021"
 path="src/lib.rs"
 
 [dependencies]
-thiserror={version="1.0", package="thiserror-core", default-features=false}
+# fork of wasmparser with no_std support, see https://github.com/bytecodealliance/wasmtime/issues/3495
+# TODO: create dependency free parser
 wasmparser={version="0.100", package="wasmparser-nostd", default-features=false}
 tracing={version="0.1.38", default-features=false} # logging
-hashbrown="0.14"
 
 [features]
 default=["std"]
-std=["thiserror/std"]
+std=[]
diff --git a/crates/tinywasm/src/error.rs b/crates/tinywasm/src/error.rs
index a253880..9b97a59 100644
--- a/crates/tinywasm/src/error.rs
+++ b/crates/tinywasm/src/error.rs
@@ -1,18 +1,27 @@
 use alloc::string::{String, ToString};
-use thiserror::Error;
+use core::fmt::Display;
 
-#[derive(Debug, Error)]
+#[derive(Debug)]
 pub enum Error {
-    #[error("error parsing module")]
     ParseError { message: String, offset: usize },
-
-    #[error("unsupported feature: {0}")]
     UnsupportedFeature(String),
-
-    #[error("unknown error: {0}")]
     Other(String),
 }
 
+impl Display for Error {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        match self {
+            Self::ParseError { message, offset } => {
+                write!(f, "error parsing module: {} at offset {}", message, offset)
+            }
+            Self::UnsupportedFeature(feature) => write!(f, "unsupported feature: {}", feature),
+            Self::Other(message) => write!(f, "unknown error: {}", message),
+        }
+    }
+}
+
+impl crate::std::error::Error for Error {}
+
 impl Error {
     pub fn other<T>(message: &str) -> Result<T, Self> {
         Err(Self::Other(message.to_string()))