rust: expose writer function and some new helpers (#80)

Author: tjdevries

bindings/rust/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "scip"
-version = "0.1.0"
+version = "0.1.1"
 edition = "2021"
 license = "Apache-2.0"
 description = """

bindings/rust/src/mod.rs

@@ -3,8 +3,29 @@
 // This will pull generated code into `scip::types`
 #[path = "generated/mod.rs"]
 mod scip_mod;
-
 pub use scip_mod::scip as types;
 
 // Exports symbol usage under scip::symbol namespace
 pub mod symbol;
+
+/// Write a message to a particular filepath.
+///
+/// This allows users of the SCIP library to not add protobuf as
+/// a direct dependency of the project (which can be useful to limit
+/// usage of protobuf elsewhere if not desired).
+pub fn write_message_to_file<P>(
+    path: P,
+    msg: impl protobuf::Message,
+) -> Result<(), Box<dyn std::error::Error>>
+where
+    P: AsRef<std::path::Path>,
+{
+    use std::io::Write;
+
+    let res = msg.write_to_bytes()?;
+    let output = std::fs::File::create(path)?;
+    let mut writer = std::io::BufWriter::new(output);
+    writer.write_all(&res)?;
+
+    Ok(())
+}

bindings/rust/src/symbol.rs

@@ -105,6 +105,12 @@ pub fn format_symbol(symbol: Symbol) -> String {
     format_symbol_with(symbol, SymbolFormatOptions::default())
 }
 
+impl Symbol {
+    pub fn new_local(id: usize) -> Self {
+        internal_local_symbol(id.to_string().as_str())
+    }
+}
+
 pub fn parse_symbol(symbol: &str) -> Result<Symbol, SymbolError> {
     fn dot(s: String) -> String {
         if s.as_str() == "." {
@@ -118,7 +124,7 @@ pub fn parse_symbol(symbol: &str) -> Result<Symbol, SymbolError> {
 
     let scheme = parser.accept_space_escaped_identifier("scheme")?;
     if scheme == "local" {
-        return Ok(new_local_symbol(
+        return Ok(internal_local_symbol(
             symbol
                 .chars()
                 .skip(parser.index)
@@ -338,7 +344,7 @@ impl SymbolParser {
     }
 }
 
-fn new_local_symbol(id: &str) -> Symbol {
+fn internal_local_symbol(id: &str) -> Symbol {
     let descriptor = Descriptor {
         name: id.to_string(),
         disambiguator: "".to_string(),
@@ -376,7 +382,7 @@ mod test {
     fn parses_local() {
         assert_eq!(
             parse_symbol("local a").expect("to parse local"),
-            new_local_symbol("a")
+            internal_local_symbol("a")
         );
     }