change proc macro argument parsing to use syn

crates/generate/src/config.rs

@@ -0,0 +1,64 @@
+use std::path::PathBuf;
+
+use syn::{
+    bracketed,
+    parse::{Parse, ParseStream},
+    punctuated::Punctuated,
+    token, LitStr, Result, Token,
+};
+
+pub struct Config {
+    _bracket_token: token::Bracket,
+    path_lits: Punctuated<LitStr, Token![,]>,
+}
+
+impl Config {
+    pub fn witx_paths(&self) -> Vec<PathBuf> {
+        self.path_lits
+            .iter()
+            .map(|lit| PathBuf::from(lit.value()))
+            .collect()
+    }
+}
+
+impl Parse for Config {
+    fn parse(input: ParseStream) -> Result<Self> {
+        let content;
+        Ok(Config {
+            _bracket_token: bracketed!(content in input),
+            path_lits: content.parse_terminated(Parse::parse)?,
+        })
+    }
+}
+
+/*
+    let arg_strings = args
+        .into_iter()
+        .map(|arg| match arg {
+            TokenTree::Literal(lit) => string_literal(lit),
+            _ => bail!("expected string literal, got: {:?}", arg),
+        })
+        .collect::<Result<Vec<String>>>()?;
+
+    if arg_strings.is_empty() {
+        bail!("expected at least one argument");
+    }
+    Ok(arg_strings)
+}
+
+fn string_literal(literal: Literal) -> Result<String> {
+    let s = literal.to_string();
+    if !s.starts_with('"') || !s.ends_with('"') {
+        bail!("string literal must be enclosed in double quotes");
+    }
+
+    let trimmed = s[1..s.len() - 1].to_owned();
+    if trimmed.contains('"') {
+        bail!("string literal must not contain quotes");
+    }
+    if trimmed.contains('\\') {
+        bail!("string literal must not contain backslashes");
+    }
+    Ok(trimmed)
+}
+*/