code: strinto

strinto/src/lib.rs

@@ -0,0 +1,62 @@
+extern crate proc_macro;
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, Expr, ExprStruct};
+
+/// # literal strings in a struct insantiation are converted .into().
+///
+/// ```rust
+/// use strinto::strinto;
+///    #[derive(Debug)]
+///    struct TestStruct {
+///        name: String,
+///        title: String,
+///        description: String,
+///        age: usize,
+///    }
+///
+///    let descr = "description";
+///
+///    let output = strinto!(TestStruct {
+///        name: "John", // Literal string.
+///        title: String::from("Wicked"),
+///        description: descr.to_string(),
+///        age: 30,
+///    });
+///
+///    let output_string = format!("{:?}", output);
+///    assert_eq!(
+///        output_string,
+///        "TestStruct { name: \"John\", title: \"Wicked\", description: \"description\", age: 30 }"
+///    );
+/// ```
+
+#[proc_macro]
+pub fn strinto(input: TokenStream) -> TokenStream {
+    let expr_struct = parse_macro_input!(input as ExprStruct);
+
+    // Extract struct name and fields
+    let struct_name = &expr_struct.path;
+    let fields = expr_struct.fields.iter().map(|field| {
+        let field_name = field.member.clone();
+        let field_value = &field.expr;
+        // Determine if the field value is a string literal and transform it
+        if let Expr::Lit(expr_lit) = field_value {
+            if let syn::Lit::Str(_) = expr_lit.lit {
+                quote! { #field_name: #field_value.into() }
+            } else {
+                quote! { #field_name: #field_value }
+            }
+        } else {
+            quote! { #field_name: #field_value }
+        }
+    });
+
+    let expanded = quote! {
+        #struct_name {
+            #(#fields,)*
+        }
+    };
+
+    expanded.into()
+}