Quote symbolic arguments before formatting

Author: lionel-

crates/harp/src/exec.rs

@@ -472,6 +472,9 @@ pub fn r_source_exprs_in(exprs: impl Into<SEXP>, env: impl Into<SEXP>) -> crate:
     let exprs = exprs.into();
     let env = env.into();
 
+    // `exprs` is an EXPRSXP and doesn't need to be quoted when passed as
+    // literal argument. Only the R-level `eval()` function evaluates expression
+    // vectors.
     RFunction::new("base", "source")
         .param("exprs", exprs)
         .param("local", env)

crates/harp/src/utils.rs

@@ -14,6 +14,7 @@ use libr::*;
 use once_cell::sync::Lazy;
 use regex::Regex;
 
+use crate::call::r_expr_quote;
 use crate::call::RArgument;
 use crate::environment::Environment;
 use crate::environment::R_ENVS;
@@ -401,7 +402,9 @@ pub unsafe fn r_stringify(object: SEXP, delimiter: &str) -> Result<String> {
     }
 
     // call format on the object
-    let object = RFunction::new("base", "format").add(object).call()?;
+    let object = RFunction::new("base", "format")
+        .add(r_expr_quote(object))
+        .call()?;
 
     // paste into a single string
     let object = RFunction::new("base", "paste")