docstrings and other cleanup

codex-rs/execpolicy2/src/parser.rs

@@ -207,12 +207,11 @@ fn policy_builtins(builder: &mut GlobalsBuilder) {
         let rules: Vec<Rule> = first_token
             .alternatives()
             .iter()
-            .zip(std::iter::repeat(rest.clone()))
-            .map(|(head, rest)| {
+            .map(|head| {
                 Rule::Prefix(PrefixRule {
                     pattern: PrefixPattern {
                         first: Arc::from(head.as_str()),
-                        rest,
+                        rest: rest.clone(),
                     },
                     decision,
                 })

codex-rs/execpolicy2/src/policy.rs

@@ -59,6 +59,7 @@ impl Evaluation {
     }
 }
 
+/// Count how many rules match each provided example and error if any example is unmatched.
 pub(crate) fn validate_match_examples(rules: &[Rule], matches: &[Vec<String>]) -> Result<()> {
     let match_counts = rules.iter().fold(vec![0; matches.len()], |counts, rule| {
         counts
@@ -71,10 +72,15 @@ pub(crate) fn validate_match_examples(rules: &[Rule], matches: &[Vec<String>]) -
     let unmatched_examples: Vec<String> = matches
         .iter()
         .zip(&match_counts)
-        .filter(|(_, count)| **count == 0)
-        .map(|(example, _)| {
-            try_join(example.iter().map(String::as_str))
-                .unwrap_or_else(|_| "unable to render example".to_string())
+        .filter_map(|(example, count)| {
+            if *count == 0 {
+                Some(
+                    try_join(example.iter().map(String::as_str))
+                        .unwrap_or_else(|_| "unable to render example".to_string()),
+                )
+            } else {
+                None
+            }
         })
         .collect();
 

codex-rs/execpolicy2/src/rule.rs

@@ -139,6 +139,7 @@ impl Rule {
         }
     }
 
+    /// Return a boolean for each example indicating whether this rule matches it.
     pub fn validate_matches(&self, matches: &[Vec<String>]) -> Vec<bool> {
         match self {
             Self::Prefix(rule) => rule.validate_matches(matches),

codex-rs/execpolicy2/tests/basic.rs

@@ -1,7 +1,6 @@
 use std::sync::Arc;
 
 use codex_execpolicy2::Decision;
-use codex_execpolicy2::Error;
 use codex_execpolicy2::Evaluation;
 use codex_execpolicy2::PolicyParser;
 use codex_execpolicy2::Rule;