fn choose_dependencies<'a>(
    available_params: &ParamTypes,
    deps: &'a [(SelectKey, Vec<Entry>)],
  ) -> Result<Option<Vec<(&'a SelectKey, &'a Entry)>>, Diagnostic> {
    let mut combination = Vec::new();
    for (key, input_entries) in deps {
      let provided_param = match &key {
        &SelectKey::JustSelect(_) => None,
        &SelectKey::JustGet(ref g) => Some(&g.subject),
      };
      let satisfiable_entries = input_entries
        .iter()
        .filter(|input_entry| {
          input_entry
            .params()
            .iter()
            .all(|p| available_params.contains(p) || Some(p) == provided_param)
        })
        .collect::<Vec<_>>();

      let chosen_entries = Self::choose_dependency(satisfiable_entries);
      match chosen_entries.len() {
        0 => {
          return Ok(None);
        }
        1 => {
          combination.push((key, chosen_entries[0]));
        }
        _ => {
          return Err(Diagnostic::ambiguous(available_params, key, chosen_entries));
        }
      }
    }

    Ok(Some(combination))
  }
///
/// Given a set of available Params, choose one combination of satisfiable Entry dependencies if
/// it exists (it may not, because we're searching for sets of legal parameters in the powerset
/// of all used params).
///
/// If an ambiguity is detected in rule dependencies (ie, if multiple rules are satisfiable for
/// a single dependency key), fail with a Diagnostic.
///
Given a set of available Params, choose one combination of satisfiable Entry dependencies if
it exists (it may not, because we're searching for sets of legal parameters in the powerset
of all used params).

If an ambiguity is detected in rule dependencies , fail with a Diagnostic.
Given a set of available Params choose one combination of satisfiable Entry dependencies if it exists ( it may not because we ' re searching for sets of legal parameters in the powerset of all used params ) . If an ambiguity is detected in rule dependencies fail with a Diagnostic .
fn choose_dependencies<'a>(
    available_params: &ParamTypes,
    deps: &'a [(SelectKey, Vec<Entry>)],
  ) -> Result<Option<Vec<(&'a SelectKey, &'a Entry)>>, Diagnostic> {
    let mut combination = Vec::new();
    for (key, input_entries) in deps {
      let provided_param = match &key {
        &SelectKey::JustSelect(_) => None,
        &SelectKey::JustGet(ref g) => Some(&g.subject),
      };
      let satisfiable_entries = input_entries
        .iter()
        .filter(|input_entry| {
          input_entry
            .params()
            .iter()
            .all(|p| available_params.contains(p) || Some(p) == provided_param)
        })
        .collect::<Vec<_>>();
      let chosen_entries = Self::choose_dependency(satisfiable_entries);
      match chosen_entries.len() {
        0 => {
          return Ok(None);
        }
        1 => {
          combination.push((key, chosen_entries[0]));
        }
        _ => {
          return Err(Diagnostic::ambiguous(available_params, key, chosen_entries));
        }
      }
    }
    Ok(Some(combination))
  }
fn choose_dependencies < ' a > ( available_params : & ParamTypes , deps : & ' a [ ( SelectKey , Vec < Entry > ) ] , ) -> Result < Option < Vec < ( & ' a SelectKey , & ' a Entry ) > > , Diagnostic > { let mut combination = Vec :: new ( ) ; for ( key , input_entries ) in deps { let provided_param = match & key { & SelectKey :: JustSelect ( _ ) => None , & SelectKey :: JustGet ( ref g ) => Some ( & g . subject ) , } ; let satisfiable_entries = input_entries . iter ( ) . filter ( | input_entry | { input_entry . params ( ) . iter ( ) . all ( | p | available_params . contains ( p ) || Some ( p ) == provided_param ) } ) . collect :: < Vec < _ > > ( ) ; let chosen_entries = Self :: choose_dependency ( satisfiable_entries ) ; match chosen_entries . len ( ) { 0 => { return Ok ( None ) ; } 1 => { combination . push ( ( key , chosen_entries [ 0 ] ) ) ; } _ => { return Err ( Diagnostic :: ambiguous ( available_params , key , chosen_entries ) ) ; } } } Ok ( Some ( combination ) ) }
Given a set of available Params, choose one combination of satisfiable Entry dependencies if
it exists (it may not, because we're searching for sets of legal parameters in the powerset
of all used params).
Given a set of available Params choose one combination of satisfiable Entry dependencies if it exists ( it may not because we ' re searching for sets of legal parameters in the powerset of all used params ) .
available_params
&ParamTypes
deps
&'a [(SelectKey, Vec<Entry>)]
available_params
&ParamTypes
deps
&'a [(SelectKey, Vec<Entry>)]