cleanup on reading predicates, add get_char/{1,2}

src/prolog/machine/machine_errors.rs

@@ -496,7 +496,7 @@ pub enum ValidType {
     Evaluable,
     Float,
     InByte,
-    //    InCharacter,
+    InCharacter,
     Integer,
     List,
     //    Number,
@@ -519,7 +519,7 @@ impl ValidType {
             ValidType::Evaluable => "evaluable",
             ValidType::Float => "float",
             ValidType::InByte => "in_byte",
-            //            ValidType::InCharacter => "in_character",
+            ValidType::InCharacter => "in_character",
             ValidType::Integer => "integer",
             ValidType::List => "list",
             //            ValidType::Number => "number",
@@ -555,7 +555,7 @@ impl DomainErrorType {
 // from 7.12.2 f) of 13211-1:1995
 #[derive(Debug, Clone, Copy)]
 pub enum RepFlag {
-    Character,
+    //    Character,
     CharacterCode,
     //    InCharacterCode,
     MaxArity,
@@ -566,7 +566,7 @@ pub enum RepFlag {
 impl RepFlag {
     pub fn as_str(self) -> &'static str {
         match self {
-            RepFlag::Character => "character",
+            //            RepFlag::Character => "character",
             RepFlag::CharacterCode => "character_code",
             //            RepFlag::InCharacterCode => "in_character_code",
             RepFlag::MaxArity => "max_arity",