[parser] More usability improvements

Implicit sequences in arguments, and now you can use terminals when
constructing regular expressions.

parser/parser.py

@@ -1807,14 +1807,23 @@ def seq(*args: Rule) -> Rule:
 
 
 def opt(*args: Rule) -> Rule:
+    """Mark a sequence as optional."""
     return AlternativeRule(seq(*args), Nothing)
 
 
 def mark(rule: Rule, **kwargs) -> Rule:
+    """Mark the specified rules with metadata."""
     return MetadataRule(rule, kwargs)
 
 
-def one_or_more(r: Rule) -> Rule:
+def one_or_more(*args: Rule) -> Rule:
+    """Generate a rule that matches a repetition of one or more of the specified
+    rule.
+
+    The resulting list is transparent, i.e., in the parse tree all of the members
+    of the list will be in-line with the parent. If you want to name the list
+    create a named nonterminal to contain it.
+    """
     global _CURRENT_DEFINITION
     global _CURRENT_GEN_INDEX
 
@@ -1822,7 +1831,7 @@ def one_or_more(r: Rule) -> Rule:
     def impl() -> Rule:
         nonlocal tail
         assert(tail is not None)
-        return opt(tail) + r
+        return opt(tail) + seq(*args)
 
     tail = NonTerminal(
         fn=impl,
@@ -1833,8 +1842,15 @@ def one_or_more(r: Rule) -> Rule:
 
     return tail
 
-def zero_or_more(r:Rule) -> Rule:
-    return opt(one_or_more(r))
+def zero_or_more(*args: Rule) -> Rule:
+    """Generate a rule that matches a repetition of zero or more of the specified
+    rule.
+
+    The resulting list is transparent, i.e., in the parse tree all of the members
+    of the list will be in-line with the parent. If you want to name the list
+    create a named nonterminal to contain it.
+    """
+    return opt(one_or_more(*args))
 
 @typing.overload
 def rule(f: typing.Callable, /) -> NonTerminal: ...
@@ -2155,11 +2171,25 @@ class Re:
     def question(self) -> "Re":
         return ReQuestion(self)
 
-    def __or__(self, value: "Re", /) -> "Re":
-        return ReAlt(self, value)
+    def __or__(self, value: "Re | Terminal", /) -> "Re":
+        if isinstance(value, Re):
+            other = value
+        elif isinstance(value.pattern, Re):
+            other = value.pattern
+        else:
+            other = Re.literal(value.pattern)
 
-    def __add__(self, value: "Re") -> "Re":
-        return ReSeq(self, value)
+        return ReAlt(self, other)
+
+    def __add__(self, value: "Re | Terminal") -> "Re":
+        if isinstance(value, Re):
+            other = value
+        elif isinstance(value.pattern, Re):
+            other = value.pattern
+        else:
+            other = Re.literal(value.pattern)
+
+        return ReSeq(self, other)
 
 
 UNICODE_MAX_CP = 1114112