document barewords

lib/Language/syntax.pod

@@ -154,6 +154,8 @@ expressions. Examples for terms are variables (C<$x>), barewords such as type
 names (C<Int>), literals (C<42>), declarations (C<sub f() { }>) and calls
 (C<f()>).
 
+For example, in the expression C<2 * $salary>, C<2> and C<$salary> are two
+terms (an L<integer|/type/Int> literal and a L<variable|/language/variables>).
 
 =head2 Variables
 
@@ -168,11 +170,31 @@ them.
 
 See the L<documentation on variables|/language/variables> for more details.
 
-=begin comment
 
 =head2 Barewords (Constants, Type Names)
 
-TODO
+Pre-declared identifiers can be terms on their own. Those are typically type
+names or constants, but also the term C<self> which refers to an objectt that
+a method was called on (see L<objects|/language/objects>), and sigilles
+variables:
+
+    say Int;                # (Int)
+    #   ^^^ type name (built in)
+
+    constant answer = 42;
+    say answer;
+    #   ^^^^^^ constant
+
+    class Meta {
+        method type-name {
+            self.^name;
+          # ^^^^ built-in term 'self'
+        }
+    }
+    say Meta.type-name;     # Meta
+    #   ^^^^ type name
+
+=begin comment
 
 =head2 Literals