S-expressions: Difference between revisions

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@@ Line 5,320: / Line 5,320: @@
        unparsed tokens that remain.
     '''
-    def finished(xr):
-        r = xr[1]
-        return (not r) or (r[0] == ")")
-    def parseToken(xsr):
-        xs, r = xsr
-        h, *t = r
-        if "(" == h:
-            expr, rest = parseExpr(t)
-            return xs + [expr], rest[1:]
-        else:
-            return (xs, t) if ")" == h else (
-                xs + [atom(h)], t
-            )
     return until(finished)(parseToken)(
         ([], tokens)
     )
+# finished :: ([Expr], [String]) -> Bool
+def finished(xr):
+    '''True if no tokens remain,
+       or the next token is a closing bracket.
+    '''
+    r = xr[1]
+    return (not r) or (r[0] == ")")
+# parseToken :: ([Expr], [String]) -> ([Expr], [String])
+def parseToken(xsr):
+    '''A tuple of an expanded expression
+       and a reduced token list.
+    '''
+    xs, r = xsr
+    h, *t = r
+    if "(" == h:
+        expr, rest = parseExpr(t)
+        return xs + [expr], rest[1:]
+    else:
+        return (xs, t) if ")" == h else (
+            xs + [atom(h)], t
+        )
 # --------------------- ATOM PARSER ----------------------