[PATCH 2 of 3 RFC] revset: add function to build dict of positional and keyword arguments

Yuya Nishihara yuya at tcha.org
Mon Jun 29 09:51:30 CDT 2015


# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1435393501 -32400
#      Sat Jun 27 17:25:01 2015 +0900
# Node ID acaa4d55a0524e607e354cc873b4008f4fe48f70
# Parent  164e1587bcf1164dad21f7f01b2ba160a011898d
revset: add function to build dict of positional and keyword arguments

Keyword arguments will be convenient for functions that will take more than
one optional or boolean flags. For example,

  file(pattern[, subrepos=false])
  subrepo([[pattern], status])

Because I don't think all functions should accept key=value syntax, getkwargs()
does not support variadic functions such as 'ancestor(*changeset)'.

The core logic is placed in the parser module because keyword arguments will
be more useful in the templater, where functions take more options. Test cases
will be added by the next patch.

diff --git a/mercurial/parser.py b/mercurial/parser.py
--- a/mercurial/parser.py
+++ b/mercurial/parser.py
@@ -91,6 +91,38 @@ class parser(object):
             return self.eval(t)
         return t
 
+def buildargsdict(trees, funcname, keys, keyvaluenode, keynode):
+    """Build dict from list containing positional and keyword arguments
+
+    Invalid keywords or too many positional arguments are rejected, but
+    missing arguments are just omitted.
+    """
+    if len(trees) > len(keys):
+        raise error.ParseError(_("%(func)s takes at most %(nargs)d arguments")
+                               % {'func': funcname, 'nargs': len(keys)})
+    args = {}
+    # consume positional arguments
+    for k, x in zip(keys, trees):
+        if x[0] == keyvaluenode:
+            break
+        args[k] = x
+    # remainder should be keyword arguments
+    for x in trees[len(args):]:
+        if x[0] != keyvaluenode or x[1][0] != keynode:
+            raise error.ParseError(_("%(func)s got an invalid argument")
+                                   % {'func': funcname})
+        k = x[1][1]
+        if k not in keys:
+            raise error.ParseError(_("%(func)s got an unexpected keyword "
+                                     "argument '%(key)s'")
+                                   % {'func': funcname, 'key': k})
+        if k in args:
+            raise error.ParseError(_("%(func)s got multiple values for keyword "
+                                     "argument '%(key)s'")
+                                   % {'func': funcname, 'key': k})
+        args[k] = x[2]
+    return args
+
 def _prettyformat(tree, leafnodes, level, lines):
     if not isinstance(tree, tuple) or tree[0] in leafnodes:
         lines.append((level, str(tree)))
diff --git a/mercurial/revset.py b/mercurial/revset.py
--- a/mercurial/revset.py
+++ b/mercurial/revset.py
@@ -282,6 +282,10 @@ def getargs(x, min, max, err):
         raise error.ParseError(err)
     return l
 
+def getkwargs(x, funcname, keys):
+    return parser.buildargsdict(getlist(x), funcname, keys.split(),
+                                keyvaluenode='keyvalue', keynode='symbol')
+
 def isvalidsymbol(tree):
     """Examine whether specified ``tree`` is valid ``symbol`` or not
     """


More information about the Mercurial-devel mailing list