added modes and template mode

glom/__init__.py

@@ -7,6 +7,7 @@
                        OMIT,  # backwards compat
                        SKIP,
                        STOP,
+                       MODE,
                        Check,
                        Path,
                        Literal,
@@ -21,6 +22,7 @@
 
 from glom.reduction import Sum, Fold, Flatten, flatten, FoldError, Merge, merge
 from glom.mutation import Assign, assign, PathAssignError
+from glom.template import Template
 
 # there's no -ion word that really fits what "streaming" means.
 # generation, production, iteration, all have more relevant meanings

glom/core.py

@@ -80,6 +80,8 @@
 [0, 1, 2, 3, 4]
 """
 
+MODE =  make_sentinel('MODE')
+
 
 class GlomError(Exception):
     """The base exception for all the errors that might be raised from
@@ -1134,6 +1136,22 @@ def glomit(self, target, scope):
         return ret
 
 
+class Build(object):
+    """
+    switch to builder mode (the default)
+
+    TODO: this seems like it should be a sub-class of class Spec() --
+    if Spec() could help define the interface for new "modes" or dialects
+    that would also help make match mode feel less duct-taped on
+    """
+    def __init__(self, spec):
+        self.spec = spec
+
+    def glomit(self, target, scope):
+        scope[MODE] = _glom_build
+        return scope[glom](target, self.spec, scope)
+
+
 class _AbstractIterable(_AbstractIterableBase):
     __metaclass__ = ABCMeta
     @classmethod
@@ -1442,7 +1460,8 @@ def glom(target, spec, **kwargs):
     skip_exc = kwargs.pop('skip_exc', () if default is _MISSING else GlomError)
     scope = _DEFAULT_SCOPE.new_child({
         Path: kwargs.pop('path', []),
-        Inspect: kwargs.pop('inspector', None)
+        Inspect: kwargs.pop('inspector', None),
+        MODE: _glom_build,
     })
     scope.update(kwargs.pop('scope', {}))
     if kwargs:
@@ -1465,7 +1484,12 @@ def _glom(target, spec, scope):
         return _t_eval(target, spec, scope)
     elif callable(getattr(spec, 'glomit', None)):
         return spec.glomit(target, scope)
-    elif isinstance(spec, dict):
+
+    return scope[MODE](target, spec, scope)
+
+
+def _glom_build(target, spec, scope):
+    if isinstance(spec, dict):
         return _handle_dict(target, spec, scope)
     elif isinstance(spec, list):
         return _handle_list(target, spec, scope)

glom/template.py

@@ -0,0 +1,28 @@
+"""
+template mode is for building python literals,
+similar to quasi-quoting in lisp
+"""
+from glom import glom, MODE
+
+
+class Template(object):
+	def __init__(self, spec):
+		self.spec = spec
+
+	def glomit(self, target, scope):
+		scope[MODE] = _template
+		return scope[glom](target, self.spec, scope)
+
+
+def _template(target, spec, scope):
+	recurse = lambda val: scope[glom](target, val, scope)
+	if type(spec) is dict:
+		return {recurse(key): recurse(val) for key, val in spec.items()}
+	if type(spec) in (list, tuple, set, frozenset):
+		result = [recurse(val) for val in spec]
+		if type(spec) is list:
+			return result
+		return type(spec)(result)
+	if callable(spec):
+		return spec(target)
+	return spec

glom/test/test_template.py

@@ -0,0 +1,7 @@
+from glom import Template, T, glom
+
+def test():
+	assert glom('abc', Template((T[0], {T[1]: T[2]}))) == ('a', {'b': 'c'})
+	assert glom('123', Template({T[0], frozenset([T[1], T[2]])})) == {'1', frozenset(['2', '3'])}
+	assert glom('xyz', Template([T[0], T[1], T[2]]))
+	assert glom('abc', Template(lambda t: t.upper())) == 'ABC'