Added substrings_to_isolate to TexMobject configuration

mobject/svg/tex_mobject.py

@@ -4,6 +4,7 @@ from svg_mobject import SVGMobject
 from svg_mobject import VMobjectFromSVGPathstring
 from mobject.shape_matchers import BackgroundRectangle
 from utils.config_ops import digest_config
+from utils.strings import split_string_list_to_isolate_substring
 from mobject.types.vectorized_mobject import VGroup
 from mobject.types.vectorized_mobject import VMobject
 from mobject.types.vectorized_mobject import VectorizedPoint
@@ -15,6 +16,7 @@ import operator as op
 
 TEX_MOB_SCALE_FACTOR = 0.05
 
+
 class TexSymbol(VMobjectFromSVGPathstring):
     def pointwise_become_partial(self, mobject, a, b):
         # TODO, this assumes a = 0
@@ -128,10 +130,12 @@ class SingleStringTexMobject(SVGMobject):
 class TexMobject(SingleStringTexMobject):
     CONFIG = {
         "arg_separator": " ",
+        "substrings_to_isolate": [],
     }
 
     def __init__(self, *tex_strings, **kwargs):
         digest_config(self, kwargs)
+        tex_strings = self.break_up_tex_strings(tex_strings)
         self.tex_strings = tex_strings
         SingleStringTexMobject.__init__(
             self, self.arg_separator.join(tex_strings), **kwargs
@@ -141,6 +145,14 @@ class TexMobject(SingleStringTexMobject):
         if self.organize_left_to_right:
             self.organize_submobjects_left_to_right()
 
+    def break_up_tex_strings(self, tex_strings):
+        split_list = split_string_list_to_isolate_substring(
+            tex_strings, *self.substrings_to_isolate
+        )
+        split_list = map(str.strip, split_list)
+        split_list = filter(lambda s: s != '', split_list)
+        return split_list
+
     def break_up_by_substrings(self):
         """
         Reorganize existing submojects one layer

utils/strings.py

@@ -27,25 +27,35 @@ def complex_string(complex_num):
     return filter(lambda c: c not in "()", str(complex_num))
 
 
-def break_up_string_by_terms(full_string, *terms):
+def split_string_to_isolate_substrings(full_string, *substrings_to_isolate):
     """
     Given a string, and an arbitrary number of possible substrings, returns a list
     of strings which would concatenate to make the full string, and in which
     these special substrings appear as their own elements.
 
-    For example, break_up_string_by_terms("to be or not to be", "to", "be") would
+    For example, split_string_to_isolate_substrings("to be or not to be", "to", "be") would
     return ["to", " ", "be", " or not ", "to", " ", "be"]
     """
-    if len(terms) == 0:
+    if len(substrings_to_isolate) == 0:
         return [full_string]
-    term = terms[0]
-    substrings = list(it.chain(*zip(
-        full_string.split(term),
-        it.repeat(term)
+    substring_to_isolate = substrings_to_isolate[0]
+    all_substrings = list(it.chain(*zip(
+        full_string.split(substring_to_isolate),
+        it.repeat(substring_to_isolate)
     )))
-    substrings.pop(-1)
-    substrings = filter(lambda s: s != "", substrings)
+    all_substrings.pop(-1)
+    all_substrings = filter(lambda s: s != "", all_substrings)
+    return split_string_list_to_isolate_substring(
+        all_substrings, *substrings_to_isolate[1:]
+    )
+
+
+def split_string_list_to_isolate_substring(string_list, *substrings_to_isolate):
+    """
+    Similar to split_string_to_isolate_substrings, but the first argument
+    is a list of strings, thought of as something already broken up a bit.
+    """
     return list(it.chain(*[
-        break_up_string_by_terms(substring, *terms[1:])
-        for substring in substrings
+        split_string_to_isolate_substrings(s, *substrings_to_isolate)
+        for s in string_list
     ]))