1 files changed, 107 insertions, 0 deletions
diff --git a/third_party/python/fluent.migrate/fluent/migrate/util.py b/third_party/python/fluent.migrate/fluent/migrate/util.py
new file mode 100644
index 0000000000..43d9e62c19
--- /dev/null
+++ b/third_party/python/fluent.migrate/fluent/migrate/util.py
@@ -0,0 +1,107 @@
+import textwrap
+
+import fluent.syntax.ast as FTL
+from fluent.syntax.parser import FluentParser, FluentParserStream
+
+
+fluent_parser = FluentParser(with_spans=False)
+
+
+def parse(Parser, string):
+    if Parser is FluentParser:
+        return fluent_parser.parse(string)
+
+    # Parsing a legacy resource.
+
+    # Parse the string into the internal Context.
+    parser = Parser()
+    # compare-locales expects ASCII strings.
+    parser.readContents(string.encode("utf8"))
+    # Transform the parsed result which is an iterator into a dict.
+    return {ent.key: ent for ent in parser}
+
+
+def ftl_resource_to_ast(code):
+    return fluent_parser.parse(ftl(code))
+
+
+def ftl_resource_to_json(code):
+    return fluent_parser.parse(ftl(code)).to_json()
+
+
+def ftl_pattern_to_json(code):
+    ps = FluentParserStream(ftl(code))
+    return fluent_parser.maybe_get_pattern(ps).to_json()
+
+
+def to_json(merged_iter):
+    return {path: resource.to_json() for path, resource in merged_iter}
+
+
+LOCALIZABLE_ENTRIES = (FTL.Message, FTL.Term)
+
+
+def get_message(body, ident):
+    """Get message called `ident` from the `body` iterable."""
+    for entity in body:
+        if isinstance(entity, LOCALIZABLE_ENTRIES) and entity.id.name == ident:
+            return entity
+
+
+def get_transform(body, ident):
+    """Get entity called `ident` from the `body` iterable."""
+    for transform in body:
+        if transform.id.name == ident:
+            return transform
+
+
+def skeleton(node):
+    """Create a skeleton copy of the given node.
+
+    For localizable entries, the value is None and the attributes are {}.
+    That's not a valid Fluent entry, so it requires further manipulation to
+    set values and/or attributes.
+    """
+    if isinstance(node, LOCALIZABLE_ENTRIES):
+        return type(node)(id=node.id.clone(), value=None)
+    return node.clone()
+
+
+def ftl(code):
+    """Nicer indentation for FTL code.
+
+    The code returned by this function is meant to be compared against the
+    output of the FTL Serializer.  The input code will end with a newline to
+    match the output of the serializer.
+    """
+
+    # The code might be triple-quoted.
+    code = code.lstrip("\n")
+
+    return textwrap.dedent(code)
+
+
+def fold(fun, node, init):
+    """Reduce `node` to a single value using `fun`.
+
+    Apply `fun` against an accumulator and each subnode of `node` (in postorder
+    traversal) to reduce it to a single value.
+    """
+
+    def fold_(vals, acc):
+        if not vals:
+            return acc
+
+        head = list(vals)[0]
+        tail = list(vals)[1:]
+
+        if isinstance(head, FTL.BaseNode):
+            acc = fold(fun, head, acc)
+        if isinstance(head, list):
+            acc = fold_(head, acc)
+        if isinstance(head, dict):
+            acc = fold_(head.values(), acc)
+
+        return fold_(tail, fun(acc, head))
+
+    return fold_(vars(node).values(), init)