feat: mf6 input file parser

Author: wpbonelli

autotest/test_codec.py

@@ -0,0 +1,15 @@
+from modflow_devtools.codec import make_parser
+
+
+def test_parser():
+    parser = make_parser()
+    text = """
+BEGIN OPTIONS
+    AN OPTION
+    ANOTHER OPTION
+END OPTIONS
+BEGIN PACKAGEDATA
+END PACKAGEDATA
+"""
+    tree = parser.parse(text)
+    print(tree.pretty())

docs/md/codec.md

@@ -0,0 +1,5 @@
+from lark import Lark
+
+
+def make_parser(**kwargs) -> Lark:
+    return Lark.open("mf6.lark", parser="lalr", rel_to=__file__, **kwargs)

modflow_devtools/codec.py

@@ -157,14 +157,16 @@ class Dfn(TypedDict):
     MODFLOW 6 input definition. An input definition
     specifies a component in an MF6 simulation, e.g.
     a model or package, containing input variables.
+
+    # TODO: use dataclass, mypy says static methods in a typed dict are invalid
     """
 
     name: str
-    advanced: bool = False
-    multi: bool = False
-    ref: Ref | None = None
-    sln: Sln | None = None
-    fkeys: Dfns | None = None
+    advanced: bool
+    multi: bool
+    ref: Optional[Ref]
+    sln: Optional[Sln]
+    fkeys: Optional[Dfns]
 
     @staticmethod
     def _load_v1_flat(f, common: dict | None = None) -> tuple[Mapping, list[str]]:

modflow_devtools/dfn.py

@@ -0,0 +1,15 @@
+start: [WS] block+ [WS]
+
+block: "begin"i CNAME _NL _content "end"i CNAME _NL
+_content: line* [WS]
+line: [WS] value* _NL
+value: WORD | NUMBER
+
+
+%import common.NEWLINE -> _NL
+%import common.WS
+%import common.WS_INLINE
+%import common.CNAME
+%import common.WORD
+%import common.NUMBER
+%ignore WS_INLINE

modflow_devtools/mf6.lark

@@ -81,6 +81,9 @@ models = [
     "tomli",
     "tomli-w"
 ]
+codec = [
+    "lark"
+]
 dev = ["modflow-devtools[lint,test,docs,dfn,models]"]
 
 [dependency-groups]
@@ -126,13 +129,17 @@ models = [
     "tomli",
     "tomli-w"
 ]
+codec = [
+    "lark"
+]
 dev = [
     {include-group = "build"},
     {include-group = "lint"},
     {include-group = "test"},
     {include-group = "docs"},
     {include-group = "dfn"},
     {include-group = "models"},
+    {include-group = "codec"},
 ]
 
 [project.urls]