1 files changed, 289 insertions, 0 deletions
diff --git a/gerbonara/cad/kicad/sexp_mapper.py b/gerbonara/cad/kicad/sexp_mapper.py
new file mode 100644
index 0000000..cb7c99f
--- /dev/null
+++ b/gerbonara/cad/kicad/sexp_mapper.py
@@ -0,0 +1,289 @@
+
+from dataclasses import MISSING
+from .sexp import *
+
+
+SEXP_END = type('SEXP_END', (), {})
+
+
+class AtomChoice:
+    def __init__(self, *choices):
+        self.choices = choices
+
+    def __contains__(self, value):
+        return value in self.choices
+
+    def __atoms__(self):
+        return self.choices
+
+    def __map__(self, obj, parent=None):
+        obj, = obj
+        if obj not in self:
+            raise TypeError(f'Invalid atom {obj} for {type(self)}, valid choices are: {", ".join(map(str, self.choices))}')
+        return obj
+
+    def __sexp__(self, value):
+        yield value
+
+
+class Flag:
+    def __init__(self, atom=None, invert=None):
+        self.atom, self.invert = atom, invert
+
+    def __bind_field__(self, field):
+        if self.atom is None:
+            self.atom = Atom(field.name)
+        if self.invert is None:
+            self.invert = bool(field.default)
+
+    def __atoms__(self):
+        return [self.atom]
+
+    def __map__(self, obj, parent=None):
+        return not self.invert
+
+    def __sexp__(self, value):
+        if bool(value) == (not self.invert):
+            yield self.atom
+
+
+def sexp(t, v):
+    if v is None:
+        return []
+    elif t in (int, float, str, Atom):
+        return [t(v)]
+    elif hasattr(t, '__sexp__'):
+        return list(t.__sexp__(v))
+    elif isinstance(t, list):
+        t, = t
+        return [sexp(t, elem) for elem in v]
+    else:
+        raise TypeError(f'Python type {t} has no defined s-expression serialization')
+
+
+def map_sexp(t, v, parent=None):
+    if t is not Atom and hasattr(t, '__map__'):
+        return t.__map__(v, parent=parent)
+    elif t in (int, float, str, Atom):
+        v, = v
+        if not isinstance(v, t):
+            types = set({type(v), t})
+            if types == {int, float} or types == {str, Atom}:
+                v = t(v)
+            else:
+                raise TypeError(f'Cannot map s-expression value {v} of type {type(v)} to Python type {t}')
+        return v
+    elif isinstance(t, list):
+        t, = t
+        return [map_sexp(t, elem, parent=parent) for elem in v]
+    else:
+        raise TypeError(f'Python type {t} has no defined s-expression deserialization')
+
+
+class WrapperType:
+    def __init__(self, next_type):
+        self.next_type = next_type
+
+    def __bind_field__(self, field):
+        self.field = field
+        getattr(self.next_type, '__bind_field__', lambda x: None)(field)
+
+    def __atoms__(self):
+        if hasattr(self, 'name_atom'):
+            return [self.name_atom]
+        elif self.next_type is Atom:
+            return []
+        else:
+            return getattr(self.next_type, '__atoms__', lambda: [])()
+
+class Named(WrapperType):
+    def __init__(self, next_type, name=None):
+        super().__init__(next_type)
+        self.name_atom = Atom(name) if name else None
+
+    def __bind_field__(self, field):
+        if self.next_type is not Atom:
+            getattr(self.next_type, '__bind_field__', lambda x: None)(field)
+        if self.name_atom is None:
+            self.name_atom = Atom(field.name)
+
+    def __map__(self, obj, parent=None):
+        k, *obj = obj
+        if self.next_type in (int, float, str, Atom) or isinstance(self.next_type, AtomChoice):
+            return map_sexp(self.next_type, [*obj], parent=parent)
+        else:
+            return map_sexp(self.next_type, obj, parent=parent)
+
+    def __sexp__(self, value):
+        value = sexp(self.next_type, value)
+        if value is not None:
+            yield [self.name_atom, *value]
+
+
+class Rename(WrapperType):
+    def __init__(self, next_type, name=None):
+        super().__init__(next_type)
+        self.name_atom = Atom(name) if name else None
+
+    def __bind_field__(self, field):
+        if self.name_atom is None:
+            self.name_atom = Atom(field.name)
+
+    def __map__(self, obj, parent=None):
+        return map_sexp(self.next_type, obj, parent=parent)
+
+    def __sexp__(self, value):
+        value, = sexp(self.next_type, value)
+        if self.next_type in (str, float, int, Atom): 
+            yield [self.name_atom, *value]
+        else:
+            key, *rest = value
+            yield [self.name_atom, *rest]
+
+
+class OmitDefault(WrapperType):
+    def __bind_field__(self, field):
+        getattr(self.next_type, '__bind_field__', lambda x: None)(field)
+        if field.default_factory != MISSING:
+            self.default = field.default_factory()
+        else:
+            self.default = field.default
+
+    def __map__(self, obj, parent=None):
+        return map_sexp(self.next_type, obj, parent=parent)
+
+    def __sexp__(self, value):
+        if value != self.default:
+            yield from sexp(self.next_type, value)
+
+
+class YesNoAtom:
+    def __init__(self, yes=Atom.yes, no=Atom.no):
+        self.yes, self.no = yes, no
+
+    def __map__(self, value, parent=None):
+        value, = value
+        return value == self.yes
+
+    def __sexp__(self, value):
+        yield self.yes if value else self.no
+
+
+class Wrap(WrapperType):
+    def __map__(self, value, parent=None):
+        value, = value
+        return map_sexp(self.next_type, value, parent=parent)
+
+    def __sexp__(self, value):
+        for inner in sexp(self.next_type, value):
+            yield [inner]
+
+
+class Array(WrapperType):
+    def __map__(self, value, parent=None):
+        return [map_sexp(self.next_type, [elem], parent=parent) for elem in value]
+    
+    def __sexp__(self, value):
+        for e in value:
+            yield from sexp(self.next_type, e)
+
+
+class List(WrapperType):
+    def __bind_field__(self, field):
+        self.attr = field.name
+
+    def __map__(self, value, parent):
+        l = getattr(parent, self.attr, [])
+        mapped = map_sexp(self.next_type, value, parent=parent)
+        l.append(mapped)
+        setattr(parent, self.attr, l)
+
+    def __sexp__(self, value):
+        for elem in value:
+            yield from sexp(self.next_type, elem)
+
+
+class _SexpTemplate:
+    @staticmethod
+    def __atoms__(kls):
+        return [kls.name_atom]
+
+    @staticmethod
+    def __map__(kls, value, parent=None):
+        positional = iter(kls.positional)
+        inst = kls()
+
+        for v in value[1:]: # skip key
+            if isinstance(v, Atom) and v in kls.keys:
+                name, etype = kls.keys[v]
+                mapped = map_sexp(etype, [v], parent=inst)
+                if mapped is not None:
+                    setattr(inst, name, mapped)
+
+            elif isinstance(v, list):
+                name, etype = kls.keys[v[0]]
+                mapped = map_sexp(etype, v, parent=inst)
+                if mapped is not None:
+                    setattr(inst, name, mapped)
+
+            else:
+                try:
+                    pos_key = next(positional)
+                    setattr(inst, pos_key.name, v)
+                except StopIteration:
+                    raise TypeError(f'Unhandled positional argument {v!r} while parsing {kls}')
+
+        getattr(inst, '__after_parse__', lambda x: None)(parent)
+        return inst
+
+    @staticmethod
+    def __sexp__(kls, value):
+        getattr(value, '__before_sexp__', lambda: None)()
+
+        out = [kls.name_atom]
+        for f in fields(kls):
+            if f.type is SEXP_END:
+                break
+            out += sexp(f.type, getattr(value, f.name))
+        yield out
+
+    @staticmethod
+    def parse(kls, data):
+        return kls.__map__(parse_sexp(data))
+
+    @staticmethod
+    def sexp(self):
+        return next(self.__sexp__(self))
+
+
+def sexp_type(name=None):
+    def register(cls):
+        cls = dataclass(cls)
+        cls.name_atom = Atom(name) if name is not None else None
+        for key in '__sexp__', '__map__', '__atoms__', 'parse':
+            if not hasattr(cls, key):
+                setattr(cls, key, classmethod(getattr(_SexpTemplate, key)))
+
+        if not hasattr(cls, 'sexp'):
+            setattr(cls, 'sexp', getattr(_SexpTemplate, 'sexp'))
+        cls.positional = []
+        cls.keys = {}
+        for f in fields(cls):
+            f_type = f.type
+            if f_type is SEXP_END:
+                break
+
+            if hasattr(f_type, '__bind_field__'):
+                f_type.__bind_field__(f)
+
+            atoms = getattr(f_type, '__atoms__', lambda: [])
+            atoms = list(atoms())
+            for atom in atoms:
+                cls.keys[atom] = (f.name, f_type)
+            if not atoms:
+                cls.positional.append(f)
+
+        return cls
+    return register
+
+