diff --git a/src/kyupy/def_file.py b/src/kyupy/def_file.py
new file mode 100644
index 0000000..3368e82
--- /dev/null
+++ b/src/kyupy/def_file.py
@@ -0,0 +1,285 @@
+from collections import defaultdict
+
+from lark import Lark, Transformer, Tree
+
+from kyupy import readtext
+
+
+class DefNet:
+    def __init__(self, name):
+        self.name = name
+        self.pins = []
+
+    @property
+    def wires(self):
+        ww = defaultdict(list)
+        [ww[dw.layer].append((int(dw.width), dw.wire_points)) for dw in self.routed if len(dw.wire_points) > 0]
+        return ww
+
+    @property
+    def vias(self):
+        vv = defaultdict(list)
+        [vv[vtype].extend(locs) for dw in self.routed for vtype, locs in dw.vias.items()]
+        return vv
+
+
+class DefWire:
+    def __init__(self):
+        self.layer = None
+        self.width = None
+        self.points = []
+
+    @property
+    def wire_points(self):
+        start = [self.points[0]]
+        rest = [p for p in self.points[1:] if not isinstance(p[0], str)]  # skip over vias
+        return start + rest if len(rest) > 0 else []
+
+    @property
+    def vias(self):
+        vv = defaultdict(list)
+        loc = self.points[0]
+        for p in self.points[1:]:
+            if not isinstance(p[0], str):  # new location
+                loc = (loc[0] if p[0] is None else p[0], loc[1] if p[1] is None else p[1])  # if None, keep previous value
+                continue
+            vtype, param = p
+            if isinstance(param, tuple):  # expand "DO x BY y STEP xs ys"
+                x_cnt, y_cnt, x_sp, y_sp = param
+                [vv[vtype].append((loc[0] + x*x_sp, loc[1] + y*y_sp, 'N')) for x in range(x_cnt) for y in range(y_cnt)]
+            else:
+                vv[vtype].append((loc[0], loc[1], param or 'N'))
+        return vv
+
+    def __repr__(self):
+        return f'<DefWire {self.layer} {self.width} {self.points}>'
+
+
+class DefVia:
+    def __init__(self, name):
+        self.name = name
+        self.rowcol = [1, 1]
+        self.cutspacing = [0, 0]
+
+
+class DefPin:
+    def __init__(self, name):
+        self.name = name
+        self.points = []
+
+
+class DefFile:
+    def __init__(self):
+        self.rows = []
+        self.tracks = []
+        self.units = []
+        self.vias = {}
+        self.components = {}
+        self.pins = {}
+        self.specialnets = {}
+        self.nets = {}
+
+
+class DefTransformer(Transformer):
+    def __init__(self): self.def_file = DefFile()
+    def start(self, args): return self.def_file
+    def design(self, args): self.def_file.design = args[0].value
+    def point(self, args): return tuple(int(arg.value) if arg != '*' else None for arg in args)
+    def do_step(self, args): return tuple(map(int, args))
+    def spnet_wires(self, args): return args[0].lower(), args[1:]
+    def net_wires(self, args): return args[0].lower(), args[1:]
+    def sppoints(self, args): return args
+    def points(self, args): return args
+    def net_pin(self, args): return '__pin__', (args[0].value, args[1].value)
+    def net_opt(self, args): return args[0].lower(), args[1].value
+
+    def file_stmt(self, args):
+        value = args[1].value
+        value = value[1:-1] if value[0] == '"' else value
+        setattr(self.def_file, args[0].lower(), value)
+
+    def design_stmt(self, args):
+        stmt = args[0].lower()
+        if stmt == 'units': self.def_file.units.append((args[1].value, args[2].value, int(args[3])))
+        elif stmt == 'diearea': self.def_file.diearea = args[1:]
+        elif stmt == 'row':
+            self.def_file.rows.append((args[1].value,  # rowName
+                                       args[2].value,  # siteName
+                                       (int(args[3]), int(args[4])),  # origin x/y
+                                       args[5].value,  # orientation
+                                       max(args[6][0], args[6][1]),  # number of sites
+                                       max(args[6][2], args[6][3])  # site width
+                                      ))
+        elif stmt == 'tracks':
+            self.def_file.tracks.append((args[1].value,  # orientation
+                                         int(args[2]),  # start
+                                         int(args[3]),  # number of tracks
+                                         int(args[4]),  # spacing
+                                         args[5].value  # layer
+                                        ))
+
+    def vias_stmt(self, args):
+        via = DefVia(args[0].value)
+        [setattr(via, opt, val) for opt, val in args[1:]]
+        self.def_file.vias[via.name] = via
+
+    def vias_opt(self, args):
+        opt = args[0].lower()
+        if opt in ['viarule', 'pattern']: val = args[1].value
+        elif opt in ['layers']: val = [arg.value for arg in args[1:]]
+        else: val = [int(arg) for arg in args[1:]]
+        return opt, val
+
+    def comp_stmt(self, args):
+        name = args[0].value
+        kind = args[1].value
+        point = args[2]
+        orientation = args[3].value
+        self.def_file.components[name] = (kind, point, orientation)
+
+    def pins_stmt(self, args):
+        pin = DefPin(args[0].value)
+        [pin.points.append(val) if opt == 'placed' else setattr(pin, opt, val) for opt, val in args[1:]]
+        self.def_file.pins[pin.name] = pin
+
+    def pins_opt(self, args):
+        opt = args[0].lower()
+        if opt in ['net', 'direction', 'use']: val = args[1].value
+        elif opt in ['layer']: val = [args[1].value] + args[2:]
+        elif opt in ['placed']: val = (args[1][0], args[1][1], args[2].value)
+        else: val = []
+        return opt, val
+
+    def spnets_stmt(self, args):
+        dnet = DefNet(args[0].value)
+        for arg in args[1:]:
+            if arg[0] == '__pin__': dnet.pins.append(arg[1])
+            else: setattr(dnet, arg[0], arg[1])
+        self.def_file.specialnets[dnet.name] = dnet
+
+    def nets_stmt(self, args):
+        dnet = DefNet(args[0].value)
+        for arg in args[1:]:
+            if arg[0] == '__pin__': dnet.pins.append(arg[1])
+            else: setattr(dnet, arg[0], arg[1])
+        self.def_file.nets[dnet.name] = dnet
+
+    def spwire(self, args):
+        wire = DefWire()
+        wire.layer = args[0].value
+        wire.width = args[1].value
+        wire.points = args[-1]
+        return wire
+
+    def wire(self, args):
+        wire = DefWire()
+        wire.layer = args[0].value
+        wire.points = args[-1]
+        return wire
+
+    def sppoints_via(self, args):
+        if len(args) == 1: return args[0].value, None
+        else: return args[0].value, args[1]
+
+    def points_via(self, args):
+        if len(args) == 1: return args[0].value, 'N'
+        else: return args[0].value, args[1].value.strip()
+
+
+GRAMMAR = r"""
+    start: /#[^\n]*/? file_stmt*
+
+    ?file_stmt: /VERSION/ ID ";"
+              | /DIVIDERCHAR/ STRING ";"
+              | /BUSBITCHARS/ STRING ";"
+              | design
+
+    design: "DESIGN" ID ";" design_stmt* "END" "DESIGN"
+
+    ?design_stmt: /UNITS/ ID ID NUMBER ";"
+                | /DIEAREA/ point+ ";"
+                | /ROW/ ID ID NUMBER NUMBER ID do_step ";"
+                | /TRACKS/ /[XY]/ NUMBER "DO" NUMBER "STEP" NUMBER "LAYER" ID ";"
+                | propdef | vias | nondef | comp | pins | pinprop | spnets | nets
+
+    propdef: "PROPERTYDEFINITIONS" propdef_stmt* "END" "PROPERTYDEFINITIONS"
+    propdef_stmt: /COMPONENTPIN/ ID ID ";"
+
+    vias: "VIAS" NUMBER ";" vias_stmt* "END" "VIAS"
+    vias_stmt: "-" ID vias_opt* ";"
+    vias_opt: "+" /VIARULE/ ID
+            | "+" /CUTSIZE/ NUMBER NUMBER
+            | "+" /LAYERS/ ID ID ID
+            | "+" /CUTSPACING/ NUMBER NUMBER
+            | "+" /ENCLOSURE/ NUMBER NUMBER NUMBER NUMBER
+            | "+" /ROWCOL/ NUMBER NUMBER
+            | "+" /PATTERN/ ID
+
+    nondef: "NONDEFAULTRULES" NUMBER ";" nondef_stmt+ "END" "NONDEFAULTRULES"
+    nondef_stmt: "-" ID ( "+" /HARDSPACING/
+                        | "+" /LAYER/ ID "WIDTH" NUMBER "SPACING" NUMBER
+                        | "+" /VIA/ ID )* ";"
+
+    comp: "COMPONENTS" NUMBER ";" comp_stmt* "END" "COMPONENTS"
+    comp_stmt: "-" ID ID "+" "PLACED" point ID ";"
+
+    pins: "PINS" NUMBER ";" pins_stmt* "END" "PINS"
+    pins_stmt: "-" ID pins_opt* ";"
+    pins_opt: "+" /NET/ ID
+            | "+" /SPECIAL/
+            | "+" /DIRECTION/ ID
+            | "+" /USE/ ID
+            | "+" /PORT/
+            | "+" /LAYER/ ID point point
+            | "+" /PLACED/ point ID
+
+    pinprop: "PINPROPERTIES" NUMBER ";" pinprop_stmt* "END" "PINPROPERTIES"
+    pinprop_stmt: "-" "PIN" ID "+" "PROPERTY" ID STRING ";"
+
+    spnets: "SPECIALNETS" NUMBER ";" spnets_stmt* "END" "SPECIALNETS"
+    spnets_stmt: "-" ID ( net_pin | net_opt | spnet_wires )* ";"
+
+    spnet_wires: "+" ( /COVER/ | /FIXED/ | /ROUTED/ ) spwire ( "NEW" spwire )*
+
+    spwire: ID NUMBER spwire_opt* sppoints
+    spwire_opt: "+" /SHAPE/ ID
+              | "+" /STYLE/ ID
+
+    sppoints: point ( point | sppoints_via )+
+    sppoints_via: ID do_step?
+
+    nets: "NETS" NUMBER ";" nets_stmt* "END" "NETS"
+    nets_stmt: "-" ID ( net_pin | net_opt | net_wires )* ";"
+
+    net_pin: "(" ID ID ")"
+    net_opt: "+" /USE/ ID
+           | "+" /NONDEFAULTRULE/ ID
+    net_wires: "+" ( /COVER/ | /FIXED/ | /ROUTED/ | /NOSHIELD/ ) wire ( "NEW" wire )*
+
+    wire: ID wire_opt points
+    wire_opt: ( "TAPER" | "TAPERRULE" ID )? ("STYLE" ID)?
+
+    points: point ( point | points_via )+
+    points_via: ID ORIENTATION?
+
+    point: "(" (NUMBER|/\*/) (NUMBER|/\*/) NUMBER? ")"
+
+    do_step: "DO" NUMBER "BY" NUMBER "STEP" (NUMBER|SIGNED_NUMBER) (NUMBER|SIGNED_NUMBER)
+
+    ORIENTATION.2: /F?[NWES]/ WS
+    ID: /[^ \t\f\r\n+][^ \t\f\r\n]*/
+    STRING : "\"" /.*?/s /(?<!\\)(\\\\)*?/ "\""
+    WS: /[ \t\f\r\n]/
+
+    %import common.NUMBER
+    %import common.SIGNED_NUMBER
+    %ignore WS (/#[^\n]*/)?
+    """
+
+
+def parse(text):
+    return Lark(GRAMMAR, parser="lalr", transformer=DefTransformer()).parse(text)
+
+
+def load(file):
+    return parse(readtext(file))
\ No newline at end of file