1 files changed, 123 insertions, 0 deletions
diff --git a/src/ee/kicad/sexpr/__init__.py b/src/ee/kicad/sexpr/__init__.py
new file mode 100644
index 0000000..a8604dc
--- /dev/null
+++ b/src/ee/kicad/sexpr/__init__.py
@@ -0,0 +1,123 @@
+EVENT_START = 1
+EVENT_END = 2
+EVENT_LPAREN = 3
+EVENT_RPAREN = 4
+EVENT_TEXT = 5
+
+def state_to_str(s):
+    if s == EVENT_START:
+        return "EVENT_START"
+    if s == EVENT_END:
+        return "EVENT_END"
+    if s == EVENT_LPAREN:
+        return "EVENT_LPAREN"
+    if s == EVENT_RPAREN:
+        return "EVENT_RPAREN"
+    if s == EVENT_TEXT:
+        return "EVENT_TEXT"
+    return "UNKNOWN STATE"
+
+def logging_parser(parser):
+    for (event, token) in parser:
+        if token:
+            print("SEXPR: event={}, token={}".format(state_to_str(event), token or ""))
+        else:
+            print("SEXPR: event={}".format(state_to_str(event)))
+        yield (event, token)
+
+def parse(path):
+    class state(object):
+        def __init__(self):
+            self.f = open(path, "r")#, 128 * 1024)
+            self.state = EVENT_START
+            self.buffer = []
+
+        def text(self):
+            return self._text
+
+        def close(self):
+            if self.f:
+                f = self.f
+                self.f = None
+                f.close()
+
+        def _read_c(self):
+            # TODO: count lines and characters
+            if self.buffer:
+                c = self.buffer[0]
+                del self.buffer[0]
+                return c
+
+            c = self.f.read(1)
+            while c and c == '\n':
+                c = self.f.read(1)
+            return c
+
+        def _unread(self, s):
+            for c in s:
+                self.buffer.append(c)
+
+        def _read_token(self):
+            s = ""
+            while True:
+                c = self._read_c()
+
+                if not c:
+                    return s if s else None
+
+                if c == " ":
+                    # Ignore leading blanks
+                    if not s:
+                        continue
+
+                if c == "(" or c == ")":
+                    if not s:
+                        return c
+                    self._unread(c)
+                    return s.rstrip()
+
+                if c == " ":
+                    return s
+
+                if c == "\"":
+                    while c:
+                        c = self._read_c()
+
+                        if c == "\"":
+                          break
+
+                        s += c
+                    return s
+                s += c
+
+            return s.rstrip()
+
+        def next(self):
+            s = self.state
+            self._text = None
+            if s == EVENT_END:
+                raise Exception("Invalid state, state=END")
+
+            token = self._read_token()
+
+            if token is None:
+                self.state = EVENT_END
+                self.close()
+                return (EVENT_END, None)
+
+            if token == "(":
+                self.state = EVENT_LPAREN
+                return (EVENT_LPAREN, None)
+            if token == ")":
+                self.state = EVENT_RPAREN
+                return (EVENT_RPAREN, None)
+
+            self._text = token
+            self.state = EVENT_TEXT
+            return (EVENT_TEXT, token)
+
+    s = state()
+    (event, token) = s.next()
+    while event != EVENT_END:
+        yield (event, token)
+        (event, token) = s.next()