* Move all struct definitions to structs.pxd, to avoid circular dependencies

spacy/structs.pxd

@@ -0,0 +1,63 @@
+from libc.stdint cimport uint8_t, uint32_t
+
+from .typedefs cimport flags_t, attr_t, id_t, hash_t
+
+
+cdef struct Lexeme:
+    flags_t flags
+   
+    attr_t id
+    attr_t sic
+    attr_t dense
+    attr_t shape
+    attr_t prefix
+    attr_t suffix
+ 
+    attr_t length
+    attr_t cluster
+    attr_t pos_type
+
+    float prob
+    float sentiment
+
+
+cdef struct Morphology:
+    uint8_t number
+    uint8_t tenspect # Tense/aspect/voice
+    uint8_t mood
+    uint8_t gender
+    uint8_t person
+    uint8_t case
+    uint8_t misc
+
+
+cdef struct PosTag:
+    Morphology morph
+    int id
+    int pos
+
+
+cdef struct TokenC:
+    const Lexeme* lex
+    Morphology morph
+    int idx
+    int pos
+    int lemma
+    int sense
+    int head
+    int dep_tag
+    uint32_t l_kids
+    uint32_t r_kids
+
+
+cdef struct Utf8Str:
+    id_t i
+    hash_t key
+    unsigned char* chars
+    int length
+
+
+cdef struct UniStr:
+    Py_UNICODE* chars
+    size_t n
+    hash_t key