Added index type for case-folded strings.

diff --git a/didex/index.py b/didex/index.py
index 65b1b12..c2c55b6 100644 (file)
--- a/didex/index.py
+++ b/didex/index.py
@@ -2,7 +2,7 @@ import struct, contextlib, math
 from . import db, lib
 from .db import bd, txnfun, dloopfun
 
-__all__ = ["maybe", "t_int", "t_uint", "t_dbid", "t_float", "t_str", "ordered"]
+__all__ = ["maybe", "t_int", "t_uint", "t_dbid", "t_float", "t_str", "t_casestr", "ordered"]
 
 deadlock = bd.DBLockDeadlockError
 notfound = bd.DBNotFoundError
@@ -29,6 +29,14 @@ class simpletype(object):
         return cls(lambda ob: struct.pack(fmt, ob),
                    lambda dat: struct.unpack(fmt, dat)[0])
 
+class foldtype(simpletype):
+    def __init__(self, encode, decode, fold):
+        super().__init__(encode, decode)
+        self.fold = fold
+
+    def compare(self, a, b):
+        return super().compare(self.fold(a), self.fold(b))
+
 class maybe(object):
     def __init__(self, bk):
         self.bk = bk
@@ -138,6 +146,8 @@ t_dbid = t_uint
 t_float = simpletype.struct(">d")
 t_float.compare = floatcmp
 t_str = simpletype((lambda ob: ob.encode("utf-8")), (lambda dat: dat.decode("utf-8")))
+t_casestr = foldtype((lambda ob: ob.encode("utf-8")), (lambda dat: dat.decode("utf-8")),
+                     (lambda st: st.lower()))
 
 class index(object):
     def __init__(self, db, name, datatype):