Productionize manifest generator.

* Better output.
* Better error checking and reporting.
* Clearer names.
* Python style.

bin/python/ripple/ledger/SField.py

@@ -0,0 +1,51 @@
+# Constants from ripple/protocol/SField.h
+
+# special types
+STI_UNKNOWN     = -2
+STI_DONE        = -1
+STI_NOTPRESENT  = 0
+
+# # types (common)
+STI_UINT16 = 1
+STI_UINT32 = 2
+STI_UINT64 = 3
+STI_HASH128 = 4
+STI_HASH256 = 5
+STI_AMOUNT = 6
+STI_VL = 7
+STI_ACCOUNT = 8
+# 9-13 are reserved
+STI_OBJECT = 14
+STI_ARRAY = 15
+
+# types (uncommon)
+STI_UINT8 = 16
+STI_HASH160 = 17
+STI_PATHSET = 18
+STI_VECTOR256 = 19
+
+# high level types
+# cannot be serialized inside other types
+STI_TRANSACTION = 10001
+STI_LEDGERENTRY = 10002
+STI_VALIDATION  = 10003
+STI_METADATA    = 10004
+
+def field_code(sti, name):
+    if sti < 16:
+        if name < 16:
+            bytes = [(sti << 4) + name]
+        else:
+            bytes = [sti << 4, name]
+    elif name < 16:
+        bytes = [name, sti]
+    else:
+        bytes = [0, sti, name]
+    return ''.join(chr(i) for i in bytes)
+
+# Selected constants from SField.cpp
+
+sfSequence          = field_code(STI_UINT32, 4)
+sfPublicKey         = field_code(STI_VL, 1)
+sfSigningPubKey     = field_code(STI_VL, 3)
+sfSignature         = field_code(STI_VL, 6)