Host ABI definition and ergonomics in TC

lib/arboricx.tri

@@ -51,3 +51,86 @@ runArboricxArgsByName = (nameBytes bs args :
 
 runArboricxArgs = (bs args :
   runArboricxArgsByName [] bs args)
+
+errHostCodecFailed = 14
+
+hostTreeTag = 0
+hostStringTag = 1
+hostNumberTag = 2
+hostBoolTag = 3
+hostListTag = 4
+hostBytesTag = 5
+
+hostTree = (value : pair hostTreeTag value)
+hostString = (bytes : pair hostStringTag bytes)
+hostNumber = (n : pair hostNumberTag n)
+hostBool = (b : pair hostBoolTag b)
+hostList = (xs : pair hostListTag xs)
+hostBytes = (bytes : pair hostBytesTag bytes)
+
+hostValueTag = (hostValue : pairFirst hostValue)
+hostValuePayload = (hostValue : pairSecond hostValue)
+
+hostBool? = (value : or? (equal? value false) (equal? value true))
+
+hostNumber? = y (self value :
+  triage
+    true
+    (_ : false)
+    (bit rest :
+      and?
+        (or? (equal? bit false) (equal? bit true))
+        (self rest))
+    value)
+
+hostList? = y (self value :
+  triage
+    true
+    (_ : false)
+    (_ rest : self rest)
+    value)
+
+hostString? = y (self value :
+  matchList
+    true
+    (byte rest : and? (hostNumber? byte) (self rest))
+    value)
+
+hostBytes? = hostString?
+
+wrapHostValue = (validator wrapper resultValue rest :
+  matchBool
+    (ok (wrapper resultValue) rest)
+    (err errHostCodecFailed resultValue)
+    (validator resultValue))
+
+runArboricxByNameToTree = (nameBytes bs args :
+  bindResult (runArboricxArgsByName nameBytes bs args)
+    (value rest : ok (hostTree value) rest))
+
+runArboricxByNameToString = (nameBytes bs args :
+  bindResult (runArboricxArgsByName nameBytes bs args)
+    (value rest : wrapHostValue hostString? hostString value rest))
+
+runArboricxByNameToNumber = (nameBytes bs args :
+  bindResult (runArboricxArgsByName nameBytes bs args)
+    (value rest : wrapHostValue hostNumber? hostNumber value rest))
+
+runArboricxByNameToBool = (nameBytes bs args :
+  bindResult (runArboricxArgsByName nameBytes bs args)
+    (value rest : wrapHostValue hostBool? hostBool value rest))
+
+runArboricxByNameToList = (nameBytes bs args :
+  bindResult (runArboricxArgsByName nameBytes bs args)
+    (value rest : wrapHostValue hostList? hostList value rest))
+
+runArboricxByNameToBytes = (nameBytes bs args :
+  bindResult (runArboricxArgsByName nameBytes bs args)
+    (value rest : wrapHostValue hostBytes? hostBytes value rest))
+
+runArboricxToTree = (bs args : runArboricxByNameToTree [] bs args)
+runArboricxToString = (bs args : runArboricxByNameToString [] bs args)
+runArboricxToNumber = (bs args : runArboricxByNameToNumber [] bs args)
+runArboricxToBool = (bs args : runArboricxByNameToBool [] bs args)
+runArboricxToList = (bs args : runArboricxByNameToList [] bs args)
+runArboricxToBytes = (bs args : runArboricxByNameToBytes [] bs args)