1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
module Builtins where
import Code
( Builtin(..)
, BuiltinFn
, Cho(..)
, Datum(..)
, Instr(..)
, Interp(..)
, heapStruct
)
import qualified Compiler as Co
import Control.Monad.IO.Class (liftIO)
import Control.Monad.Trans.Class (lift)
import Control.Monad.Trans.State.Lazy (get, gets, modify)
import Data.Functor.Identity (runIdentity)
import Data.List (intercalate)
import qualified Data.Map as M
import Env (PrlgEnv(..), findAtom, findStruct)
import qualified IR
import Interpreter (backtrack)
import qualified Operators as O
import System.Console.Haskeline (getInputChar, outputStr, outputStrLn)
bi = Builtin
showTerm itos heap = runIdentity . heapStruct atom struct hrec heap
where
atom (Atom a) = pure $ itos M.! a
atom VoidRef = pure "_"
struct (Struct (IR.Id h _)) args =
pure $ itos M.! h ++ "(" ++ intercalate "," args ++ ")"
hrec (HeapRef hr) ref =
pure $
(if hr == ref
then "_X"
else "_Rec") ++
show hr
printLocals :: BuiltinFn
printLocals = do
scope <- gets (gvar . cur)
heap <- gets (heap . cur)
IR.StrTable _ _ itos <- gets strtable
flip traverse (M.elems scope) $ \(ref, name) ->
lift . outputStrLn $
(maybe "_" id $ itos M.!? name) ++ " = " ++ showTerm itos heap ref
return Nothing
promptRetry :: BuiltinFn
promptRetry = do
last <- gets (null . cho)
if last
then return Nothing
else promptRetry'
promptRetry' :: BuiltinFn
promptRetry' = do
x <- lift $ getInputChar "? "
case x of
Just ';' -> backtrack
_ -> return Nothing
write :: BuiltinFn
write = do
scope <- gets (hvar . cur)
heap <- gets (heap . cur)
IR.StrTable _ _ itos <- gets strtable
lift . outputStr . showTerm itos heap . fst $ scope M.! 0
return Nothing
nl :: BuiltinFn
nl = do
lift $ outputStrLn ""
return Nothing
writeln :: BuiltinFn
writeln = write >> nl
assertFact :: BuiltinFn
assertFact = do
scope <- gets (hvar . cur)
heap <- gets (heap . cur)
case Co.compileGoal . Co.squashVars <$>
Co.heapStructPrlgInt Nothing heap (fst $ scope M.! 0) of
Just (U (Struct s):head) -> do
addClause s $ head ++ [NoGoal]
return Nothing
_ -> backtrack --TODO actually throw
assertClause :: BuiltinFn
assertClause = do
scope <- gets (hvar . cur)
heap <- gets (heap . cur)
commaId <- findStruct "," 2
cut <- findAtom "!"
case Co.squashVars . IR.CallI (IR.Id 0 0) <$>
traverse (Co.heapStructPrlgInt Nothing heap . fst . (M.!) scope) [0, 1] of
Just (IR.CallI (IR.Id 0 0) [hs, gs]) ->
let (U (Struct s):cs) =
Co.compileGoal hs ++ Co.seqGoals (Co.compileGoals commaId cut gs)
in do addClause s cs
return Nothing
_ -> backtrack
retractall :: BuiltinFn
retractall = do
return Nothing
{- adding the builtins -}
addOp op = modify $ \s -> s {ops = op : ops s}
addClause struct code =
modify $ \s ->
s {defs = M.alter (Just . maybe [code] (\hs -> code : hs)) struct $ defs s}
addProcedure struct heads =
modify $ \s -> s {defs = M.insert struct heads $ defs s}
addProc n a c = do
sym <- findStruct n a
addProcedure sym c
addBi0 n b = addProc n 0 [[Invoke $ bi b]]
addPrelude :: PrlgEnv ()
addPrelude = do
pure undefined
{- primitives -}
addBi0 "true" (pure Nothing)
addBi0 "fail" backtrack
addOp $ O.xfx "=" 700
addProc "=" 2 [[U (LocalRef 0 0), U (LocalRef 0 0), NoGoal]]
{- clauses -}
addOp $ O.xfy "," 1000
addOp $ O.xfx ":-" 1200
horn2 <- findStruct ":-" 2
--addOp $ O.fx ":-" 1200
addProc
"assert"
1
[ [ U (Struct horn2)
, U (LocalRef 0 0)
, U (LocalRef 1 0)
, Cut
, Invoke (bi assertClause)
]
, [U (LocalRef 0 0), Invoke (bi assertFact)]
]
addProc "retractall" 1 [[U (LocalRef 0 0), Invoke (bi retractall)]]
{- query tools -}
addBi0 "print_locals" printLocals
addBi0 "prompt_retry" promptRetry'
addBi0 "query" (printLocals >> promptRetry)
{- IO -}
addProc "write" 1 [[U (LocalRef 0 0), Invoke (bi write)]]
addProc "writeln" 1 [[U (LocalRef 0 0), Invoke (bi writeln)]]
addBi0 "nl" nl
{- debug -}
addBi0 "interpreter_trace" (get >>= liftIO . print >> pure Nothing)
|
