summaryrefslogtreecommitdiffstats
path: root/src/interpreter.hs
blob: 9ba4b3cc8e96e54c8724427b901a10663ea34446 (plain)
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
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
module Interpreter where

import Control.Monad.Except
import Data.Char
import Data.Map (Map, (!))
import qualified Data.Map as M
import LTypes
import System.IO (BufferMode (NoBuffering), hSetBuffering, stdin)
import Utils

debugWaitForChar Config {configDebugMode = mode} =
  if mode
    then do
      hSetBuffering stdin NoBuffering
      c <- getChar
      pure $ case c of
        'q' -> ExecExit
        _ -> ExecContinue
    else pure ExecContinue

debugPrint Config {configDebugMode = mode} message =
  if mode
    then liftIO $ putStrLn $ "[debug] " ++ message
    else pure ()

interpretSource :: Config -> LState -> ExceptT LException IO ()
interpretSource config LState {lSource = []} = pure ()
interpretSource config state@LState {lSource = (word : rest)} = do
  newState <- interpretWord state {lSource = rest} word
  liftIO $ debugPrint config $ "processed " ++ show word ++ ", newState ="
  liftIO $ debugState config newState
  step <- liftIO $ debugWaitForChar config
  case step of
    ExecContinue -> interpretSource config newState
    ExecExit -> pure ()

interpretWord :: LState -> LWord -> ExceptT LException IO LState
-- non-nestable structures
interpretWord state@LState {lStack = stack, lPhraseDepth = phraseDepth} word@(LSymbol "define") =
  pure $
    state
      { lPhraseDepth = phraseDepth + 1,
        lStack = word : stack
      }
interpretWord state@LState {lDefs = defs, lStack = stack, lPhraseDepth = phraseDepth} word@(LSymbol ";") = do
  let defineSpan = takeWhile (\word -> word /= LSymbol "define") stack
  let newStack = dropWhile (\word -> word /= LSymbol "define") stack $> tail
  (LSymbol identifier, body) <- consume1 LSymbolT (reverse defineSpan)
  let newDefs = M.insert identifier body defs
  pure $
    state
      { lPhraseDepth = phraseDepth - 1,
        lDefs = newDefs,
        lStack = newStack
      }
-- words that simply move from source to stack
interpretWord state@LState {lStack = stack} word@(LInteger _) = pure $ state {lStack = word : stack}
interpretWord state@LState {lStack = stack} word@(LFloat _) = pure $ state {lStack = word : stack}
interpretWord state@LState {lStack = stack} word@(LBool _) = pure $ state {lStack = word : stack}
interpretWord state@LState {lStack = stack} word@(LChar _) = pure $ state {lStack = word : stack}
interpretWord state@LState {lStack = stack} word@(LLabel _) = pure $ state {lStack = word : stack}
interpretWord state@LState {lStack = stack} word@(LPhrase _) = pure $ state {lStack = word : stack}
-- string literals
interpretWord state@LState {lSource = source, lStrLitRefMap = strLitRefMap} (LStringLitRef ref) =
  let strLitP = strLitRefMap ! ref
   in pure $ state {lSource = strLitP ++ source}
-- phrase markers are always evaled
interpretWord state@LState {lStack = stack, lPhraseDepth = phraseDepth} word@(LSymbol "[") =
  pure $ state {lPhraseDepth = phraseDepth + 1, lStack = word : stack}
interpretWord state@LState {lStack = stack, lPhraseDepth = phraseDepth} word@(LSymbol "]") = do
  (phrase, _ : stack') <- safeBreak (== LSymbol "[") (LException "phrase-start marker '[' missing in stack") stack
  let newStack = LPhrase (reverse phrase) : stack'
  pure $ state {lPhraseDepth = phraseDepth - 1, lStack = newStack}
-- definition lookup
interpretWord state@LState {lDefs = defs, lDict = dict, lSource = source, lPhraseDepth = phraseDepth, lStack = stack} word@(LSymbol symbol)
  | phraseDepth == 0 =
    case M.lookup symbol defs of
      Just body -> pure $ state {lSource = body ++ source}
      Nothing ->
        case symbol of
          "dup" -> pure $ state {lStack = head stack : stack}
          "drop" -> pure $ state {lStack = tail stack}
          "clear" -> pure $ state {lStack = []}
          "noop" -> pure state
          "true" -> pure $ state {lStack = LBool True : stack}
          "false" -> pure $ state {lStack = LBool False : stack}
          "not" -> do
            (LBool a, stack') <- consume1 LBoolT stack
            pure $ state {lStack = LBool (not a) : stack'}
          "float" -> do
            (LInteger a, stack') <- consume1 LIntegerT stack
            pure $ state {lStack = LFloat (fromIntegral a) : stack'}
          "round" -> do
            (LFloat a, stack') <- consume1 LFloatT stack
            pure $ state {lStack = LInteger (round a) : stack'}
          "!" -> do
            (LLabel a, b, stack') <- consume2 LLabelT AnyT stack
            let newDict = M.insert a b dict
            pure $ state {lDict = newDict, lStack = stack'}
          "@" -> do
            (LLabel a, stack') <- consume1 LLabelT stack
            let lookupWord = dict ! a
            pure $ state {lStack = lookupWord : stack'}
          "forget" -> do
            (LLabel a, stack') <- consume1 LLabelT stack
            let newDict = M.delete a dict
            pure $ state {lStack = stack', lDict = newDict}
          "." -> do
            (a, stack') <- consume1 AnyT stack
            liftIO . putStrLn $ reprWord a
            pure $ state {lStack = stack'}
          "s." -> do
            (wordP, stack') <- consume1 LPhraseT stack
            let LPhrase ws = wordP
            let isLChar w = case w of LChar _ -> True; _ -> False
            unless (all isLChar ws) $ throwError $ LException $ "cannot string-print heterogenous or non-string phrase: " ++ reprWord wordP
            let stringRepr = ws $> map (\(LChar c) -> c)
            liftIO . putStrLn $ stringRepr
            pure $ state {lStack = stack'}
          "?" -> do
            (LLabel a, stack') <- consume1 LLabelT stack
            let lookupWord = dict ! a
            liftIO . putStrLn $ reprWord lookupWord
            pure $ state {lStack = stack'}
          "+" -> do
            (a, b, stack') <- consume2 AnyT AnyT stack
            result <- lAddNumbers b a
            pure $ state {lStack = result : stack'}
          "-" -> do
            (a, b, stack') <- consume2 AnyT AnyT stack
            result <- lSubNumbers b a
            pure $ state {lStack = result : stack'}
          "*" -> do
            (a, b, stack') <- consume2 AnyT AnyT stack
            result <- lMultiplyNumbers b a
            pure $ state {lStack = result : stack'}
          "/" -> do
            (a, b, stack') <- consume2 AnyT AnyT stack
            result <- lDivideNumbers b a
            pure $ state {lStack = result : stack'}
          "mod" -> do
            (a, b, stack') <- consume2 AnyT AnyT stack
            result <- lModNumbers b a
            pure $ state {lStack = result : stack'}
          "eq?" -> do
            (a, b, stack') <- consume2 AnyT AnyT stack
            pure $ state {lStack = LBool (a == b) : stack'}
          "gt?" -> do
            (a, b, stack') <- consume2 AnyT AnyT stack
            result <- lGreaterThan b a
            pure $ state {lStack = result : stack'}
          "lt?" -> do
            (a, b, stack') <- consume2 AnyT AnyT stack
            result <- lLesserThan b a
            pure $ state {lStack = result : stack'}
          "unphrase" -> do
            (LPhrase phrase, stack') <- consume1 LPhraseT stack
            pure $ state {lSource = phrase ++ source, lStack = stack'}
          "phrase" -> do
            (LSymbol "]", stack') <- consume1 LSymbolT stack
            (body, _ : newStack) <- safeBreak (== LSymbol "[") (LException "phrase-start marker '[' missing in stack") stack'
            pure $ state {lStack = LPhrase (reverse body) : newStack}
          "repr" -> do
            (word, stack') <- consume1 AnyT stack
            let reprStr = reprWord word $> map LChar .> LPhrase
            pure $ state {lStack = reprStr : stack'}
          "pop" -> do
            (LPhrase phrase, stack') <- consume1 LPhraseT stack
            let (first : rest) = phrase
            pure $ state {lStack = first : LPhrase rest : stack'}
          "stack-size" ->
            let size = LInteger $ fromIntegral (length stack)
             in pure $ state {lStack = size : stack}
          "']" ->
            pure $ state {lStack = LSymbol "]" : stack}
          "'[" ->
            pure $ state {lStack = LSymbol "[" : stack}
          "cond" -> do
            (fb, tb, LBool cond, stack') <- consume3 LPhraseT LPhraseT LBoolT stack
            let LPhrase branch = if cond then tb else fb
            let newSource = branch ++ source
            pure $ state {lStack = stack', lSource = newSource}
          "loop" -> do
            (bodyP, condP, stack') <- consume2 LPhraseT LPhraseT stack
            let (LPhrase body, LPhrase cond) = (bodyP, condP)
            let ifWords = cond ++ [LPhrase (body ++ [condP, bodyP, LSymbol "loop"])] ++ [LPhrase [], LSymbol "cond"]
            let newSource = ifWords ++ source
            pure $ state {lStack = stack', lSource = newSource}
          _ -> throwError $ LException $ "not defined: " ++ symbol
  | otherwise = pure $ state {lStack = word : stack}

lAddNumbers :: LWord -> LWord -> ExceptT LException IO LWord
lAddNumbers (LInteger a) (LInteger b) = pure $ LInteger (a + b)
lAddNumbers (LFloat a) (LFloat b) = pure $ LFloat (a + b)
lAddNumbers a b = throwError $ LException $ "sum is not defined for " ++ show a ++ ", " ++ show b

lSubNumbers :: LWord -> LWord -> ExceptT LException IO LWord
lSubNumbers (LInteger a) (LInteger b) = pure $ LInteger (a - b)
lSubNumbers (LFloat a) (LFloat b) = pure $ LFloat (a - b)
lSubNumbers a b = throwError $ LException $ "difference is not defined for " ++ show a ++ ", " ++ show b

lMultiplyNumbers :: LWord -> LWord -> ExceptT LException IO LWord
lMultiplyNumbers (LInteger a) (LInteger b) = pure $ LInteger (a * b)
lMultiplyNumbers (LFloat a) (LFloat b) = pure $ LFloat (a * b)
lMultiplyNumbers a b = throwError $ LException $ "product is not defined for " ++ show a ++ ", " ++ show b

lDivideNumbers :: LWord -> LWord -> ExceptT LException IO LWord
lDivideNumbers (LInteger a) (LInteger b) =
  case b of
    0 -> throwError $ LException "division by zero"
    _ -> pure $ LInteger (a `div` b)
lDivideNumbers (LFloat a) (LFloat b) =
  case b of
    0 -> throwError $ LException "division by zero"
    _ -> pure $ LFloat (a / b)
lDivideNumbers a b = throwError $ LException $ "division is not defined for " ++ show a ++ ", " ++ show b

lGreaterThan :: LWord -> LWord -> ExceptT LException IO LWord
lGreaterThan (LInteger a) (LInteger b) = pure $ LBool (a > b)
lGreaterThan (LFloat a) (LFloat b) = pure $ LBool (a > b)
lGreaterThan a b = throwError $ LException $ "greater-than is not defined for " ++ show a ++ ", " ++ show b

lLesserThan :: LWord -> LWord -> ExceptT LException IO LWord
lLesserThan (LInteger a) (LInteger b) = pure $ LBool (a < b)
lLesserThan (LFloat a) (LFloat b) = pure $ LBool (a < b)
lLesserThan a b = throwError $ LException $ "lesser-than is not defined for " ++ show a ++ ", " ++ show b

lModNumbers :: LWord -> LWord -> ExceptT LException IO LWord
lModNumbers (LInteger a) (LInteger b) = pure $ LInteger (a `mod` b)
lModNumbers a b = throwError $ LException $ "modulo is not defined for " ++ show a ++ ", " ++ show b