Somewhat working lambdas

Architectural changes to lambda evaluation and parsing to allow
for correct expression evaluation. Contains several failing AI-generated
tests and we're still failing tests for erroring incomplete definitions
This commit is contained in:
2024-12-27 12:27:00 -06:00
committed by James Eversole
parent 5e574d2ca1
commit c3c6646cb2
5 changed files with 420 additions and 336 deletions

View File

@ -2,121 +2,93 @@ module Eval where
import Parser
import Research
import Data.Set (Set)
import qualified Data.Set as Set
import Data.List (foldl')
import qualified Data.Map as Map
import Data.Map (Map)
evalSingle :: Map.Map String T -> SaplingAST -> Map.Map String T
import Data.Map (Map)
import qualified Data.Map as Map
import Data.List (foldl')
import qualified Data.Set as Set
evalSingle :: Map String T -> SaplingAST -> Map String T
evalSingle env term = case term of
SFunc name [] body ->
let result = evalAST env body
in Map.insert name result env
SApp func arg ->
let result = apply (evalAST env func) (evalAST env arg)
in Map.insert "__result" result env
SVar name -> case Map.lookup name env of
Just value -> Map.insert "__result" value env
Nothing -> error $ "Variable " ++ name ++ " not defined"
_ ->
let result = evalAST env term
in Map.insert "__result" result env
SFunc name [] body ->
let
lineNoLambda = eliminateLambda body
result = evalAST env lineNoLambda
in Map.insert name result env
SLambda _ body ->
let result = evalAST env body
in Map.insert "__result" result env
SApp func arg ->
let result = apply (evalAST env func) (evalAST env arg)
in Map.insert "__result" result env
SVar name ->
case Map.lookup name env of
Just value -> Map.insert "__result" value env
Nothing -> error $ "Variable " ++ name ++ " not defined"
_ ->
let result = evalAST env term
in Map.insert "__result" result env
evalSapling :: Map String T -> [SaplingAST] -> Map String T
evalSapling env [] = env
evalSapling env [lastLine] =
let
lastLineNoLambda = eliminateLambda lastLine
let lastLineNoLambda = eliminateLambda lastLine
updatedEnv = evalSingle env lastLineNoLambda
in Map.insert "__result" (result updatedEnv) updatedEnv
evalSapling env (line:rest) =
let
lineNoLambda = eliminateLambda line
let lineNoLambda = eliminateLambda line
updatedEnv = evalSingle env lineNoLambda
in evalSapling updatedEnv rest
evalAST :: Map String T -> SaplingAST -> T
evalAST env term = case term of
SVar name ->
case Map.lookup name env of
Just value -> value
Nothing -> error $ "Variable " ++ name ++ " not defined"
SVar name -> case Map.lookup name env of
Just value -> value
Nothing -> error $ "Variable " ++ name ++ " not defined"
TLeaf -> Leaf
TStem t ->
Stem (evalAST env t)
TFork t1 t2 ->
Fork (evalAST env t1) (evalAST env t2)
SApp t1 t2 ->
apply (evalAST env t1) (evalAST env t2)
TStem t -> Stem (evalAST env t)
TFork t1 t2 -> Fork (evalAST env t1) (evalAST env t2)
SApp t1 t2 -> apply (evalAST env t1) (evalAST env t2)
SStr str -> toString str
SInt num -> toNumber num
SList elems -> toList (map (evalAST Map.empty) elems)
SFunc name args body ->
error $ "Unexpected function definition " ++ name
++ " in evalAST; define via evalSingle."
SLambda {} ->
error "Internal error: SLambda found in evalAST after elimination."
result :: Map String T -> T
result r = case Map.lookup "__result" r of
Just a -> a
Nothing -> error "No __result field found in provided environment"
SLambda {} -> error "Internal error: SLambda found in evalAST after elimination."
eliminateLambda :: SaplingAST -> SaplingAST
eliminateLambda (SLambda (v:vs) body)
| null vs = lambdaToT v (eliminateLambda body)
| otherwise =
eliminateLambda (SLambda [v] (SLambda vs body))
eliminateLambda (SApp f arg) =
SApp (eliminateLambda f) (eliminateLambda arg)
eliminateLambda (TStem t) =
TStem (eliminateLambda t)
eliminateLambda (TFork l r) =
TFork (eliminateLambda l) (eliminateLambda r)
eliminateLambda (SList xs) =
SList (map eliminateLambda xs)
eliminateLambda (SFunc n vs b) =
SFunc n vs (eliminateLambda b)
| null vs = lambdaToT v (eliminateLambda body)
| otherwise = eliminateLambda (SLambda [v] (SLambda vs body))
eliminateLambda (SApp f arg) = SApp (eliminateLambda f) (eliminateLambda arg)
eliminateLambda (TStem t) = TStem (eliminateLambda t)
eliminateLambda (TFork l r) = TFork (eliminateLambda l) (eliminateLambda r)
eliminateLambda (SList xs) = SList (map eliminateLambda xs)
eliminateLambda other = other
lambdaToT :: String -> SaplingAST -> SaplingAST
lambdaToT x (SVar y)
| x == y = tI
| x == y = tI
lambdaToT x (SVar y)
| x /= y =
SApp tK (SVar y)
| x /= y = SApp tK (SVar y)
lambdaToT x t
| not (isFree x t) =
SApp tK t
| not (isFree x t) = SApp tK t
lambdaToT x (SApp n u)
| not (isFree x (SApp n u)) =
SApp tK (SApp (eliminateLambda n) (eliminateLambda u))
lambdaToT x (SApp n u) =
SApp
(SApp tS (lambdaToT x (eliminateLambda n)))
(lambdaToT x (eliminateLambda u))
lambdaToT x (SApp f args) = lambdaToT x f
| not (isFree x (SApp n u)) = SApp tK (SApp (eliminateLambda n) (eliminateLambda u))
lambdaToT x (SApp n u) = SApp (SApp tS (lambdaToT x (eliminateLambda n))) (lambdaToT x (eliminateLambda u))
lambdaToT x body
| not (isFree x body) =
SApp tK body
| otherwise =
SApp
(SApp tS (lambdaToT x body))
tLeaf
| not (isFree x body) = SApp tK body
| otherwise = SApp (SApp tS (lambdaToT x body)) TLeaf
tLeaf :: SaplingAST
tLeaf = TLeaf
freeVars :: SaplingAST -> Set String
freeVars :: SaplingAST -> Set.Set String
freeVars (SVar v) = Set.singleton v
freeVars (SInt _) = Set.empty
freeVars (SStr _) = Set.empty
freeVars (SList xs) = foldMap freeVars xs
freeVars (SFunc _ _ b) = freeVars b
freeVars (SApp f arg) = freeVars f <> freeVars arg
freeVars TLeaf = Set.empty
freeVars (SFunc _ _ b) = freeVars b
freeVars (TStem t) = freeVars t
freeVars (TFork l r) = freeVars l <> freeVars r
freeVars (SLambda vs b) = foldr Set.delete (freeVars b) vs
@ -130,11 +102,15 @@ toAST (Stem a) = TStem (toAST a)
toAST (Fork a b) = TFork (toAST a) (toAST b)
tI :: SaplingAST
tI = toAST _I
tI = SApp (SApp TLeaf (SApp TLeaf (SApp TLeaf TLeaf))) TLeaf
tK :: SaplingAST
tK = toAST _K
tK = SApp TLeaf TLeaf
tS :: SaplingAST
tS = toAST _S
tS = SApp (SApp TLeaf (SApp TLeaf (SApp (SApp TLeaf TLeaf) TLeaf))) TLeaf
result :: Map String T -> T
result r = case Map.lookup "__result" r of
Just a -> a
Nothing -> error "No __result field found in provided environment"