cspm/src/HST/CSPM/Environments.hs
cspm/tests/HST/CSPM/Tests/Environments.hs
@@ -8,9 +8,11 @@ Author: Douglas Creager
Library
HS-Source-Dirs: src, tests
- Build-Depends: base, haskell98, QuickCheck >= 1.1
+ Build-Depends: base, haskell98, containers,
+ QuickCheck >= 1.1
Exposed-Modules: HST.CSPM
- Other-Modules: HST.CSPM.Evaluate,
+ Other-Modules: HST.CSPM.Environments,
+ HST.CSPM.Evaluate,
HST.CSPM.Expressions,
HST.CSPM.Values
cspm/HST.cabal
@@ -24,10 +24,12 @@ module HST.CSPM
(
module HST.CSPM.Expressions,
module HST.CSPM.Values,
- module HST.CSPM.Evaluate
+ module HST.CSPM.Evaluate,
+ module HST.CSPM.Environments
)
where
import HST.CSPM.Expressions
import HST.CSPM.Values
import HST.CSPM.Evaluate
+import HST.CSPM.Environments
cspm/src/HST/CSPM.hs
@@ -29,6 +29,7 @@ import HST.CSPM.Values
eval :: Expression -> Value
+eval EBottom = VBottom
eval (ENumber id) = VNumber (evalNumber id)
eval (ESequence s) = VSequence (evalSequence s)
eval (ESet a) = VSet (evalSet a)
cspm/src/HST/CSPM/Evaluate.hs
@@ -22,18 +22,37 @@
module HST.CSPM.Expressions where
+-- Identifiers
+
+newtype Identifier
+ = Identifier String
+ deriving (Eq, Ord)
+
+instance Show Identifier where
+ show (Identifier s) = show s
+
+data Binding
+ = Binding Identifier Expression
+ deriving (Eq, Ord)
+
+instance Show Binding where
+ show (Binding id x) = show id ++ " = " ++ show x
+
-- Expressions
data Expression
- = ENumber Number
+ = EBottom
+ | ENumber Number
| ESequence Sequence
| ESet Set
| EBoolean Boolean
| ETuple Tuple
| QHead Expression
| EIfThenElse Expression Expression Expression
+ deriving (Eq, Ord)
instance Show Expression where
+ show EBottom = "Bottom"
show (ENumber n) = show n
show (ESequence s) = show s
show (ESet a) = show a
@@ -66,6 +85,7 @@ data Number
| NRem Expression Expression
| QLength Expression
| SCardinality Expression
+ deriving (Eq, Ord)
instance Show Number where
show (NLit i) = show i
@@ -87,6 +107,7 @@ data Sequence
| QConcat Expression Expression
| QTail Expression
-- TODO: sequence comprehension
+ deriving (Eq, Ord)
instance Show Sequence where
show (QLit xs) = "<" ++ show xs ++ ">"
@@ -110,6 +131,7 @@ data Set
| SPowerset Expression
| SSequenceset Expression
-- TODO: set comprehension
+ deriving (Eq, Ord)
instance Show Set where
show (SLit xs) = "{" ++ show xs ++ "}"
@@ -142,6 +164,7 @@ data Boolean
| QIn Expression Expression
| SIn Expression Expression
| SEmpty Expression
+ deriving (Eq, Ord)
instance Show Boolean where
show BTrue = "true"
@@ -164,4 +187,4 @@ instance Show Boolean where
data Tuple
= TLit [Expression]
- deriving Show
+ deriving (Eq, Ord, Show)
cspm/src/HST/CSPM/Expressions.hs
@@ -53,7 +53,8 @@ listOf g = sized listOf'
where
listOf' n = sequence [g | i <- [1..n]]
-esequence = listOf enumber
+qsequence = listOf enumber
+esequence = liftM (ESequence . QLit) qsequence
boolean :: Gen Boolean
boolean = sized boolean'
@@ -67,3 +68,10 @@ boolean = sized boolean'
subbool = liftM EBoolean $ boolean' (n `div` 2)
eboolean = liftM EBoolean boolean
+
+expression = oneof [enumber, esequence, eboolean]
+
+identifier = elements $ map (Identifier . (:[])) ['a'..'z']
+
+pair :: Gen a -> Gen b -> Gen (a, b)
+pair = liftM2 (curry id)
cspm/tests/HST/CSPM/Tests/Generators.hs
@@ -58,7 +58,7 @@ prop_SeqClosedRange = forAll (two enumber) tester
VNumber i1 = eval n1
VNumber i2 = eval n2
-prop_SeqConcat = forAll (two esequence) tester
+prop_SeqConcat = forAll (two qsequence) tester
where
tester (ns1, ns2) = v0 == v12
where
@@ -71,7 +71,7 @@ prop_SeqConcat = forAll (two esequence) tester
VSequence q2 = v2
v12 = VSequence (q1 ++ q2)
-prop_SeqTail = forAll esequence tester
+prop_SeqTail = forAll qsequence tester
where
tester ns = (length ns > 0) ==> v0 == v1
where
cspm/tests/HST/CSPM/Tests/Sequences.hs
eefa050ea24b224a956ca442752678d9a23c441c
Douglas Creager
dcreager@alum.mit.edu
http://github.com/dcreager/hst/commit/2a3f31e387e7b41c1856ff79a47ad5bfebdea5cc
2a3f31e387e7b41c1856ff79a47ad5bfebdea5cc
2008-08-30T13:42:50-07:00
2008-08-30T13:04:21-07:00
CSPM environments
An environment is the symbol table that hold CSPM definitions. They
provide a standard mapping between identifiers and the expressions
that define them. Environments can also have an optional parent,
which allows nested scoping; if an identifier is not found in the
current environment, we then proceed to look for it in the containing
environment.
This patch introduces the basic API for creating and using
environments, but does not extend the evaluation rules to use them.
Lighthouse: [#11]
d8fb5b18d814a7e331d40eae76b846b903ee0479
Douglas Creager
dcreager@alum.mit.edu