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034bb562d4
This patch adds the `Matcher` monad, which is capable of filtering any recursive data structure, bottom-up, yielding a list of (or an optional) result. These functions are probably going to be used over `Term` values, so API is provided to wrap common projection functions. The API was more or less copied directly from that of Clang's AST matching facilities. There are a lot of things we can do in the future: * Binding results yielded in matchers to associated names, for future transformation stages to look up and modify. * Actual transformation stages. * Optimizations. This is not very fast. A million thanks to @robrix, whose sage advice managed to turn my kooky idea for an API into something really special and exciting.
41 lines
1.4 KiB
Haskell
41 lines
1.4 KiB
Haskell
{-# LANGUAGE TypeOperators #-}
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module Matching.Go.Spec (spec) where
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import Control.Abstract.Matching
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import Data.Abstract.Module
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import Data.List
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import qualified Data.Syntax.Declaration as Decl
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import qualified Data.Syntax.Literal as Lit
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import qualified Data.Syntax.Statement as Stmt
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import Data.Union
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import SpecHelpers
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-- This gets the ByteString contents of all integers
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integerMatcher :: (Lit.Integer :< fs) => Matcher (Term (Union fs) ann) ByteString
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integerMatcher = match Lit.integerContent target
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-- This matches all for-loops with its index variable new variable bound to 0,
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-- e.g. `for i := 0; i < 10; i++`
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loopMatcher :: ( Stmt.For :< fs
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, Stmt.Assignment :< fs
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, Lit.Integer :< fs)
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=> TermMatcher fs ann
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loopMatcher = target <* go where
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go = match Stmt.forBefore $
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match Stmt.assignmentValue $
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match Lit.integerContent $
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ensure (== "0")
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spec :: Spec
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spec = describe "matching/go" $ do
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it "extracts integers" $ do
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parsed <- moduleBody <$> parseFile goParser Nothing "test/fixtures/go/matching/integers.go"
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let matched = runMatcher integerMatcher parsed
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sort matched `shouldBe` ["1", "2", "3"]
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it "counts for loops" $ do
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parsed <- moduleBody <$> parseFile goParser Nothing "test/fixtures/go/matching/for.go"
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let matched = runMatcher @[] loopMatcher parsed
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length matched `shouldBe` 2
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