Initial commit

14 files changed, 372 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
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--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+.stack-work/
+*~
\ No newline at end of file
diff --git a/ChangeLog.md b/ChangeLog.md
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index 0000000..dd254c3
--- /dev/null
+++ b/ChangeLog.md
@@ -0,0 +1,3 @@
+# Changelog for bruijn
+
+## Unreleased changes
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..342c588
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,30 @@
+Copyright Author name here (c) 2022
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Author name here nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..c443c77
--- /dev/null
+++ b/README.md
@@ -0,0 +1 @@
+# bruijn
diff --git a/Setup.hs b/Setup.hs
new file mode 100644
index 0000000..9a994af
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/app/Main.hs b/app/Main.hs
new file mode 100644
index 0000000..7d20262
--- /dev/null
+++ b/app/Main.hs
@@ -0,0 +1,6 @@
+module Main where
+
+import Eval
+
+main :: IO ()
+main = evalMain
diff --git a/bruijn.cabal b/bruijn.cabal
new file mode 100644
index 0000000..8d443f6
--- /dev/null
+++ b/bruijn.cabal
@@ -0,0 +1,76 @@
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.34.4.
+--
+-- see: https://github.com/sol/hpack
+
+name:           bruijn
+version:        0.1.0.0
+description:    Please see the README on GitHub at <https://github.com/githubuser/bruijn#readme>
+homepage:       https://github.com/githubuser/bruijn#readme
+bug-reports:    https://github.com/githubuser/bruijn/issues
+author:         Author name here
+maintainer:     example@example.com
+copyright:      2022 Author name here
+license:        BSD3
+license-file:   LICENSE
+build-type:     Simple
+extra-source-files:
+    README.md
+    ChangeLog.md
+
+source-repository head
+  type: git
+  location: https://github.com/githubuser/bruijn
+
+library
+  exposed-modules:
+      Eval
+      Parser
+  other-modules:
+      Paths_bruijn
+  hs-source-dirs:
+      src
+  default-extensions:
+      LambdaCase
+  build-depends:
+      base >=4.7 && <5
+    , haskeline
+    , mtl
+    , parsec
+  default-language: Haskell2010
+
+executable bruijn-exe
+  main-is: Main.hs
+  other-modules:
+      Paths_bruijn
+  hs-source-dirs:
+      app
+  default-extensions:
+      LambdaCase
+  ghc-options: -threaded -rtsopts -with-rtsopts=-N
+  build-depends:
+      base >=4.7 && <5
+    , bruijn
+    , haskeline
+    , mtl
+    , parsec
+  default-language: Haskell2010
+
+test-suite bruijn-test
+  type: exitcode-stdio-1.0
+  main-is: Spec.hs
+  other-modules:
+      Paths_bruijn
+  hs-source-dirs:
+      test
+  default-extensions:
+      LambdaCase
+  ghc-options: -threaded -rtsopts -with-rtsopts=-N
+  build-depends:
+      base >=4.7 && <5
+    , bruijn
+    , haskeline
+    , mtl
+    , parsec
+  default-language: Haskell2010
diff --git a/package.yaml b/package.yaml
new file mode 100644
index 0000000..d5e1c58
--- /dev/null
+++ b/package.yaml
@@ -0,0 +1,54 @@
+name:                bruijn
+version:             0.1.0.0
+github:              "githubuser/bruijn"
+license:             BSD3
+author:              "Author name here"
+maintainer:          "example@example.com"
+copyright:           "2022 Author name here"
+
+extra-source-files:
+- README.md
+- ChangeLog.md
+
+# Metadata used when publishing your package
+# synopsis:            Short description of your package
+# category:            Web
+
+# To avoid duplicated efforts in documentation and dealing with the
+# complications of embedding Haddock markup inside cabal files, it is
+# common to point users to the README.md file.
+description:         Please see the README on GitHub at <https://github.com/githubuser/bruijn#readme>
+
+default-extensions:
+  - LambdaCase
+
+dependencies:
+- base >= 4.7 && < 5
+- mtl
+- haskeline
+- parsec
+
+library:
+  source-dirs: src
+
+executables:
+  bruijn-exe:
+    main:                Main.hs
+    source-dirs:         app
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - bruijn
+
+tests:
+  bruijn-test:
+    main:                Spec.hs
+    source-dirs:         test
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - bruijn
diff --git a/src/Eval.hs b/src/Eval.hs
new file mode 100644
index 0000000..72c8985
--- /dev/null
+++ b/src/Eval.hs
@@ -0,0 +1,45 @@
+module Eval
+  ( evalMain
+  ) where
+
+import           Control.Exception
+import           Control.Monad.State
+import           System.Console.Haskeline
+import           System.Environment
+import           System.Exit
+import           System.IO
+
+type Environment = [String]
+
+eval :: String -> IO ()
+eval code = putStrLn "ok"
+
+evalFile :: String -> IO ()
+evalFile path = do
+  file <- try $ readFile path :: IO (Either IOError String)
+  case file of
+    Left  exception -> print (exception :: IOError)
+    Right file      -> eval file
+
+evalRepl :: String -> Environment -> InputT IO Environment
+evalRepl line env = outputStrLn (show env) >> pure env
+
+repl :: Environment -> InputT IO ()
+repl env =
+  getInputLine ":: "
+    >>= (\case
+          Nothing   -> pure ()
+          Just line -> evalRepl line env >>= repl
+        )
+
+usage :: IO ()
+usage = putStrLn "Invalid arguments. Use 'bruijn [file]' instead"
+
+evalMain :: IO ()
+evalMain = do
+  args <- getArgs
+  case args of
+    [] -> runInputT defaultSettings { historyFile = Just ".brown-history" }
+      $ repl []
+    [path] -> evalFile path
+    _      -> usage
diff --git a/src/Parser.hs b/src/Parser.hs
new file mode 100644
index 0000000..611261f
--- /dev/null
+++ b/src/Parser.hs
@@ -0,0 +1,66 @@
+module Parser where
+
+import           Data.Functor.Identity
+import           Text.Parsec
+import           Text.Parsec.Language
+import qualified Text.Parsec.Token             as Token
+
+languageDef :: GenLanguageDef String u Identity
+languageDef = emptyDef { Token.commentLine     = "#"
+                       , Token.identStart      = letter
+                       , Token.identLetter     = alphaNum <|> char '_'
+                       , Token.reservedOpNames = ["[", "]"]
+                       }
+
+type Parser = Parsec String ()
+
+lexer :: Token.GenTokenParser String u Identity
+lexer = Token.makeTokenParser languageDef
+
+identifier :: Parser String
+identifier = Token.identifier lexer
+
+reservedOp :: String -> Parser ()
+reservedOp = Token.reservedOp lexer
+
+parens :: Parser a -> Parser a
+parens = Token.parens lexer
+
+data Expression = Index Int | Abstraction Int Expression | Application Expression Expression
+  deriving (Ord, Eq)
+data Instruction = Define String Expression | Evaluate Expression | Comment String
+
+parseAbstraction :: Parser Expression
+parseAbstraction = do
+  reservedOp "["
+  idc <- endBy1 digit spaces
+  build idc <$> parseExpression
+ where
+  build (idx : idc) body =
+    Abstraction ((read . pure :: Char -> Int) idx) $ build idc body
+  curry [] body = body
+
+parseApplication :: Parser Expression
+parseApplication = do
+  s <- sepBy1 parseSingleton spaces
+  pure $ foldl1 Application s
+
+parseSingleton :: Parser Expression
+parseSingleton = parseAbstraction <|> parens parseApplication
+
+parseExpression :: Parser Expression
+parseExpression = do
+  expr <- parseApplication <|> parseSingleton
+  pure expr
+
+parseDefine :: Parser Instruction
+parseDefine = do
+  var <- identifier
+  space
+  Define var <$> parseExpression
+
+parseLine :: Parser Instruction
+parseLine = try parseDefine
+
+parseReplLine :: Parser Expression
+parseReplLine = try parseExpression
diff --git a/stack.yaml b/stack.yaml
new file mode 100644
index 0000000..63fa884
--- /dev/null
+++ b/stack.yaml
@@ -0,0 +1,67 @@
+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# https://docs.haskellstack.org/en/stable/yaml_configuration/
+
+# Resolver to choose a 'specific' stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# resolver: lts-3.5
+# resolver: nightly-2015-09-21
+# resolver: ghc-7.10.2
+#
+# The location of a snapshot can be provided as a file or url. Stack assumes
+# a snapshot provided as a file might change, whereas a url resource does not.
+#
+# resolver: ./custom-snapshot.yaml
+# resolver: https://example.com/snapshots/2018-01-01.yaml
+resolver:
+  url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/19/3.yaml
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+#   subdirs:
+#   - auto-update
+#   - wai
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver.
+# These entries can reference officially published versions as well as
+# forks / in-progress versions pinned to a git hash. For example:
+#
+# extra-deps:
+# - acme-missiles-0.3
+# - git: https://github.com/commercialhaskell/stack.git
+#   commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#
+# extra-deps: []
+
+# Override default flag values for local packages and extra-deps
+# flags: {}
+
+# Extra package databases containing global packages
+# extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=2.7"
+#
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor
diff --git a/stack.yaml.lock b/stack.yaml.lock
new file mode 100644
index 0000000..6c8ac8e
--- /dev/null
+++ b/stack.yaml.lock
@@ -0,0 +1,13 @@
+# This file was autogenerated by Stack.
+# You should not edit this file by hand.
+# For more information, please see the documentation at:
+#   https://docs.haskellstack.org/en/stable/lock_files
+
+packages: []
+snapshots:
+- completed:
+    size: 617368
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/19/3.yaml
+    sha256: a209d3455279ee76eb45f01f73bbb960ceaaa8dfad8891435384689df4dcb653
+  original:
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/19/3.yaml
diff --git a/test.bruijn b/test.bruijn
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--- /dev/null
+++ b/test.bruijn
@@ -0,0 +1,5 @@
+nil [[0]]
+true [[1]]
+false [[0]]
+id [0]
+main id true
diff --git a/test/Spec.hs b/test/Spec.hs
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index 0000000..cd4753f
--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,2 @@
+main :: IO ()
+main = putStrLn "Test suite not yet implemented"