initial commit w/ lexer & parser

.gitignore

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+.stack-work/

LICENSE

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+Copyright Abigail Magalhães (c) 2021
+
+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 Abigail Magalhães 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.

README.md

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+# cubical

Setup.hs

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+import Distribution.Simple
+main = defaultMain

cubical.cabal

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+name:                cubical
+version:             0.1.0.0
+-- synopsis:
+-- description:
+homepage:            https://github.com/plt-hokusai/cubical#readme
+license:             BSD3
+license-file:        LICENSE
+author:              Abigail Magalhães
+maintainer:          [email protected]
+copyright:           2021 Abigail Magalhães
+category:            Web
+build-type:          Simple
+cabal-version:       >=2.0
+extra-source-files:  README.md
+
+executable cubical
+  hs-source-dirs:      src
+  main-is:             Main.hs
+  default-language:    Haskell2010
+
+  build-depends:       base       ^>= 4.14
+                     , text       ^>= 1.2
+                     , array      ^>= 0.5.4
+                     , bytestring ^>= 0.10
+
+  other-modules:       Presyntax.Lexer
+                     , Presyntax.Parser
+                     , Presyntax.Tokens
+                     , Presyntax.Presyntax
+
+  build-tool-depends:  alex:alex >= 3.2.4 && < 4.0
+                    ,  happy:happy >= 1.19.12 && < 2.0
+

hie.yaml

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+cradle:
+  stack:

src/Main.hs

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+module Main where
+
+main :: IO ()
+main = do
+  putStrLn "hello world"

src/Presyntax/Lexer.x

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+{
+module Presyntax.Lexer where
+
+import qualified Data.ByteString.Lazy as Lbs
+import qualified Data.Text.Encoding as T
+import qualified Data.ByteString as Sbs
+
+import Presyntax.Tokens
+}
+
+%wrapper "monad-bytestring"
+
+$alpha = [a-zA-Z]
+$digit = [0-9]
+
+tokens :-
+  $white+                      ;
+  $alpha [$alpha $digit \_ \']* { yield TokVar }
+  
+  \=                            { always TokEqual }
+  \:                            { always TokColon }
+  
+  \\                            { always TokLambda }
+  "->"                          { always TokArrow }
+
+  \(                            { always TokOParen }
+  \{                            { always TokOBrace }
+
+  \)                            { always TokCParen }
+  \}                            { always TokCBrace }
+
+{
+alexEOF :: Alex Token
+alexEOF = do
+  (AlexPn _ l c, _, _, _) <- alexGetInput
+  pure $ Token TokEof l c
+
+yield k t@(AlexPn _ l c, _, s, _) i = pure (Token (k $! (T.decodeUtf8 (Lbs.toStrict (Lbs.take i s)))) l c)
+always k x i = yield (const k) x i
+}

src/Presyntax/Parser.y

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+{
+module Presyntax.Parser where
+
+import qualified Data.Text as T
+import Data.Text (Text)
+
+import Presyntax.Presyntax
+import Presyntax.Tokens
+import Presyntax.Lexer
+
+}
+
+%name parseExp Exp
+
+%tokentype { Token }
+
+%monad { Alex }
+%lexer { lexer } { Token TokEof _ _ }
+
+%errorhandlertype explist
+%error { parseError }
+
+%token
+  var     { Token (TokVar $$) _ _ }
+  '('     { Token TokOParen _ _ }
+  ')'     { Token TokCParen _ _ }
+
+  '{'     { Token TokOBrace _ _ }
+  '}'     { Token TokCBrace _ _ }
+
+  '\\'    { Token TokLambda _ _ }
+  
+  '->'    { Token TokArrow _ _ }
+  ':'     { Token TokColon _ _ }
+  '='     { Token TokEqual _ _ }
+
+%%
+
+Exp :: { Expr }
+Exp
+  : ExpFun Exp                       { App Ex $1 $2 }
+  | ExpFun '{' Exp '}'               { App Im $1 $3 }
+  | '\\' LambdaList '->' Exp         { makeLams $2 $4 }
+  | '(' VarList ':' Exp ')' '->' Exp { makePis Ex $2 $4 $7 }
+  | '{' VarList ':' Exp '}' '->' Exp { makePis Im $2 $4 $7 }
+  | ExpFun '->' Exp                  { Pi Ex (T.singleton '_') $1 $3 }
+  | ExpFun                           { $1 }
+
+LambdaList :: { [(Plicity, Text)] }
+  : var            { [(Ex, $1)] }
+  | var LambdaList { (Ex, $1):$2 }
+
+  | '{'var'}'            { [(Im, $2)] }
+  | '{'var'}' LambdaList { (Im, $2):$4 }
+
+VarList :: { [Text] }
+  : var         { [$1] }
+  | var VarList { $1:$2 }
+
+ExpFun :: { Expr }
+  : Atom        { $1 }
+  | '(' Exp ')' { $2 }
+
+Atom :: { Expr }
+  : var { Var $1 }
+
+{
+lexer cont = alexMonadScan >>= cont
+
+parseError x = alexError (show x)
+
+makeLams xs b = foldr (uncurry Lam) b xs
+makePis p xs t b = foldr (flip (Pi p) t) b xs
+}

src/Presyntax/Presyntax.hs

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+module Presyntax.Presyntax where
+
+import Data.Text (Text)
+
+data Plicity
+  = Im | Ex
+  deriving (Eq, Show, Ord)
+
+data Expr
+  = Var Text
+  | App Plicity Expr Expr
+  | Lam Plicity Text Expr
+  | Pi  Plicity Text Expr Expr
+  deriving (Eq, Show, Ord)
+
+data Statement
+  = Decl Text Expr
+  | Defn Text Expr
+  deriving (Eq, Show, Ord)

src/Presyntax/Tokens.hs

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+module Presyntax.Tokens where
+
+import Data.Text (Text)
+
+data TokenClass
+  = TokVar Text
+  | TokEof
+
+  | TokLambda
+  | TokArrow
+
+  | TokOParen
+  | TokOBrace
+  | TokCParen
+  | TokCBrace
+
+  | TokColon
+  | TokEqual
+  deriving (Eq, Show, Ord)
+
+data Token
+  = Token { tokenClass   :: TokenClass
+          , tokStartLine :: !Int
+          , tokStartCol  :: !Int
+          }
+  deriving (Eq, Show, Ord)

stack.yaml

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+# 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/17/1.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: ">=2.5"
+#
+# 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

stack.yaml.lock

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+# 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: 563098
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/17/1.yaml
+    sha256: 395775c03e66a4286f134d50346b0b6f1432131cf542886252984b4cfa5fef69
+  original:
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/17/1.yaml