Add support for importing paths as raw Text

Part of #23 You can now add ` as Text` to the end of any path and the raw contents at that path will be imported as a raw `Text` literal. For example: ``` $ dhall <<< "http://example.com as Text" Text "<!doctype html>\n<html>\n<head>\n <title>Example Domain</title>\n\n <meta charset=\"utf-8\" />\n <meta http-equiv=\"Content-type\" content=\"text/html ; charset=utf-8\" />\n <meta name=\"viewport\" content=\"width=device-width, initial-scale=1\" />\n <style type=\"text/css\">\n body {\n backgro und-color: #f0f0f2;\n margin: 0;\n padding: 0;\n font-famil y: \"Open Sans\", \"Helvetica Neue\", Helvetica, Arial, sans-serif;\n \n }\n div {\n width: 600px;\n margin: 5em auto;\n paddi ng: 50px;\n background-color: #fff;\n border-radius: 1em;\n }\n a:link, a:visited {\n color: #38488f;\n text-decoration: none; \n }\n @media (max-width: 700px) {\n body {\n background -color: #fff;\n }\n div {\n width: auto;\n m argin: 0 auto;\n border-radius: 0;\n padding: 1em;\n }\n }\n </style> \n</head>\n\n<body>\n<div>\n <h1>Example Domain</ h1>\n <p>This domain is established to be used for illustrative examples in d ocuments. You may use this\n domain in examples without prior coordination or asking for permission.</p>\n <p><a href=\"http://www.iana.org/domains/exampl e\">More information...</a></p>\n</div>\n</body>\n</html>\n" ```
dhall-lang · Mar 31, 2017 · fbdfa42 · fbdfa42
1 parent dce4b20
commit fbdfa42
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diff --git a/src/Dhall/Core.hs b/src/Dhall/Core.hs
@@ -1,11 +1,12 @@
-{-# LANGUAGE BangPatterns               #-}
-{-# LANGUAGE CPP                        #-}
-{-# LANGUAGE DeriveFoldable             #-}
-{-# LANGUAGE DeriveFunctor              #-}
-{-# LANGUAGE DeriveTraversable          #-}
-{-# LANGUAGE OverloadedStrings          #-}
-{-# LANGUAGE QuasiQuotes                #-}
-{-# LANGUAGE RankNTypes                 #-}
+{-# LANGUAGE BangPatterns      #-}
+{-# LANGUAGE CPP               #-}
+{-# LANGUAGE DeriveFoldable    #-}
+{-# LANGUAGE DeriveFunctor     #-}
+{-# LANGUAGE DeriveTraversable #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes       #-}
+{-# LANGUAGE RankNTypes        #-}
+{-# LANGUAGE RecordWildCards   #-}
 {-# OPTIONS_GHC -Wall #-}
 
 {-| This module contains the core calculus for the Dhall language.
@@ -18,6 +19,8 @@ module Dhall.Core (
     -- * Syntax
       Const(..)
     , HasHome(..)
+    , PathType(..)
+    , PathMode(..)
     , Path(..)
     , Var(..)
     , Expr(..)
@@ -89,8 +92,8 @@ instance Buildable Const where
 -- | Whether or not a path is relative to the user's home directory
 data HasHome = Home | Homeless deriving (Eq, Ord, Show)
 
--- | Path to an external resource
-data Path
+-- | The type of path to import (i.e. local vs. remote vs. environment)
+data PathType
     = File HasHome FilePath
     -- ^ Local path
     | URL  Text
@@ -99,7 +102,7 @@ data Path
     -- ^ Environment variable
     deriving (Eq, Ord, Show)
 
-instance Buildable Path where
+instance Buildable PathType where
     build (File Home     file)
         = "~/" <> build txt
       where
@@ -116,6 +119,22 @@ instance Buildable Path where
     build (URL  str ) = build str <> " "
     build (Env  env ) = "env:" <> build env
 
+-- | How to interpret the path's contents (i.e. as Dhall code or raw text)
+data PathMode = Code | RawText deriving (Eq, Ord, Show)
+
+-- | Path to an external resource
+data Path = Path
+    { pathType :: PathType
+    , pathMode :: PathMode
+    } deriving (Eq, Ord, Show)
+
+instance Buildable Path where
+    build (Path {..}) = build pathType <> suffix
+      where
+        suffix = case pathMode of
+            RawText -> " as Text"
+            Code    -> ""
+
 {-| Label for a bound variable
 
     The `Text` field is the variable's name (i.e. \"@x@\").