From: Luke Lau <luke_lau@icloud.com>
Date: Sun, 19 May 2019 13:16:31 +0000 (+0100)
Subject: Parse call expressions
X-Git-Url: https://git.lukelau.me/?p=kaleidoscope-hs.git;a=commitdiff_plain;h=0daa38ae816488b94b57154c11a7bff5d376a28d

Parse call expressions

The Call constructor stores the name of the callee and the list of
arguments being passed to it.
---

diff --git a/AST.hs b/AST.hs
index e491b64..b57d7cb 100644
--- a/AST.hs
+++ b/AST.hs
@@ -7,6 +7,7 @@ import Text.ParserCombinators.ReadP hiding ((+++), choice)
 data Expr = Num Float
           | Var String
           | BinOp BinOp Expr Expr
+          | Call String [Expr]
   deriving Show
 
 data BinOp = Add | Sub | Mul | Cmp Ordering
@@ -15,6 +16,7 @@ data BinOp = Add | Sub | Mul | Cmp Ordering
 instance Read Expr where
   readPrec = parens $ choice [ parseNum
                              , parseVar
+                             , parseCall
                              , parseBinOp "<" 10 (Cmp LT)
                              , parseBinOp "+" 20 Add
                              , parseBinOp "-" 20 Sub
@@ -30,6 +32,12 @@ instance Read Expr where
               skipSpaces
             b <- readPrec
             return (BinOp op a b)
+          parseCall = do
+            func <- lift (munch1 isAlpha)
+            params <- lift $ between (char '(') (char ')') $
+                        sepBy (readS_to_P reads)
+                              (skipSpaces >> char ',' >> skipSpaces)
+            return (Call func params)
             
 data Prototype = Prototype String [String]
   deriving Show