parsing works

prototyping/Luau/Syntax/FromJSON.agda

@@ -1,6 +1,6 @@
 module Luau.Syntax.FromJSON where
 
-open import Luau.Syntax using (Block; Stat ; Expr; nil; _$_; var; var_∈_; function_is_end; _⟨_⟩; local_←_; return; done; _∙_; maybe; VarDec; number)
+open import Luau.Syntax using (Block; Stat ; Expr; nil; _$_; var; var_∈_; function_is_end; _⟨_⟩; local_←_; return; done; _∙_; maybe; VarDec; number; binexp; BinaryOperator; +; -; *; /)
 open import Luau.Type.FromJSON using (typeFromJSON)
 
 open import Agda.Builtin.List using (List; _∷_; [])
@@ -23,6 +23,9 @@ type = fromString "type"
 value = fromString "value"
 values = fromString "values"
 vars = fromString "vars"
+op = fromString "op"
+left = fromString "left"
+right = fromString "right"
 
 data Lookup : Set where
   _,_ : String → Value → Lookup
@@ -34,6 +37,8 @@ lookupIn (key ∷ keys) obj with lookup (fromString key) obj
 lookupIn (key ∷ keys) obj | nothing = lookupIn keys obj
 lookupIn (key ∷ keys) obj | just value = (key , value)
 
+binOpFromJSON : Value → Either String BinaryOperator
+binOpFromString : String → Either String BinaryOperator
 varDecFromJSON : Value → Either String (VarDec maybe)
 varDecFromObject : Object → Either String (VarDec maybe)
 exprFromJSON : Value → Either String (Expr maybe)
@@ -43,6 +48,15 @@ statFromObject : Object → Either String (Stat maybe)
 blockFromJSON : Value → Either String (Block maybe)
 blockFromArray : Array → Either String (Block maybe)
 
+binOpFromJSON (string s) = binOpFromString s
+binOpFromJSON val = Left "Binary operator not a string"
+
+binOpFromString "Add" = Right +
+binOpFromString "Sub" = Right -
+binOpFromString "Mul" = Right *
+binOpFromString "Div" = Right /
+binOpFromString s = Left ("'" ++ s ++ "' is not a valid operator")
+
 varDecFromJSON (object arg) = varDecFromObject arg
 varDecFromJSON val = Left "VarDec not an object"
 
@@ -89,6 +103,15 @@ exprFromObject obj | just (string "AstExprConstantNumber") with lookup value obj
 exprFromObject obj | just (string "AstExprConstantNumber") | just (FFI.Data.Aeson.Value.number x) = Right (number (toFloat x))
 exprFromObject obj | just (string "AstExprConstantNumber") | just _ = Left "AstExprConstantNumber value is not a number"
 exprFromObject obj | just (string "AstExprConstantNumber") | nothing = Left "AstExprConstantNumber missing value"
+exprFromObject obj | just (string "AstExprBinary") with lookup op obj | lookup left obj | lookup right obj
+exprFromObject obj | just (string "AstExprBinary") | just o | just l | just r with binOpFromJSON o | exprFromJSON l | exprFromJSON r
+exprFromObject obj | just (string "AstExprBinary") | just o | just l | just r | Right o′ | Right l′ | Right r′ = Right (binexp l′ o′ r′)
+exprFromObject obj | just (string "AstExprBinary") | just o | just l | just r | Left err | _ | _ = Left err
+exprFromObject obj | just (string "AstExprBinary") | just o | just l | just r | _ | Left err | _ = Left err
+exprFromObject obj | just (string "AstExprBinary") | just o | just l | just r | _ | _ | Left err = Left err
+exprFromObject obj | just (string "AstExprBinary") | nothing | _ | _ = Left "Missing 'op' in AstExprBinary"
+exprFromObject obj | just (string "AstExprBinary") | _ | nothing | _ = Left "Missing 'left' in AstExprBinary"
+exprFromObject obj | just (string "AstExprBinary") | _ | _ | nothing = Left "Missing 'right' in AstExprBinary"
 exprFromObject obj | just (string ty) = Left ("TODO: Unsupported AstExpr " ++ ty)
 exprFromObject obj | just _ = Left "AstExpr type not a string"
 exprFromObject obj | nothing = Left "AstExpr missing type"
@@ -146,3 +169,4 @@ blockFromArray arr | just value | Left err = Left err
 blockFromArray arr | just value | Right S with blockFromArray(tail arr)
 blockFromArray arr | just value | Right S | Left err = Left (err)
 blockFromArray arr | just value | Right S | Right B  = Right (S ∙ B)
+   

prototyping/Tests/Interpreter/binary_exps/in.lua

@@ -1 +1 @@
-return 1 + 2 - 3
+return 1 + 2 - 2 * 2 / 2

prototyping/Tests/Interpreter/binary_exps/out.txt

@@ -1 +1 @@
--1.0
+1.0