Add fixity declarations

Author: polytypic

lexer.mll

@@ -269,6 +269,9 @@ rule token = parse
   | "fun" { FUN }
   | "if" { IF }
   | "in" { IN }
+  | "infix" { INFIX }
+  | "infixl" { INFIXL }
+  | "infixr" { INFIXR }
   | "..." { ELLIPSIS }
   | "let" { LET }
   | "||" { LOGICAL_OR }

parser.mly

@@ -39,6 +39,7 @@ let parse_error s = raise (Source.Error (Source.nowhere_region, s))
 %token IMPORT
 %token WRAP_OP UNWRAP_OP
 %token ROLL_OP UNROLL_OP
+%token INFIX INFIXL INFIXR
 
 %token EOF
 
@@ -227,6 +228,37 @@ opttypdef :
     { Some (typE($2)@@ati 2) }
 ;
 
+syms :
+  | sym
+    { [$1] }
+  | syms sym
+    { $2::$1 }
+;
+optsyms :
+  |
+    { [] }
+  | syms
+    { $1 }
+;
+infix :
+  | INFIX
+    { () }
+  | INFIXL
+    { () }
+  | INFIXR
+    { () }
+;
+optprecedence :
+  |
+    { 0@@at() }
+  | NUM
+    { $1@@at() }
+;
+fixitydec :
+  | infix optprecedence optsyms
+    { EmptyD@@at() }
+;
+
 atdec :
   | name typparamlist COLON typ
     { VarD($1, funT($2, $4, Pure@@ati 2)@@span[ati 2; ati 4])@@at() }
@@ -249,6 +281,8 @@ atdec :
     { InclD($2)@@at() }
   | LET bind IN typ
     { InclD(letT($2, $4)@@at())@@at() }
+  | fixitydec
+    { $1 }
 /*
   | LPAR dec RPAR
     { $2 }
@@ -453,6 +487,8 @@ atbind :
     { InclB(letE($2, $4)@@at())@@at() }
   | IMPORT TEXT
     { InclB(ImportE($2@@ati 2)@@at())@@at() }
+  | fixitydec
+    { EmptyB@@at() }
 /*
   | LPAR bind RPAR
     { $2 }

prelude/index.1mls

@@ -1,5 +1,20 @@
 local import "./primitives"
 
+infixl 8 * / %
+
+infixl 7 + -
+
+infixr 6 :: ++
+
+infix  5 < > <= >= == <>
+
+infixl 4 << >>
+
+infixl 3 |>
+infixr 3 <|
+
+;;
+
 Alt: {
   type t _ _
   inl 'a 'b: a -> t a b