[WIP] UnTypedX

UnTypedX is gradually typed language.

"untyped" is not good to stand for dynamically typed, but "untyped" is simple so we use this keyword.

Example

let x = 1
let add = fn x y => x + y
println (add 1.1 2)

Language Specification

Reserved

->, =>, :, fn, infix, infixr, let

Special Characters

These Characters are not allowed in identifier.

\t \r \n ( ) { } [ ] < > : , |

BNF

<atexp>                := <cons>
                        | <ident_except_infopr>
                        | "(" <multispace>* ")"
                        | "(" <multispace>* <exp> <multispace>* ")"
                        | "(" <multispace>* <exp> <multispace>* "," <multispace>* ")"
                        | "(" <multispace>* <exp> (<multispace>* "," <multispace>* <exp>)+ <multispace>* ")"
                        | <blockexp>
                        | <letexp>
                        | <fnexp>
<appexp>               := <atexp> (<space>+ <atexp>)*
<infexp>               := <appexp> (<space>* <infopr> <space>* <appexp>)*
<exp>                  := (
                            <infexp>
                          | <untypedexp>
                          )
                          (
                            <space>* ":" <space>* <ty>
                          )?

<untypedexp>           := "untyped" <space>+ <exp>
<blcokexp>             := "{" <multispace>* <stmts> <multispace>* "}"
<letexp>               := "let" <space>+ <ident_except_infopr>
<fnexp>                := "fn" <multispace>+ <fnrule> (<multispace>* "|" <multispace>* <fnrule>)*
<fnrule>               := <fnpats> <multispace>* "=>" <multispace>* <exp>
<fnpats>               := (<multispace>* <pat>)*
<pat>                  := <atpat> (<space>* ":" <space>* <ty>)?
<atpat>                := "_"
                        | <cons>
                        | <ident_except_infopr>
                        | "(" <multispace>* ")"
                        | "(" <multispace>* <pat> <multispace>* ")"
                        | "(" <multispace>* <pat> <multispace>* "," <multispace>* ")"
                        | "(" <multispace>* <pat> (<multispace>* "," <multispace>* <pat>)+ ")"

<stmt>                 := <exp> <space>* "\n"
                        | <reginfexp>
<reginfstmt>           := ("infix" | "infixr") <space>+ <integer> <space>+ <ident_except_infopr> <space>* "=" <space>* <fnexp>
<stmts>                := (<multispace>* <stmt>)* <multispace>* <exp>?

<ty>                   := (
                            <ident_except_infopr> (<space>* "<" <space>* <ty> (<space>* "," <space>* <ty>)* <space>* ">")?
                          | "(" <multispace>* <ty> <multispace>* ")"
                          | "(" <multispace>* <ty> <multispace>* "," <multispace>* ")"
                          | "(" <multispace>* <ty> (<multispace>* "," <multispace>* <ty>)+ ")"
                          )
                          (
                            <space>* "->" <space>* <ty>
                          )?

Types

Primitive types

int: Integer, real: Floating point number, string: String,

Default infix operator

infix  3 =
infix  4 <>
infix  4 !=
infix  4 <
infix  4 >
infix  4 <=
infix  4 >=
infix  6 +
infix  6 -
infix  7 *
infix  7 /
infix  7 %

cordx56/untypedx