JML: A ML dialect based on Julia

P.S: The python backend is broken.

The Syntax rules of JML could be found at Parser.jl. Not all valid syntax constructs are implemented in the compiler yet. Type checker is WIP.

Features

• infix operators with custom associativities and precendences:

      infix add 5
      infix cons 2 right
  

• pure lexical scope, and distinguish let-in bindings from let rec - in bindings.

• FFI via foreign keyword

      foreign Base
      def p = Base.getproperty
  

• provide accurate source code positions when reporting errors

• match expression

• type inference with type classes

• parameterised modules

Usage

Press \ to enter jml mode.

julia> \
jml>

Constructs Support Status

• Str := value=str
• Nil := ["()"]
• Bind := [name=id %get_str, '=', value=Exp]
• Let := [loc=:let %get_loc, rec=:rec.? % maybe_to_bool, ...
• Fun := [loc=:fn %get_loc, "(", args=join_rule(",", ...
• Match := [loc=:match %get_loc, sc=Exp, :with,
• If := [loc=:if %get_loc, cond=Exp, :then, ...
• Num := [neg="-".? % maybe_to_bool, (int=integer) | (float=float)]
• Boolean := value=("true" | "false")
• NestedExpr = ['(', value=Exp, ')'] => _.value
• Var := value=id %get_str
• Block := [loc='{' %get_loc, stmts=Stmt{*}, '}']]
• Atom = Nil | NestedExpr | Num | Str | Boolean | Var | List
• Attr := [value=Atom, attrs=(['.', id % get_str] % second){*}]
• Call := [fn=Attr, ['(', args = join_rule(",", Attr), ')'].?]
• List := [loc='[', elts=join_rule(',', Exp), ']']
• Comp = Call | Let | Fun | Match | If | Block
• Op := ...
• Top := [hd=Comp, tl=[Op, Comp]{*}]
• Custom := [value=Exp, [',', next=Custom].?] | [kw=id, value=Exp, [',', next=Custom].?]
• Exp := [top=Top, [do_custom::Bool='{' => true, [custom=Custom].?, '}'].?]
• Define := [loc=:def %get_loc, name=id_str, '=', value=Exp]
• Infix := [loc=:infix %get_loc, name=id_str, prec=integer %get_str, is_right="right".? % maybe_to_bool]
• Foreign := [loc=:foreign %get_loc, paths=join_rule('.', id_str)]
• Import := [loc=:import %get_loc, is_qual=:qualified.? %maybe_to_bool, paths=join_rule('.', id_str)]
• Ops := [loc=:export %get_loc, names=id_str{*}]
• Stmt = [Exp | Import | Module, ';'.?] % first
• TopStmt = Define | Import | Infix | Stmt | Foreign | Ops
• [?] Module := [loc=:module %get_loc, name=id_str, params=id_str{*}, :where, stmts=TopStmt{*}, :end.?]