Hindley-Milner typing. More...

Classes
class	Apply

class	Con

class	HMType

class	HMVar

class	Ident

class	Lambda

class	Lambda2

class	Let

class	Oper

class	Syntax

Static Public Member Functions
static HMType	HM (Syntax prog)

Static Package Functions
static void	reset ()

Detailed Description

Hindley-Milner typing.

A Java clone from: http://dysphoria.net/code/hindley-milner/HindleyMilner.scala Andrew Forrest Based heavily on Nikita Borisov's Perl implementation at http://web.archive.org/web/20050420002559/www.cs.berkeley.edu/~nikitab/courses/cs263/hm.html which in turn is based on the paper by Luca Cardelli at http://lucacardelli.name/Papers/BasicTypechecking.pdf

Complete stand-alone, for my research. MEETs base types, instead of declaring type error. Does standard lexical scoping, which is not needed for SSA form.

Definition at line 23 of file HM1.java.

Member Function Documentation

◆ HM()

static HMType com.cliffc.aa.HM.HM1.HM ( Syntax prog )

static

Definition at line 24 of file HM1.java.

                                        {
     HashMap<String,HMType> env = new HashMap<>();
     // Simple types
     HMVar bool  = new HMVar(TypeInt.BOOL);
     HMVar int64 = new HMVar(TypeInt.INT64);
     HMVar flt64 = new HMVar(TypeFlt.FLT64);
     HMVar strp  = new HMVar(TypeMemPtr.STRPTR);
  
     // Primitives
     HMVar var1 = new HMVar();
     HMVar var2 = new HMVar();
     env.put("pair",Oper.fun(var1, Oper.fun(var2, new Oper("pair",var1,var2))));
  
     HMVar var3 = new HMVar();
     env.put("if/else" ,Oper.fun(bool,Oper.fun(var3,Oper.fun(var3,var3))));
     env.put("if/else3",Oper.fun(bool,         var3,         var3,var3  ));
  
     env.put("dec",Oper.fun(int64,int64));
     env.put("*"  ,Oper.fun(int64,Oper.fun(int64,int64)));
     env.put("*2" ,Oper.fun(int64,         int64,int64 ));
     env.put("==0",Oper.fun(int64,bool));
  
     // Convert integer to a string; int->str
     env.put("str",Oper.fun(int64,strp));
     // Floating point Factor; sorta like {div/mod}
     env.put("factor",Oper.fun(flt64,new Oper("pair",flt64,flt64)));
  
     return prog.hm(env, new HashSet<>());
   }