diff options
| -rw-r--r-- | sketch.py | 68 |
1 files changed, 47 insertions, 21 deletions
@@ -109,6 +109,7 @@ class _builtin_lambda(SpecialOptObj): para_list.append(par.obj) par = par.sib body = pc.chd.sib + pc.chd.skip = body.skip = False return (ProcObj(body, envt, para_list), False) def __str__(self): return "#<builtin opt lambda>" @@ -218,6 +219,8 @@ class AbsSynTree(EvalObj): self.tree = stack[0] +def is_obj(string): + return isinstance(string, SyntaxObj) def is_identifier(string): return isinstance(string, IdObj) def is_leaf(node): @@ -239,7 +242,16 @@ class Environment(object): self.binding[name] = eval_obj def get_obj(self, id_obj): if is_identifier(id_obj): - return self.binding[id_obj.name] + ptr = self + while ptr: + try: + t = ptr.binding[id_obj.name] + except KeyError: + t = None + if t: return t + ptr = ptr.prev_envt + raise KeyError + else: print "Not an id: " + str(id_obj) return id_obj @@ -313,7 +325,7 @@ class Evaluator(object): stack = [0] * 100 # Stack ostack = [0] * 100 # Pending operators pc = prog.tree # Set to the root - cont = None + cont = Continuation(None, pc, None) envt = self.envt top = -1 # Stack top otop = -1 @@ -333,6 +345,17 @@ class Evaluator(object): pc.skip = not i pc = pc.sib + def nxt_addr(ret_addr, otop): + notop = otop + if otop > -1 and ret_addr is ostack[notop]: + notop -= 1 + res = ostack[notop].chd + notop -= 1 + else: + res = ret_addr.sib + return (res, notop) + + def push(pc, top, otop): ntop = top notop = otop @@ -357,7 +380,7 @@ class Evaluator(object): pc.obj.print_() # Step in to resolve operator npc = pc.obj else: - print "Getting operand: " + print "Getting operand: " + str(pc.obj.name) ntop += 1 stack[ntop] = envt.get_obj(pc.obj) if is_special_opt(stack[ntop]): @@ -379,7 +402,17 @@ class Evaluator(object): pc = pc.sib # Skip the masked branches if pc is None: - if is_ret_addr(stack[top]): + + if top > 0 and is_ret_addr(stack[top - 1]) and \ + stack[top - 1].get_addr() is False: + stack[top - 1] = stack[top] + top -= 1 + envt = cont.envt + (pc, otop) = nxt_addr(cont.pc, otop) + cont = cont.old_cont + # Revert to the original cont. + else: + print "Poping..." arg_list = list() while not is_ret_addr(stack[top]): @@ -389,19 +422,12 @@ class Evaluator(object): print "Arg List: " + str(arg_list) opt = arg_list[0] ret_addr = stack[top].get_addr() - if ret_addr is ostack[otop]: - print "yay!" - otop -= 1 - nxt_addr = ostack[otop].chd - otop -= 1 - else: - nxt_addr = ret_addr.sib - + if is_builtin_proc(opt): # Built-in Procedures print "builtin" stack[top] = opt.call(arg_list[1:]) - pc = nxt_addr - + (pc, otop) = nxt_addr(ret_addr, otop) + elif is_special_opt(opt): # Sepecial Operations print "specialopt" (res, flag) = opt.call(arg_list[1:], ret_addr, envt, cont) @@ -412,16 +438,16 @@ class Evaluator(object): pc = ret_addr.chd # Again else: stack[top] = res # Done - pc = nxt_addr + (pc, otop) = nxt_addr(ret_addr, otop) elif is_user_defined_proc(opt): # User-defined Procedures - print "body:" + str(opt.body.sib) - ncont = Continuation(evnt, ret_addr, cont) # Create a new continuation + ncont = Continuation(envt, ret_addr, cont) # Create a new continuation cont = ncont # Make chain envt = Environment(opt.envt) # New ENV and recover the closure #TODO: Compare the arguments to the parameters for i in xrange(1, len(arg_list)): - envt.add_binding(para_list[i - 1].name, + envt.add_binding(opt.para_list[i - 1].name, arg_list[i]) # Create bindings + stack[top] = RetAddr(False) # Mark the exit of the continuation pc = opt.body # Get to the entry point print_stack() @@ -434,14 +460,14 @@ class Evaluator(object): print " Done...\n" return stack[0] - +import pdb t = Tokenizor() e = Evaluator() e.envt.add_binding("x", IntObj(100)) #t.feed("(+ (- (* 10 2) (+ x 4)) (+ 1 2) (/ 25 5))") #t.feed("(if (> 2 2) (if (> 2 1) 1 2) 3)") -t.feed("((lambda (x) (* x x)) 2)") -#t.feed("(lambda (x) (* x x))") +t.feed("((lambda (x y) ((lambda (z) (+ z (* x y))) 10)) ((lambda (x y) (+ x y)) 3 2) 4)") +#t.feed("(lambda (x y) (* x x))") a = AbsSynTree(t) #a.tree.print_() #a.tree.obj.print_() |