[NO TESTS] WIP

components/milkshake/BUILD

@@ -1,6 +1,7 @@
 py_project(
     name = "milkshake",
     lib_deps = [
+        py_requirement("attrs"),
         py_requirement("lark"),
     ],
 )

components/milkshake/src/python/milkshake/__init__.py

@@ -3,6 +3,7 @@
 
 from importlib.resources import files
 
+from attrs import define
 from lark import Lark, Tree, Token, Transformer, v_args
 
 
@@ -10,6 +11,19 @@ with files(__package__).joinpath("grammar.lark").open("r", encoding="utf-8") as
     GRAMMAR = fp.read()
 
 
+@define(frozen=True)
+class Symbol:
+    name: str
+
+    def __eq__(self, other):
+        if isinstance(other, str):
+            return self.name == other
+        elif isinstance(other, type(self)):
+            return self.name == other.name
+        else:
+            return False
+
+
 @v_args(tree=True)
 class T(Transformer):
     """A prepackaged transformer that cleans up the quoting details."""
@@ -25,7 +39,9 @@ class T(Transformer):
     qq_map = un_qq
     qq_set = un_qq
     qq_atom = un_qq
-    qq_symbol = un_qq
+
+    def qq_symbol(self, obj):
+        return self.symbol(self.un_qq(obj))
 
     def qq_quote(self, obj):
         return self.quote(self.un_qq(obj))
@@ -37,6 +53,9 @@ class T(Transformer):
     unquote = quote
     unquote_splicing = quote
 
+    def symbol(self, obj):
+        return Symbol(obj.children[0].value)
+
 
 PARSER = Lark(GRAMMAR, start=["module", "expr"])
 

components/milkshake/src/python/milkshake/grammar.lark

@@ -56,7 +56,11 @@ string: /"([^"]|\\")+"/
 
 pattern: /\/([^\/]|\\\/)+\//
 
-number: /[+-]?(\d+r)?(\d[\d,_\.]*)([\.,][\d,_\.]*)?(e[+-]?\d+)?/
+number: US_FORMAT_NUMBER | EU_FORMAT_NUMBER | UNDERSCORE_NUMBER
+
+US_FORMAT_NUMBER: /[+-]?(\d+r)?(\d+(,\d{3})*)(\.\d+(,\d{3})*)?(e[+-]?\d+)?/
+EU_FORMAT_NUMBER: /[+-]?(\d+r)?(\d+(\.\d{3})*)(,\d+(\.\d{3})*)?(e[+-]?\d+)?/
+UNDERSCORE_NUMBER: /[+-]?(\d+r)?(\d+(_\d{3})*)([,\.]\d+(_\d{3})*)?(e[+-]?\d+)?/
 
 // Note that we're demoting Symbol from the default parse priority of 0 to -1
 // This because _anything more specific_ should be chosen over symbol

components/milkshake/test/python/test_examples.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 
-from milkshake import slurp
+from milkshake import slurp, Symbol
 
 from lark import Tree, Token
 import pytest
@@ -10,26 +10,26 @@ import pytest
     "input, val",
     [
         ("()", Tree("list", [])),
-        ("nil", nil := Tree("symbol", ["nil"])),
+        ("nil", nil := Symbol("nil")),
         ("(nil nil nil)", Tree("list", [nil, nil, nil])),
         (
             "(/ + - * % ^ \\ & # @ ! = |)",
             Tree(
                 "list",
                 [
-                    Tree("symbol", ["/"]),
+                    Symbol("/"),
-                    Tree("symbol", ["+"]),
+                    Symbol("+"),
-                    Tree("symbol", ["-"]),
+                    Symbol("-"),
-                    Tree("symbol", ["*"]),
+                    Symbol("*"),
-                    Tree("symbol", ["%"]),
+                    Symbol("%"),
-                    Tree("symbol", ["^"]),
+                    Symbol("^"),
-                    Tree("symbol", ["\\"]),
+                    Symbol("\\"),
-                    Tree("symbol", ["&"]),
+                    Symbol("&"),
-                    Tree("symbol", ["#"]),
+                    Symbol("#"),
-                    Tree("symbol", ["@"]),
+                    Symbol("@"),
-                    Tree("symbol", ["!"]),
+                    Symbol("!"),
-                    Tree("symbol", ["="]),
+                    Symbol("="),
-                    Tree("symbol", ["|"]),
+                    Symbol("|"),
                 ],
             ),
         ),
@@ -48,12 +48,12 @@ import pytest
             Tree(
                 "list",
                 [
-                    Tree("symbol", ["+inf"]),
+                    Symbol("+inf"),
-                    Tree("symbol", ["-inf"]),
+                    Symbol("-inf"),
-                    Tree("symbol", ["inf"]),
+                    Symbol("inf"),
-                    Tree("symbol", ["nan"]),
+                    Symbol("nan"),
-                    Tree("symbol", ["+nan"]),
+                    Symbol("+nan"),
-                    Tree("symbol", ["-nan"]),
+                    Symbol("-nan"),
                 ],
             ),
         ),
@@ -66,7 +66,7 @@ import pytest
                     Tree(
                         "list",
                         [
-                            Tree("symbol", ["nil"]),
+                            Symbol("nil"),
                             Tree(
                                 "unquote",
                                 [

components/typhon/src/python/typhon/evaluator.py

@@ -8,6 +8,8 @@ to implement a flat, stackless, serializable interpreter.
 
 import typing as t
 
+from milkshake import Symbol
+
 from .models import *
 from .util import *
 
@@ -18,24 +20,24 @@ class Operator:
     """Stack operators."""
 
 
-class Task:
+class Op:
     @attrs.define()
     class Complete:
         """Signals program termination."""
 
-        pass
+    @attrs.define()
+    class Drop:
+        """Drop or void the top of the data stack."""
 
     @attrs.define()
     class Eval:
         """Evaluate the current term."""
 
-        pass
-
     @attrs.define()
-    class Apply:
+    class Invoke:
-        """Apply an operator to the stack."""
+        """Consuming the top N items of the stack of the format [... <fn>, <... args>] invoke fn with args."""
 
-        operator: "Operator" = attrs.field()
+        n: int
 
     @attrs.define()
     class Next:
@@ -67,19 +69,64 @@ def step(vm: Vm, cont: Cont, frame: Frame):
 
     """
 
+    if frame.op_stack:
+        expr = frame.op_stack.pop()
+
+    else:
+        expr = get_in(vm.log, frame.pc)
+
     match expr:
-        case ["native", native_fn, arg_exprs, vararg_expr]:
+        # AST entries
+        case ["py", native_expr, arg_exprs, vararg_expr]:
             pass
 
-        case ["invoke", fn_expr, arg_exprs, vararg_expr]:
+        case ["lambda", arg_expr, body_expr]:
+            # "now this one;s hard"
             pass
 
-        case ["var", name]:
+        case ["do", *body_exprs]:
             pass
 
-        case int() | float() | str() | bool():
+        case ["if", test_expr, then_expr, else_expr]:
             pass
 
+        case ["if", test_expr, then_expr]:
+            pass
+
+        # Generalized "simple" invoke expression
+        case [fn_expr, *arg_exprs]:
+            pass
+
+        # Literals/terminals
+        case Symbol(name):
+            # Resolve a value from the scope(s)
+            for frame in reversed(cont.frames):
+                if name in frame.frame_ns:
+                    frame.data_stack.append(frame.frame_ns[name])
+                    break
+            else:
+                raise NameError(f"{name!r} is not bound")
+
+        case int() | float() | str() | bool() | dict() | set():
+            # Literals push
+            frame.data_stack.append(expr)
+
+        # Semi-VM instructions
+        case Op.Drop():
+            frame.data_stack.pop()
+
+        case Op.Invoke(n):
+            data = [frame.data_stack.pop() for _ in range(n)]
+            fn = data[-1]
+            args = data[-1::]
+
+            # Need to trampoline the call through the wrapping loop
+            return Op.Frame(fn, args)
+
+        # FIXME: Do we still need this?
+        case Op.Complete():
+            return expr
+
 
 def run(program, state=None):
     vm = state or Vm([], {}, [])

components/typhon/src/python/typhon/models.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 
+from collections import deque
 import typing as t
 
 import attrs
@@ -40,5 +41,5 @@ class Frame:
 
     pc: list = attrs.field(factory=lambda: [0])
     frame_ns: dict = attrs.field(factory=dict)
-    op_stack: list = attrs.field(factory=list)
+    op_stack: deque = attrs.field(factory=deque)
-    data_stack: list = attrs.field(factory=list)
+    data_stack: deque = attrs.field(factory=deque)