refactor: make neb a module

1 files changed, 0 insertions, 876 deletions

diff --git a/interpreter.py b/interpreter.py
deleted file mode 100644
index c675930..0000000
--- a/interpreter.py
+++ /dev/null
@@ -1,876 +0,0 @@
-from structs import *
-from exceptions import *
-from lexer import lex
-from parser import parse
-from typeclass import TypeEnum, is_subtype_of
-from pathlib import Path
-from glob import glob
-import subprocess
-import shlex
-import random
-import sys
-import math
-
-
-class Arg:
-
-    def __init__(self, name, type_, *, optional=False, lazy=False):
-        self.name = name
-        self.type_ = type_
-        self.optional = optional
-        self.lazy = lazy
-
-    def __str__(self):
-        opt = "?" if self.optional else ""
-        lazy = "~" if self.lazy else ""
-        return f"{lazy}{opt}{self.name} {self.type_}"
-
-
-class Function:
-
-    def __init__(self, name, params, body, args=None, many=None):
-        self.name = name
-        self.params = params
-        self.body = body
-        self.args = args
-        self.many = many
-        self.type_ = TypeEnum.ANY  # TODO no it's not
-
-    def describe(self, name=None):
-        if name is None:
-            name = self.name
-        out = [f"({name}"]
-        if self.args is not None:
-            for arg in self.args:
-                out.append(f"{arg}")
-        if self.many is not None:
-            out.append(f"{self.many}")
-        return " ".join(out) + ")"
-
-    def arity_check(self, symbol, params):
-        min_arity = len([a for a in self.args if not a.optional])
-        max_arity = -1 if self.many is not None else len(self.args)
-
-        if len(params) < min_arity or (max_arity >= 0 and len(params) > max_arity):
-            if max_arity < 0:
-                fmt = f"{min_arity}+"
-            elif min_arity != max_arity: 
-                fmt = f"{min_arity}-{max_arity}"
-            else:
-                fmt = f"{min_arity}"
-            raise InterpretPanic(symbol, f"expected [{fmt}] arguments, received {len(params)}")
-        return True
-
-    def evaluate_args(self, symbol, params, env, ns):
-        self.arity_check(symbol, params)
-        ret = []
-
-        for idx, param in enumerate(params):
-            if idx < len(self.args):
-                arg = self.args[idx]
-            else:
-                arg = self.many
-            if arg.lazy:
-                ret.append(param)
-                continue
-            ev = evaluate(param, env, ns)
-            if not is_subtype_of(ev.type_, arg.type_):
-                exp = f"{arg.type_}"
-                rec = f"{ev.type_}"
-                raise InterpretPanic(symbol, f"received {rec}, expected {exp}", ev)
-            ret.append(ev)
-        return ret
-
-    def call(self, expr, env):
-        pass
-
-class Builtin(Function):
-    
-    def __init__(self, callable_, args=None, many=None):
-        super().__init__("<builtin>", None, callable_, args, many)
-
-    def call(self, expr, env, ns):
-        self.arity_check(expr.args[0], expr.args[1:])
-        evaluated_args = self.evaluate_args(expr.args[0], expr.args[1:], env, ns)
-        return self.body(expr.args[0], evaluated_args, env, ns)
-
-
-class UserFunction(Function):
-    
-    def __init__(self, name, params, body):
-        newparams, args, many = self.process_params(name, params)
-        super().__init__(name, newparams, body, args, many)
-
-    def process_params(self, name, params):
-        newparams = []
-        args = []
-        many = None
-        prev_type = False
-        first = True
-        for param in params:
-            if isinstance(param, Symbol):
-                if many is not None:
-                    raise NebPanic("& must be last argument")
-                if param.name == "&":
-                    many = Arg(param.name, TypeEnum.ANY)
-                else:
-                    newparams.append(param)
-                    args.append(Arg(param.name, TypeEnum.ANY))
-                prev_type = False
-            elif isinstance(param, Type) and not prev_type and not first:
-                typ = TypeEnum.__getattr__(param.name[1:].upper())
-                if many is None:
-                    args[-1].type_ = typ
-                else:
-                    many.type_ = typ
-                prev_type = True
-            else:
-                raise NebPanic("invalid :func signature", param)
-            first = False
-        return newparams, args, many
-
-    def call(self, expr, env, ns):
-        self.arity_check(expr.args[0], expr.args[1:])
-        evaluated_args = self.evaluate_args(expr.args[0], expr.args[1:], env, ns)
-        this_env = Environment(env)
-        for idx, param in enumerate(self.params):
-            this_env.register(param.name, evaluated_args[idx])
-
-        # if we got "many", wrap the rest in a list
-        if self.many:
-            this_env.register(self.many.name, List(evaluated_args[len(self.params):], True))
-
-        return interpret(self.body, env=this_env, ns=ns)
-
-class Environment:
-    
-    def __init__(self, parent=None):
-        self.parent = parent
-        self.environment = {}
-
-    def register(self, key, value):
-        self.environment[key] = value
-
-    def reregister(self, key, value):
-        if not self.contains(key):
-            raise NebPanic(f"undefined symbol: '{key}")
-        if key in self.environment:
-            self.register(key, value)
-        else:
-            self.parent.reregister(key, value)
-
-    def contains(self, key):
-        if key in self.environment:
-            return True
-        elif self.parent is not None:
-            return self.parent.contains(key)
-        else:
-            return False
-
-    def get(self, key):
-        if not self.contains(key):
-            raise NebPanic(f"undefined symbol: '{key}")
-        if key in self.environment:
-            return self.environment[key]
-        else:
-            return self.parent.get(key)
-
-    def __str__(self):
-        out = ""
-        for k, v in self.environment.items():
-            out += f"{k}: {v}, "
-        return out
-
-GLOBALS = Environment()
-
-def interpret(exprs, *, env=GLOBALS, ns=None):
-    ret = None
-    for expr in exprs:
-        ret = evaluate(expr, env, ns)
-    return ret
-
-def evaluate(expr, env, ns=None):
-    if isinstance(expr, Literal) or isinstance(expr, Function) or isinstance(expr, Type):
-        return expr
-    elif isinstance(expr, Symbol):
-        if env.contains(expr.name):
-            return evaluate(env.get(expr.name), env, ns)
-        elif ns is not None and env.contains(f"{ns}/{expr.name}"):
-            return evaluate(env.get(f"{ns}/{expr.name}"), env, ns)
-        else:
-            raise NebPanic(f"no such symbol: {expr}")
-
-    # if it's a literal list, return it
-    if expr.data:
-        return expr
-    # if it's an empty list, return it
-    elif len(expr.args) == 0:
-        return expr
-
-    if not isinstance(expr.args[0], Symbol):
-        raise NebPanic("can't evaluate without a symbol")
-    name = expr.args[0].name
-    if env.contains(name):
-        return env.get(name).call(expr, env, ns)
-    elif ns is not None and env.contains(f"{ns}/{name}"):
-        return env.get(f"{ns}/{name}").call(expr, env, ns)
-    else:
-        raise InterpretPanic(expr.args[0], "unable to evaluate")
-
-def interpretOr(symbol, args, env, ns):
-    # or returns true for the first expression that returns true
-    for arg in args:
-        ev = evaluate(arg, env, ns)
-        if not isinstance(ev, Bool):
-            raise InterpretPanic(symbol, "requires :bool arguments")
-        if ev.value == True:
-            return ev
-    return Bool(False)
-
-or_arg = Arg("arg", TypeEnum.BOOL, lazy=True)
-GLOBALS.register("or", Builtin(interpretOr, [or_arg, or_arg], or_arg))
-
-def interpretAnd(symbol, args, env, ns):
-    # and returns false for the first expression that returns false
-    for arg in args:
-        ev = evaluate(arg, env, ns)
-        if not isinstance(ev, Bool):
-            raise InterpretPanic(symbol, "requires :bool arguments")
-        if ev.value == False:
-            return ev
-    return Bool(True)
-
-GLOBALS.register("and", Builtin(interpretAnd, [or_arg, or_arg], or_arg))
-
-def interpretEq(symbol, args, env, ns):
-    # NOTE this currently only works for literals
-    # compare types because 0 != #false in neb
-    if type(args[0]) == type(args[1]) and args[0].value == args[1].value:
-        return Bool(True)
-    else:
-        return Bool(False)
-
-eq_arg = Arg("value", TypeEnum.LITERAL)
-GLOBALS.register("eq?", Builtin(interpretEq, [eq_arg, eq_arg]))
-
-def interpretGreaterThan(symbol, args, env, ns):
-    return Bool(args[0].value > args[1].value)
-
-compare_arg = Arg("num", TypeEnum.NUMBER)
-GLOBALS.register(">", Builtin(interpretGreaterThan, [compare_arg, compare_arg]))
-
-def interpretGreaterThanEqual(symbol, args, env, ns):
-    return Bool(args[0].value >= args[1].value)
-
-GLOBALS.register(">=", Builtin(interpretGreaterThanEqual, [compare_arg, compare_arg]))
-
-def interpretLessThan(symbol, args, env, ns):
-    return Bool(args[0].value < args[1].value)
-
-GLOBALS.register("<", Builtin(interpretLessThan, [compare_arg, compare_arg]))
-
-def interpretLessThanEqual(symbol, args, env, ns):
-    return Bool(args[0].value <= args[1].value)
-
-GLOBALS.register("<=", Builtin(interpretLessThanEqual, [compare_arg, compare_arg]))
-
-def interpretAddition(symbol, args, env, ns):
-    res = 0
-    for arg in args:
-        res += arg.value
-    if isinstance(res, float):
-        return Float(res)
-    else:
-        return Int(res)
-
-term_arg = Arg("term", TypeEnum.NUMBER)
-GLOBALS.register("+", Builtin(interpretAddition, [term_arg], term_arg))
-
-def interpretSubtraction(symbol, args, env, ns):
-    if len(args) == 1:
-        res = -args[0].value
-    else:
-        res = args[0].value
-    for arg in args[1:]:
-        res -= arg.value
-    if isinstance(res, float):
-        return Float(res)
-    else:
-        return Int(res)
-
-GLOBALS.register("-", Builtin(interpretSubtraction, [term_arg], term_arg))
-
-def interpretMultiplication(symbol, args, env, ns):
-    res = args[0].value
-    for arg in args[1:]:
-        res = res * arg.value
-    if isinstance(res, float):
-        return Float(res)
-    else:
-        return Int(res)
-
-factor_arg = Arg("factor", TypeEnum.NUMBER)
-GLOBALS.register("*", Builtin(interpretMultiplication, [factor_arg, factor_arg], factor_arg))
-
-def interpretDivision(symbol, args, env, ns):
-    ret = args[0].value / args[1].value
-    if int(ret) == ret:
-        return Int(int(ret))
-    else:
-        return Float(ret)
-
-GLOBALS.register("/", Builtin(interpretDivision, [factor_arg, factor_arg]))
-
-def interpretNot(symbol, args, env, ns):
-    return Bool(not args[0].value)
-
-not_arg = Arg("not", TypeEnum.BOOL)
-GLOBALS.register("not", Builtin(interpretNot, [not_arg]))
-
-def interpretIf(symbol, args, env, ns):
-    if args[0].value:
-        return evaluate(args[1], env, ns)
-    elif len(args) == 3:
-        return evaluate(args[2], env, ns)
-    return List([])
-
-cond = Arg("cond", TypeEnum.BOOL)
-t_branch = Arg("t-branch", TypeEnum.ANY, lazy=True)
-f_branch = Arg("f-branch", TypeEnum.ANY, optional=True, lazy=True)
-GLOBALS.register("if", Builtin(interpretIf, [cond, t_branch, f_branch]))
-
-def interpretPrint(symbol, args, env, ns):
-    print(args[0].value)
-    return List([])  # print returns nothing
-
-GLOBALS.register("print", Builtin(interpretPrint, [Arg("arg", TypeEnum.STRING)]))
-
-def interpretDef(symbol, args, env, ns):
-
-    if not isinstance(args[0], Symbol):
-        raise InterpretPanic(symbol, "requires a :string name", args[0])
-    name = args[0].name  # NOTE: we are not evaluating the name!!
-    if not isinstance(name, str):
-        raise InterpretPanic(symbol, "requires a :string name")
-
-    env.register(name, args[1])  # TODO since this isn't lazily evaluated, side effects are allowed (bad!)
-
-    return List([])
-
-def_name_arg = Arg("name", TypeEnum.ANY, lazy=True)
-def_val_arg = Arg("value", TypeEnum.ANY)
-GLOBALS.register("def", Builtin(interpretDef, [def_name_arg, def_val_arg]))
-
-def interpretRedef(symbol, args, env, ns):
-    if not isinstance(args[0], Symbol):
-        raise InterpretPanic(symbol, "requires a :string name", args[0])
-    name = args[0].name  # NOTE: we are not evaluating the name!!
-    if not env.contains(name):
-        raise InterpretPanic(symbol, "not previously defined", args[0])
-
-    env.reregister(name, args[1])
-    return List([])
-
-GLOBALS.register("redef", Builtin(interpretRedef, [def_name_arg, def_val_arg]))
-
-def interpretLambda(symbol, args, env, ns):
-    if len(args[0].args) != 0:
-        func = UserFunction("<lambda>", args[0].args, args[1:])
-    else:
-        func = UserFunction("<lambda>", [], args[1:])
-    return func
-
-lambda_args_arg = Arg("args", TypeEnum.ANY, lazy=True)
-lambda_body_arg = Arg("body", TypeEnum.ANY, lazy=True)
-GLOBALS.register("lambda", Builtin(interpretLambda, [lambda_args_arg, lambda_body_arg], lambda_body_arg))
-
-def interpretToString(symbol, args, env, ns):
-    item = args[0]
-    if isinstance(item, String):
-        return item
-    elif isinstance(item, Literal):
-        return String(str(item))
-    else:
-        return String(f"{item}")
-
-GLOBALS.register("->string", Builtin(interpretToString, [Arg("arg", TypeEnum.ANY)]))
-
-def interpretConcat(symbol, args, env, ns):
-    out = ""
-    for arg in args:
-        out += arg.value
-    return String(out)
-
-string_arg = Arg("arg", TypeEnum.STRING)
-GLOBALS.register("concat", Builtin(interpretConcat, [string_arg, string_arg], string_arg))
-
-def interpretForCount(symbol, args, env, ns):
-    new_env = Environment(env)
-    ret = None
-    for idx in range(0, args[0].value):
-        new_env.register("idx", Int(idx + 1))
-        for arg in args[1:]:
-            ret = evaluate(arg, new_env, ns)
-    if ret is None:
-        return List([])
-    return ret
-
-for_count_arg = Arg("count", TypeEnum.INT)
-for_body_arg = Arg("body", TypeEnum.ANY, lazy=True)
-GLOBALS.register("for-count", Builtin(interpretForCount, [for_count_arg, for_body_arg], for_body_arg))
-
-def interpretForEach(symbol, args, env, ns):
-    new_env = Environment(env)
-    ret = None
-    for item in args[0].args:
-        new_env.register("_item_", evaluate(item, env, ns))
-        for arg in args[1:]:
-            ret = evaluate(arg, new_env, ns)
-    if ret is None:
-        return List([])
-    return ret
-
-for_each_arg = Arg("list", TypeEnum.LIST)
-GLOBALS.register("for-each", Builtin(interpretForEach, [for_each_arg, for_body_arg], for_body_arg))
-
-def interpretPipe(symbol, args, env, ns):
-    new_env = Environment(env)
-    pipe = None
-    for arg in args:
-        if pipe is not None:
-            new_env.register("items", pipe)
-        pipe = evaluate(arg, new_env, ns)
-    if pipe is None:
-        return List([])
-    return pipe
-
-# TODO
-GLOBALS.register("|", Builtin(interpretPipe, 2))
-
-def interpretBranch(symbol, args, env, ns):
-    for arg in args:
-        if len(arg.args) != 2:
-            raise InterpretPanic(symbol, "each branch requires two expressions")
-        cond = evaluate(arg.args[0], env, ns)  # this is the condition
-        if not isinstance(cond, Bool):
-            raise InterpretPanic(symbol, "branch condition must be :bool", cond)
-        if cond.value:
-            return evaluate(arg.args[1], env, ns)
-    return List([])
-
-GLOBALS.register("branch", Builtin(interpretBranch, [for_body_arg], for_body_arg))
-
-def interpretFunc(symbol, args, env, ns):
-    if not isinstance(args[0], Symbol):
-        raise InterpretPanic(symbol, "requires a :string name")
-    name = args[0].name  # NOTE: we are not evaluating the name!!
-
-    if ns is not None:
-        name = f"{ns}/{name}"
-
-    # compose a lambda
-    func = interpretLambda(None, args[1:], env, ns)
-
-    env.register(name, func)
-    return List([])
-
-GLOBALS.register("func", Builtin(interpretFunc, [def_name_arg, lambda_args_arg, lambda_body_arg], lambda_body_arg))
-
-def interpretReadLines(symbol, args, env, ns):
-    target_file_name = args[0].value
-    target_file = Path(target_file_name).resolve()
-    if not target_file.exists():
-        raise InterpretPanic(symbol, "no such file", target_file)
-    with open(target_file, "r") as fil:
-        data = fil.readlines()
-    out = List([String(d) for d in data], True) # all lines are strings
-    return out
-
-GLOBALS.register("read-lines", Builtin(interpretReadLines, [Arg("filename", TypeEnum.STRING)]))
-
-def interpretStrip(symbol, args, env, ns):
-    return String(args[0].value.strip())
-
-GLOBALS.register("strip", Builtin(interpretStrip, [Arg("filename", TypeEnum.STRING)]))
-
-#  - string->int and string->float
-def interpretStringToInt(symbol, args, env, ns):
-    try:
-        val = int(args[0].value)
-        return Int(val)
-    except:
-        raise InterpretPanic(symbol, "can't convert to an :int", args[0])
-
-GLOBALS.register("string->int", Builtin(interpretStringToInt, [Arg("arg", TypeEnum.STRING)]))
-
-def interpretSplit(symbol, args, env, ns):
-    target = args[0]
-    if len(args) == 1:
-        return List([String(char) for char in target.value], True)
-    splitter = args[1]
-    ret = target.value.split(splitter.value)
-    return List([String(r) for r in ret], True)
-
-GLOBALS.register("split", Builtin(interpretSplit, [Arg("target", TypeEnum.STRING)], Arg("splitter", TypeEnum.STRING, optional=True)))
-    
-def interpretListLength(symbol, args, env, ns):
-    return Int(len(args[0].args))
-
-GLOBALS.register("list-length", Builtin(interpretListLength, [Arg("arg", TypeEnum.LIST)]))
-    
-def interpretFirst(symbol, args, env, ns):
-    if len(args[0].args) == 0:
-        raise InterpretPanic(symbol, "list is empty")
-    return evaluate(args[0].args[0], env, ns)
-
-GLOBALS.register("first", Builtin(interpretFirst, [Arg("arg", TypeEnum.LIST, )]))
-
-def interpretRest(symbol, args, env, ns):
-    # TODO do we know it's not evaluated?
-    return List(args[0].args[1:], True) # we don't evaluate the remainder of the list
-
-GLOBALS.register("rest", Builtin(interpretRest, [Arg("arg", TypeEnum.LIST)]))
-
-def interpretMap(symbol, args, env, ns):
-    func = args[0]
-    if not isinstance(func, Function):
-        raise InterpretPanic(symbol, "requires a :func as its first argument", func)
-    lst = evaluate(args[1], env, ns)
-    if not isinstance(lst, List):
-        raise InterpretPanic(symbol, "requires a :list as its second argument", lst)
-    out = []
-    for arg in lst.args:
-        ev = func.call(List([func, arg]), env, ns)
-        out.append(ev)
-    return List(out, True)
-
-GLOBALS.register("map", Builtin(interpretMap, [Arg("func", TypeEnum.ANY), Arg("list", TypeEnum.LIST)]))
-
-def interpretZip(symbol, args, env, ns):
-    z1 = args[0]
-    z2 = args[1]
-    if len(z1.args) != len(z2.args):
-        raise InterpretPanic(symbol, "requires two :lists of the same size")
-    out = []
-    for idx in range(len(z1.args)):
-        f = z1.args[idx]
-        s = z2.args[idx]
-        out.append(List([f, s], True))
-    return List(out, True)
-
-zip_arg = Arg("list", TypeEnum.LIST)
-GLOBALS.register("zip", Builtin(interpretZip, [zip_arg, zip_arg]))
-
-def interpretList(symbol, args, env, ns):
-    return List(args, True)
-
-GLOBALS.register("list", Builtin(interpretList, [], Arg("item", TypeEnum.ANY)))
-
-def interpretListReverse(symbol, args, env, ns):
-    new_args = args[0].args[:] # make a copy of the args
-    new_args.reverse()
-    return List(new_args, True)
-
-GLOBALS.register("list-reverse", Builtin(interpretListReverse, [Arg("list", TypeEnum.LIST)]))
-
-def interpretApply(symbol, args, env, ns):
-    # TODO: to support lambdas, we can't assume the func is defined
-    func = args[0]
-    if not isinstance(func, Symbol):
-        raise InterpretPanic(symbol, "requires a symbol as its first argument", func)
-    new_lst = List([func] + args[1].args)
-    return evaluate(new_lst, env, ns)
-
-GLOBALS.register("apply", Builtin(interpretApply, [Arg("func", TypeEnum.ANY, lazy=True), Arg("list", TypeEnum.LIST)]))
-
-def interpretGlob(symbol, args, env, ns):
-    items = glob(args[0].value)
-    return List([String(item) for item in items], True)
-
-GLOBALS.register("glob", Builtin(interpretGlob, [Arg("regex", TypeEnum.STRING)]))
-
-def interpretShell(symbol, args, env, ns):
-    ret = subprocess.run(shlex.split(args[0].value), capture_output=True)
-    return List([String(r) for r in ret.stdout.decode("utf-8").split("\n")], True)
-
-GLOBALS.register("$", Builtin(interpretShell, [Arg("command", TypeEnum.STRING)]))
-
-def interpretEmpty(symbol, args, env, ns):
-    return Bool(len(args[0].args) == 0)
-
-GLOBALS.register("empty?", Builtin(interpretEmpty, [Arg("list", TypeEnum.LIST)]))
-
-def interpretShuf(symbol, args, env, ns):
-    items = args[0].args[:]
-    random.shuffle(items)
-    return List(items, True)
-
-GLOBALS.register("shuf", Builtin(interpretShuf, [Arg("list", TypeEnum.LIST)]))
-
-def interpretIsList(symbol, args, env, ns):
-    return Bool(isinstance(args[0], List))
-
-GLOBALS.register("list?", Builtin(interpretIsList, [Arg("arg", TypeEnum.ANY)]))
-
-def interpretBlock(symbol, args, env, ns):
-    ret = List([])
-    for arg in args:
-        ret = evaluate(arg, env, ns)
-    return ret
-
-block_arg = Arg("expr", TypeEnum.ANY, lazy=True)
-GLOBALS.register("block", Builtin(interpretBlock, [block_arg], block_arg))
-
-def interpretExit(symbol, args, env, ns):
-    status = 0 if len(args) == 0 else args[0].value
-    sys.exit(status)
-    return List([])
-
-exit_arg = Arg("status", TypeEnum.INT, optional=True)
-GLOBALS.register("exit", Builtin(interpretExit, [exit_arg]))
-
-def interpretUnlink(symbol, args, env, ns):
-    target_path = Path(args[0].value).resolve()
-    if not target_path.exists():
-        raise InterpretPanic(symbol, "target file does not exist", target_path)
-    target_path.unlink()
-    return List([])
-
-GLOBALS.register("unlink", Builtin(interpretUnlink, [Arg("filename", TypeEnum.STRING)]))
-
-def interpretArgv(symbol, args, env, ns):
-    out = []
-    for arg in sys.argv[1:]:
-        out.append(String(arg))
-    return List(out, True)
-
-GLOBALS.register("argv", Builtin(interpretArgv, []))
-
-def interpretIn(symbol, args, env, ns):
-    target = args[0]
-    lst = args[1]
-    for arg in lst.args:
-        if type(arg) == type(target) and arg.value == target.value:
-            return Bool(True)
-    return Bool(False)
-
-in_target_arg = Arg("target", TypeEnum.LITERAL)
-in_list_arg = Arg("list", TypeEnum.LIST)
-GLOBALS.register("in?", Builtin(interpretIn, [in_target_arg, in_list_arg]))
-
-def interpretLast(symbol, args, env, ns):
-    if len(args[0].args) == 0:
-        raise InterpretPanic("List is empty")
-    return evaluate(args[0].args[-1], env, ns)
-
-GLOBALS.register("last", Builtin(interpretLast, [Arg("list", TypeEnum.LIST)]))
-
-def interpretJoin(symbol, args, env, ns):
-    lst = args[0]
-    target = args[1]
-    return String(target.value.join([a.value for a in lst.args]))
-
-join_list_arg = Arg("list", TypeEnum.LIST)
-join_string_arg = Arg("joiner", TypeEnum.STRING)
-GLOBALS.register("join", Builtin(interpretJoin, [join_list_arg, join_string_arg]))
-
-def interpretWithWrite(symbol, args, env, ns):
-    target_file = args[0]
-    new_env = Environment(env)
-    target_path = Path(target_file.value).resolve()
-    ret = Literal([])
-    with open(str(target_path), "w") as fil:
-        new_env.register("_file_", List([fil], True)) # TODO wrong!
-        for arg in args[1:]:
-            ret = evaluate(arg, new_env, ns)
-    return ret
-
-GLOBALS.register("with-write", Builtin(interpretWithWrite, [Arg("filename", TypeEnum.STRING)], Arg("exprs", TypeEnum.ANY, lazy=True)))
-
-def interpretWrite(symbol, args, env, ns):
-    # write :string :filehandle
-    line = args[0]
-    handle = args[1]
-    handle.args[0].write(line.value)  # TODO wrong! how do we evaluate a handle?
-    return Literal([])
-
-GLOBALS.register("write", Builtin(interpretWrite, [Arg("string", TypeEnum.STRING), Arg("filename", TypeEnum.LIST)]))
-
-def interpretNewline(symbol, args, env, ns):
-    return String("\n")
-
-GLOBALS.register("newline", Builtin(interpretNewline, []))
-
-def interpretExists(symbol, args, env, ns):
-    return Bool(Path(args[0].value).resolve().exists())
-
-GLOBALS.register("exists?", Builtin(interpretExists, [Arg("filename", TypeEnum.STRING)]))
-
-def interpretFirstChar(symbol, args, env, ns):
-    if len(args[0].value) == 0:
-        raise InterpretPanic(symbol, ":string is empty", ev)
-    return String(args[0].value[0])
-
-GLOBALS.register("first-char", Builtin(interpretFirstChar, [Arg("string", TypeEnum.STRING)]))
-
-def interpretRestChar(symbol, args, env, ns):
-    return String(args[0].value[1:])
-
-GLOBALS.register("rest-char", Builtin(interpretRestChar, [Arg("string", TypeEnum.STRING)]))
-
-def interpretSlice(symbol, args, env, ns):
-    lst = args[0]
-    idx = args[1]
-    if len(args) == 2:
-        return List(lst.args[idx.value - 1:])
-    length = args[2]
-    diff = idx.value - 1 + length.value
-    return List(lst.args[idx.value - 1:diff])
-
-slice_list_arg = Arg("list", TypeEnum.LIST)
-slice_idx_arg = Arg("idx", TypeEnum.INT)
-slice_length_arg = Arg("length", TypeEnum.INT, optional=True)
-GLOBALS.register("slice", Builtin(interpretSlice, [slice_list_arg, slice_idx_arg, slice_length_arg]))
-
-def interpretClear(symbol, args, env, ns):
-    subprocess.run(["clear"])
-    return List([])
-
-GLOBALS.register("clear", Builtin(interpretClear, []))
-
-def interpretReadLine(symbol, args, env, ns):
-    ret = input(args[0].value)
-    return String(ret)
-
-GLOBALS.register("read-line", Builtin(interpretReadLine, [Arg("prompt", TypeEnum.STRING)]))
-
-def interpretReadChar(symbol, args, env, ns):
-    import termios, tty
-    fd = sys.stdin.fileno()
-    old = termios.tcgetattr(fd)
-    try:
-        tty.setraw(fd)
-        ch = sys.stdin.buffer.read1(4)  # some keys are >1 bytes
-    except Exception:
-        raise
-    finally:
-        termios.tcsetattr(fd, termios.TCSADRAIN, old)
-    return String(ch.decode("utf-8"))
-
-GLOBALS.register("read-char", Builtin(interpretReadChar, []))
-
-def interpretAppend(symbol, args, env, ns):
-    lst = args[0]
-    val = args[1]
-    items = lst.args[:]
-    return List(items + [val], True)
-
-GLOBALS.register("append", Builtin(interpretAppend, [Arg("list", TypeEnum.LIST), Arg("item", TypeEnum.ANY)]))
-
-# TODO: this is actually for records/structs/whatever they're called
-def interpretRemove(symbol, args, env, ns):
-    lst = args[0]
-    key = args[1]
-    out = []
-    for arg in lst.args:
-        if arg.args[0].value != key.value:
-            out.append(arg)
-    return List(out, True)
-
-GLOBALS.register("remove", Builtin(interpretRemove, [Arg("list", TypeEnum.LIST), Arg("key", TypeEnum.ANY)]))
-
-def interpretWhile(symbol, args, env, ns):
-    cond = args[0]
-    ret = List([])
-    while True:
-        ev = evaluate(cond, env, ns)
-        if not isinstance(ev, Bool):
-            raise InterpretPanic(symbol, "expects a :bool condition", ev)
-        if not ev.value:
-            break
-        for arg in args[1:]:
-            ret = evaluate(arg, env, ns)
-    return ret
-
-GLOBALS.register("while", Builtin(interpretWhile, [Arg("cond", TypeEnum.BOOL, lazy=True)], Arg("expr", TypeEnum.ANY, lazy=True)))
-
-def interpretUse(symbol, args, env, ns):
-    target_file_name = args[0].value
-    target_file = Path(target_file_name).resolve()
-    if not target_file.exists():
-        raise InterpretPanic(symbol, "no such file", target_file)
-    with open(target_file, "r") as fil:
-        data = fil.read()
-    interpret(parse(lex(data)))
-    return List([])
-
-GLOBALS.register("use", Builtin(interpretUse, [Arg("filename", TypeEnum.STRING)]))
-
-def interpretAssert(symbol, args, env, ns):
-    if args[0].value != True:
-        raise InterpretPanic(symbol, "assertion failed")
-    return List([])
-
-GLOBALS.register("assert", Builtin(interpretAssert, [Arg("cond", TypeEnum.BOOL)]))
-
-def interpretHowTo(symbol, args, env, ns):
-    if not isinstance(args[0], Symbol):
-        raise InterpretPanic(symbol, "expects a symbol", args[0])
-    sym = env.get(args[0].name)
-    print(sym.describe(args[0].name))
-    return List([])
-
-GLOBALS.register("howto", Builtin(interpretHowTo, [Arg("symbol", TypeEnum.ANY, lazy=True)]))
-
-def interpretSymbols(symbol, args, env, ns):
-    keys = list(env.environment.keys())
-    keys.sort()
-    out = ""
-    for idx, key in enumerate(keys):
-        if idx % 6 == 0:
-            print(out)
-            out = f"{key}"
-        else:
-            out = f"{out} {key}"
-    print(out)
-    return List([])
-
-GLOBALS.register("symbols", Builtin(interpretSymbols, []))
-
-def interpretUseAs(symbol, args, env, ns):
-    target_file_name = args[0].value
-    target_file = Path(target_file_name).resolve()
-    if not target_file.exists():
-        raise InterpretPanic(symbol, "no such file", target_file)
-    with open(target_file, "r") as fil:
-        data = fil.read()
-    interpret(parse(lex(data)), ns=args[1].name)
-    return List([])
-
-GLOBALS.register("use-as", Builtin(interpretUseAs, [Arg("filename", TypeEnum.STRING), Arg("namespace", TypeEnum.ANY, lazy=True)]))
-
-def interpretFloor(symbol, args, env, ns):
-    return Int(math.floor(args[0].value))
-
-GLOBALS.register("floor", Builtin(interpretFloor, [Arg("floor", TypeEnum.NUMBER)]))
-
-def interpretFilter(symbol, args, env, ns):
-    func = args[0]
-    if not isinstance(func, Function):
-        raise InterpretPanic(symbol, "requires a :func as its first argument", func)
-    lst = args[1]
-    out = []
-    for arg in lst.args:
-        ev = func.call(List([func, arg]), env, ns)
-        if not isinstance(ev, Bool):
-            raise InterpretPanic(symbol, "function must return :bool", ev)
-        if ev.value:
-            out.append(arg)
-    return List(out, True)
-
-GLOBALS.register("filter", Builtin(interpretFilter, [Arg("func", TypeEnum.ANY), Arg("list", TypeEnum.LIST)]))
-
-def interpretTypeOf(symbol, args, env, ns):
-    return Type(f"{args[0].type_}")
-
-GLOBALS.register("typeof", Builtin(interpretTypeOf, [Arg("candidate", TypeEnum.ANY)]))