refactor: more literal types

1 files changed, 94 insertions, 96 deletions

diff --git a/interpreter.py b/interpreter.py
index 04160cd..ef0bc4a 100644
--- a/interpreter.py
+++ b/interpreter.py
@@ -1,4 +1,4 @@
-from structs import Literal, Symbol, List
+from structs import *
 from pathlib import Path
 from glob import glob
 import subprocess
@@ -126,12 +126,11 @@ def interpretOr(symbol, args, env):
         raise Exception("'or' has at least two operands")
     for arg in args:
         ev = evaluate(arg, env)
-        #if ev not in (True, False):
-        if not isinstance(ev, Literal) and ev.value not in (True, False):
+        if not isinstance(ev, Bool):
             raise Exception("'or' needs boolean arguments")
         if ev.value == True:
             return ev
-    return Literal(False)
+    return Bool(False)
 
 GLOBALS.register("or", Builtin(interpretOr))
 
@@ -141,12 +140,11 @@ def interpretAnd(symbol, args, env):
         raise Exception("'and' has at least two operands")
     for arg in args:
         ev = evaluate(arg, env)
-        #if ev not in (True, False):
-        if not isinstance(ev, Literal) and ev.value not in (True, False):
+        if not isinstance(ev, Bool):
             raise Exception("'and' needs boolean arguments")
         if ev.value == False:
             return ev
-    return Literal(True)
+    return Bool(True)
 
 GLOBALS.register("and", Builtin(interpretAnd))
 
@@ -157,29 +155,31 @@ def interpretEq(symbol, args, env):
     second = evaluate(args[1], env)
     if not (isinstance(first, Literal) and isinstance(second, Literal)):
         raise Exception("'eq?' can only compare literals")
-    if first.value == second.value:
-        return Literal(True)
+    # compare types because 0 != #false in neb
+    # TODO number equality?
+    if type(first) == type(second) and first.value == second.value:
+        return Bool(True)
     else:
-        return Literal(False)
+        return Bool(False)
 
 GLOBALS.register("eq?", Builtin(interpretEq, 2))
 
 def interpretComparison(symbol, args, env):
     left = evaluate(args[0], env)
-    if not isinstance(left, Literal) or type(left.value) not in (int, float):
+    if not (isinstance(left, Int) or isinstance(left, Float)):
         raise Exception("'left' must be a number")
     right = evaluate(args[1], env)
-    if not isinstance(right, Literal) or type(right.value) not in (int, float):
+    if not (isinstance(right, Int) or isinstance(right, Float)):
         raise Exception("'right' must be a number")
 
     if symbol.name == ">":
-        return Literal(left.value > right.value)
+        return Bool(left.value > right.value)
     elif symbol.name == ">=":
-        return Literal(left.value >= right.value)
+        return Bool(left.value >= right.value)
     elif symbol.name == "<":
-        return Literal(left.value < right.value)
+        return Bool(left.value < right.value)
     elif symbol.name == "<=":
-        return Literal(left.value <= right.value)
+        return Bool(left.value <= right.value)
 
 GLOBALS.register(">", Builtin(interpretComparison, 2))
 GLOBALS.register(">=", Builtin(interpretComparison, 2))
@@ -192,7 +192,7 @@ def interpretTerm(symbol, args, env):
     res = None
     for arg in args:
         ev = evaluate(arg, env)
-        if not isinstance(ev, Literal) or type(ev.value) not in (int, float):
+        if not (isinstance(ev, Int) or isinstance(ev, Float)):
             raise Exception("term must be a number")
         if res is None:
             res = ev.value
@@ -200,7 +200,10 @@ def interpretTerm(symbol, args, env):
             res += ev.value
         elif symbol.name == "-":
             res -= ev.value
-    return Literal(res)
+    if isinstance(res, float):
+        return Float(res)
+    else:
+        return Int(res)
 
 GLOBALS.register("+", Builtin(interpretTerm))
 GLOBALS.register("-", Builtin(interpretTerm))
@@ -208,61 +211,64 @@ GLOBALS.register("-", Builtin(interpretTerm))
 def interpretFactor(symbol, args, env):
     if symbol.name == "/":
         num = evaluate(args[0], env)
-        if not isinstance(num, Literal) or type(num.value) not in (int, float):
+        if not (isinstance(num, Int) or isinstance(num, Float)):
             raise Exception("numerator must be a number")
         denom = evaluate(args[1], env)
-        if not isinstance(denom, Literal) or type(denom.value) not in (int, float):
+        if not (isinstance(denom, Int) or isinstance(denom, Float)):
             raise Exception("denominator must be a number")
         ret = num.value / denom.value
         if int(ret) == ret:
-            return Literal(int(ret))
+            return Int(int(ret))
         else:
-            return Literal(ret)
+            return Float(ret)
     else:
         if len(args) < 2:
             raise Exception("'*' requires at least two operands")
         first = evaluate(args[0], env)
-        if not isinstance(first, Literal) or type(first.value) not in (int, float):
+        if not (isinstance(first, Int) or isinstance(first, Float)):
             raise Exception("'*' operand must be a number")
         res = first.value
         for arg in args[1:]:
             tmp = evaluate(arg, env)
-            if not isinstance(tmp, Literal) or type(tmp.value) not in (int, float):
+            if not (isinstance(tmp, Int) or isinstance(tmp, Float)):
                 raise Exception("'*' operand must be a number")
             res = res * tmp.value
-        return Literal(res)
+        if isinstance(res, float):
+            return Float(res)
+        else:
+            return Int(res)
 
 GLOBALS.register("*", Builtin(interpretFactor))
 GLOBALS.register("/", Builtin(interpretFactor, 2))
 
 def interpretNot(symbol, args, env):
     res = evaluate(args[0], env)
-    if not isinstance(res, Literal) or res.value not in (True, False):
+    if not isinstance(res, Bool):
         raise Exception("'not' only works on booleans")
-    return Literal(not res.value)
+    return Bool(not res.value)
 
 GLOBALS.register("not", Builtin(interpretNot, 1))
 
 def interpretIf(symbol, args, env):
     # if cond t-branch [f-branch]
     cond = evaluate(args[0], env)
-    if not isinstance(cond, Literal) or cond.value not in (True, False):
+    if not isinstance(cond, Bool):
         raise Exception("'if' condition must be boolean")
     if cond.value:
         return evaluate(args[1], env)
     elif len(args) == 3:
         return evaluate(args[2], env)
-    return None  # this shouldn't be reached
+    return List([])  # this shouldn't be reached
 
 GLOBALS.register("if", Builtin(interpretIf, 2, 3))
 
 def interpretPrint(symbol, args, env):
     ev = evaluate(args[0], env)
-    if not isinstance(ev, Literal) or not isinstance(ev.value, str):
+    if not isinstance(ev, String):
         raise Exception("can only 'print' strings")
     print(ev.value)
 
-    return None  # print returns nothing
+    return List([])  # print returns nothing
 
 GLOBALS.register("print", Builtin(interpretPrint, 1))
 
@@ -275,13 +281,7 @@ def interpretDef(symbol, args, env):
 
     ev = evaluate(args[1], env)
     env.register(name, ev)
-    '''
-    if isinstance(ev, UserFunction):
-        env.register(name, ev)
-    else:
-        env.register(name, args[1])
-    '''
-    return None
+    return List([])
 
 GLOBALS.register("def", Builtin(interpretDef, 2))
 
@@ -294,7 +294,7 @@ def interpretRedef(symbol, args, env):
 
     ev = evaluate(args[1], env)
     env.reregister(name, ev)
-    return None
+    return List([])
 
 GLOBALS.register("redef", Builtin(interpretRedef, 2))
 
@@ -309,10 +309,12 @@ GLOBALS.register("lambda", Builtin(interpretLambda))
 
 def interpretToString(symbol, args, env):
     ev = evaluate(args[0], env)
-    if isinstance(ev, Literal):
-        return Literal(str(ev.value))
+    if isinstance(ev, String):
+        return ev
+    elif isinstance(ev, Literal):
+        return String(str(ev))
     else:
-        return Literal(f"{ev}")
+        return String(f"{ev}")
 
 GLOBALS.register("->string", Builtin(interpretToString, 1))
 
@@ -323,24 +325,26 @@ def interpretConcat(symbol, args, env):
     out = ""
     for arg in args:
         tmp = evaluate(arg, env)
-        if not isinstance(tmp, Literal) and not isinstance(tmp.value, str):
+        if not isinstance(tmp, String):
             raise Exception("'concat' arguments must be strings")
         out += tmp.value
-    return Literal(out)
+    return String(out)
 
 GLOBALS.register("concat", Builtin(interpretConcat))
 
 def interpretForCount(symbol, args, env):
     # for-count int exprs
     num = evaluate(args[0], env)
-    if not isinstance(num, Literal) or type(num.value) is not int:
+    if not isinstance(num, Int):
         raise Exception("'for-count' count must be an integer")
     new_env = Environment(env)
     ret = None
     for idx in range(0, num.value):
-        new_env.register("idx", Literal(idx + 1))
+        new_env.register("idx", Int(idx + 1))
         for arg in args[1:]:
             ret = evaluate(arg, new_env)
+    if ret is None:
+        return List([])
     return ret
 
 GLOBALS.register("for-count", Builtin(interpretForCount))
@@ -356,6 +360,8 @@ def interpretForEach(symbol, args, env):
         new_env.register("_item_", item)
         for arg in args[1:]:
             ret = evaluate(arg, new_env)
+    if ret is None:
+        return List([])
     return ret
 
 GLOBALS.register("for-each", Builtin(interpretForEach))
@@ -369,6 +375,8 @@ def interpretPipe(symbol, args, env):
         if pipe is not None:
             new_env.register("items", pipe)
         pipe = evaluate(arg, new_env)
+    if pipe is None:
+        return List([])
     return pipe
 
 GLOBALS.register("|", Builtin(interpretPipe))
@@ -382,7 +390,7 @@ def interpretBranch(symbol, args, env):
         cond = evaluate(arg.args[0], env)  # this is the condition
         if cond.value:
             return evaluate(arg.args[1], env)
-    return None
+    return List([])
 
 GLOBALS.register("branch", Builtin(interpretBranch))
 
@@ -398,7 +406,7 @@ def interpretFunc(symbol, args, env):
     func = interpretLambda(None, args[1:], env)
 
     env.register(name, func)
-    return None
+    return List([])
 
 GLOBALS.register("func", Builtin(interpretFunc))
 
@@ -411,7 +419,7 @@ def interpretReadLines(symbol, args, env):
         raise Exception(f"no such file: {target_file}")
     with open(target_file, "r") as fil:
         data = fil.readlines()
-    out = List([Literal(d) for d in data], True) # all lines are strings
+    out = List([String(d) for d in data], True) # all lines are strings
     return out
 
 GLOBALS.register("read-lines", Builtin(interpretReadLines, 1))
@@ -419,30 +427,33 @@ GLOBALS.register("read-lines", Builtin(interpretReadLines, 1))
 #  - strip whitespace from string
 def interpretStrip(symbol, args, env):
     out = evaluate(args[0], env)
-    return Literal(out.value.strip())
+    return String(out.value.strip())
 
 GLOBALS.register("strip", Builtin(interpretStrip, 1))
 
 #  - string->int and string->float
 def interpretStringToInt(symbol, args, env):
+    ev = evaluate(args[0], env)
+    if not isinstance(ev, String):
+        raise Exception("'string->int' expects a string")
     try:
-        val = int(args[0].value)
-        return Literal(val)
+        val = int(ev.value)
+        return Int(val)
     except:
-        raise Exception(f"can't convert {args[0].value} to an int")
+        raise Exception(f"can't convert {ev} to an int")
 
 GLOBALS.register("string->int", Builtin(interpretStringToInt, 1))
 
 #  - split a string by a given field
 def interpretSplit(symbol, args, env):
     target = evaluate(args[0], env)
-    if not isinstance(target, Literal) or not isinstance(target.value, str):
+    if not isinstance(target, String):
         raise Exception("'split' expects a string")
     splitter = evaluate(args[1], env)
-    if not isinstance(splitter, Literal) or not isinstance(splitter.value, str):
+    if not isinstance(splitter, String):
         raise Exception("'split' expects a string as it's splitter")
     ret = target.value.split(splitter.value)
-    return List([Literal(r) for r in ret], True)
+    return List([String(r) for r in ret], True)
 
 GLOBALS.register("split", Builtin(interpretSplit, 2))
     
@@ -450,7 +461,7 @@ GLOBALS.register("split", Builtin(interpretSplit, 2))
 def interpretListLength(symbol, args, env):
     ev = evaluate(args[0], env)
     if not isinstance(ev, List):
-        raise Exception("'first' expects a List")
+        raise Exception("'list-length' expects a List")
     return Literal(len(ev.args))
 
 GLOBALS.register("list-length", Builtin(interpretListLength, 1))
@@ -487,10 +498,7 @@ def interpretMap(symbol, args, env):
         raise Exception("'map' takes a List as its second argument")
     out = []
     for arg in lst.args:
-        #arg_ev = evaluate(arg, env)
         ev = evaluate(List([func, arg]), env)
-        #ev = evaluate(List([func, arg_ev]), env)
-        #out.append(Literal(ev)) # TODO this is probably wrong
         out.append(ev)
     return List(out, True)
 
@@ -507,12 +515,6 @@ def interpretZip(symbol, args, env):
         raise Exception("'zip' expects two lists of the same size")
     out = []
     for idx in range(len(z1.args)):
-        #f = z1.args[idx]
-        #if not isinstance(f, Literal):
-        #    f = evaluate(f, env)
-        #s = z2.args[idx]
-        #if not isinstance(s, Literal):
-        #    s = evaluate(s, env)
         f = evaluate(z1.args[idx], env)
         s = evaluate(z2.args[idx], env)
         out.append(List([f, s], True))
@@ -543,7 +545,6 @@ def interpretApply(symbol, args, env):
     if not isinstance(func, Symbol):
         raise Exception("'apply' takes a function as its first argument")
     lst = evaluate(args[1], env)
-    #lst = args[1]
     if not isinstance(lst, List):
         raise Exception("'apply' takes a List as its second argument")
     new_lst = List([func] + lst.args)
@@ -553,23 +554,20 @@ GLOBALS.register("apply", Builtin(interpretApply, 2))
 
 def interpretGlob(symbol, args, env):
     ev = evaluate(args[0], env)
-    if not isinstance(ev, Literal):
+    if not isinstance(ev, String):
         raise Exception("'glob' expects a string")
     items = glob(ev.value)
-    out = []
-    for item in items:
-        out.append(Literal(item))
-    return List(out, True)
+    return List([String(item) for item in items], True)
 
 GLOBALS.register("glob", Builtin(interpretGlob, 1))
 
 def interpretShell(symbol, args, env):
     ev = evaluate(args[0], env)
-    if not isinstance(ev, Literal):
+    if not isinstance(ev, String):
         raise Exception("'$' expects a string")
     # TODO either fail or throw exception (?) on error
     ret = subprocess.run(shlex.split(ev.value), capture_output=True)
-    return List([Literal(r) for r in ret.stdout.decode("utf-8").split("\n")], True)
+    return List([String(r) for r in ret.stdout.decode("utf-8").split("\n")], True)
 
 GLOBALS.register("$", Builtin(interpretShell, 1))
 
@@ -577,7 +575,7 @@ def interpretEmpty(symbol, args, env):
     ev = evaluate(args[0], env)
     if not isinstance(ev, List):
         raise Exception("'empty?' expects a List")
-    return Literal(len(ev.args) == 0)
+    return Bool(len(ev.args) == 0)
 
 GLOBALS.register("empty?", Builtin(interpretEmpty, 1))
 
@@ -593,7 +591,7 @@ GLOBALS.register("shuf", Builtin(interpretShuf, 1))
 
 def interpretIsList(symbol, args, env):
     ev = evaluate(args[0], env)
-    return Literal(isinstance(ev, List))
+    return Bool(isinstance(ev, List))
 
 GLOBALS.register("list?", Builtin(interpretIsList, 1))
 
@@ -608,8 +606,8 @@ GLOBALS.register("block", Builtin(interpretBlock))
 def interpretExit(symbol, args, env):
     if len(args) > 1:
         raise Exception("'exit' only takes one (optional) argument")
-    status = 0 if len(args) == 0 else args[0].value
-    if type(status) is not int:
+    status = 0 if len(args) == 0 else evaluate(args[0], env).value
+    if not isinstance(status, int):
         raise Exception("'exit' requires an :int")
     sys.exit(status)
     return List([])
@@ -618,7 +616,7 @@ GLOBALS.register("exit", Builtin(interpretExit, 0, 1))
 
 def interpretUnlink(symbol, args, env):
     ev = evaluate(args[0], env)
-    if not isinstance(ev, Literal):
+    if not isinstance(ev, String):
         raise Exception("'unlink' expects a string")
     target_path = Path(ev.value).resolve()
     if not target_path.exists():
@@ -631,7 +629,7 @@ GLOBALS.register("unlink", Builtin(interpretUnlink, 1))
 def interpretArgv(symbol, args, env):
     out = []
     for arg in sys.argv[1:]:
-        out.append(Literal(arg))
+        out.append(String(arg))
     return List(out, True)
 
 GLOBALS.register("argv", Builtin(interpretArgv, 0))
@@ -645,9 +643,9 @@ def interpretIn(symbol, args, env):
         raise Exception("'in?' expects a list as its second argument")
     for arg in lst.args:
         ev = evaluate(arg, env)
-        if isinstance(ev, Literal) and ev.value == target.value:
-            return Literal(True)
-    return Literal(False)
+        if type(ev) == type(target) and ev.value == target.value:
+            return Bool(True)
+    return Bool(False)
 
 GLOBALS.register("in?", Builtin(interpretIn, 2))
 
@@ -666,9 +664,9 @@ def interpretJoin(symbol, args, env):
     if not isinstance(lst, List):
         raise Exception("'join' expects a List as its first argument")
     target = evaluate(args[1], env)
-    if not isinstance(target, Literal):
+    if not isinstance(target, String):
         raise Exception("'join' expects a :string as its second argument")
-    return Literal(target.value.join(lst.args))
+    return String(target.value.join(lst.args))
 
 GLOBALS.register("join", Builtin(interpretJoin, 2))
 
@@ -676,7 +674,7 @@ def interpretWithWrite(symbol, args, env):
     if len(args) == 0:
         raise Exception("'with-write' expects at least one argument")
     target_file = evaluate(args[0], env)
-    if not isinstance(target_file, Literal):
+    if not isinstance(target_file, String):
         raise Exception("'with-write' expects a filename as its first argument")
     new_env = Environment(env)
     target_path = Path(target_file.value).resolve()
@@ -692,7 +690,7 @@ GLOBALS.register("with-write", Builtin(interpretWithWrite))
 def interpretWrite(symbol, args, env):
     # write :string :filehandle
     line = evaluate(args[0], env)
-    if not isinstance(line, Literal):
+    if not isinstance(line, String):
         raise Exception("'write' expects a string as its first argument")
     handle = evaluate(args[1], env)
     handle.args[0].write(line.value)  # TODO wrong! how do we evaluate a handle?
@@ -701,33 +699,33 @@ def interpretWrite(symbol, args, env):
 GLOBALS.register("write", Builtin(interpretWrite, 2))
 
 def interpretNewline(symbol, args, env):
-    return Literal("\n")
+    return String("\n")
 
 GLOBALS.register("newline", Builtin(interpretNewline, 0))
 
 def interpretExists(symbol, args, env):
     file_or_dir = evaluate(args[0], env)
-    if not isinstance(file_or_dir, Literal):
+    if not isinstance(file_or_dir, String):
         raise Exception("'exists?' expects a string as its first argument")
-    return Literal(Path(file_or_dir.value).resolve().exists())
+    return Bool(Path(file_or_dir.value).resolve().exists())
 
 GLOBALS.register("exists?", Builtin(interpretExists, 1))
 
 def interpretFirstChar(symbol, args, env):
     ev = evaluate(args[0], env)
-    if not isinstance(ev, Literal):
+    if not isinstance(ev, String):
         raise Exception("'first-char' expects a string")
     if len(ev.value) == 0:
         raise Exception("string is empty")
-    return Literal(ev.value[0])
+    return String(ev.value[0])
 
 GLOBALS.register("first-char", Builtin(interpretFirstChar, 1))
 
 def interpretRestChar(symbol, args, env):
     ev = evaluate(args[0], env)
-    if not isinstance(ev, Literal):
+    if not isinstance(ev, String):
         raise Exception("'rest-char' expects a string")
-    return Literal(ev.value[1:])
+    return String(ev.value[1:])
 
 GLOBALS.register("rest-char", Builtin(interpretRestChar, 1))
 
@@ -736,12 +734,12 @@ def interpretSlice(symbol, args, env):
     if not isinstance(lst, List):
         raise Exception("'slice' expects a list as its first argument")
     idx = evaluate(args[1], env)
-    if not isinstance(idx, Literal):
+    if not isinstance(idx, Int):
         raise Exception("'slice' expects an integer as its second argument")
     if len(args) == 2:
         return List(lst.args[idx.value - 1:])
     length = evaluate(args[2], env)
-    if not isinstance(length, Literal):
+    if not isinstance(length, Int):
         raise Exception("'slice' expects an integer as its third argument")
     diff = idx.value - 1 + length.value
     return List(lst.args[idx.value - 1:diff])