3 files changed, 42 insertions, 20 deletions

diff --git a/runner.py b/runner.py
index a2c7e99..8e4f86d 100644
--- a/runner.py
+++ b/runner.py
@@ -1,15 +1,6 @@
 from tokens import *
+from std import STD
 
-def std_print(arg):
-    print(arg.value)
-    #return []  # TODO this should return empty list
-    return NebLiteral(NebType.BOOL, True)
-
-std = {
-    "print": {
-        "func": NebFunction("print", [NebType.STRING], NebType.BOOL),
-        "impl": std_print }
-    }
 
 def peek(inp):
     if len(inp) == 0:
@@ -24,19 +15,17 @@ def evaluate(items, pop):
         pop = nxt.value
         return evaluate(items[1:], pop)
     elif isinstance(nxt, NebSymbol):
-        if not nxt.name in std:
+        if not nxt.name in STD:
             raise Exception(f"no such symbol: '{nxt.name}'")
-        this_func = std[nxt.name]
-        return evaluate(items[1:], this_func["impl"])
+        this_func = STD[nxt.name]
+        return evaluate(items[1:], this_func[list(this_func.keys())[0]].impl) # TODO show all
     elif isinstance(nxt, NebExpression):
-        if not nxt.symbol.name in std:
+        if not nxt.symbol.name in STD:
             raise Exception(f"no such symbol: {nxt.symbol.name}")
-        this_func = std[nxt.symbol.name]
-        #expected_sig = " ".join(x.type_.name for x in nxt.args)
-        #if this_func["func"].in_sig() != expected_sig:
-        if this_func["func"].in_sig() != nxt.maybe_sig():
-            raise Exception(f"{nxt.symbol.name} expects '{this_func['func'].in_sig()}', got '{nxt.maybe_sig()}'")
-        ret = this_func["impl"](*(nxt.args))
+        this_func = STD[nxt.symbol.name]
+        if nxt.maybe_sig() not in this_func:
+            raise Exception(f"'{nxt.symbol.name}' called with unknown signature: '{nxt.maybe_sig()}'")
+        ret = this_func[nxt.maybe_sig()].impl(*(nxt.args))
         return evaluate(items[1:], ret)
     else:
         raise Exception("expected a literal or an expression")
diff --git a/std.py b/std.py
new file mode 100644
index 0000000..dfa1cef
--- /dev/null
+++ b/std.py
@@ -0,0 +1,32 @@
+from tokens import *
+import sys
+from collections import namedtuple
+
+FuncImpl = namedtuple("FuncImpl", ("func", "impl"))
+
+STD = {}
+
+def std_exit(status=0):
+    sys.exit(status)
+    return NebLiteral(NebType.BOOL, True)
+
+def std_print(arg):
+    print(arg.value)
+    #return []  # TODO this should return empty list
+    return NebLiteral(NebType.BOOL, True)
+
+def build_std():
+    print_string = FuncImpl(NebFunction("print", [NebType.STRING], NebType.BOOL), std_print)
+    STD["print"] = {
+        print_string.func.in_sig(): print_string
+    }
+
+    exit_ = FuncImpl(NebFunction("exit", [], NebType.BOOL), std_exit)
+    exit_int = FuncImpl(NebFunction("exit", [NebType.INT], NebType.BOOL), std_exit)
+
+    STD["exit"] = {
+        exit_.func.in_sig(): exit_,
+        exit_int.func.in_sig(): exit_int
+    }
+    
+build_std()
diff --git a/tokens.py b/tokens.py
index e7f137b..688fb7f 100644
--- a/tokens.py
+++ b/tokens.py
@@ -61,3 +61,4 @@ class NebFunction(NebToken):
 
     def sig(self):
         return (self.in_sig() + " > " + self.out_sig()).strip()
+