initial commit of multi-type support (only list of strings for now)

5 files changed, 35 insertions, 4 deletions

diff --git a/neb/__init__.py b/neb/__init__.py
index 9b3c1e9..ab0f836 100644
--- a/neb/__init__.py
+++ b/neb/__init__.py
@@ -13,7 +13,7 @@ def interpret(exprs, env, ns=None):
 def evaluate(expr, env, ns=None):
     if isinstance(expr, Literal) or isinstance(expr, Function) or isinstance(expr, TypeWrap) or isinstance(expr, List):
         return expr
-    elif isinstance(expr, Symbol) or isinstance(expr, Type):
+    elif isinstance(expr, Symbol) or isinstance(expr, Type) or isinstance(expr, MultiType):
         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}"):
@@ -144,7 +144,7 @@ class UserFunction(Function):
                     newparams.append(param)
                     args.append(Arg(param.name, TypeEnum.ANY))
                 prev_type = False
-            elif isinstance(param, Type) and not prev_type and not first:
+            elif (isinstance(param, Type) or isinstance(param, MultiType)) and not prev_type and not first:
                 if many is None:
                     args[-1].type_ = param.name
                 else:
diff --git a/neb/parser.py b/neb/parser.py
index bbaf7a8..10c6633 100644
--- a/neb/parser.py
+++ b/neb/parser.py
@@ -45,8 +45,19 @@ def parseLiteral(token, prev, tokens):
 
 def parseType(token, prev, tokens):
     # if the next token is a symbol, combine for a type
-    if len(tokens) > 0 and tokens[0].type_ == TokenType.SYMBOL:
+    if tokens[0].type_ == TokenType.SYMBOL:
         return Type(f":{tokens[0].text}"), 2
+    elif tokens[0].type_ == TokenType.OPEN_BRACKET:
+        # only format currently supported:
+        # [ <type> ]
+        if tokens[1].type_ != TokenType.COLON:
+            raise ParseError("invalid type definition (expecting colon)", tokens[1].line)
+        typ, counter = parseType(tokens[1], tokens[0], tokens[2:])
+        if tokens[1+counter].type_ != TokenType.CLOSE_BRACKET:
+            raise ParseError("invalid type definition (expecting close bracket)", tokens[1+counter].line)
+        return MultiType(f":[{typ.name}]", typ), counter + 3
+    else:
+        raise ParseError("invalid type definition!", tokens[0].line)
 
 def parse(tokens):
     idx = 0
diff --git a/neb/std/core.py b/neb/std/core.py
index 1c3c4b4..750594e 100644
--- a/neb/std/core.py
+++ b/neb/std/core.py
@@ -47,7 +47,7 @@ CORE.register("redef", Builtin("redef", interpretRedef, [def_name_arg, def_val_a
 def interpretLambda(symbol, args, env, ns):
     new_args = args
     return_type = Type(":any")
-    if isinstance(args[0], Type):
+    if isinstance(args[0], Type) or isinstance(args[0], MultiType):
         return_type = args[0]
         new_args = args[1:]
 
diff --git a/neb/std/types.py b/neb/std/types.py
index f8d5405..b5422da 100644
--- a/neb/std/types.py
+++ b/neb/std/types.py
@@ -69,6 +69,16 @@ def interpretIsLiteral(symbol, args, env, ns):
 
 TYPES.register("literal?", Builtin("literal?", interpretIsLiteral, [Arg("arg", TypeEnum.ANY)], return_type=Type(":bool")))
 
+def interpretIsListOfString(symbol, args, env, ns):
+    if not isinstance(args[0], List):
+        return Bool(False)
+    for arg in args[0].args:
+        if not isinstance(arg, String):
+            return Bool(False)
+    return Bool(True)
+
+TYPES.register("list-of-string?", Builtin("list-of-string?", interpretIsListOfString, [Arg("arg", TypeEnum.ANY)], return_type=Type(":bool")))
+
 # add types to env
 any_type = NebType(":any", None, interpretIsAny)
 literal_type = NebType(":literal", any_type, interpretIsLiteral)
@@ -79,6 +89,8 @@ number_type = NebType(":number", literal_type, interpretIsNumber)
 int_type = NebType(":int", number_type, interpretIsInt)
 float_type = NebType(":float", number_type, interpretIsFloat)
 
+list_of_string_type = NebType(":[:string]", list_type, interpretIsListOfString)
+
 TYPES.register(":any", any_type)
 TYPES.register(":literal", literal_type)
 TYPES.register(":string", string_type)
@@ -87,3 +99,4 @@ TYPES.register(":bool", bool_type)
 TYPES.register(":number", number_type)
 TYPES.register(":int", int_type)
 TYPES.register(":float", float_type)
+TYPES.register(":[:string]", list_of_string_type)
diff --git a/neb/structs.py b/neb/structs.py
index b8effd0..80252a0 100644
--- a/neb/structs.py
+++ b/neb/structs.py
@@ -97,6 +97,13 @@ class Type:
     def __str__(self):
         return self.name
 
+class MultiType:
+    def __init__(self, name, inner):
+        self.name = name
+        self.inner = inner
+    def __str__(self):
+        return self.name
+
 class Symbol:
     def __init__(self, name, line):
         self.name = name