Allow sequences and hashes to be called as functions.

This is already supported in the DWIM operator.

* eval.c (apply): If object isn't a function, gather the
arguments into an array and delegate to generic_funcall.

* lib.c (generic_funcall): Changed from static to external linkage.
Supports sequences and hashes as functions. Error messages
fixed not to refer to "funcall".
(funcall, funcall1, funcall2, funcall3, funcall4): Do not throw
exception if fun is not of FUN type; instead, delegate
to generic_funcall. Error messages fixed not to refer to "funcall".

* lib.h (generic_function): Declared.

4 files changed, 79 insertions, 25 deletions

diff --git a/ChangeLog b/ChangeLog
index b205fcd7..9db42ac8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,22 @@
 2014-02-05  Kaz Kylheku  <kaz@kylheku.com>
 
+	Allow sequences and hashes to be called as functions.
+	This is already supported in the DWIM operator.
+
+	* eval.c (apply): If object isn't a function, gather the
+	arguments into an array and delegate to generic_funcall.
+
+	* lib.c (generic_funcall): Changed from static to external linkage.
+	Supports sequences and hashes as functions. Error messages
+	fixed not to refer to "funcall".
+	(funcall, funcall1, funcall2, funcall3, funcall4): Do not throw
+	exception if fun is not of FUN type; instead, delegate
+	to generic_funcall. Error messages fixed not to refer to "funcall".
+
+	* lib.h (generic_function): Declared.
+
+2014-02-05  Kaz Kylheku  <kaz@kylheku.com>
+
 	* arith.c (lognot): Conform to new scheme for defaulting optional args.
 
 	* eval.c (apply): Unconditionally use colon_k for missing optional
diff --git a/eval.c b/eval.c
index 61459838..a70d8474 100644
--- a/eval.c
+++ b/eval.c
@@ -340,6 +340,16 @@ val apply(val fun, val arglist, val ctx_form)
     fun = cdr(binding);
   }
 
+  if (!functionp(fun)) {
+    for (nargs = 0;
+         (p < arg + 32) && consp(arglist);
+         nargs++, p++, arglist = cdr(arglist))
+    {
+      *p = car(arglist);
+    }
+    return generic_funcall(fun, arg, nargs);
+  }
+
   type_check (fun, FUN);
 
   if (!listp(arglist)) {
diff --git a/lib.c b/lib.c
index ea3df4b9..771bb46d 100644
--- a/lib.c
+++ b/lib.c
@@ -3230,11 +3230,47 @@ val interp_fun_p(val obj)
   return (functionp(obj) && obj->f.functype == FINTERP) ? t : nil;
 }
 
-static val generic_funcall(val fun, val arg[], int nargs)
+val generic_funcall(val fun, val arg[], int nargs)
 {
   int variadic, fixparam, reqargs;
 
-  type_check (fun, FUN);
+  switch (type(fun)) {
+  case FUN:
+    break;
+  case NIL:
+  case CONS:
+  case LCONS:
+  case VEC:
+  case STR:
+  case LIT:
+  case LSTR:
+    switch (nargs) {
+    case 0:
+      uw_throw(error_s, lit("call: missing required arguments"));
+    case 1:
+      return ref(fun, arg[0]);
+    case 2:
+      return sub(fun, arg[0], arg[1]);
+    default:
+      uw_throw(error_s, lit("call: too many arguments"));
+    }
+  case COBJ:
+    if (fun->co.cls == hash_s) {
+      switch (nargs) {
+      case 0:
+        uw_throw(error_s, lit("call: missing required arguments"));
+      case 1:
+        return gethash(fun, arg[0]);
+      case 2:
+        return gethash_n(fun, arg[0], arg[1]);
+      default:
+        uw_throw(error_s, lit("call: too many arguments"));
+      }
+    }
+    /* fallthrough */
+  default:
+    type_mismatch(lit("call: ~s is not callable"), fun, nao);
+  }
 
   variadic = fun->f.variadic;
   fixparam = fun->f.fixparam;
@@ -3242,10 +3278,10 @@ static val generic_funcall(val fun, val arg[], int nargs)
 
   if (!variadic) {
     if (nargs < reqargs)
-      uw_throw(error_s, lit("funcall: missing required arguments"));
+      uw_throw(error_s, lit("call: missing required arguments"));
     
     if (nargs > fixparam)
-      uw_throw(error_s, lit("funcall: too many arguments"));
+      uw_throw(error_s, lit("call: too many arguments"));
 
     for (; nargs < fixparam; )
       arg[nargs++] = colon_k;
@@ -3287,7 +3323,7 @@ static val generic_funcall(val fun, val arg[], int nargs)
       nargs = fixparam;
 
     if (nargs < reqargs)
-      uw_throw(error_s, lit("funcall: missing required arguments"));
+      uw_throw(error_s, lit("call: missing required arguments"));
 
     for (; nargs < fixparam; )
       arg[nargs++] = colon_k;
@@ -3332,9 +3368,7 @@ static val generic_funcall(val fun, val arg[], int nargs)
 
 val funcall(val fun)
 {
-  type_check(fun, FUN);
-
-  if (fun->f.optargs) {
+  if (fun->f.optargs || type(fun) != FUN) {
     val arg[32] = { nil };
     return generic_funcall(fun, arg, 0);
   }
@@ -3360,14 +3394,12 @@ val funcall(val fun)
       break;
     }
   }
-  uw_throw(error_s, lit("funcall: wrong number of arguments"));
+  uw_throw(error_s, lit("call: wrong number of arguments"));
 }
 
 val funcall1(val fun, val arg)
 {
-  type_check(fun, FUN);
-
-  if (fun->f.optargs) {
+  if (fun->f.optargs || type(fun) != FUN) {
     val args[32];
     args[0] = arg;
     return generic_funcall(fun, args, 1);
@@ -3398,14 +3430,12 @@ val funcall1(val fun, val arg)
       break;
     }
   }
-  uw_throw(error_s, lit("funcall1: wrong number of arguments"));
+  uw_throw(error_s, lit("call: wrong number of arguments"));
 }
 
 val funcall2(val fun, val arg1, val arg2)
 {
-  type_check(fun, FUN);
-
-  if (fun->f.optargs) {
+  if (fun->f.optargs || type(fun) != FUN) {
     val arg[32];
     arg[0] = arg1;
     arg[1] = arg2;
@@ -3442,14 +3472,12 @@ val funcall2(val fun, val arg1, val arg2)
       break;
     }
   }
-  uw_throw(error_s, lit("funcall2: wrong number of arguments"));
+  uw_throw(error_s, lit("call: wrong number of arguments"));
 }
 
 val funcall3(val fun, val arg1, val arg2, val arg3)
 {
-  type_check(fun, FUN);
-
-  if (fun->f.optargs) {
+  if (fun->f.optargs || type(fun) != FUN) {
     val arg[32];
     arg[0] = arg1;
     arg[1] = arg2;
@@ -3491,14 +3519,12 @@ val funcall3(val fun, val arg1, val arg2, val arg3)
       break;
     }
   }
-  uw_throw(error_s, lit("funcall3: wrong number of arguments"));
+  uw_throw(error_s, lit("call: wrong number of arguments"));
 }
 
 val funcall4(val fun, val arg1, val arg2, val arg3, val arg4)
 {
-  type_check(fun, FUN);
-
-  if (fun->f.optargs) {
+  if (fun->f.optargs || type(fun) != FUN) {
     val arg[32];
     arg[0] = arg1;
     arg[1] = arg2;
@@ -3545,7 +3571,7 @@ val funcall4(val fun, val arg1, val arg2, val arg3, val arg4)
       break;
     }
   }
-  uw_throw(error_s, lit("funcall4: wrong number of arguments"));
+  uw_throw(error_s, lit("call: wrong number of arguments"));
 }
 
 val reduce_left(val fun, val list, val init, val key)
diff --git a/lib.h b/lib.h
index 1fc95a00..00fb35e5 100644
--- a/lib.h
+++ b/lib.h
@@ -603,6 +603,7 @@ val func_get_env(val fun);
 val func_set_env(val fun, val env);
 val functionp(val);
 val interp_fun_p(val);
+val generic_funcall(val fun, val arg[], int nargs);
 val funcall(val fun);
 val funcall1(val fun, val arg);
 val funcall2(val fun, val arg1, val arg2);