Add binding constructors

Author: DavisVaughan

src/include/Rinternals.h

@@ -720,6 +720,9 @@ Rboolean R_EnvironmentIsLocked(SEXP env); // envir.c
 void R_LockBinding(SEXP sym, SEXP env);
 void R_unLockBinding(SEXP sym, SEXP env);
 void R_MakeActiveBinding(SEXP sym, SEXP fun, SEXP env);
+void R_MakeDelayedPromiseBinding(SEXP sym, SEXP promiseExpr, SEXP promiseEnv, SEXP env);
+void R_MakeForcedPromiseBinding(SEXP sym, SEXP promiseExpr, SEXP promiseValue, SEXP env);
+void R_MakeMissingBinding(SEXP sym, SEXP env);
 Rboolean R_BindingIsLocked(SEXP sym, SEXP env); // envir.c
 Rboolean R_BindingIsActive(SEXP sym, SEXP env); // envir.c
 SEXP R_ActiveBindingFunction(SEXP sym, SEXP env);

src/main/envir.c

@@ -3485,6 +3485,32 @@ void R_unLockBinding(SEXP sym, SEXP env)
     }
 }
 
+void R_MakeDelayedPromiseBinding(SEXP sym, SEXP promiseExpr, SEXP promiseEnv, SEXP env) {
+    if (TYPEOF(sym) != SYMSXP)
+	error(_("not a symbol"));
+    if (TYPEOF(env) != ENVSXP)
+	error(_("not an environment"));
+    if (TYPEOF(promiseEnv) != ENVSXP)
+	error(_("not an environment"));
+    defineVar(sym, Rf_mkPROMISE(promiseExpr, promiseEnv), env);
+}
+
+void R_MakeForcedPromiseBinding(SEXP sym, SEXP promiseExpr, SEXP promiseValue, SEXP env) {
+    if (TYPEOF(sym) != SYMSXP)
+	error(_("not a symbol"));
+    if (TYPEOF(env) != ENVSXP)
+	error(_("not an environment"));
+    defineVar(sym, R_mkEVPROMISE(promiseExpr, promiseValue), env);
+}
+
+void R_MakeMissingBinding(SEXP sym, SEXP env) {
+    if (TYPEOF(sym) != SYMSXP)
+	error(_("not a symbol"));
+    if (TYPEOF(env) != ENVSXP)
+	error(_("not an environment"));
+    defineVar(sym, R_MissingArg, env);
+}
+
 void R_MakeActiveBinding(SEXP sym, SEXP fun, SEXP env)
 {
     if (TYPEOF(sym) != SYMSXP)