Recognize that "id" is the K combinator in disguise. Rename it as "K" and extend its semantics accordingly.tip429_only_id

4 files changed, 35 insertions, 32 deletions

diff --git a/generic/tclBasic.c b/generic/tclBasic.c
index edf127d..38c0de3 100644
--- a/generic/tclBasic.c
+++ b/generic/tclBasic.c
@@ -221,10 +221,10 @@ static const CmdInfo builtInCmds[] = {
     {"foreach",		Tcl_ForeachObjCmd,	TclCompileForeachCmd,	TclNRForeachCmd,	CMD_IS_SAFE},
     {"format",		Tcl_FormatObjCmd,	TclCompileFormatCmd,	NULL,	CMD_IS_SAFE},
     {"global",		Tcl_GlobalObjCmd,	TclCompileGlobalCmd,	NULL,	CMD_IS_SAFE},
-    {"id",		Tcl_IdObjCmd,		TclCompileIdCmd,	NULL,	CMD_IS_SAFE},
     {"if",		Tcl_IfObjCmd,		TclCompileIfCmd,	TclNRIfObjCmd,	CMD_IS_SAFE},
     {"incr",		Tcl_IncrObjCmd,		TclCompileIncrCmd,	NULL,	CMD_IS_SAFE},
     {"join",		Tcl_JoinObjCmd,		NULL,			NULL,	CMD_IS_SAFE},
+    {"K",		Tcl_KObjCmd,		TclCompileKCmd,	NULL,	CMD_IS_SAFE},
     {"lappend",		Tcl_LappendObjCmd,	TclCompileLappendCmd,	NULL,	CMD_IS_SAFE},
     {"lassign",		Tcl_LassignObjCmd,	TclCompileLassignCmd,	NULL,	CMD_IS_SAFE},
     {"lindex",		Tcl_LindexObjCmd,	TclCompileLindexCmd,	NULL,	CMD_IS_SAFE},
diff --git a/generic/tclCmdIL.c b/generic/tclCmdIL.c
index ec6ad14..8b4b859 100644
--- a/generic/tclCmdIL.c
+++ b/generic/tclCmdIL.c
@@ -191,14 +191,13 @@ static const EnsembleImplMap defaultInfoMap[] = {
 /*
  *----------------------------------------------------------------------
  *
- * Tcl_IdObjCmd --
+ * Tcl_KObjCmd --
  *
- *	This procedure is invoked to process the "id" Tcl command. See the
+ *	This procedure is invoked to process the "K" Tcl command. See the
  *	user documentation for details on what it does.
  *
- *	With the bytecode compiler, this procedure is only called in case of
- *	wrong #args, or if the #args is not known at compile time (expand
- *	operator).
+ *	With the bytecode compiler, this procedure is only called when the
+ *	#args is not known at compile time (expand operator).
  *
  * Results:
  *	A standard Tcl result.
@@ -210,17 +209,20 @@ static const EnsembleImplMap defaultInfoMap[] = {
  */
 
 int
-Tcl_IdObjCmd(
+Tcl_KObjCmd(
     ClientData dummy,		/* Not used. */
     Tcl_Interp *interp,		/* Current interpreter. */
     int objc,			/* Number of arguments. */
     Tcl_Obj *const objv[])	/* Argument objects. */
 {
-    if (objc !=2) {
-	Tcl_WrongNumArgs(interp, 0, objv, "id value");
-	return TCL_ERROR;
+    if (objc>=2) {
+	Tcl_SetObjResult(interp, objv[1]);
+    } else {
+	Tcl_Obj *empty;
+
+	TclNewObj(empty);
+	Tcl_SetObjResult(interp, empty);
     }
-    Tcl_SetObjResult(interp, objv[1]);
     return TCL_OK;
 }
 
diff --git a/generic/tclCompCmdsGR.c b/generic/tclCompCmdsGR.c
index 620c2ff..345c19e 100644
--- a/generic/tclCompCmdsGR.c
+++ b/generic/tclCompCmdsGR.c
@@ -163,23 +163,23 @@ TclCompileGlobalCmd(
 /*
  *----------------------------------------------------------------------
  *
- * TclCompileIdCmd --
+ * TclCompileKCmd --
  *
- *	Procedure called to compile the "id" command.
+ *	Procedure called to compile the "K" combinator command.
  *
  * Results:
  *	Returns TCL_OK for a successful compile. Returns TCL_ERROR to defer
  *	evaluation to runtime.
  *
  * Side effects:
- *	Instructions are added to envPtr to execute the "id" command at
+ *	Instructions are added to envPtr to execute the "K" command at
  *	runtime.
  *
  *----------------------------------------------------------------------
  */
 
 int
-TclCompileIdCmd(
+TclCompileKCmd(
     Tcl_Interp *interp,		/* Used for error reporting. */
     Tcl_Parse *parsePtr,	/* Points to a parse structure for the command
 				 * created by Tcl_ParseCommand. */
@@ -188,24 +188,25 @@ TclCompileIdCmd(
     CompileEnv *envPtr)		/* Holds resulting instructions. */
 {
     /*
-     * General syntax: [id value]
+     * General syntax: [K ?value ...?]
      */
     int numWords = parsePtr->numWords;
     Tcl_Token *wordTokenPtr = TokenAfter(parsePtr->tokenPtr);
     DefineLineInformation;	/* TIP #280 */
 
-    if (numWords!=2) {
-	/*
-	 * Wrong #args. Clear the error message,
-	 * and report back to the compiler that this must be interpreted at
-	 * runtime.
-	 */
+    if (numWords>=2) {
+	int i;
 
-	Tcl_ResetResult(interp);
-	return TCL_ERROR;
+	for (i = 1; i < numWords; i++) {
+	    CompileWord(envPtr, wordTokenPtr, interp, i);
+	    wordTokenPtr = TokenAfter(wordTokenPtr);
+	    if (i>1) {
+		TclEmitOpcode(INST_POP,	envPtr);
+	    }
+	}
+    } else {
+	PushStringLiteral(envPtr, "");
     }
-    
-    CompileWord(envPtr, wordTokenPtr, interp, numWords-1);
 
     return TCL_OK;
 }
diff --git a/generic/tclInt.h b/generic/tclInt.h
index 119b22e..872761e 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -3294,9 +3294,6 @@ MODULE_SCOPE int	Tcl_GlobalObjCmd(ClientData clientData,
 MODULE_SCOPE int	Tcl_GlobObjCmd(ClientData clientData,
 			    Tcl_Interp *interp, int objc,
 			    Tcl_Obj *const objv[]);
-MODULE_SCOPE int	Tcl_IdObjCmd(ClientData clientData,
-			    Tcl_Interp *interp, int objc,
-			    Tcl_Obj *const objv[]);
 MODULE_SCOPE int	Tcl_IfObjCmd(ClientData clientData,
 			    Tcl_Interp *interp, int objc,
 			    Tcl_Obj *const objv[]);
@@ -3310,6 +3307,9 @@ MODULE_SCOPE int	Tcl_InterpObjCmd(ClientData clientData,
 MODULE_SCOPE int	Tcl_JoinObjCmd(ClientData clientData,
 			    Tcl_Interp *interp, int objc,
 			    Tcl_Obj *const objv[]);
+MODULE_SCOPE int	Tcl_KObjCmd(ClientData clientData,
+			    Tcl_Interp *interp, int objc,
+			    Tcl_Obj *const objv[]);
 MODULE_SCOPE int	Tcl_LappendObjCmd(ClientData clientData,
 			    Tcl_Interp *interp, int objc,
 			    Tcl_Obj *const objv[]);
@@ -3547,9 +3547,6 @@ MODULE_SCOPE int	TclCompileFormatCmd(Tcl_Interp *interp,
 MODULE_SCOPE int	TclCompileGlobalCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
-MODULE_SCOPE int	TclCompileIdCmd(Tcl_Interp *interp,
-			    Tcl_Parse *parsePtr, Command *cmdPtr,
-			    struct CompileEnv *envPtr);
 MODULE_SCOPE int	TclCompileIfCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
@@ -3577,6 +3574,9 @@ MODULE_SCOPE int	TclCompileInfoObjectNamespaceCmd(Tcl_Interp *interp,
 MODULE_SCOPE int	TclCompileIncrCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);
+MODULE_SCOPE int	TclCompileKCmd(Tcl_Interp *interp,
+			    Tcl_Parse *parsePtr, Command *cmdPtr,
+			    struct CompileEnv *envPtr);
 MODULE_SCOPE int	TclCompileLappendCmd(Tcl_Interp *interp,
 			    Tcl_Parse *parsePtr, Command *cmdPtr,
 			    struct CompileEnv *envPtr);