From eb6e0484af3cc99b8c753465f2706e4d6722fe4b Mon Sep 17 00:00:00 2001
From: hyung-hwan <hyunghwan.chung@gmail.com>
Date: Sun, 14 Jan 2024 01:28:00 +0900
Subject: [PATCH] WIP - multi-variable assigment. experimental convertion from
 := to set/set-r done

---
 lib/err.c  |  5 +++--
 lib/hcl.h  |  3 ++-
 lib/read.c | 37 +++++++++++++++++++++----------------
 3 files changed, 26 insertions(+), 19 deletions(-)

diff --git a/lib/err.c b/lib/err.c
index 1c9f0d8..9f9bf3c 100644
--- a/lib/err.c
+++ b/lib/err.c
@@ -161,8 +161,9 @@ static char* synerrstr[] =
 	"unbalanced key/value pair",
 	"unbalanced parenthesis/brace/bracket",
 	"unexpected semicolon",
-	"block expression expected"
-	"block expression disallowed"
+	"block expression expected",
+	"block expression disallowed",
+	"invalid lvalue"
 };
 
 /* --------------------------------------------------------------------------
diff --git a/lib/hcl.h b/lib/hcl.h
index 6579229..da65b43 100644
--- a/lib/hcl.h
+++ b/lib/hcl.h
@@ -166,7 +166,8 @@ enum hcl_synerrnum_t
 	HCL_SYNERR_UNBALPBB,      /* unbalanced parenthesis/brace/bracket */
 	HCL_SYNERR_SEMICOLON,     /* unexpected semicolon */
 	HCL_SYNERR_BLOCK,         /* block expression expected */
-	HCL_SYNERR_BLOCKBANNED    /* block expression disallowed */
+	HCL_SYNERR_BLOCKBANNED,   /* block expression disallowed */
+	HCL_SYNERR_LVALUE         /* invalid lvalue */
 };
 typedef enum hcl_synerrnum_t hcl_synerrnum_t;
 
diff --git a/lib/read.c b/lib/read.c
index 33ed288..92620a6 100644
--- a/lib/read.c
+++ b/lib/read.c
@@ -572,36 +572,40 @@ static HCL_INLINE hcl_cnode_t* leave_list (hcl_t* hcl, hcl_loc_t* list_loc, int*
 		if (concode == HCL_CONCODE_ALIST)
 		{
 			/* tranform (var := val) to (set var val) */
-			hcl_cnode_t* sym, * newhead, * rval;
+			hcl_cnode_t* sym, * newhead, * lval;
 			hcl_oocs_t fake_tok, * fake_tok_ptr = HCL_NULL;
 
-			rval = HCL_CNODE_CONS_CAR(head);
-			if (rval && HCL_CNODE_IS_CONS(rval) && HCL_CNODE_CONS_CONCODE(rval) == HCL_CONCODE_ARRAY)
+			lval = HCL_CNODE_CONS_CAR(head);
+			if (lval && HCL_CNODE_IS_ELIST(lval))
 			{
-				hcl_cnode_t* tmp, * lval;
+				/* invalid lvalue */
+				hcl_setsynerr (hcl, HCL_SYNERR_LVALUE, HCL_CNODE_GET_LOC(lval), HCL_CNODE_GET_TOK(lval));
+				if (head) hcl_freecnode (hcl, head);
+				return HCL_NULL;
+			}
+			else if (lval && HCL_CNODE_IS_CONS(lval) && HCL_CNODE_CONS_CONCODE(lval) == HCL_CONCODE_ARRAY)
+			{
+				hcl_cnode_t* tmp, * rval;
 
 				fake_tok.ptr = vocas[VOCA_SYM_SET_R].str;
 				fake_tok.len = vocas[VOCA_SYM_SET_R].len;
 				fake_tok_ptr = &fake_tok;
 
-				/* move the array item up to the main list */
-		/* TODO: check ELIST separately??? */
-				lval = HCL_CNODE_CONS_CDR(lval);
-				HCL_CNODE_CONS_CAR(head) = HCL_CNODE_CONS_CAR(rval);
-	hcl_dumpcnode(hcl, tmp, 1);
-	hcl_dumpcnode(hcl, rval, 1);
-				for (tmp = rval; tmp && HCL_CNODE_IS_CONS(tmp); tmp = HCL_CNODE_CONS_CDR(tmp))
+				/* move the array item up to the main list and join the original lval to the end of it */
+				rval = HCL_CNODE_CONS_CDR(head);
+
+				hcl_freesinglecnode (hcl, head);
+				head = lval;
+
+/* TODO: check in advance if array items are all symbols... */
+				for (tmp = lval; tmp && HCL_CNODE_IS_CONS(tmp); tmp = HCL_CNODE_CONS_CDR(tmp))
 				{
 					if (!HCL_CNODE_CONS_CDR(tmp))
 					{
-				//		HCL_CNODE_CONS_CDR(tmp) = lval;
+						HCL_CNODE_CONS_CDR(tmp) = rval;
 						break;
 					}
 				}
-	hcl_dumpcnode(hcl, rval, 1);
-
-				hcl_freesinglecnode (hcl, rval);
-	hcl_dumpcnode(hcl, head, 1);
 			}
 			else
 			{
@@ -621,6 +625,7 @@ static HCL_INLINE hcl_cnode_t* leave_list (hcl_t* hcl, hcl_loc_t* list_loc, int*
 			}
 
 
+			/* create a new head joined with set or set-r */
 			newhead = hcl_makecnodecons(hcl, 0, &loc, fake_tok_ptr, sym, head);
 			if (HCL_UNLIKELY(!newhead))
 			{