Special case assignment to allow assigning to ⍺ if unset, and throw syntax error on assignment to ⍵

2 files changed, 7 insertions, 2 deletions

diff --git a/eval.c b/eval.c
index ee0de84..658dde8 100644
--- a/eval.c
+++ b/eval.c
@@ -225,7 +225,11 @@ nameis(Datum left, Datum right)
 Datum
 assign(Datum left, Datum right)
 {
-	if(left.symbol->setfn != nil)
+	if(runestrcmp(left.symbol->name, L"⍵") == 0)
+		throwerror(nil, ESyntax);
+	else if(runestrcmp(left.symbol->name, L"⍺") == 0 && !left.symbol->undefined)
+		goto end;
+	else if(left.symbol->setfn != nil)
 		left.symbol->setfn(right);
 	else{
 		if(left.symbol->undefined == 0 && left.symbol->value.tag == ArrayTag)
@@ -237,6 +241,7 @@ assign(Datum left, Datum right)
 			incref(right.array); /* for the binding */
 		}
 	}
+end:
 	right.shy = 1;
 	if(right.tag == ArrayTag)
 		incref(right.array); /* for the returned array */
diff --git a/lexer.c b/lexer.c
index 24d7e00..706db23 100644
--- a/lexer.c
+++ b/lexer.c
@@ -168,7 +168,7 @@ get_digits:
 		}else if(runestrchr(L"⍺⍵", peek)){
 			Rune name[2] = {peek, 0};
 			stmt->toks[stmt->ntoks].tag = NameTag;
-			stmt->toks[stmt->ntoks].symbol = getsym(name, 0);
+			stmt->toks[stmt->ntoks].symbol = getsym(name, 1);
 		}else if(isalpharune(peek)){
 			Rune buf[64];
 			Rune *p = buf;