nooc

commit 10191547db64537e9393892c77dbc3fb09f2f5cb
parent 67645c1dff4b1482e6730c6e00001072e5c695af
Author: Nihal Jere <nihal@nihaljere.xyz>
Date:   Sat,  4 Dec 2021 22:28:15 -0600

add loops

Diffstat:
M
main.c
 | 
14
+++++++++++++-
M
nooc.h
 | 
11
+++++++++--
M
prog.nc
 | 
4
+---

3 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/main.c b/main.c
@@ -39,6 +39,9 @@ lex(struct slice start)
 		} else if (slice_cmplit(&start, "else") == 0) {
 			cur->type = TOK_ELSE;
 			ADVANCE(4);
+		} else if (slice_cmplit(&start, "loop") == 0) {
+			cur->type = TOK_LOOP;
+			ADVANCE(4);
 		} else if (isblank(*start.ptr)) {
 			ADVANCE(1);
 			continue;
@@ -248,6 +251,11 @@ parseexpr(struct token **tok)
 {
 	struct expr expr = { 0 };
 	switch ((*tok)->type) {
+	case TOK_LOOP:
+		*tok = (*tok)->next;
+		expr.kind = EXPR_LOOP;
+		expr.d.loop.block = parse(tok);
+		break;
 	case TOK_IF:
 		*tok = (*tok)->next;
 		expr.kind = EXPR_COND;
@@ -345,7 +353,7 @@ parse(struct token **tok)
 
 	while ((*tok)->type != TOK_NONE && (*tok)->type != TOK_RCURLY) {
 		item = (struct item){ 0 };
-		if ((*tok)->type != TOK_IF) {
+		if ((*tok)->type != TOK_IF && (*tok)->type != TOK_LOOP) {
 			expect((*tok), TOK_NAME);
 			name = (*tok);
 		}
@@ -526,6 +534,10 @@ genblock(char *buf, struct block *block)
 				total += genblock(buf ? buf + total : NULL, &expr.d.cond.bif);
 				total += jmp(buf ? buf + total: NULL, elselen);
 				total += genblock(buf ? buf + total : NULL, &expr.d.cond.belse);
+			} else if (expr.kind == EXPR_LOOP) {
+				size_t back = genblock(NULL, &expr.d.loop.block) + jmp(NULL, 0);
+				total += genblock(buf ? buf + total : NULL, &expr.d.loop.block);
+				total += jmp(buf ? buf + total: NULL, -back);
 			} else {
 				error("unhandled toplevel expression type!");
 			}
diff --git a/nooc.h b/nooc.h
@@ -21,7 +21,8 @@ enum tokentype {
 	TOK_STRING,
 
 	TOK_IF,
-	TOK_ELSE
+	TOK_ELSE,
+	TOK_LOOP
 };
 
 struct slice {
@@ -91,6 +92,10 @@ struct cond {
 	struct block belse;
 };
 
+struct loop {
+	struct block block;
+};
+
 
 enum binop {
 	OP_PLUS,
@@ -110,7 +115,8 @@ enum exprkind {
 	EXPR_IDENT,
 	EXPR_BINARY,
 	EXPR_FCALL,
-	EXPR_COND
+	EXPR_COND,
+	EXPR_LOOP
 };
 
 enum class {
@@ -127,6 +133,7 @@ struct expr {
 		struct slice s;
 		struct fcall call;
 		struct cond cond;
+		struct loop loop;
 	} d;
 	size_t left;
 	size_t right;
diff --git a/prog.nc b/prog.nc
@@ -1,8 +1,6 @@
 exit i64 = 60
 write i64 = 1
-if > 0 1 {
+loop {
 	syscall(write, 0, "hello", 5)
-} else {
-	syscall(write, 0, "world", 5)
 }
 syscall(exit, 0)