hare

commit cce8406cf5b73b6098f81a8d55cb9ab3437e71ab
parent da23ff58f3971c73c29d3f719c59631f89890221
Author: Sebastian <sebastian@sebsite.pw>
Date:   Thu, 24 Feb 2022 20:52:17 -0500

ast: add copy allocation form

Signed-off-by: Sebastian <sebastian@sebsite.pw>

Diffstat:
M
hare/ast/expr.ha
 | 
12
++++++++++++
M
hare/parse/+test/expr.ha
 | 
1
+
M
hare/parse/expr.ha
 | 
37
++++++++++++++++++++++++++-----------
M
hare/unparse/expr.ha
 | 
5
++++-

4 files changed, 43 insertions(+), 12 deletions(-)
diff --git a/hare/ast/expr.ha b/hare/ast/expr.ha
@@ -37,11 +37,23 @@ export type access_tuple = struct {
 export type access_expr =
 	(access_identifier | access_index | access_field | access_tuple);
 
+// The form of an allocation expression.
+//
+// 	alloc(foo)    // OBJECT
+// 	alloc(foo...) // COPY
+export type alloc_form = enum {
+	OBJECT,
+	COPY,
+};
+
 // An allocation expression.
 //
 // 	alloc(foo)
+// 	alloc(foo...)
+// 	alloc(foo, bar)
 export type alloc_expr = struct {
 	init: *expr,
+	form: alloc_form,
 	capacity: nullable *expr,
 };
 
diff --git a/hare/parse/+test/expr.ha b/hare/parse/+test/expr.ha
@@ -45,6 +45,7 @@
 @test fn builtin() void = {
 	roundtrip(`export fn main() void = {
 	alloc(1234);
+	alloc(1234...);
 	alloc(4321, 1234);
 	append(x, 10);
 	append(x, 10...);
diff --git a/hare/parse/expr.ha b/hare/parse/expr.ha
@@ -171,21 +171,36 @@ fn alloc_expr(lexer: *lex::lexer) (ast::expr | error) = {
 	const start = want(lexer, ltok::ALLOC)?;
 	want(lexer, ltok::LPAREN)?;
 
-	const init = expression(lexer)?;
-	const cap: nullable *ast::expr =
-		if (try(lexer, ltok::COMMA)? is lex::token) {
-			yield alloc(expression(lexer)?);
-		} else null;
-
-	want(lexer, ltok::RPAREN)?;
+	const init = alloc(expression(lexer)?);
+	const expr =
+		switch (want(lexer, ltok::COMMA, ltok::ELLIPSIS, ltok::RPAREN)?.0) {
+		case ltok::COMMA =>
+			const cap = alloc(expression(lexer)?);
+			want(lexer, ltok::RPAREN)?;
+			yield ast::alloc_expr {
+				init = init,
+				form = ast::alloc_form::COPY,
+				capacity = cap,
+			};
+		case ltok::ELLIPSIS =>
+			want(lexer, ltok::RPAREN)?;
+			yield ast::alloc_expr {
+				init = init,
+				form = ast::alloc_form::COPY,
+				capacity = null,
+			};
+		case ltok::RPAREN =>
+			yield ast::alloc_expr {
+				init = init,
+				form = ast::alloc_form::OBJECT,
+				capacity = null,
+			};
+		};
 
 	return ast::expr {
 		start = start.2,
 		end = lex::prevloc(lexer),
-		expr = ast::alloc_expr {
-			init = alloc(init),
-			capacity = cap,
-		},
+		expr = expr,
 	};
 };
 
diff --git a/hare/unparse/expr.ha b/hare/unparse/expr.ha
@@ -41,7 +41,10 @@ export fn expr(
 		let z = fmt::fprint(out, "alloc(")?;
 		z += expr(out, indent, *e.init)?;
 		match (e.capacity) {
-		case null => void;
+		case null =>
+			if (e.form == ast::alloc_form::COPY) {
+				z += fmt::fprint(out, "...")?;
+			};
 		case let e: *ast::expr =>
 			z += fmt::fprint(out, ", ")?;
 			z += expr(out, indent, *e)?;