hare

commit 99edd27a4cbefdab5debe6745c4672bb1575d428
parent de30fe2fcf07c7aa7921af384adf1aeb929c1de8
Author: Sebastian <sebastian@sebsite.pw>
Date:   Sat,  9 Dec 2023 21:11:30 -0500

hare::*: support for/switch/match labels

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

Diffstat:
M
hare/ast/expr.ha
 | 
5
+++++
M
hare/parse/+test/expr_test.ha
 | 
7
+++++--
M
hare/parse/expr.ha
 | 
20
++++++++++++++++++--
M
hare/unparse/expr.ha
 | 
15
+++++++++++++++

4 files changed, 43 insertions(+), 4 deletions(-)
diff --git a/hare/ast/expr.ha b/hare/ast/expr.ha
@@ -281,6 +281,7 @@ export type for_expr = struct {
 	cond: *expr,
 	afterthought: nullable *expr,
 	body: *expr,
+	label: label,
 };
 
 // A free expression.
@@ -328,6 +329,7 @@ export type match_case = struct {
 export type match_expr = struct {
 	value: *expr,
 	cases: []match_case,
+	label: label,
 };
 
 // An offset expression.
@@ -378,6 +380,7 @@ export type switch_case = struct {
 export type switch_expr = struct {
 	value: *expr,
 	cases: []switch_case,
+	label: label,
 };
 
 // A unary operator
@@ -595,6 +598,7 @@ case let e: *expr =>
 		expr_finish(l);
 		free(l);
 	case let m: match_expr =>
+		free(m.label);
 		expr_finish(m.value);
 		free(m.value);
 		for (let i = 0z; i < len(m.cases); i += 1) {
@@ -629,6 +633,7 @@ case let e: *expr =>
 		expr_finish(s.end);
 		free(s.end);
 	case let s: switch_expr =>
+		free(s.label);
 		expr_finish(s.value);
 		free(s.value);
 		for (let i = 0z; i < len(s.cases); i += 1) {
diff --git a/hare/parse/+test/expr_test.ha b/hare/parse/+test/expr_test.ha
@@ -197,7 +197,7 @@
 	for (true) {
 		x;
 	};
-	for (true) :label {
+	for :label (true) {
 		x;
 	};
 	for (let x = 0; x < 10) {
@@ -268,6 +268,9 @@
 	case =>
 		defer x;
 	};
+	switch :label (x) {
+	case => void;
+	};
 };
 ");
 };
@@ -286,7 +289,7 @@
 	case null => void;
 	case => abort();
 	};
-	match (x) {
+	match :label (x) {
 	case let s: matchdata =>
 		return y;
 	case str =>
diff --git a/hare/parse/expr.ha b/hare/parse/expr.ha
@@ -678,6 +678,10 @@ fn stmt(lexer: *lex::lexer) (ast::expr | error) = {
 
 fn for_expr(lexer: *lex::lexer) (ast::expr | error) = {
 	const tok = want(lexer, ltok::FOR)?;
+	const label = if (try(lexer, ltok::COLON)? is lex::token) {
+		const tok = want(lexer, ltok::NAME)?;
+		yield tok.1 as str;
+	} else "";
 	want(lexer, ltok::LPAREN)?;
 
 	const bindings: nullable *ast::expr =
@@ -721,6 +725,7 @@ fn for_expr(lexer: *lex::lexer) (ast::expr | error) = {
 			cond = cond,
 			afterthought = afterthought,
 			body = body,
+			label = label,
 		},
 	};
 };
@@ -1109,6 +1114,11 @@ fn static_expr(lexer: *lex::lexer) (ast::expr | error) = {
 fn switch_expr(lexer: *lex::lexer) (ast::expr | error) = {
 	const start = want(lexer, ltok::SWITCH)?;
 
+	const label = if (try(lexer, ltok::COLON)? is lex::token) {
+		const tok = want(lexer, ltok::NAME)?;
+		yield tok.1 as str;
+	} else "";
+
 	want(lexer, ltok::LPAREN)?;
 	const value = expr(lexer)?;
 	want(lexer, ltok::RPAREN)?;
@@ -1159,6 +1169,7 @@ fn switch_expr(lexer: *lex::lexer) (ast::expr | error) = {
 		expr = ast::switch_expr {
 			value = alloc(value),
 			cases = cases,
+			label = label,
 		},
 	};
 };
@@ -1204,6 +1215,10 @@ fn match_case(lexer: *lex::lexer) (ast::match_case | error) = {
 
 fn match_expr(lexer: *lex::lexer) (ast::expr | error) = {
 	const start = want(lexer, ltok::MATCH)?;
+	const label = if (try(lexer, ltok::COLON)? is lex::token) {
+		const tok = want(lexer, ltok::NAME)?;
+		yield tok.1 as str;
+	} else "";
 	want(lexer, ltok::LPAREN)?;
 	const value = expr(lexer)?;
 	want(lexer, ltok::RPAREN)?;
@@ -1221,8 +1236,9 @@ fn match_expr(lexer: *lex::lexer) (ast::expr | error) = {
 		start = start.2,
 		end = lex::prevloc(lexer),
 		expr = ast::match_expr {
-			value   = alloc(value),
-			cases   = cases,
+			value = alloc(value),
+			cases = cases,
+			label = label,
 		},
 	};
 };
diff --git a/hare/unparse/expr.ha b/hare/unparse/expr.ha
@@ -743,6 +743,11 @@ fn for_expr(
 ) (size | io::error) = {
 	let z = syn(ctx, "for", synkind::KEYWORD)?;
 	z += space(ctx)?;
+	if (e.label != "") {
+		z += syn(ctx, ":", synkind::LABEL)?;
+		z += syn(ctx, e.label, synkind::LABEL)?;
+		z += space(ctx)?;
+	};
 	z += syn(ctx, "(", synkind::PUNCTUATION)?;
 	match (e.bindings) {
 	case null => void;
@@ -775,6 +780,11 @@ fn switch_expr(
 ) (size | io::error) = {
 	let z = syn(ctx, "switch", synkind::KEYWORD)?;
 	z += space(ctx)?;
+	if (e.label != "") {
+		z += syn(ctx, ":", synkind::LABEL)?;
+		z += syn(ctx, e.label, synkind::LABEL)?;
+		z += space(ctx)?;
+	};
 	z += syn(ctx, "(", synkind::PUNCTUATION)?;
 	z += _expr(ctx, syn, e.value)?;
 	z += syn(ctx, ")", synkind::PUNCTUATION)?;
@@ -816,6 +826,11 @@ fn match_expr(
 ) (size | io::error) = {
 	let z = syn(ctx, "match", synkind::KEYWORD)?;
 	z += space(ctx)?;
+	if (e.label != "") {
+		z += syn(ctx, ":", synkind::LABEL)?;
+		z += syn(ctx, e.label, synkind::LABEL)?;
+		z += space(ctx)?;
+	};
 	z += syn(ctx, "(", synkind::PUNCTUATION)?;
 	z += _expr(ctx, syn, e.value)?;
 	z += syn(ctx, ")", synkind::PUNCTUATION)?;