hare

commit 80d03addce474489fb3be95293d454a667f4951f
parent 1dba69e7a4c6bfcc2ba87757fb046799d030bf6e
Author: Drew DeVault <sir@cmpwn.com>
Date:   Fri, 16 Apr 2021 09:20:50 -0400

hare::parse: implement struct field access

Diffstat:
M
hare/parse/+test/expr.ha
 | 
6
++++++
M
hare/parse/expr.ha
 | 
19
++++++++++++++++---
M
hare/unparse/expr.ha
 | 
5
++++-

3 files changed, 26 insertions(+), 4 deletions(-)
diff --git a/hare/parse/+test/expr.ha b/hare/parse/+test/expr.ha
@@ -21,6 +21,12 @@
 		"export fn main() void = void: int as uint: u16 is u8;\n");
 };
 
+@test fn postfix() void = {
+	roundtrip("export fn main() void = x.y;\n"
+		"export fn main() void = x.y.z.q;\n"
+		"export fn main() void = x().y;\n");
+};
+
 @test fn unarithm() void = {
 	// TODO: object selectors/addr operator
 	roundtrip("export fn main() void = +void;\n"
diff --git a/hare/parse/expr.ha b/hare/parse/expr.ha
@@ -1,6 +1,7 @@
 use hare::ast;
 use hare::lex::{ltok};
 use hare::lex;
+use fmt;
 
 // Parses an expression.
 export fn expression(lexer: *lex::lexer) (ast::expr | error) = {
@@ -207,11 +208,11 @@ fn postfix(lexer: *lex::lexer, lvalue: (ast::expr | void)) (ast::expr | error) =
 		ex: ast::expr => ex,
 	};
 
-	lvalue = match (try(lexer, ltok::LPAREN, ltok::DOT, ltok::LBRACKET,
-			ltok::QUESTION)) {
+	lvalue = match (try(lexer, ltok::LPAREN,
+			ltok::DOT, ltok::LBRACKET, ltok::QUESTION)) {
 		tok: lex::token => switch (tok.0) {
 			ltok::LPAREN => call(lexer, lvalue)?,
-			ltok::DOT => abort(), // TODO: Field access
+			ltok::DOT => postfix_dot(lexer, lvalue)?,
 			ltok::LBRACKET => abort(), // TODO: Indexing
 			ltok::QUESTION => abort(), // TODO: Propagation
 			* => abort(),
@@ -222,6 +223,18 @@ fn postfix(lexer: *lex::lexer, lvalue: (ast::expr | void)) (ast::expr | error) =
 	return postfix(lexer, lvalue);
 };
 
+fn postfix_dot(lexer: *lex::lexer, lvalue: ast::expr) (ast::expr | error) = {
+	let tok = want(lexer, ltok::NAME, ltok::LIT_INT)?;
+	return switch (tok.0) {
+		ltok::NAME => ast::access_field {
+			object = alloc(lvalue),
+			field = tok.1 as str,
+		},
+		ltok::LIT_INT => abort(), // TODO: Tuple access
+		* => abort(),
+	};
+};
+
 fn unarithm(lexer: *lex::lexer) (ast::expr | error) = {
 	const tok = match (try(lexer,
 			ltok::PLUS, ltok::MINUS, ltok::BNOT,
diff --git a/hare/unparse/expr.ha b/hare/unparse/expr.ha
@@ -12,7 +12,10 @@ export fn expr(
 		e: ast::access_expr => match (e) {
 			id: ast::access_identifier => ident(out, id),
 			ix: ast::access_index => abort(),
-			fl: ast::access_field => abort(),
+			fi: ast::access_field => {
+				let z = expr(out, indent, *fi.object)?;
+				z + fmt::fprintf(out, ".{}", fi.field)?;
+			},
 			tp: ast::access_tuple => abort(),
 		},
 		e: ast::alloc_expr => abort(),