harec

commit 1c2d30ac9180186a1853609d31a036f9c770c875
parent 6a318a2529db284b56aeaad5beb5643fa23c7acf
Author: Drew DeVault <sir@cmpwn.com>
Date:   Thu, 24 Dec 2020 11:01:27 -0500

parse: parse measurement expressions

Diffstat:
M
include/ast.h
 | 
10
++++++++++
M
include/expr.h
 | 
15
+++++++++++++++
M
src/check.c
 | 
1
+
M
src/parse.c
 | 
38
+++++++++++++++++++++++++++++++++++++-

4 files changed, 63 insertions(+), 1 deletion(-)
diff --git a/include/ast.h b/include/ast.h
@@ -126,6 +126,15 @@ struct ast_expression_list {
 	struct ast_expression_list *next;
 };
 
+struct ast_expression_measure {
+	enum measure_operator op;
+	union {
+		struct ast_expression *value;
+		struct ast_type *type;
+		// TODO: Field selection
+	};
+};
+
 struct ast_expression_return {
 	struct ast_expression *value;
 };
@@ -144,6 +153,7 @@ struct ast_expression {
 		struct ast_expression_binding binding;
 		struct ast_expression_constant constant;
 		struct ast_expression_list list;
+		struct ast_expression_measure measure;
 		struct ast_expression_return _return;
 		struct ast_expression_unarithm unarithm;
 	};
diff --git a/include/expr.h b/include/expr.h
@@ -105,6 +105,21 @@ struct expression_list {
 	struct expressions exprs;
 };
 
+enum measure_operator {
+	M_LEN,
+	M_SIZE,
+	M_OFFSET,
+};
+
+struct expression_measure {
+	enum measure_operator op;
+	union {
+		struct expression *value;
+		const struct type *type;
+		// TODO: Field selection
+	};
+};
+
 struct expression_return {
 	struct expression *value;
 };
diff --git a/src/check.c b/src/check.c
@@ -369,6 +369,7 @@ check_expression(struct context *ctx,
 		break;
 	case EXPR_MATCH:
 	case EXPR_MEASURE:
+		assert(0); // TODO
 	case EXPR_RETURN:
 		check_expr_return(ctx, aexpr, expr);
 		break;
diff --git a/src/parse.c b/src/parse.c
@@ -491,6 +491,41 @@ parse_plain_expression(struct parser *par)
 	assert(0); // Unreachable
 }
 
+static struct ast_expression *parse_postfix_expression(struct parser *par);
+
+static struct ast_expression *
+parse_measurement_expression(struct parser *par)
+{
+	trace(TR_PARSE, "measurement");
+
+	struct ast_expression *exp = calloc(1, sizeof(struct ast_expression));
+	exp->type = EXPR_MEASURE;
+
+	struct token tok;
+	lex(par->lex, &tok);
+
+	want(par, T_LPAREN, NULL);
+	switch (tok.token) {
+	case T_SIZE:
+		exp->measure.op = M_SIZE;
+		exp->measure.type = calloc(1, sizeof(struct ast_type));
+		parse_type(par, exp->measure.type);
+		break;
+	case T_LEN:
+		exp->measure.op = M_LEN;
+		exp->measure.value = parse_postfix_expression(par);
+		break;
+	case T_OFFSET:
+		exp->measure.op = M_OFFSET;
+		assert(0); // TODO
+	default:
+		synassert(false, &tok, T_SIZE, T_LEN, T_OFFSET, T_EOF);
+	}
+
+	want(par, T_RPAREN, NULL);
+	return exp;
+}
+
 static struct ast_expression *
 parse_postfix_expression(struct parser *par)
 {
@@ -506,7 +541,8 @@ parse_postfix_expression(struct parser *par)
 	case T_SIZE:
 	case T_LEN:
 	case T_OFFSET:
-		assert(0); // TODO: measurement expression
+		unlex(par->lex, &tok);
+		return parse_measurement_expression(par);
 	case T_LPAREN:
 		lvalue = parse_complex_expression(par);
 		want(par, T_LPAREN, &tok);