From 4c655865e5d9af83a98c137609b01972f4e51beb Mon Sep 17 00:00:00 2001
From: gingerBill <bill@gingerbill.org>
Date: Mon, 18 Oct 2021 16:52:19 +0100
Subject: Begin work on matrix type

---
 src/parser.cpp | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 53 insertions(+), 1 deletion(-)

(limited to 'src/parser.cpp')

diff --git a/src/parser.cpp b/src/parser.cpp
index 716986b5d..499bd337b 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -159,6 +159,11 @@ Ast *clone_ast(Ast *node) {
 		n->IndexExpr.expr  = clone_ast(n->IndexExpr.expr);
 		n->IndexExpr.index = clone_ast(n->IndexExpr.index);
 		break;
+	case Ast_MatrixIndexExpr:
+		n->MatrixIndexExpr.expr  = clone_ast(n->MatrixIndexExpr.expr);
+		n->MatrixIndexExpr.row_index = clone_ast(n->MatrixIndexExpr.row_index);
+		n->MatrixIndexExpr.column_index = clone_ast(n->MatrixIndexExpr.column_index);
+		break;
 	case Ast_DerefExpr:
 		n->DerefExpr.expr = clone_ast(n->DerefExpr.expr);
 		break;
@@ -371,6 +376,11 @@ Ast *clone_ast(Ast *node) {
 		n->MapType.key   = clone_ast(n->MapType.key);
 		n->MapType.value = clone_ast(n->MapType.value);
 		break;
+	case Ast_MatrixType:
+		n->MatrixType.row_count    = clone_ast(n->MatrixType.row_count);
+		n->MatrixType.column_count = clone_ast(n->MatrixType.column_count);
+		n->MatrixType.elem         = clone_ast(n->MatrixType.elem);
+		break;
 	}
 
 	return n;
@@ -574,6 +584,15 @@ Ast *ast_deref_expr(AstFile *f, Ast *expr, Token op) {
 }
 
 
+Ast *ast_matrix_index_expr(AstFile *f, Ast *expr, Token open, Token close, Token interval, Ast *row, Ast *column) {
+	Ast *result = alloc_ast_node(f, Ast_MatrixIndexExpr);
+	result->MatrixIndexExpr.expr         = expr;
+	result->MatrixIndexExpr.row_index    = row;
+	result->MatrixIndexExpr.column_index = column;
+	result->MatrixIndexExpr.open         = open;
+	result->MatrixIndexExpr.close        = close;
+	return result;
+}
 
 
 Ast *ast_ident(AstFile *f, Token token) {
@@ -1066,6 +1085,14 @@ Ast *ast_map_type(AstFile *f, Token token, Ast *key, Ast *value) {
 	return result;
 }
 
+Ast *ast_matrix_type(AstFile *f, Token token, Ast *row_count, Ast *column_count, Ast *elem) {
+	Ast *result = alloc_ast_node(f, Ast_MatrixType);
+	result->MatrixType.token = token;
+	result->MatrixType.row_count = row_count;
+	result->MatrixType.column_count = column_count;
+	result->MatrixType.elem = elem;
+	return result;
+}
 
 Ast *ast_foreign_block_decl(AstFile *f, Token token, Ast *foreign_library, Ast *body,
                             CommentGroup *docs) {
@@ -2214,6 +2241,19 @@ Ast *parse_operand(AstFile *f, bool lhs) {
 			count_expr = parse_expr(f, false);
 			f->expr_level--;
 		}
+		if (allow_token(f, Token_Semicolon)) {
+			Ast *row_count = count_expr;
+			Ast *column_count = nullptr;
+			
+			f->expr_level++;
+			column_count = parse_expr(f, false);
+			f->expr_level--;
+			
+			expect_token(f, Token_CloseBracket);	
+			
+			return ast_matrix_type(f, token, row_count, column_count, parse_type(f));
+		}
+		
 		expect_token(f, Token_CloseBracket);
 		return ast_array_type(f, token, count_expr, parse_type(f));
 	} break;
@@ -2676,6 +2716,11 @@ Ast *parse_atom_expr(AstFile *f, Ast *operand, bool lhs) {
 			case Token_RangeHalf:
 				syntax_error(f->curr_token, "Expected a colon, not a range");
 				/* fallthrough */
+			case Token_Semicolon:  // matrix index
+				if (f->curr_token.kind == Token_Semicolon && f->curr_token.string == "\n") {
+					syntax_error(f->curr_token, "Expected a ';', not a newline");
+				}
+				/* fallthrough */
 			case Token_Colon:
 				interval = advance_token(f);
 				is_interval = true;
@@ -2691,7 +2736,14 @@ Ast *parse_atom_expr(AstFile *f, Ast *operand, bool lhs) {
 			close = expect_token(f, Token_CloseBracket);
 
 			if (is_interval) {
-				operand = ast_slice_expr(f, operand, open, close, interval, indices[0], indices[1]);
+				if (interval.kind == Token_Semicolon) {
+					if (indices[0] == nullptr || indices[1] == nullptr) {
+						syntax_error(open, "Matrix index expressions require both row and column indices");
+					}
+					operand = ast_matrix_index_expr(f, operand, open, close, interval, indices[0], indices[1]);
+				} else {
+					operand = ast_slice_expr(f, operand, open, close, interval, indices[0], indices[1]);
+				}
 			} else {
 				operand = ast_index_expr(f, operand, indices[0], open, close);
 			}
-- 
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