array lookup with a dot-number token

include/lang2/bytecode.h

@@ -153,13 +153,21 @@ enum l2_opcode {
 	L2_OP_NAMESPACE_SET,
 
 	/*
-	 * Set a namespace's name to a value.
+	 * Lookup a value from a namespace.
 	 * Pop <key>
 	 * Pop <ns>
 	 * Push <ns[<key>]>
 	 */
 	L2_OP_NAMESPACE_LOOKUP,
 
+	/*
+	 * Look up a value from an array.
+	 * Pop <key>
+	 * Pop <arr>
+	 * Push <arr[<key>]>
+	 */
+	L2_OP_DIRECT_ARRAY_LOOKUP,
+
 	/*
 	 * Halt execution.
 	 */

include/lang2/gen/gen.h

@@ -35,6 +35,7 @@ void l2_gen_function(struct l2_generator *gen, l2_word pos);
 void l2_gen_namespace(struct l2_generator *gen);
 void l2_gen_namespace_set(struct l2_generator *gen, char **ident);
 void l2_gen_namespace_lookup(struct l2_generator *gen, char **ident);
+void l2_gen_direct_array_lookup(struct l2_generator *gen, int number);
 void l2_gen_stack_frame_lookup(struct l2_generator *gen, char **ident);
 void l2_gen_func_call(struct l2_generator *gen);
 

include/lang2/parse/lex.h

@@ -13,6 +13,7 @@ enum l2_token_kind {
 	L2_TOK_QUOT,
 	L2_TOK_COMMA,
 	L2_TOK_PERIOD,
+	L2_TOK_DOT_NUMBER,
 	L2_TOK_COLON,
 	L2_TOK_COLON_EQ,
 	L2_TOK_EOL,
@@ -33,6 +34,7 @@ struct l2_token {
 	union {
 		char *str;
 		double num;
+		int integer;
 	} v;
 };
 

lib/gen/gen.c

@@ -140,6 +140,12 @@ void l2_gen_namespace_lookup(struct l2_generator *gen, char **ident) {
 	put(gen, L2_OP_NAMESPACE_LOOKUP);
 }
 
+void l2_gen_direct_array_lookup(struct l2_generator *gen, int number) {
+	put(gen, L2_OP_PUSH);
+	put(gen, number);
+	put(gen, L2_OP_DIRECT_ARRAY_LOOKUP);
+}
+
 void l2_gen_stack_frame_lookup(struct l2_generator *gen, char **ident) {
 	size_t atom_id = l2_strset_put(&gen->atomset, ident);
 	put(gen, L2_OP_PUSH);

lib/parse/lex.c

@@ -61,6 +61,8 @@ const char *l2_token_kind_name(enum l2_token_kind kind) {
 		return "comma";
 	case L2_TOK_PERIOD:
 		return "period";
+	case L2_TOK_DOT_NUMBER:
+		return "dot-number";
 	case L2_TOK_COLON:
 		return "colon";
 	case L2_TOK_COLON_EQ:
@@ -122,9 +124,13 @@ static int is_whitespace(int ch) {
 	return ch == ' ' || ch == '\r' || ch == '\n' || ch == '\t';
 }
 
+static int is_numeric(int ch) {
+	return ch >= '0' && ch <= '9';
+}
+
 static int skip_whitespace(struct l2_lexer *lexer) {
 	int nl = 0;
-	while (is_whitespace(l2_bufio_peek(&lexer->reader, 1))) {
+	while (is_whitespace(peek_ch(lexer))) {
 		int ch = read_ch(lexer);
 		if (ch == '\n') {
 			nl = 1;
@@ -134,6 +140,24 @@ static int skip_whitespace(struct l2_lexer *lexer) {
 	return nl;
 }
 
+static int read_integer(struct l2_lexer *lexer) {
+	char buffer[16]; // Should be enough
+	int len = 0;
+
+	while (len < sizeof(buffer) - 1 && is_numeric(peek_ch(lexer))) {
+		buffer[len++] = read_ch(lexer);
+	}
+
+	int num = 0;
+	int power = 1;
+	for (int i = len - 1; i >= 0; --i) {
+		num += (buffer[i] - '0') * power;
+		power *= 10;
+	}
+
+	return num;
+}
+
 static void read_string(struct l2_lexer *lexer, struct l2_token *tok) {
 	tok->kind = L2_TOK_STRING;
 	tok->v.str = malloc(16);
@@ -316,7 +340,12 @@ static void read_tok(struct l2_lexer *lexer, struct l2_token *tok) {
 
 	case '.':
 		read_ch(lexer);
-		tok->kind = L2_TOK_PERIOD;
+		if (is_numeric(peek_ch(lexer))) {
+			tok->kind = L2_TOK_DOT_NUMBER;
+			tok->v.integer = read_integer(lexer);
+		} else {
+			tok->kind = L2_TOK_PERIOD;
+		}
 		break;
 
 	case ':':

lib/parse/parse.c

@@ -71,6 +71,11 @@ static int parse_function_literal_impl(
 	l2_trace_scope("function literal");
 	// '{' and EOL already skipped by parse_object_or_function_literal
 
+	// The arguments array will be at the top of the stack
+	char *ident = malloc(2);
+	ident[0] = '$'; ident[1] = '\0';
+	l2_gen_assignment(gen, &ident);
+
 	int first = 1;
 	while (1) {
 		if (l2_lexer_peek(lexer, 1)->kind == L2_TOK_CLOSE_BRACE) {
@@ -184,6 +189,8 @@ static int parse_arg_level_expression_base(
 					l2_token_kind_name(tok->kind));
 			return -1;
 		}
+
+		l2_lexer_consume(lexer); // ')'
 	} else if (tok->kind == L2_TOK_IDENT) {
 		l2_trace_scope("ident");
 		l2_trace("ident '%s'", tok->v.str);
@@ -245,13 +252,19 @@ static int parse_arg_level_expression(
 			l2_gen_push(gen, 0);
 			l2_gen_func_call(gen);
 		} else if (tok->kind == L2_TOK_PERIOD && tok2->kind == L2_TOK_IDENT) {
-			l2_trace_scope("lookup");
+			l2_trace_scope("namespace lookup");
 			l2_trace("ident '%s'", tok2->v.str);
 			char *ident = l2_token_extract_str(tok2);
 			l2_lexer_consume(lexer); // '.'
 			l2_lexer_consume(lexer); // ident
 
 			l2_gen_namespace_lookup(gen, &ident);
+		} else if (tok->kind == L2_TOK_DOT_NUMBER) {
+			l2_trace_scope("direct array lookup");
+			int number = tok->v.integer;
+			l2_lexer_consume(lexer); // dot-number
+
+			l2_gen_direct_array_lookup(gen, number);
 		} else {
 			break;
 		}

lib/vm/print.c

@@ -197,6 +197,14 @@ void l2_vm_print_op(l2_word *ops, size_t opcount, size_t *ptr) {
 		printf("NAMESPACE_SET\n");
 		break;
 
+	case L2_OP_NAMESPACE_LOOKUP:
+		printf("NAMESPACE_LOOKUP\n");
+		break;
+
+	case L2_OP_DIRECT_ARRAY_LOOKUP:
+		printf("DIRECT_ARRAY_LOOKUP\n");
+		break;
+
 	case L2_OP_HALT:
 		printf("HALT\n");
 		break;

lib/vm/vm.c

@@ -405,6 +405,15 @@ void l2_vm_step(struct l2_vm *vm) {
 		}
 		break;
 
+	case L2_OP_DIRECT_ARRAY_LOOKUP:
+		{
+			l2_word key = vm->stack[--vm->sptr];
+			l2_word arr = vm->stack[--vm->sptr];
+			// TODO: Error if out of bounds or incorrect type
+			vm->stack[vm->sptr++] = vm->values[arr].array->data[key];
+			break;
+		}
+
 	case L2_OP_HALT:
 		break;
 	}