1 files changed, 177 insertions, 0 deletions
diff --git a/parser/parser.c b/parser/parser.c
new file mode 100644
index 0000000..42a2dcf
--- /dev/null
+++ b/parser/parser.c
@@ -0,0 +1,177 @@
+/**
+ * @file parser.c
+ * @brief 
+ */
+#include <parser.h>
+
+#include <assert.h>
+
+#include <platform/osal.h>
+#include <lib/arena.h>
+#include <lib/vector.h>
+#include <lex.h>
+
+#include <stdlib.h>
+
+void parser_print_error(struct parser *p, const char *e)
+{
+	print("error: %s\n", e);
+}
+
+struct token* parser_previous(struct parser *p)
+{
+	if (p->pos < 1) {
+		return &((struct token*)p->tokens->start)[0];
+	}
+	return &((struct token*)p->tokens->start)[p->pos - 1];
+}
+
+struct token* parser_advance(struct parser *p)
+{
+	if (p->pos >= p->size) {
+		return &((struct token*)p->tokens->start)[p->size];
+	}
+	p->pos++;
+	return &((struct token*)p->tokens->start)[p->pos];
+}
+
+struct token* parser_seek(struct parser *p, size_t o)
+{
+	if (p->pos + o >= p->size) {
+		return &((struct token*)p->tokens->start)[p->size];
+	}
+	return &((struct token*)p->tokens->start)[p->pos + o];
+}
+
+int parser_expect(struct parser *p, int t, char *e)
+{
+	assert(p != NULL);
+
+	if (parser_seek(p, 0)->type == t)
+		return 0;
+
+	p->error = 1;
+	parser_print_error(p, e);
+}
+
+int parser_match(struct parser *p, size_t n, ...)
+{
+	assert(p != NULL);
+	va_list args;
+	va_start(args, p);
+
+	int res = 0;
+	
+	struct token *t = parser_seek(p, 0);
+	for (int i = 0; i < n; i++) {
+		if (t->type == va_arg(args, int)) {
+			res = 1;
+			parser_advance(p);
+			goto cleanup;
+		}
+	}
+
+ cleanup:
+	va_end(args);
+	return res;
+}
+
+void * parser_parse_primary(struct parser *p)
+{
+	assert(p != NULL);
+
+	struct node_primary* n = (struct node_primary*)region_alloc(p->buffer, sizeof(struct node_primary));
+
+	n->ntype = N_LITERAL;
+	
+	struct token *tkn = parser_seek(p, 0);
+	char * tkn_str = tkn->lexeme;
+	
+	switch (tkn->type) {
+	case TOKEN_NUMBER:
+		n->is_number = 1;
+		n->value.number = atoi(tkn_str);
+		break;
+	case TOKEN_HEX:
+		n->is_number = 1;
+		print("TODO: to be implemented!!\n");
+		break;
+	case TOKEN_BINARY:
+		print("TODO: to be implemented!\n");
+		break;
+	}
+
+	parser_advance(p);
+	return n;
+}
+
+void *parser_parse_unary(struct parser *p)
+{
+	if (parser_match(p, 2, TOKEN_MINUS, TOKEN_BANG)) {
+		struct token *operator = parser_previous(p);
+		void *unary = parser_parse_unary(p);
+		
+		struct node_unary *mem = region_alloc(p->buffer, sizeof(struct node_unary));
+		*mem = (struct node_unary) {.ntype = N_UNARY, .operator=*operator, .expr=unary};
+		return mem;
+	}
+
+	return parser_parse_primary(p);
+}
+
+void *parser_parse_term(struct parser *p)
+{
+	assert(p != NULL);
+
+	void *expr = parser_parse_unary(p);
+
+	while (parser_match(p, 2, TOKEN_STAR, TOKEN_SLASH)) {
+		struct token *operator = parser_previous(p);
+		void *right = parser_parse_unary(p);
+		
+		void *tmp = expr;
+		expr = region_alloc(p->buffer, sizeof(struct node_binary));
+		*((struct node_binary*)expr) = (struct node_binary) {.ntype = N_BINARY, .operator=*operator, .left = tmp, .right = right};
+	}
+
+	return expr;
+}
+
+void *parser_parse_factor(struct parser *p)
+{
+	assert(p != NULL);
+
+	void *expr = parser_parse_term(p);
+
+	while (parser_match(p, 2, TOKEN_PLUS, TOKEN_MINUS)) {
+		struct token *operator = parser_previous(p);
+		void *right = parser_parse_term(p);
+		 
+		void *tmp = expr;
+		expr = region_alloc(p->buffer, sizeof(struct node_binary));
+		*((struct node_binary*)expr) = (struct node_binary) {.ntype = N_BINARY, .operator=*operator, .left = tmp, .right = right};
+	}
+
+	return expr;
+}
+
+void *parser_parse_expression(struct parser *p)
+{
+	assert(p != NULL);
+}
+
+void *parser_parse_statement(struct parser *p)
+{
+	assert(p != NULL);
+	parser_parse_primary(p);
+	parser_expect(p, TOKEN_SEMICOLON, "A statement must end with a semicolon!");
+}
+
+void parser_parse(struct parser *p)
+{
+	assert(p != NULL);
+
+	while (p->pos < p->size && (((struct token*)p->tokens->start) + p->pos) != NULL) {
+		vector_emplace_back(p->result, parser_parse_factor(p));
+	}
+}