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/**
* @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));
}
}
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