implemented basic parsing

This commit is contained in:
Lorenzo Torres 2025-11-30 21:56:39 +01:00
parent 038930d881
commit abf1d7c066
10 changed files with 588 additions and 486 deletions

483
test.c
View file

@ -1,482 +1 @@
#include "lexer.h"
#include <stdbool.h>
#include <ctype.h>
#include <stdio.h>
#include <string.h>
static const char *token_type_str[] = {
[TOKEN_ERROR] = "TOKEN_ERROR",
[TOKEN_END] = "TOKEN_END",
[TOKEN_PLUS] = "TOKEN_PLUS",
[TOKEN_PLUS_PLUS] = "TOKEN_PLUS_PLUS",
[TOKEN_MINUS] = "TOKEN_MINUS",
[TOKEN_MINUS_MINUS] = "TOKEN_MINUS_MINUS",
[TOKEN_SLASH] = "TOKEN_SLASH",
[TOKEN_PERC] = "TOKEN_PERC",
[TOKEN_STAR] = "TOKEN_STAR",
[TOKEN_AND] = "TOKEN_AND",
[TOKEN_HAT] = "TOKEN_HAT",
[TOKEN_PIPE] = "TOKEN_PIPE",
[TOKEN_EQ] = "TOKEN_EQ",
[TOKEN_ARROW] = "TOKEN_ARROW",
[TOKEN_LSHIFT] = "TOKEN_LSHIFT",
[TOKEN_RSHIFT] = "TOKEN_RSHIFT",
[TOKEN_DOUBLE_EQ] = "TOKEN_DOUBLE_EQ",
[TOKEN_LESS_THAN] = "TOKEN_LESS_THAN",
[TOKEN_GREATER_THAN] = "TOKEN_GREATER_THAN",
[TOKEN_LESS_EQ] = "TOKEN_LESS_EQ",
[TOKEN_GREATER_EQ] = "TOKEN_GREATER_EQ",
[TOKEN_NOT_EQ] = "TOKEN_NOT_EQ",
[TOKEN_PLUS_EQ] = "TOKEN_PLUS_EQ",
[TOKEN_MINUS_EQ] = "TOKEN_MINUS_EQ",
[TOKEN_STAR_EQ] = "TOKEN_STAR_EQ",
[TOKEN_SLASH_EQ] = "TOKEN_SLASH_EQ",
[TOKEN_AND_EQ] = "TOKEN_AND_EQ",
[TOKEN_HAT_EQ] = "TOKEN_HAT_EQ",
[TOKEN_PIPE_EQ] = "TOKEN_PIPE_EQ",
[TOKEN_PERC_EQ] = "TOKEN_PERC_EQ",
[TOKEN_LSHIFT_EQ] = "TOKEN_LSHIFT_EQ",
[TOKEN_RSHIFT_EQ] = "TOKEN_RSHIFT_EQ",
[TOKEN_OR] = "TOKEN_OR",
[TOKEN_DOUBLE_AND] = "TOKEN_DOUBLE_AND",
[TOKEN_COLON] = "TOKEN_COLON",
[TOKEN_SEMICOLON] = "TOKEN_SEMICOLON",
[TOKEN_DOT] = "TOKEN_DOT",
[TOKEN_BANG] = "TOKEN_BANG",
[TOKEN_COMMA] = "TOKEN_COMMA",
[TOKEN_LPAREN] = "TOKEN_LPAREN",
[TOKEN_RPAREN] = "TOKEN_RPAREN",
[TOKEN_LSQUARE] = "TOKEN_LSQUARE",
[TOKEN_RSQUARE] = "TOKEN_RSQUARE",
[TOKEN_LCURLY] = "TOKEN_LCURLY",
[TOKEN_RCURLY] = "TOKEN_RCURLY",
[TOKEN_INTEGER] = "TOKEN_INTEGER",
[TOKEN_FLOAT] = "TOKEN_FLOAT",
[TOKEN_IDENTIFIER] = "TOKEN_IDENTIFIER",
[TOKEN_STRING] = "TOKEN_STRING",
[TOKEN_CHAR] = "TOKEN_CHAR",
[TOKEN_WHILE] = "TOKEN_WHILE",
[TOKEN_FOR] = "TOKEN_FOR",
[TOKEN_GOTO] = "TOKEN_GOTO",
[TOKEN_IF] = "TOKEN_IF",
[TOKEN_ELSE] = "TOKEN_ELSE",
[TOKEN_SWITCH] = "TOKEN_SWITCH",
[TOKEN_CASE] = "TOKEN_CASE",
[TOKEN_DO] = "TOKEN_DO",
[TOKEN_DEFER] = "TOKEN_DEFER",
[TOKEN_MODULE] = "TOKEN_MODULE",
[TOKEN_STATIC] = "TOKEN_STATIC",
[TOKEN_CONST] = "TOKEN_CONST",
[TOKEN_EXTERN] = "TOKEN_EXTERN",
[TOKEN_VOLATILE] = "TOKEN_VOLATILE",
};
trie_node *keywords;
void lexer_print_token(token *t)
{
printf("%s: ", token_type_str[t->type]);
for (usize i=0; i < t->lexeme_len; i++) {
printf("%c", t->lexeme[i]);
}
}
static void add_token(lexer *l, token_type type, usize len)
{
token *t = arena_alloc(l->allocator, sizeof(token));
t->type = type;
t->lexeme_len = len;
t->lexeme = l->source + l->index;
t->position.row = l->row;
t->position.column = l->column;
if (!l->tokens) {
l->tokens = t;
l->tail = t;
} else {
l->tail->next = t;
l->tail = t;
}
}
static void add_error(lexer *l, char *msg)
{
token *t = arena_alloc(l->allocator, sizeof(token));
t->type = TOKEN_ERROR;
t->lexeme_len = strlen(msg);
t->lexeme = msg;
t->position.row = l->row;
t->position.column = l->column;
if (!l->tokens) {
l->tokens = t;
l->tail = t;
} else {
l->tail->next = t;
l->tail = t;
}
}
static void parse_number(lexer *l)
{
char c = l->source[l->index];
/* Is the number a float? */
bool f = false;
usize len = 0;
while (isdigit(c)) {
/* If a dot is found, and the character after it is a digit, this is a float. */
if (l->source[l->index+1] == '.' && isdigit(l->source[l->index+2])) {
f = true;
len += 3;
l->index += 3;
} else {
len += 1;
l->index += 1;
}
c = l->source[l->index];
}
l->index -= len;
if (f) {
add_token(l, TOKEN_FLOAT, len);
} else {
add_token(l, TOKEN_INTEGER, len);
}
l->index += len;
}
static void parse_identifier(lexer *l)
{
char c = l->source[l->index];
usize len = 0;
while (isalnum(c) || c == '_') {
len += 1;
l->index += 1;
c = l->source[l->index];
}
l->index -= len;
token_type keyword = trie_get(keywords, l->source + l->index, len);
if (keyword) {
add_token(l, keyword, len);
} else {
add_token(l, TOKEN_IDENTIFIER, len);
}
l->index += len;
}
static void parse_string(lexer *l)
{
char c = l->source[l->index];
usize len = 0;
while (c != '"') {
if (c == '\0' || c == '\n') {
printf("%c", c);
l->index -= len;
add_error(l, "unclosed string literal.");
l->index += len;
return;
}
len += 1;
l->index += 1;
c = l->source[l->index];
}
l->index -= len;
add_token(l, TOKEN_STRING, len);
l->index += len + 1;
}
static bool parse_special(lexer *l)
{
switch (l->source[l->index]) {
case '+':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_PLUS_EQ, 2);
l->index += 2;
} else if (l->source[l->index+1] == '+') {
add_token(l, TOKEN_PLUS_PLUS, 2);
l->index += 2;
} else {
add_token(l, TOKEN_PLUS, 1);
l->index += 1;
}
return true;
case '-':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_MINUS_EQ, 2);
l->index += 2;
} else if (l->source[l->index+1] == '-') {
add_token(l, TOKEN_MINUS_MINUS, 2);
l->index += 2;
} else if (l->source[l->index+1] == '>') {
add_token(l, TOKEN_ARROW, 2);
l->index += 2;
} else {
add_token(l, TOKEN_MINUS, 1);
l->index += 1;
}
return true;
case '/':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_SLASH_EQ, 2);
l->index += 2;
} else {
add_token(l, TOKEN_SLASH, 1);
l->index += 1;
}
return true;
case '*':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_STAR_EQ, 2);
l->index += 2;
} else {
add_token(l, TOKEN_STAR, 1);
l->index += 1;
}
return true;
case '%':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_PERC_EQ, 2);
l->index += 2;
} else {
add_token(l, TOKEN_PERC, 1);
l->index += 1;
}
return true;
case '&':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_AND_EQ, 2);
l->index += 2;
} else if (l->source[l->index+1] == '&') {
add_token(l, TOKEN_DOUBLE_AND, 2);
l->index += 2;
} else {
add_token(l, TOKEN_AND, 1);
l->index += 1;
}
return true;
case '^':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_HAT_EQ, 2);
l->index += 2;
} else {
add_token(l, TOKEN_HAT, 1);
l->index += 1;
}
return true;
case '|':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_PIPE_EQ, 2);
l->index += 2;
} else if (l->source[l->index+1] == '|') {
add_token(l, TOKEN_OR, 2);
l->index += 2;
} else {
add_token(l, TOKEN_PIPE, 1);
l->index += 1;
}
return true;
case '=':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_DOUBLE_EQ, 2);
l->index += 2;
} else {
add_token(l, TOKEN_EQ, 1);
l->index += 1;
}
return true;
case '>':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_GREATER_EQ, 2);
l->index += 2;
} else if (l->source[l->index+1] == '>') {
if (l->source[l->index+2] == '=') {
add_token(l, TOKEN_RSHIFT_EQ, 3);
l->index += 3;
return true;
}
add_token(l, TOKEN_RSHIFT, 2);
l->index += 2;
} else {
add_token(l, TOKEN_GREATER_THAN, 1);
l->index += 1;
}
return true;
case '<':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_LESS_EQ, 2);
l->index += 2;
} else if (l->source[l->index+1] == '<') {
if (l->source[l->index+2] == '=') {
add_token(l, TOKEN_LSHIFT_EQ, 3);
l->index += 3;
return true;
}
add_token(l, TOKEN_LSHIFT, 2);
l->index += 2;
} else {
add_token(l, TOKEN_LESS_THAN, 1);
l->index += 1;
}
return true;
case '!':
if (l->source[l->index+1] == '=') {
add_token(l, TOKEN_NOT_EQ, 2);
l->index += 2;
} else {
add_token(l, TOKEN_BANG, 1);
l->index += 1;
}
return true;
case ':':
add_token(l, TOKEN_COLON, 1);
l->index += 1;
return true;
case ';':
add_token(l, TOKEN_SEMICOLON, 1);
l->index += 1;
return true;
case '.':
add_token(l, TOKEN_DOT, 1);
l->index += 1;
return true;
case ',':
add_token(l, TOKEN_COMMA, 1);
l->index += 1;
return true;
case '(':
add_token(l, TOKEN_LPAREN, 1);
l->index += 1;
return true;
case ')':
add_token(l, TOKEN_RPAREN, 1);
l->index += 1;
return true;
case '[':
add_token(l, TOKEN_LSQUARE, 1);
l->index += 1;
return true;
case ']':
add_token(l, TOKEN_RSQUARE, 1);
l->index += 1;
return true;
case '{':
add_token(l, TOKEN_LCURLY, 1);
l->index += 1;
return true;
case '}':
add_token(l, TOKEN_RCURLY, 1);
l->index += 1;
return true;
case '\'':
if (l->source[l->index+1] == '\\') {
if (l->source[l->index+3] != '\'') {
add_error(l, "unclosed character literal.");
return true;
}
l->index += 1;
add_token(l, TOKEN_CHAR, 2);
l->index += 3;
return true;
} else {
if (l->source[l->index+2] != '\'') {
add_error(l, "unclosed character literal.");
return false;
}
l->index += 1;
add_token(l, TOKEN_CHAR, 1);
l->index += 2;
return true;
}
default:
return false;
}
}
static void parse(lexer *l)
{
char c;
while (l->index <= l->size) {
c = l->source[l->index];
l->column += 1;
if (c == '\n') {
l->index += 1;
l->row += 1;
l->column = 0;
continue;
}
if (isspace(c)) {
l->index += 1;
continue;
}
usize head = l->index;
if (parse_special(l)) {
l->column += (l->index - head - 1);
continue;
}
if (isdigit(c)) {
parse_number(l);
l->column += (l->index - head - 1);
continue;
}
if (isalpha(c)) {
parse_identifier(l);
l->column += (l->index - head - 1);
continue;
}
if (c == '"') {
l->index += 1;
parse_string(l);
l->column += (l->index - head - 1);
continue;
}
l->index += 1;
}
}
lexer *lexer_init(char *source, usize size, arena *arena)
{
lexer *lex = arena_alloc(arena, sizeof(lexer));
lex->column = 0;
lex->row = 0;
lex->index = 0;
lex->size = size;
lex->tokens = 0;
lex->tail = 0;
lex->allocator = arena;
lex->source = source;
keywords = arena_alloc(arena, sizeof(trie_node));
trie_insert(keywords, lex->allocator, "while", TOKEN_WHILE);
trie_insert(keywords, lex->allocator, "for", TOKEN_FOR);
trie_insert(keywords, lex->allocator, "goto", TOKEN_GOTO);
trie_insert(keywords, lex->allocator, "if", TOKEN_IF);
trie_insert(keywords, lex->allocator, "else", TOKEN_ELSE);
trie_insert(keywords, lex->allocator, "switch", TOKEN_SWITCH);
trie_insert(keywords, lex->allocator, "case", TOKEN_CASE);
trie_insert(keywords, lex->allocator, "do", TOKEN_DO);
trie_insert(keywords, lex->allocator, "defer", TOKEN_DEFER);
trie_insert(keywords, lex->allocator, "module", TOKEN_MODULE);
trie_insert(keywords, lex->allocator, "static", TOKEN_STATIC);
trie_insert(keywords, lex->allocator, "const", TOKEN_CONST);
trie_insert(keywords, lex->allocator, "extern", TOKEN_EXTERN);
trie_insert(keywords, lex->allocator, "volatile", TOKEN_VOLATILE);
parse(lex);
return lex;
}
hello+3-(--ciao)