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#include "../include/tokenizer.h"
#include <string.h>
#include <stdio.h>
void tsl_tokenizer_init(TslTokenizer *self, const char *code, size_t code_size) {
self->code = code;
self->code_size = code_size;
self->code_index = 0;
self->identifier.data = NULL;
self->identifier.size = 0;
self->string.data = NULL;
self->string.size = 0;
self->bool_value = 0;
self->number_value = 0;
}
static char tsl_tokenizer_get_char(TslTokenizer *self) {
if(self->code_index < self->code_size)
return self->code[self->code_index];
return '\0';
}
static void tsl_tokenizer_skip_whitespace(TslTokenizer *self) {
for(;;) {
char c = tsl_tokenizer_get_char(self);
switch(c) {
case ' ':
case '\n':
case '\t':
case '\r':
++self->code_index;
break;
default:
return;
}
}
}
static int is_alpha(char c) {
return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
}
static int is_num(char c) {
return c >= '0' && c <= '9';
}
static int is_identifier_start(char c) {
return is_alpha(c) || c == '_';
}
static int is_identifier_continue(char c) {
return is_alpha(c) || is_num(c) || c == '_';
}
const int64_t num_multipliers[] = {
1,
10,
100,
1000,
10000,
100000,
1000000,
10000000,
100000000,
1000000000,
10000000000,
100000000000,
1000000000000,
10000000000000,
100000000000000,
1000000000000000,
10000000000000000,
100000000000000000,
1000000000000000000
};
/* TODO: Check if the number if too large to fit into the result */
static int64_t string_to_int(TslStringView *str) {
int64_t num = 0;
size_t i = 0;
for(; i < str->size; ++i) {
char digit = str->data[str->size - 1 - i] - '0';
num += digit * num_multipliers[i];
}
return num;
}
static int tsl_tokenizer_goto_end_of_string(TslTokenizer *self, char string_start_symbol) {
int string_escape = 0;
for(;;) {
char c = tsl_tokenizer_get_char(self);
if(c == string_start_symbol) {
++self->code_index;
if(!string_escape)
return 1;
string_escape = 0;
} else if(c == '\\') {
++self->code_index;
string_escape = !string_escape;
} else if(c == '\0') {
return 0;
} else {
++self->code_index;
string_escape = 0;
}
}
}
TslToken tsl_tokenizer_next(TslTokenizer *self) {
char c;
tsl_tokenizer_skip_whitespace(self);
c = tsl_tokenizer_get_char(self);
if(is_identifier_start(c)) {
size_t identifier_start = self->code_index;
++self->code_index;
for(;;) {
c = tsl_tokenizer_get_char(self);
if(!is_identifier_continue(c))
break;
++self->code_index;
}
self->identifier.data = self->code + identifier_start;
self->identifier.size = self->code_index - identifier_start;
switch(self->identifier.size) {
case 4: {
if(memcmp(self->identifier.data, "true", 4) == 0) {
self->bool_value = 1;
return TSL_TOKEN_BOOL;
} else if(memcmp(self->identifier.data, "null", 4) == 0) {
return TSL_TOKEN_NULL;
}
break;
}
case 5: {
if(memcmp(self->identifier.data, "false", 5) == 0) {
self->bool_value = 0;
return TSL_TOKEN_BOOL;
}
break;
}
}
return TSL_TOKEN_IDENTIFIER;
} else if(is_num(c)) {
size_t num_start = self->code_index;
++self->code_index;
for(;;) {
c = tsl_tokenizer_get_char(self);
if(!is_num(c))
break;
++self->code_index;
}
self->identifier.data = self->code + num_start;
self->identifier.size = self->code_index - num_start;
self->number_value = string_to_int(&self->identifier);
return TSL_TOKEN_NUM;
} else if(c == '"') {
char string_start_symbol = c;
size_t string_start;
++self->code_index;
string_start = self->code_index;
if(tsl_tokenizer_goto_end_of_string(self, string_start_symbol)) {
self->string.data = self->code + string_start;
self->string.size = self->code_index - 1 - string_start;
return TSL_TOKEN_STRING;
} else {
return TSL_TOKEN_END_OF_FILE;
}
} else if(c == '=') {
++self->code_index;
return TSL_TOKEN_EQUAL;
} else if(c == '{') {
++self->code_index;
return TSL_TOKEN_LBRACE;
} else if(c == '}') {
++self->code_index;
return TSL_TOKEN_RBRACE;
} else if(c == '[') {
++self->code_index;
return TSL_TOKEN_LBRACKET;
} else if(c == ']') {
++self->code_index;
return TSL_TOKEN_RBRACKET;
} else if(c == '\0') {
return TSL_TOKEN_END_OF_FILE;
} else {
fprintf(stderr, "Unexpected symbol '%c'\n", c);
return TSL_TOKEN_UNEXPECTED_SYMBOL;
}
}
int tsl_tokenizer_accept(TslTokenizer *self, TslToken expected_token) {
TslToken actual_token = tsl_tokenizer_next(self);
if(actual_token != expected_token) {
fprintf(stderr, "Error: Expected TODO, got TODO\n");
return 0;
}
return 1;
}
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