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#include "lexer.h"
#include "errors.h"
static const char* token_str[] = {
[TOKEN_UNKNOWN] = "TOKEN_UNKNOWN",
[TOKEN_LPAREN] = "TOKEN_LPAREN",
[TOKEN_RPAREN] = "TOKEN_RPAREN",
[TOKEN_FIXNUM] = "TOKEN_FIXNUM",
[TOKEN_SYMBOL] = "TOKEN_SYMBOL",
[TOKEN_STRING] = "TOKEN_STRING",
[TOKEN_NIL] = "TOKEN_NIL",
[TOKEN_TRUE] = "TOKEN_TRUE",
[TOKEN_FALSE] = "TOKEN_FALSE",
[TOKEN_LAMBDA] = "TOKEN_LAMBDA",
[TOKEN_IF] = "TOKEN_IF",
[TOKEN_DEF] = "TOKEN_DEF",
[TOKEN_SET] = "TOKEN_SET",
[TOKEN_FUN] = "TOKEN_FUN",
[TOKEN_EOF] = "TOKEN_EOF",
};
void
print_token(Token tok) {
printf("[%4ld:%-4ld] ", tok.line, tok.col);
printf("%s", token_str[tok.type]);
switch (tok.type) {
case TOKEN_FIXNUM: {
printf(" -> ");
sv_write(&tok.value);
} break;
case TOKEN_SYMBOL: {
printf(" -> ");
sv_write(&tok.value);
} break;
case TOKEN_STRING: {
printf(" -> ");
sv_write(&tok.value);
} break;
default: {
} break;
}
printf("\n");
}
char
scan_next(Scanner *scanner) {
char c = sv_next(&scanner->current);
if (c == '\n') {
scanner->line_number++;
scanner->col_number = 1;
} else {
scanner->col_number++;
}
scanner->offset++;
return c;
}
char
scan_peek(const Scanner *scanner) {
return sv_peek(&scanner->current);
}
bool
scan_has_next(const Scanner *scanner) {
return scanner->current.n != 0;
}
void
skip_whitespace(Scanner *scanner) {
while (scan_has_next(scanner)) {
char c = scan_peek(scanner);
switch (c) {
case ' ':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v': {
scan_next(scanner);
} break;
default: {
return;
} break;
}
}
}
bool
is_delimiter(char c) {
switch (c) {
case EOF:
case '\0':
case ';':
case '"':
case '\'':
case '(':
case ')':
case ' ':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v': {
return true;
} break;
}
return false;
}
#define TOKEN_IS_KEYWORD(VAL, KEYWORD) \
sv_equal(&(VAL), &(StringView){(KEYWORD), sizeof(KEYWORD) - 1})
TokenType
find_primitive_type(const StringView value) {
bool is_fixnum = true;
for (size_t i = 0; i < value.n; i++) {
char c = value.start[i];
if (i == 0 && c == '-' && value.n > 1) {
continue;
}
if (!(c >= '0' && c <= '9')) {
is_fixnum = false;
break;
}
}
if (is_fixnum) {
return TOKEN_FIXNUM;
}
if (TOKEN_IS_KEYWORD(value, "nil")) { return TOKEN_NIL; }
if (TOKEN_IS_KEYWORD(value, "true")) { return TOKEN_TRUE; }
if (TOKEN_IS_KEYWORD(value, "false")) { return TOKEN_FALSE; }
if (TOKEN_IS_KEYWORD(value, "lambda")) { return TOKEN_LAMBDA; }
if (TOKEN_IS_KEYWORD(value, "if")) { return TOKEN_IF; }
if (TOKEN_IS_KEYWORD(value, "def")) { return TOKEN_DEF; }
if (TOKEN_IS_KEYWORD(value, "set!")) { return TOKEN_SET; }
if (TOKEN_IS_KEYWORD(value, "fun")) { return TOKEN_FUN; }
return TOKEN_SYMBOL;
}
Token *
tokenize(const StringView *sv, Errors *errors) {
Token *tokens = NULL;
array_init(tokens, 1);
Scanner scanner = (Scanner){
.current = *sv,
.line_number = 1,
.col_number = 1,
};
while (scan_has_next(&scanner)) {
skip_whitespace(&scanner);
size_t line = scanner.line_number;
size_t col = scanner.col_number;
size_t offset = scanner.offset;
char c = scan_next(&scanner);
switch (c) {
case ';': {
while ((c = scan_next(&scanner)) != '\n' && c != '\0') {}
} break;
case '"': {
char prev = c;
bool found = false;
size_t n = 0;
while (scan_has_next(&scanner)) {
c = scan_next(&scanner);
if (c == '"' && prev != '\\') {
found = true;
break;
}
prev = c;
n++;
}
if (!found) {
error_push(errors, (Error){
.type = ERR_TYPE_LEXER,
.value = ERR_UNMATCHED_STRING,
.line = line,
.col = col,
});
return tokens;
}
Token token = (Token){
.value = (StringView){
.start = &sv->start[offset + 1],
.n = n,
},
.type = TOKEN_STRING,
.line = line,
.col = col,
};
array_push(tokens, token);
} break;
case '(': {
if (scan_peek(&scanner) == ')') {
scan_next(&scanner);
Token token = (Token){
.type = TOKEN_NIL,
.line = line,
.col = col,
};
array_push(tokens, token);
} else {
Token token = (Token){
.type = TOKEN_LPAREN,
.line = line,
.col = col,
};
array_push(tokens, token);
}
} break;
case ')': {
Token token = (Token){
.type = TOKEN_RPAREN,
.line = line,
.col = col,
};
array_push(tokens, token);
} break;
default: {
size_t n = 1;
while (!is_delimiter(scan_peek(&scanner))) {
scan_next(&scanner);
n++;
}
if (c == EOF || c == '\0') {
break;
}
Token token = (Token){
.value = (StringView){
.start = &sv->start[offset],
.n = n,
},
.type = TOKEN_SYMBOL,
.line = line,
.col = col,
};
token.type = find_primitive_type(token.value);
array_push(tokens, token);
} break;
}
}
// Push EOF token.
Token token = (Token){
.type = TOKEN_EOF,
.line = scanner.line_number,
.col = 1,
};
array_push(tokens, token);
return tokens;
}
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