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#include "parser.h"
#include "darray.h"
Token
next_token(Parser *parser) {
return parser->tokens[parser->current++];
}
Token
peek_token(Parser *parser) {
return parser->tokens[parser->current];
}
bool
has_next(Parser *parser) {
return parser->current < array_size(parser->tokens);
}
Node
parse_number(Parser *parser) {
Token tok = next_token(parser);
bool negative = false;
int base = 10;
char c = sv_next(&tok.value);
if (c == '-') {
negative = true;
c = sv_next(&tok.value);
}
if (c == '+') {
c = sv_next(&tok.value);
}
if (c == '0') {
c = sv_next(&tok.value);
if (c == 'x') {
base = 16;
c = sv_next(&tok.value);
} else if (c == 'b') {
base = 2;
c = sv_next(&tok.value);
} else if (!(c >= '0' && c <= '9')){
push_error(ERR_TYPE_PARSER, ERR_MALFORMED_NUMBER, tok.line, tok.col);
return (Node){.type = NODE_ERR};
}
}
// Integral part.
u64 integral = 0;
while (c != '\0') {
ssize_t current = 0;
if (c >= 'a' && c <= 'z' && base == 16) {
current = (c - 'a') + 10;
} else if (c >= 'A' && c <= 'Z' && base == 16) {
current = (c - 'A') + 10;
} else if (c >= '0' && c <= '9') {
current = (c - '0');
} else if (c == '.') {
c = sv_next(&tok.value);
break;
} else {
push_error(ERR_TYPE_PARSER, ERR_MALFORMED_NUMBER, tok.line, tok.col);
return (Node){.type = NODE_ERR};
}
integral = integral * base + current;
c = sv_next(&tok.value);
}
// Fractional part.
u64 fractional = 0;
while (c != '\0') {
ssize_t current = 0;
if (c >= 'a' && c <= 'z' && base == 16) {
current = (c - 'a') + 10;
} else if (c >= 'A' && c <= 'Z' && base == 16) {
current = (c - 'A') + 10;
} else if (c >= '0' && c <= '9') {
current = (c - '0');
} else {
push_error(ERR_TYPE_PARSER, ERR_MALFORMED_NUMBER, tok.line, tok.col);
return (Node){.type = NODE_ERR};
}
fractional = fractional * base + current;
c = sv_next(&tok.value);
}
return (Node){
.type = NODE_NUMBER,
.number.negative = negative,
.number.integral = integral,
.number.fractional = fractional,
};
}
Node
parse_next(Parser *parser) {
Token tok = peek_token(parser);
switch (tok.type) {
case TOKEN_NUMBER: {
return parse_number(parser);
} break;
case TOKEN_STRING: {
// TODO: return parse_string(parser);
next_token(parser);
return (Node){.type = NODE_STRING, .string = tok.value};
} break;
case TOKEN_LPAREN: {
// TODO: return parse_paren(parser);
push_error(ERR_TYPE_PARSER, ERR_UNIMPLEMENTED, tok.line, tok.col);
return (Node){.type = NODE_ERR};
} break;
default: {
push_error(ERR_TYPE_PARSER, ERR_UNKNOWN_TOK_TYPE, tok.line, tok.col);
return (Node){.type = NODE_ERR};
} break;
}
}
void
print_node(Node node) {
switch (node.type) {
case NODE_NUMBER: {
if (node.number.negative) {
printf("-");
}
if (node.number.fractional != 0) {
printf("%zu.%zu\n", node.number.integral, node.number.fractional);
} else {
printf("%zu\n", node.number.integral);
}
} break;
case NODE_STRING: {
sv_write(&node.string);
printf("\n");
} break;
default: {
// ...
} break;
}
}
void
parse(Token *tokens) {
Parser parser = {
.tokens = tokens,
.current = 0,
};
// DEBUG: TOKENS
for (size_t i = 0; i < array_size(tokens); i++) {
print_token(tokens[i]);
}
while (has_next(&parser)) {
Node node = parse_next(&parser);
if (node.type == NODE_ERR) {
return;
}
print_node(node);
}
}
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