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#ifndef BDL_COMPILER_H
#define BDL_COMPILER_H
#include "chunk.h"
#include "lexer.h"
typedef struct Visitor {
Token *tokens;
size_t current;
} Visitor;
// Mimics the functionality in the Scanner functions, but for entire tokens.
Token next_token(Visitor *visitor);
Token peek_token(const Visitor *visitor);
bool has_next_token(const Visitor *visitor);
Chunk * compile(Token *tokens);
Token
peek_token(const Visitor *visitor) {
return visitor->tokens[visitor->current];
}
Token
next_token(Visitor *visitor) {
return visitor->tokens[visitor->current++];
}
bool
has_next_token(const Visitor *visitor) {
return visitor->current < array_size(visitor->tokens);
}
void
emit_constant(Chunk *chunk, Token tok, Object obj) {
// TODO: Should we deduplicate constants? For example why store a number
// more than once instead of reusing the existing index?
size_t num_idx = add_constant(chunk, obj);
add_code(chunk, OP_CONSTANT, tok.line, tok.column);
add_code(chunk, num_idx, tok.line, tok.column);
}
void
parse_fixnum(Chunk *chunk, Token tok) {
ssize_t num = 0;
int sign = 1;
for (size_t i = 0; i < tok.value.n; i++) {
char c = tok.value.start[i];
if (c == '-') {
sign = -1;
continue;
}
num = num * 10 + (c - '0');
}
emit_constant(chunk, tok, num);
}
void parse_tree(Chunk *chunk, Visitor *vs);
void
compile_list_primitive(Chunk *chunk, Visitor *vs, Token op_tok) {
Ops op;
switch (op_tok.type) {
case TOKEN_ADD: {
emit_constant(chunk, op_tok, 0);
op = OP_SUM;
} break;
case TOKEN_SUB: {
// TODO: fetch first element.
emit_constant(chunk, op_tok, 0);
op = OP_SUB;
} break;
case TOKEN_MUL: {
emit_constant(chunk, op_tok, 1);
op = OP_MUL;
} break;
case TOKEN_DIV: {
// TODO: fetch first element.
emit_constant(chunk, op_tok, 1);
op = OP_DIV;
} break;
case TOKEN_MOD: {
// TODO: fetch first element.
emit_constant(chunk, op_tok, 1);
op = OP_MOD;
} break;
default: {
} break;
}
while (has_next_token(vs)) {
Token tok = peek_token(vs);
if (tok.type == TOKEN_EOF) {
error_push((Error){
.type = ERR_TYPE_PARSER,
.value = ERR_UNBALANCED_PAREN,
.line = op_tok.line,
.col = op_tok.column,
});
return;
}
if (tok.type == TOKEN_RPAREN) {
next_token(vs);
break;
}
parse_tree(chunk, vs);
add_code(chunk, op, tok.line, tok.column);
}
}
void
parse_list(Chunk *chunk, Visitor *vs) {
if (has_next_token(vs)) {
Token tok = next_token(vs);
print_token(tok);
// TODO: check if is function call.
switch (tok.type) {
case TOKEN_ADD:
case TOKEN_SUB:
case TOKEN_MUL:
case TOKEN_DIV:
case TOKEN_MOD:{
compile_list_primitive(chunk, vs, tok);
} break;
default: {
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_OBJ_NOT_CALLABLE,
.line = tok.line,
.line = tok.column,
});
} break;
}
}
}
void
parse_tree(Chunk *chunk, Visitor *vs) {
Token tok = next_token(vs);
switch (tok.type) {
case TOKEN_FIXNUM: {
parse_fixnum(chunk, tok);
return ;
} break;
case TOKEN_TRUE: {
// return obj_true;
return;
} break;
case TOKEN_FALSE: {
// return obj_false;
return;
} break;
case TOKEN_RPAREN: {
error_push((Error){
.type = ERR_TYPE_PARSER,
.value = ERR_UNBALANCED_PAREN,
.line = tok.line,
.col = tok.column,
});
return;
} break;
case TOKEN_QUOTE: {
// Object *base = make_pair(obj_quote, obj_nil);
// base->cdr = make_pair(obj_nil, obj_nil);
// push_root(base);
// Object *next_obj = parse_tree(vs);
// if (next_obj == obj_err) {
// return obj_err;
// }
// base->cdr->car = next_obj;
// return base;
return;
} break;
case TOKEN_LPAREN: {
parse_list(chunk, vs);
// Object *obj = parse_list(vs);
// if (obj == obj_err) {
// error_push((Error){
// .type = ERR_TYPE_PARSER,
// .value = ERR_UNBALANCED_PAREN,
// .line = tok.line,
// .col = tok.column,
// });
// }
// return obj;
return;
} break;
case TOKEN_STRING: {
// Object *obj = make_string();
// push_root(obj);
// append_string(obj, tok.value);
// return obj;
return;
} break;
case TOKEN_SYMBOL: {
// Object *obj = make_symbol(tok.value);
// push_root(obj);
// return obj;
return;
} break;
case TOKEN_NIL: {
// return obj_nil;
return;
} break;
default: {
break;
} break;
}
error_push((Error){
.type = ERR_TYPE_PARSER,
.value = ERR_EOF_REACHED,
.line = tok.line,
.col = tok.column,
});
return;
}
Chunk *
compile(Token *tokens) {
Chunk *chunk = NULL;
chunk = chunk_init();
Visitor visitor = (Visitor){
.tokens = tokens,
.current = 0,
};
while (has_next_token(&visitor) && peek_token(&visitor).type != TOKEN_EOF) {
parse_tree(chunk, &visitor);
}
// error_push((Error){
// .type = ERR_TYPE_COMPILER,
// .value = ERR_UNKNOWN,
// });
// size_t const_a = add_constant(chunk, 7);
// add_code(chunk, OP_CONSTANT, 1, 1);
// add_code(chunk, const_a, 1, 1);
// size_t const_b = add_constant(chunk, 2);
// add_code(chunk, OP_CONSTANT, 1, 2);
// add_code(chunk, const_b, 1, 2);
// add_code(chunk, OP_MOD, 1, 3);
add_code(chunk, OP_RETURN, 1, 1);
return chunk;
}
#endif // BDL_COMPILER_H
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