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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, FIXNUM_VAL(num * sign));
}
void parse_tree(Chunk *chunk, Visitor *vs);
void
compile_list_binary_op(Chunk *chunk, Visitor *vs, Token list_start, Ops op) {
size_t n = 0;
while (has_next_token(vs)) {
Token tok = peek_token(vs);
if (tok.type == TOKEN_EOF) {
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_UNBALANCED_PAREN,
.line = list_start.line,
.col = list_start.column,
});
return;
}
if (tok.type == TOKEN_RPAREN) {
next_token(vs);
if (n <= 1) {
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_NOT_ENOUGH_ARGS,
.line = list_start.line,
.col = list_start.column,
});
}
return;
}
parse_tree(chunk, vs);
n++;
if (n > 1) {
add_code(chunk, op, list_start.line, list_start.column);
}
}
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_NOT_ENOUGH_ARGS,
.line = list_start.line,
.col = list_start.column,
});
}
void
compile_list_unary_op(Chunk *chunk, Visitor *vs, Token list_start, Ops op) {
size_t n = 0;
while (has_next_token(vs)) {
Token tok = peek_token(vs);
if (tok.type == TOKEN_EOF) {
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_UNBALANCED_PAREN,
.line = list_start.line,
.col = list_start.column,
});
return;
}
if (tok.type == TOKEN_RPAREN) {
next_token(vs);
if (n == 0) {
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_NOT_ENOUGH_ARGS,
.line = list_start.line,
.col = list_start.column,
});
}
return;
}
parse_tree(chunk, vs);
add_code(chunk, op, list_start.line, list_start.column);
n++;
if (n > 1) {
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_TOO_MANY_ARGS,
.line = list_start.line,
.col = list_start.column,
});
}
}
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_UNBALANCED_PAREN,
.line = list_start.line,
.col = list_start.column,
});
}
void
parse_list(Chunk *chunk, Visitor *vs, Token list_start) {
if (!has_next_token(vs)) {
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_UNBALANCED_PAREN,
.line = list_start.line,
.col = list_start.column,
});
}
Token tok = next_token(vs);
switch (tok.type) {
case TOKEN_ADD: { compile_list_binary_op(chunk, vs, list_start, OP_SUM); } break;
case TOKEN_SUB: { compile_list_binary_op(chunk, vs, list_start, OP_SUB); } break;
case TOKEN_MUL: { compile_list_binary_op(chunk, vs, list_start, OP_MUL); } break;
case TOKEN_DIV: { compile_list_binary_op(chunk, vs, list_start, OP_DIV); } break;
case TOKEN_MOD: { compile_list_binary_op(chunk, vs, list_start, OP_MOD); } break;
case TOKEN_NOT: { compile_list_unary_op(chunk, vs, list_start, OP_NOT); } break;
case TOKEN_AND: { compile_list_binary_op(chunk, vs, list_start, OP_AND); } break;
case TOKEN_OR: { compile_list_binary_op(chunk, vs, list_start, OP_OR); } break;
case TOKEN_EQUAL: { compile_list_binary_op(chunk, vs, list_start, OP_EQUAL); } break;
case TOKEN_LESS: { compile_list_binary_op(chunk, vs, list_start, OP_LESS); } break;
case TOKEN_GREATER: { compile_list_binary_op(chunk, vs, list_start, OP_GREATER); } break;
case TOKEN_LESS_EQUAL: { compile_list_binary_op(chunk, vs, list_start, OP_LESS_EQUAL); } break;
case TOKEN_GREATER_EQUAL: { compile_list_binary_op(chunk, vs, list_start, OP_GREATER_EQUAL); } break;
default: {
error_push((Error){
.type = ERR_TYPE_COMPILER,
.value = ERR_OBJ_NOT_CALLABLE,
.line = tok.line,
.col = 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: {
emit_constant(chunk, tok, TRUE_VAL);
return;
} break;
case TOKEN_FALSE: {
emit_constant(chunk, tok, FALSE_VAL);
return;
} break;
case TOKEN_RPAREN: {
error_push((Error){
.type = ERR_TYPE_COMPILER,
.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, tok);
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: {
emit_constant(chunk, tok, NIL_VAL);
return;
} break;
default: {
break;
} break;
}
error_push((Error){
.type = ERR_TYPE_COMPILER,
.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,
};
Token start_tok = peek_token(&visitor);
while (has_next_token(&visitor) && peek_token(&visitor).type != TOKEN_EOF) {
parse_tree(chunk, &visitor);
}
add_code(chunk, OP_RETURN, start_tok.line, start_tok.column);
return chunk;
}
#endif // BDL_COMPILER_H
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