diff options
| -rw-r--r-- | builtin.cpp | 39 | ||||
| -rw-r--r-- | builtin.h | 13 | ||||
| -rw-r--r-- | eval.cpp | 1 | ||||
| -rw-r--r-- | main.cpp | 6 | ||||
| -rw-r--r-- | model.cpp | 34 | ||||
| -rw-r--r-- | model.h | 52 | ||||
| -rw-r--r-- | parser.cpp | 107 |
7 files changed, 204 insertions, 48 deletions
diff --git a/builtin.cpp b/builtin.cpp index de8bd12..a0b3830 100644 --- a/builtin.cpp +++ b/builtin.cpp @@ -34,7 +34,7 @@ double str_to_double(string repr, bool &flag) { const char *nptr = repr.c_str(); char *endptr; double val = strtod(nptr, &endptr); - if (endptr != nptr + repr.length()) + if (endptr == nptr || endptr != nptr + repr.length()) { flag = false; return 0; @@ -47,7 +47,7 @@ int str_to_int(string repr, bool &flag) { const char *nptr = repr.c_str(); char *endptr; int val = strtol(nptr, &endptr, 10); - if (endptr != nptr + repr.length()) + if (endptr == nptr || endptr != nptr + repr.length()) { flag = false; return 0; @@ -72,10 +72,10 @@ CompNumObj::CompNumObj(double _real, double _imag) : CompNumObj *CompNumObj::from_string(string repr) { // spos: the position of the last sign // ipos: the position of i - int spos = -1, ipos = -1, - len = repr.length(); + int spos = -1, ipos = -1; + size_t len = repr.length(); bool sign; - for (int i = 0; i < len; i++) + for (size_t i = 0; i < len; i++) if (repr[i] == '+' || repr[i] == '-') { spos = i; @@ -257,8 +257,9 @@ RatNumObj::RatNumObj(int _a, int _b) : RatNumObj *RatNumObj::from_string(string repr) { int a, b; - int len = repr.length(), pos = -1; - for (int i = 0; i < len; i++) + size_t len = repr.length(); + int pos = -1; + for (size_t i = 0; i < len; i++) if (repr[i] == '/') { pos = i; break; } bool flag; a = str_to_int(repr.substr(0, pos), flag); @@ -344,7 +345,7 @@ IntNumObj::IntNumObj(int _val) : ExactNumObj(NUM_LVL_INT), val(_val) {} IntNumObj *IntNumObj::from_string(string repr) { int val = 0; - for (int i = 0; i < repr.length(); i++) + for (size_t i = 0; i < repr.length(); i++) { if (!('0' <= repr[i] && repr[i] <= '9')) return NULL; @@ -474,7 +475,6 @@ SpecialOptLambda::SpecialOptLambda() : SpecialOptObj() {} ptr->skip = flag void SpecialOptLambda::prepare(Cons *pc) { - //TODO check number of arguments // Do not evaluate anything FILL_MARKS(pc, true); } @@ -528,7 +528,6 @@ Cons *SpecialOptDefine::call(ArgList *args, Environment * &envt, Cons *pc = static_cast<Cons*>(ret_addr->car); EvalObj *obj; SymObj *id; - // TODO: check identifier EvalObj *first = TO_CONS(pc->cdr)->car; if (first->is_simple_obj()) { @@ -605,6 +604,26 @@ SpecialOptSet::SpecialOptSet() {} string SpecialOptSet::ext_repr() { return string("#<Builtin Macro: set!>"); } +SpecialOptQuote::SpecialOptQuote() {} + +void SpecialOptQuote::prepare(Cons *pc) { + // Do not evaluate anything + FILL_MARKS(pc, true); +} + +Cons *SpecialOptQuote::call(ArgList *args, Environment * &envt, + Continuation * &cont, FrameObj ** &top_ptr) { + Cons *ret_addr = static_cast<RetAddr*>(*top_ptr)->addr; + Cons *pc = static_cast<Cons*>(ret_addr->car); + // revert + FILL_MARKS(pc, false); + *top_ptr++ = TO_CONS(pc->cdr)->car; + return ret_addr->next; +} + +string SpecialOptQuote::ext_repr() { return string("#<Builtin Macro: quote>"); } + + EvalObj *builtin_cons(ArgList *args) { if (args == empty_list || args->cdr == empty_list || @@ -191,6 +191,19 @@ class SpecialOptSet: public SpecialOptObj { string ext_repr(); }; +/** @class SpecialOptLambda + * The implementation of `lambda` operator + */ +class SpecialOptQuote: public SpecialOptObj { + public: + SpecialOptQuote(); + void prepare(Cons *pc); + Cons *call(ArgList *args, Environment * &envt, + Continuation * &cont, FrameObj ** &top_ptr); + + string ext_repr(); +}; + EvalObj *builtin_plus(ArgList *); EvalObj *builtin_minus(ArgList *); EvalObj *builtin_multi(ArgList *); @@ -31,6 +31,7 @@ void Evaluator::add_builtin_routines() { ADD_ENTRY("lambda", new SpecialOptLambda()); ADD_ENTRY("define", new SpecialOptDefine()); ADD_ENTRY("set!", new SpecialOptSet()); + ADD_ENTRY("quote", new SpecialOptQuote()); } Evaluator::Evaluator() { @@ -21,6 +21,7 @@ int main() { ASTGenerator *ast = new ASTGenerator(); Evaluator *eval = new Evaluator(); + int rcnt = 0; while (1) { printf("Sonsi> "); @@ -29,11 +30,12 @@ int main() { Cons *tree = ast->absorb(tk); if (!tree) break; //tree_print(tree); - printf("%s\n", eval->run_expr(tree)->ext_repr().c_str()); + fprintf(stderr, "Ret> $%d = %s\n", rcnt++, + eval->run_expr(tree)->ext_repr().c_str()); } catch (GeneralError &e) { - printf("An error occured: %s\n", e.get_msg().c_str()); + fprintf(stderr, "An error occured: %s\n", e.get_msg().c_str()); } } } @@ -19,6 +19,10 @@ bool FrameObj::is_ret_addr() { return ftype & CLS_RET_ADDR; } +bool FrameObj::is_parse_bracket() { + return ftype & CLS_PAR_BRA; +} + EvalObj::EvalObj(ClassType _otype) : FrameObj(CLS_EVAL_OBJ), otype(_otype) {} void EvalObj::prepare(Cons *pc) {} @@ -94,6 +98,15 @@ RetAddr::RetAddr(Cons *_addr) : FrameObj(CLS_RET_ADDR), addr(_addr) {} string RetAddr::_debug_repr() { return string("#<Return Address>"); } #endif +ParseBracket::ParseBracket(unsigned char _btype) : + FrameObj(CLS_SIM_OBJ | CLS_PAR_BRA), btype(_btype) {} + +#ifdef DEBUG +string ParseBracket::_debug_repr() { + return string("#<Bracket>"); +} +#endif + UnspecObj::UnspecObj() : EvalObj(CLS_SIM_OBJ) {} string UnspecObj::ext_repr() { return string("#<Unspecified>"); } @@ -165,8 +178,27 @@ StrObj::StrObj(string _str) : EvalObj(CLS_SIM_OBJ), str(_str) {} string StrObj::ext_repr() { return str; } +VecObj::VecObj() : EvalObj(CLS_SIM_OBJ) {} + +void VecObj::resize(int new_size) { + vec.resize(new_size); +} + +void VecObj::push_back(EvalObj *new_elem) { + vec.push_back(new_elem); +} + +string VecObj::ext_repr() { + string res = "#("; + for (EvalObjVec::iterator it = vec.begin(); it != vec.end(); it++) + res += (*it)->ext_repr() + " "; + res[res.length() - 1] = ')'; + return res; +} + + StrObj *StrObj::from_string(string repr) { - int len = repr.length(); + size_t len = repr.length(); if (repr[0] == '\"' && repr[len - 1] == '\"') return new StrObj(repr.substr(1, len - 2)); return NULL; @@ -4,23 +4,26 @@ #include <string> #include <list> #include <map> +#include <vector> using std::list; using std::string; using std::map; +using std::vector; // the range of unsigned char is enough for these types typedef unsigned char ClassType; typedef unsigned char NumLvl; -static const int CLS_RET_ADDR = 1 << 0; -static const int CLS_EVAL_OBJ = 1 << 1; +const int CLS_RET_ADDR = 1 << 0; +const int CLS_EVAL_OBJ = 1 << 1; +const int CLS_PAR_BRA = 1 << 2; -static const int CLS_SIM_OBJ = 1 << 0; -static const int CLS_CONS_OBJ = 1 << 1; -static const int CLS_SYM_OBJ = 1 << 2; -static const int CLS_OPT_OBJ = 1 << 3; -static const int CLS_NUM_OBJ = 1 << 4; +const int CLS_SIM_OBJ = 1 << 0; +const int CLS_CONS_OBJ = 1 << 1; +const int CLS_SYM_OBJ = 1 << 2; +const int CLS_OPT_OBJ = 1 << 3; +const int CLS_NUM_OBJ = 1 << 4; #define TO_CONS(ptr) \ @@ -49,6 +52,12 @@ class FrameObj { * @return true for yes */ bool is_ret_addr(); + /** + * Tell whether the object is a bracket, according to ftype + * @return true for yes + */ + bool is_parse_bracket(); + #ifdef DEBUG virtual string _debug_repr() = 0; #endif @@ -144,6 +153,18 @@ class RetAddr : public FrameObj { #endif }; +/** @class ParseBracket + * To indiate a left bracket when parsing, used in the parse_stack + */ +class ParseBracket : public FrameObj { + public: + unsigned char btype; /**< The type of the bracket */ + /** Construct a ParseBracket object */ + ParseBracket(unsigned char btype); +#ifdef DEBUG + string _debug_repr(); +#endif +}; /** @class UnspecObj * The "unspecified" value returned by some builtin procedures @@ -310,6 +331,23 @@ class StrObj: public EvalObj { string ext_repr(); }; +typedef vector<EvalObj*> EvalObjVec; +/** + * @class VecObj + * Vector support (currently a wrapper of STL vector) + */ +class VecObj: public EvalObj { + private: + EvalObjVec vec; + public: + /** Construct a vector object */ + VecObj(); + /** Resize the vector */ + void resize(int new_size); + /** Add a new element to the rear */ + void push_back(EvalObj *new_elem); + string ext_repr(); +}; typedef map<string, EvalObj*> Str2EvalObj; /** @class Environment @@ -9,7 +9,7 @@ using std::stringstream; static char buff[TOKEN_BUFF_SIZE]; -static EvalObj *parse_stack[PARSE_STACK_SIZE]; +static FrameObj *parse_stack[PARSE_STACK_SIZE]; extern Cons *empty_list; Tokenizor::Tokenizor() : stream(stdin), buff_ptr(buff), escaping(false) {} @@ -29,8 +29,11 @@ void Tokenizor::set_stream(FILE *_stream) { ((ch) == ' ' || (ch) == '\t' || IS_NEWLINE(ch)) #define IS_COMMENT(ch) \ ((ch) == ';') +#define IS_LITERAL(ch) \ + ((ch) == '\'') #define IS_DELIMITER(ch) \ - (IS_BRACKET(ch) || IS_SPACE(ch) || IS_COMMENT(ch) || IS_QUOTE(ch)) + (IS_BRACKET(ch) || IS_SPACE(ch) || \ + IS_COMMENT(ch) || IS_QUOTE(ch)) #define POP \ do { \ @@ -38,6 +41,7 @@ void Tokenizor::set_stream(FILE *_stream) { ret = string(buff); \ buff_ptr = buff; \ } while (0) +#define TOP (*(buff_ptr - 1)) bool Tokenizor::get_token(string &ret) { char ch; @@ -63,26 +67,35 @@ bool Tokenizor::get_token(string &ret) { else { bool in_quote = buff_ptr != buff && IS_QUOTE(*buff); - if (buff_ptr != buff && - (IS_BRACKET(*buff) || - IS_DELIMITER(ch))) - + if (buff_ptr != buff) { - if (IS_COMMENT(*buff)) - { - if (IS_NEWLINE(ch)) buff_ptr = buff; - else buff_ptr = buff + 1; - } - else if (!in_quote) + if (buff_ptr - buff == 1 && IS_LITERAL(TOP)) { POP; flag = true; } - else if (IS_QUOTE(ch)) + else if ((IS_BRACKET(TOP) || IS_DELIMITER(ch))) { - *buff_ptr++ = '\"'; - POP; - return true; // discard current slash + if (IS_COMMENT(*buff)) + { + if (IS_NEWLINE(ch)) buff_ptr = buff; + else buff_ptr = buff + 1; + } + else if (!in_quote) // not in a double-quote + { + if (!(buff_ptr - buff == 1 && ch == '(' && TOP == '#')) + { + POP; + flag = true; + } + } + else if (IS_QUOTE(ch)) + { + // in a double-quote which is being enclosed + *buff_ptr++ = '\"'; + POP; + return true; // prevent duplicate quote sign + } } } if (in_quote || !IS_SPACE(ch)) @@ -109,31 +122,69 @@ EvalObj *ASTGenerator::to_obj(const string &str) { if ((res = RealNumObj::from_string(str))) return res; if ((res = CompNumObj::from_string(str))) return res; if ((res = StrObj::from_string(str))) return res; - return new SymObj(str); + return new SymObj(str); // otherwise we assume it a symbol } + +#define TO_EVAL(ptr) \ + (static_cast<EvalObj*>(ptr)) +#define TO_BRACKET(ptr) \ + (static_cast<ParseBracket*>(ptr)) +#define IS_BRAKET(ptr) \ + ((ptr)->is_parse_bracket()) + Cons *ASTGenerator::absorb(Tokenizor *tk) { - EvalObj **top_ptr = parse_stack; + FrameObj **top_ptr = parse_stack; for (;;) { - if (top_ptr > parse_stack && *parse_stack) - return new Cons(*(top_ptr - 1), empty_list); + if (top_ptr - parse_stack > 1 && + !IS_BRAKET(*(top_ptr - 1)) && + IS_BRAKET(*(top_ptr - 2))) + { + ParseBracket *bptr = TO_BRACKET(*(top_ptr - 2)); + if (bptr->btype == 2) + { + top_ptr -= 2; + Cons *lst_cdr = new Cons(TO_EVAL(*(top_ptr + 1)), empty_list); + Cons *lst = new Cons(new SymObj("quote"), lst_cdr); + lst->next = lst_cdr; + lst_cdr->next = NULL; + *top_ptr++ = lst; + } + } + + if (top_ptr > parse_stack && !IS_BRAKET(*parse_stack)) + return new Cons(TO_EVAL(*(top_ptr - 1)), empty_list); string token; if (!tk->get_token(token)) return NULL; - if (token == "(") - *top_ptr++ = NULL; // Make the beginning of a new level + if (token == "(") // a list + *top_ptr++ = new ParseBracket(0); + else if (token == "#(") // a vector + *top_ptr++ = new ParseBracket(1); + else if (token == "\'") // syntatic sugar for quote + *top_ptr++ = new ParseBracket(2); else if (token == ")") { + if (top_ptr == parse_stack) + throw NormalError(READ_ERR_UNEXPECTED_RIGHT_BRACKET); Cons *lst = empty_list; - while (top_ptr >= parse_stack && *(--top_ptr)) + while (top_ptr >= parse_stack && !IS_BRAKET(*(--top_ptr))) { - Cons *_lst = new Cons(*top_ptr, lst); // Collect the list + Cons *_lst = new Cons(TO_EVAL(*top_ptr), lst); // Collect the list _lst->next = lst == empty_list ? NULL : lst; lst = _lst; } - if (top_ptr < parse_stack) - throw NormalError(READ_ERR_UNEXPECTED_RIGHT_BRACKET); - *top_ptr++ = lst; + ParseBracket *bptr = TO_BRACKET(*top_ptr); + if (bptr->btype == 0) + *top_ptr++ = lst; + else if (bptr->btype == 1) + { + VecObj *vec = new VecObj(); + for (Cons *ptr = lst; ptr != empty_list; ptr = TO_CONS(ptr->cdr)) + vec->push_back(ptr->car); + *top_ptr++ = vec; + } } - else *top_ptr++ = ASTGenerator::to_obj(token); + else + *top_ptr++ = ASTGenerator::to_obj(token); } } |