import ast::ty_mach;
import ast_util::ty_mach_to_str;
import std::map::new_str_hash;
import util::interner;
import std::int;
import std::uint;
import std::istr;

type str_num = uint;

tag binop {
    PLUS;
    MINUS;
    STAR;
    SLASH;
    PERCENT;
    CARET;
    AND;
    OR;
    LSL;
    LSR;
    ASR;
}

tag token {


    /* Expression-operator symbols. */
    EQ;
    LT;
    LE;
    EQEQ;
    NE;
    GE;
    GT;
    ANDAND;
    OROR;
    NOT;
    TILDE;
    BINOP(binop);
    BINOPEQ(binop);


    /* Structural symbols */
    AT;
    DOT;
    ELLIPSIS;
    COMMA;
    SEMI;
    COLON;
    MOD_SEP;
    QUES;
    RARROW;
    LARROW;
    DARROW;
    LPAREN;
    RPAREN;
    LBRACKET;
    RBRACKET;
    LBRACE;
    RBRACE;
    POUND;
    POUND_LBRACE;
    POUND_LT;


    /* Literals */
    LIT_INT(int);
    LIT_UINT(uint);
    LIT_MACH_INT(ty_mach, int);
    LIT_FLOAT(str_num);
    LIT_MACH_FLOAT(ty_mach, str_num);
    LIT_STR(str_num);
    LIT_CHAR(char);
    LIT_BOOL(bool);


    /* Name components */
    IDENT(str_num, bool);
    IDX(int);
    UNDERSCORE;
    BRACEQUOTE(str_num);
    EOF;
}

fn binop_to_str(o: binop) -> istr {
    alt o {
      PLUS. { ret ~"+"; }
      MINUS. { ret ~"-"; }
      STAR. { ret ~"*"; }
      SLASH. { ret ~"/"; }
      PERCENT. { ret ~"%"; }
      CARET. { ret ~"^"; }
      AND. { ret ~"&"; }
      OR. { ret ~"|"; }
      LSL. { ret ~"<<"; }
      LSR. { ret ~">>"; }
      ASR. { ret ~">>>"; }
    }
}

fn to_str(r: lexer::reader, t: token) -> istr {
    alt t {
      EQ. { ret ~"="; }
      LT. { ret ~"<"; }
      LE. { ret ~"<="; }
      EQEQ. { ret ~"=="; }
      NE. { ret ~"!="; }
      GE. { ret ~">="; }
      GT. { ret ~">"; }
      NOT. { ret ~"!"; }
      TILDE. { ret ~"~"; }
      OROR. { ret ~"||"; }
      ANDAND. { ret ~"&&"; }
      BINOP(op) { ret binop_to_str(op); }
      BINOPEQ(op) { ret binop_to_str(op) + ~"="; }


      /* Structural symbols */
      AT. {
        ret ~"@";
      }
      DOT. { ret ~"."; }
      ELLIPSIS. { ret ~"..."; }
      COMMA. { ret ~","; }
      SEMI. { ret ~";"; }
      COLON. { ret ~":"; }
      MOD_SEP. { ret ~"::"; }
      QUES. { ret ~"?"; }
      RARROW. { ret ~"->"; }
      LARROW. { ret ~"<-"; }
      DARROW. { ret ~"<->"; }
      LPAREN. { ret ~"("; }
      RPAREN. { ret ~")"; }
      LBRACKET. { ret ~"["; }
      RBRACKET. { ret ~"]"; }
      LBRACE. { ret ~"{"; }
      RBRACE. { ret ~"}"; }
      POUND. { ret ~"#"; }
      POUND_LBRACE. { ret ~"#{"; }
      POUND_LT. { ret ~"#<"; }


      /* Literals */
      LIT_INT(i) {
        ret int::to_str(i, 10u);
      }
      LIT_UINT(u) { ret uint::to_str(u, 10u); }
      LIT_MACH_INT(tm, i) {
        ret int::to_str(i, 10u) + ~"_" + ty_mach_to_str(tm);
      }
      LIT_MACH_FLOAT(tm, s) {
        ret interner::get::<istr>(
            *r.get_interner(), s) + ~"_" +
            ty_mach_to_str(tm);
      }
      LIT_FLOAT(s) {
        ret interner::get::<istr>(*r.get_interner(), s);
      }
      LIT_STR(s) { // FIXME: escape.
        ret ~"\"" +
            interner::get::<istr>(*r.get_interner(), s)
            + ~"\"";
      }
      LIT_CHAR(c) {
        // FIXME: escape.
        let tmp = ~"'";
        istr::push_char(tmp, c);
        istr::push_byte(tmp, '\'' as u8);
        ret tmp;
      }
      LIT_BOOL(b) { if b { ret ~"true"; } else { ret ~"false"; } }


      /* Name components */
      IDENT(s, _) {
        ret interner::get::<istr>(*r.get_interner(), s);
      }
      IDX(i) { ret ~"_" + int::to_str(i, 10u); }
      UNDERSCORE. { ret ~"_"; }
      BRACEQUOTE(_) { ret ~"<bracequote>"; }
      EOF. { ret ~"<eof>"; }
    }
}


pure fn can_begin_expr(t: token) -> bool {
    alt t {
      LPAREN. { true }
      LBRACE. { true }
      LBRACKET. { true }
      IDENT(_, _) { true }
      UNDERSCORE. { true }
      TILDE. { true }
      LIT_INT(_) { true }
      LIT_UINT(_) { true }
      LIT_MACH_INT(_, _) { true }
      LIT_FLOAT(_) { true }
      LIT_MACH_FLOAT(_, _) { true }
      LIT_STR(_) { true }
      LIT_CHAR(_) { true }
      POUND. { true }
      AT. { true }
      NOT. { true }
      BINOP(MINUS.) { true }
      BINOP(STAR.) { true }
      MOD_SEP. { true }
      _ { false }
    }
}
// Local Variables:
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// compile-command: "make -k -C $RBUILD 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
// End: