rust/src/comp/util/ppaux.rs

import middle::ty;
import middle::ty::*;
import metadata::encoder;
import syntax::print::pprust;
import syntax::print::pprust::{path_to_str, constr_args_to_str, proto_to_str,
                               mode_to_str};
import syntax::{ast, ast_util};
import middle::ast_map;

fn ty_to_str(cx: ctxt, typ: t) -> str {
    fn fn_input_to_str(cx: ctxt, input: {mode: ast::mode, ty: t}) ->
       str {
        let {mode, ty} = input;
        let modestr = alt canon_mode(cx, mode) {
          ast::infer(_) { "" }
          ast::expl(m) {
            if !ty::type_has_vars(ty) &&
                m == ty::default_arg_mode_for_ty(ty) {
                ""
            } else {
                mode_to_str(ast::expl(m))
            }
          }
        };
        modestr + ty_to_str(cx, ty)
    }
    fn fn_to_str(cx: ctxt, proto: ast::proto, ident: option<ast::ident>,
                 inputs: [arg], output: t, cf: ast::ret_style,
                 constrs: [@constr]) -> str {
        let s = proto_to_str(proto);
        alt ident { some(i) { s += " "; s += i; } _ { } }
        s += "(";
        let strs = [];
        for a: arg in inputs { strs += [fn_input_to_str(cx, a)]; }
        s += str::connect(strs, ", ");
        s += ")";
        if ty::get(output).struct != ty_nil {
            s += " -> ";
            alt cf {
              ast::noreturn { s += "!"; }
              ast::return_val { s += ty_to_str(cx, output); }
            }
        }
        s += constrs_str(constrs);
        ret s;
    }
    fn method_to_str(cx: ctxt, m: method) -> str {
        ret fn_to_str(cx, m.fty.proto, some(m.ident), m.fty.inputs,
                      m.fty.output, m.fty.ret_style, m.fty.constraints) + ";";
    }
    fn field_to_str(cx: ctxt, f: field) -> str {
        ret f.ident + ": " + mt_to_str(cx, f.mt);
    }
    fn mt_to_str(cx: ctxt, m: mt) -> str {
        let mstr;
        alt m.mut {
          ast::mut { mstr = "mutable "; }
          ast::imm { mstr = ""; }
          ast::maybe_mut { mstr = "const "; }
        }
        ret mstr + ty_to_str(cx, m.ty);
    }
    alt ty::type_name(typ) {
      some(cs) {
        alt ty::get(typ).struct {
          ty_enum(_, tps) | ty_res(_, _, tps) {
            if vec::len(tps) > 0u {
                let strs = vec::map(tps, {|t| ty_to_str(cx, t)});
                ret cs + "<" + str::connect(strs, ",") + ">";
            }
          }
          _ {}
        }
        ret cs;
      }
      _ { }
    }
    ret alt ty::get(typ).struct {
      ty_nil { "()" }
      ty_bot { "_|_" }
      ty_bool { "bool" }
      ty_int(ast::ty_i) { "int" }
      ty_int(ast::ty_char) { "char" }
      ty_int(t) { ast_util::int_ty_to_str(t) }
      ty_uint(ast::ty_u) { "uint" }
      ty_uint(t) { ast_util::uint_ty_to_str(t) }
      ty_float(ast::ty_f) { "float" }
      ty_float(t) { ast_util::float_ty_to_str(t) }
      ty_str { "str" }
      ty_box(tm) { "@" + mt_to_str(cx, tm) }
      ty_uniq(tm) { "~" + mt_to_str(cx, tm) }
      ty_ptr(tm) { "*" + mt_to_str(cx, tm) }
      ty_vec(tm) { "[" + mt_to_str(cx, tm) + "]" }
      ty_type { "type" }
      ty_rec(elems) {
        let strs: [str] = [];
        for fld: field in elems { strs += [field_to_str(cx, fld)]; }
        "{" + str::connect(strs, ",") + "}"
      }
      ty_tup(elems) {
        let strs = [];
        for elem in elems { strs += [ty_to_str(cx, elem)]; }
        "(" + str::connect(strs, ",") + ")"
      }
      ty_fn(f) {
        fn_to_str(cx, f.proto, none, f.inputs, f.output, f.ret_style,
                  f.constraints)
      }
      ty_var(v) { "<T" + int::str(v) + ">" }
      ty_param(id, _) {
        "'" + str::from_bytes([('a' as u8) + (id as u8)])
      }
      ty_enum(did, tps) {
        let path = ty::item_path(cx, did);
        let base = ast_map::path_to_str(path);
        if vec::is_empty(tps) {
            base
        } else {
            let tps_strs = vec::map(tps) {|t| ty_to_str(cx, t) };
            #fmt["%s<%s>", base, str::connect(tps_strs, ",")]
        }
      }
      _ { ty_to_short_str(cx, typ) }
    }
}

fn ty_to_short_str(cx: ctxt, typ: t) -> str unsafe {
    let s = encoder::encoded_ty(cx, typ);
    if str::byte_len(s) >= 32u { s = str::unsafe::slice_bytes(s, 0u, 32u); }
    ret s;
}

fn constr_to_str(c: @constr) -> str {
    ret path_to_str(c.node.path) +
            pprust::constr_args_to_str(pprust::uint_to_str, c.node.args);
}

fn constrs_str(constrs: [@constr]) -> str {
    let s = "";
    let colon = true;
    for c: @constr in constrs {
        if colon { s += " : "; colon = false; } else { s += ", "; }
        s += constr_to_str(c);
    }
    ret s;
}

fn ty_constr_to_str<Q>(c: @ast::spanned<ast::constr_general_<@ast::path, Q>>)
   -> str {
    ret path_to_str(c.node.path) +
            constr_args_to_str::<@ast::path>(path_to_str, c.node.args);
}

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// mode: rust
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// indent-tabs-mode: nil
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