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Add support for a reserved-words list and reserve the various not-supported-but-plausible IEEE datatypes.
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Graydon Hoare
parent
560d7b4983
commit
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@ -599,6 +599,7 @@ Unicode characters.
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* Ref.Lex.Ignore:: Ignored characters.
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* Ref.Lex.Ident:: Identifier tokens.
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* Ref.Lex.Key:: Keyword tokens.
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* Ref.Lex.Res:: Reserved tokens.
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* Ref.Lex.Num:: Numeric tokens.
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* Ref.Lex.Text:: String and character tokens.
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* Ref.Lex.Syntax:: Syntactic extension tokens.
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@ -636,7 +637,7 @@ token or a syntactic extension token. Multi-line comments may be nested.
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Identifiers follow the pattern of C identifiers: they begin with a
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@emph{letter} or @emph{underscore}, and continue with any combination of
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@emph{letters}, @emph{decimal digits} and underscores, and must not be equal
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to any keyword. @xref{Ref.Lex.Key}.
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to any keyword or reserved token. @xref{Ref.Lex.Key}. @xref{Ref.Lex.Res}.
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A @emph{letter} is a Unicode character in the ranges U+0061-U+007A and
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U+0041-U+005A (@code{'a'}-@code{'z'} and @code{'A'}-@code{'Z'}).
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@ -728,6 +729,35 @@ The keywords are:
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@tab @code{be}
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@end multitable
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@node Ref.Lex.Res
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@subsection Ref.Lex.Res
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@c * Ref.Lex.Res:: Reserved tokens.
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The reserved tokens are:
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@cindex Reserved
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@sp 2
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@multitable @columnfractions .15 .15 .15 .15 .15
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@item @code{f16}
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@tab @code{f80}
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@tab @code{f128}
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@item @code{m32}
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@tab @code{m64}
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@tab @code{m128}
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@tab @code{dec}
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@end multitable
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@sp 2
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At present these tokens have no defined meaning in the Rust language.
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These tokens may correspond, in some current or future implementation,
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to additional built-in types for decimal floating-point, extended
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binary and interchange floating-point formats, as defined in the IEEE
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754-1985 and IEEE 754-2008 specifications.
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@node Ref.Lex.Num
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@subsection Ref.Lex.Num
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@c * Ref.Lex.Num:: Numeric tokens.
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@ -785,6 +815,10 @@ only two floating-point suffixes: @code{f32} and @code{f64}. Each of these
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gives the floating point literal the associated type, rather than
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@code{float}.
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A set of suffixes are also reserved to accommodate literal support for
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types corresponding to reserved tokens. The reserved suffixes are @code{f16},
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@code{f80}, @code{f128}, @code{m}, @code{m32}, @code{m64} and @code{m128}.
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@sp 1
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A @dfn{hex digit} is either a @emph{decimal digit} or else a character in the
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ranges U+0061-U+0066 and U+0041-U+0046 (@code{'a'}-@code{'f'},
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@ -2024,7 +2058,7 @@ The signed two's complement word types @code{i8}, @code{i16}, @code{i32} and
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@end ifhtml
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respectively.
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@item
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The IEEE 754 single-precision and double-precision floating-point types:
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The IEEE 754-2008 @code{binary32} and @code{binary64} floating-point types:
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@code{f32} and @code{f64}, respectively.
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@end itemize
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@ -27,8 +27,12 @@
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<- (bump_line lexbuf.Lexing.lex_curr_p)
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;;
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let mach_suf_table = Hashtbl.create 0
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let mach_suf_table = Hashtbl.create 10
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;;
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let reserved_suf_table = Hashtbl.create 10
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;;
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let _ =
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List.iter (fun (suf, ty) -> Common.htab_put mach_suf_table suf ty)
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[ ("u8", Common.TY_u8);
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@ -43,8 +47,24 @@
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("f64", Common.TY_f64); ]
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;;
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let _ =
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List.iter (fun suf -> Common.htab_put reserved_suf_table suf ())
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[ "f16"; (* IEEE 754-2008 'binary16' interchange format. *)
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"f80"; (* IEEE 754-1985 'extended' *)
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"f128"; (* IEEE 754-2008 'binary128' *)
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"m32"; (* IEEE 754-2008 'decimal32' *)
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"m64"; (* IEEE 754-2008 'decimal64' *)
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"m128"; (* IEEE 754-2008 'decimal128' *)
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"m"; (* One of m32, m64, m128. *)
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]
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;;
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let keyword_table = Hashtbl.create 100
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;;
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let reserved_table = Hashtbl.create 10
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;;
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let _ =
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List.iter (fun (kwd, tok) -> Common.htab_put keyword_table kwd tok)
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[ ("mod", MOD);
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@ -141,6 +161,19 @@
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("f64", MACH TY_f64)
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]
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;;
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let _ =
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List.iter (fun kwd -> Common.htab_put reserved_table kwd ())
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[ "f16"; (* IEEE 754-2008 'binary16' interchange format. *)
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"f80"; (* IEEE 754-1985 'extended' *)
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"f128"; (* IEEE 754-2008 'binary128' *)
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"m32"; (* IEEE 754-2008 'decimal32' *)
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"m64"; (* IEEE 754-2008 'decimal64' *)
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"m128"; (* IEEE 754-2008 'decimal128' *)
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"dec"; (* One of m32, m64, m128. *)
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];
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;;
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}
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let hexdig = ['0'-'9' 'a'-'f' 'A'-'F']
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@ -153,6 +186,7 @@ let flo = (dec '.' dec (exp?)) | (dec exp)
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let mach_float_suf = "f32"|"f64"
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let mach_int_suf = ['u''i']('8'|"16"|"32"|"64")
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let flo_suf = ['m''f']("16"|"32"|"64"|"80"|"128")
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let ws = [ ' ' '\t' '\r' ]
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@ -218,26 +252,39 @@ rule token = parse
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| ']' { RBRACKET }
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| id as i
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{ try
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Hashtbl.find keyword_table i
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with
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Not_found -> IDENT (i) }
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{
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match Common.htab_search keyword_table i with
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Some tok -> tok
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| None ->
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if Hashtbl.mem reserved_table i
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then fail lexbuf "reserved keyword"
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else IDENT (i)
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}
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| (bin|hex|dec) as n { LIT_INT (Int64.of_string n) }
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| ((bin|hex|dec) as n) 'u' { LIT_UINT (Int64.of_string n) }
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| ((bin|hex|dec) as n)
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(mach_int_suf as s) { try
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let tm =
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Hashtbl.find mach_suf_table s
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in
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LIT_MACH_INT
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(tm, Int64.of_string n)
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with
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Not_found ->
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fail lexbuf
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"bad mach-int suffix" }
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(mach_int_suf as s)
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{
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match Common.htab_search mach_suf_table s with
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Some tm -> LIT_MACH_INT (tm, Int64.of_string n)
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| None ->
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if Hashtbl.mem reserved_suf_table s
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then fail lexbuf "reserved mach-int suffix"
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else fail lexbuf "bad mach-int suffix"
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}
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| flo as n { LIT_FLOAT (float_of_string n) }
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| flo 'm' { fail lexbuf "reseved mach-float suffix" }
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| (flo as n) (flo_suf as s)
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{
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match Common.htab_search mach_suf_table s with
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Some tm -> LIT_MACH_FLOAT (tm, float_of_string n)
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| None ->
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if Hashtbl.mem reserved_suf_table s
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then fail lexbuf "reserved mach-float suffix"
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else fail lexbuf "bad mach-float suffix"
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}
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| '\'' { char lexbuf }
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| '"' { let buf = Buffer.create 32 in
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@ -411,3 +458,13 @@ and comment depth = parse
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comment depth lexbuf }
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| _ { comment depth lexbuf }
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(*
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* Local Variables:
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* fill-column: 78;
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* indent-tabs-mode: nil
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* buffer-file-coding-system: utf-8-unix
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* compile-command: "make -k -C ../.. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
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* End:
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*)
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