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Re: [PATCH for Dlang support] d: make enum SymbolKind idiomatic D
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From: |
Akim Demaille |
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Subject: |
Re: [PATCH for Dlang support] d: make enum SymbolKind idiomatic D |
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Date: |
Sat, 12 Sep 2020 17:10:35 +0200 |
Hi Adela,
> Le 11 sept. 2020 à 14:53, Adela Vais <adela.vais99@gmail.com> a écrit :
>
> The enum is now wrapped in a structure that contains its string
> representation.
>
> * data/skeletons/d.m4, data/skeletons/lalr1.d: here.
Great, thanks!
Please, make run you run the test suite before submitting a commit,
there were errors. I had to install the following changes to your
commit (you were still using yytname_).
diff --git a/data/skeletons/d.m4 b/data/skeletons/d.m4
index 2e086ab0..7a9d3efe 100644
--- a/data/skeletons/d.m4
+++ b/data/skeletons/d.m4
@@ -269,11 +269,7 @@ m4_define([b4_declare_symbol_enum],
put(sink, yystr);
}
}
- ]])])
- [
- }
-]])])
-
+]])
# b4-case(ID, CODE, [COMMENTS])
diff --git a/data/skeletons/lalr1.d b/data/skeletons/lalr1.d
index b452c4e0..e879dabf 100644
--- a/data/skeletons/lalr1.d
+++ b/data/skeletons/lalr1.d
@@ -373,12 +373,12 @@ b4_locations_if([, ref ]b4_location_type[ yylocationp])[)
if (0 < yydebug)
{
string message = s ~ (yykind < yyntokens_ ? " token " : " nterm ")
- ~ yytname_[yykind] ~ " ("]b4_locations_if([
+ ~ format("%s", yykind) ~ " ("]b4_locations_if([
~ yylocationp.toString() ~ ": "])[;
- static if (__traits(compiles, message ~= yyvaluep.toString ()))
- message ~= yyvaluep.toString ();
+ static if (__traits(compiles, message ~= yyvaluep.toString()))
+ message ~= yyvaluep.toString();
else
- message ~= format ("%s", &yyvaluep);
+ message ~= format("%s", &yyvaluep);
message ~= ")";
yycdebugln (message);
}
Does it really make sense to use yyvaluep.toString here, doesn't the
second case, via format, always encompasses the first one?
So I'm installing the following revised version of your commit.
With TODO updated.
Cheers!
commit 2bc886dc02f00e7ebbaa008af8fdfce45cebadcd
Author: Adela Vais <adela.vais99@gmail.com>
Date: Fri Sep 11 15:53:45 2020 +0300
d: make enum SymbolKind idiomatic D
Taking into account comments from H. S. Teoh.
https://lists.gnu.org/r/bison-patches/2020-09/msg00021.html
* data/skeletons/d.m4, data/skeletons/lalr1.d (SymbolKind): Wrap the
enum in a structure that contains its string representation.
diff --git a/TODO b/TODO
index 98849e7a..3f4d1978 100644
--- a/TODO
+++ b/TODO
@@ -242,90 +242,6 @@ are. Keep the same variable names. If you change the
wording in one place,
do it in the others too. In other words: make sure to keep the
maintenance *simple* by avoiding any gratuitous difference.
-** Rename the D example
-Move the current content of examples/d into examples/d/simple.
-
-** Create a second example
-Duplicate examples/d/simple into examples/d/calc.
-
-** Add location tracking to d/calc
-Look at the examples in the other languages to see how to do that.
-
-** yysymbol_name
-The SymbolKind is an enum. For a given SymbolKind we want to get its string
-representation. Currently it's a separate table in the parser that does
-that:
-
- /* Symbol kinds. */
- public enum SymbolKind
- {
- S_YYEMPTY = -2, /* No symbol. */
- S_YYEOF = 0, /* "end of file" */
- S_YYerror = 1, /* error */
- S_YYUNDEF = 2, /* "invalid token" */
- S_EQ = 3, /* "=" */
- ...
- S_input = 14, /* input */
- S_line = 15, /* line */
- S_exp = 16, /* exp */
- };
-
- ...
-
- /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
- First, the terminals, then, starting at \a yyntokens_, nonterminals. */
- private static immutable string[] yytname_ =
- [
- "\"end of file\"", "error", "\"invalid token\"", "\"=\"", "\"+\"",
- "\"-\"", "\"*\"", "\"/\"", "\"(\"", "\")\"", "\"end of line\"",
- "\"number\"", "UNARY", "$accept", "input", "line", "exp", null
- ];
-
- ...
-
-So to get a symbol kind, one runs `yytname_[yykind]`.
-
-Is there a way to attach this conversion to string to SymbolKind? In Java
-for instance, we have:
-
- public enum SymbolKind
- {
- S_YYEOF(0), /* "end of file" */
- S_YYerror(1), /* error */
- S_YYUNDEF(2), /* "invalid token" */
- ...
- S_input(16), /* input */
- S_line(17), /* line */
- S_exp(18); /* exp */
-
- private final int yycode_;
-
- SymbolKind (int n) {
- this.yycode_ = n;
- }
- ...
- /* YYNAMES_[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
- First, the terminals, then, starting at \a YYNTOKENS_, nonterminals. */
- private static final String[] yynames_ = yynames_init();
- private static final String[] yynames_init()
- {
- return new String[]
- {
- i18n("end of file"), i18n("error"), i18n("invalid token"), "!", "+",
"-", "*",
- "/", "^", "(", ")", "=", i18n("end of line"), i18n("number"), "NEG",
- "$accept", "input", "line", "exp", null
- };
- }
-
- /* The user-facing name of this symbol. */
- public final String getName() {
- return yynames_[yycode_];
- }
- };
-
-which allows to write more naturally `yykind.getName()` rather than
-`yytname_[yykind]`. Is there something comparable in (idiomatic) D?
-
** Change the return value of yylex
Historically people were allowed to return any int from the scanner (which
is convenient and allows `return '+'` from the scanner). Akim tends to see
diff --git a/data/skeletons/d.m4 b/data/skeletons/d.m4
index edb0c49e..7a9d3efe 100644
--- a/data/skeletons/d.m4
+++ b/data/skeletons/d.m4
@@ -204,13 +204,72 @@ m4_define([b4_symbol_enum],
# to use a signed type, which matters for yytoken.
m4_define([b4_declare_symbol_enum],
[[ /* Symbol kinds. */
- public enum SymbolKind
+ struct SymbolKind
{
+ enum
+ {
]b4_symbol(-2, kind_base)[ = -2, /* No symbol. */
]b4_symbol_foreach([b4_symbol_enum])dnl
-[ };
-]])])
-
+[ }
+
+ private int yycode_;
+ alias yycode_ this;
+
+ this(int code)
+ {
+ yycode_ = code;
+ }
+
+ /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
+ First, the terminals, then, starting at \a YYNTOKENS_, nonterminals. */
+ static immutable string[] yytname_ = @{
+ ]b4_tname[
+ @};
+
+ /* Return YYSTR after stripping away unnecessary quotes and
+ backslashes, so that it's suitable for yyerror. The heuristic is
+ that double-quoting is unnecessary unless the string contains an
+ apostrophe, a comma, or backslash (other than backslash-backslash).
+ YYSTR is taken from yytname. */
+ final void toString(W)(W sink) const
+ if (isOutputRange!(W, char))
+ {
+ string yystr = yytname_[yycode_];
+
+ if (yystr[0] == '"')
+ {
+ string yyr;
+ strip_quotes:
+ for (int i = 1; i < yystr.length; i++)
+ switch (yystr[i])
+ {
+ case '\'':
+ case ',':
+ break strip_quotes;
+
+ case '\\':
+ if (yystr[++i] != '\\')
+ break strip_quotes;
+ goto default;
+ default:
+ yyr ~= yystr[i];
+ break;
+
+ case '"':
+ put(sink, yyr);
+ return;
+ }
+ }
+ else if (yystr == "$end")
+ {
+ put(sink, "end of input");
+ return;
+ }
+
+ put(sink, yystr);
+ }
+ }
+]])
# b4-case(ID, CODE, [COMMENTS])
diff --git a/data/skeletons/lalr1.d b/data/skeletons/lalr1.d
index 761125cb..e879dabf 100644
--- a/data/skeletons/lalr1.d
+++ b/data/skeletons/lalr1.d
@@ -361,41 +361,6 @@ b4_user_union_members
return YYNEWSTATE;
}
- /* Return YYSTR after stripping away unnecessary quotes and
- backslashes, so that it's suitable for yyerror. The heuristic is
- that double-quoting is unnecessary unless the string contains an
- apostrophe, a comma, or backslash (other than backslash-backslash).
- YYSTR is taken from yytname. */
- private final string yytnamerr_ (string yystr)
- {
- if (yystr[0] == '"')
- {
- string yyr;
- strip_quotes:
- for (int i = 1; i < yystr.length; i++)
- switch (yystr[i])
- {
- case '\'':
- case ',':
- break strip_quotes;
-
- case '\\':
- if (yystr[++i] != '\\')
- break strip_quotes;
- goto default;
- default:
- yyr ~= yystr[i];
- break;
-
- case '"':
- return yyr;
- }
- }
- else if (yystr == "$end")
- return "end of input";
-
- return yystr;
- }
]b4_parse_trace_if([[
/*--------------------------------.
| Print this symbol on YYOUTPUT. |
@@ -408,12 +373,12 @@ b4_locations_if([, ref ]b4_location_type[ yylocationp])[)
if (0 < yydebug)
{
string message = s ~ (yykind < yyntokens_ ? " token " : " nterm ")
- ~ yytname_[yykind] ~ " ("]b4_locations_if([
+ ~ format("%s", yykind) ~ " ("]b4_locations_if([
~ yylocationp.toString() ~ ": "])[;
- static if (__traits(compiles, message ~= yyvaluep.toString ()))
- message ~= yyvaluep.toString ();
+ static if (__traits(compiles, message ~= yyvaluep.toString()))
+ message ~= yyvaluep.toString();
else
- message ~= format ("%s", &yyvaluep);
+ message ~= format("%s", &yyvaluep);
message ~= ")";
yycdebugln (message);
}
@@ -732,7 +697,7 @@ m4_popdef([b4_at_dollar])])dnl
// FIXME: This method of building the message is not compatible
// with internationalization.
string res = "syntax error, unexpected ";
- res ~= yytnamerr_ (yytname_[tok]);
+ res ~= format!"%s"(tok);
int yyn = yypact_[yystate];
if (!yy_pact_value_is_default_ (yyn))
{
@@ -757,7 +722,7 @@ m4_popdef([b4_at_dollar])])dnl
&& !yy_table_value_is_error_ (yytable_[x + yyn]))
{
res ~= count++ == 0 ? ", expecting " : " or ";
- res ~= yytnamerr_ (yytname_[x]);
+ res ~= format!"%s"(SymbolKind(x));
}
}
}
@@ -795,13 +760,6 @@ m4_popdef([b4_at_dollar])])dnl
]b4_parser_tables_define[
- /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
- First, the terminals, then, starting at \a yyntokens_, nonterminals. */
- private static immutable string[] yytname_ =
- @{
- ]b4_tname[
- @};
-
]b4_parse_trace_if([[
/* YYRLINE[YYN] -- Source line where rule number YYN was defined. */
private static immutable ]b4_int_type_for([b4_rline])[[] yyrline_ =
@@ -831,11 +789,10 @@ m4_popdef([b4_at_dollar])])dnl
}
]])[
- private static SymbolKind yytranslate_ (int t)
+ private static auto yytranslate_ (int t)
{
]b4_api_token_raw_if(
-[[ import std.conv : to;
- return to!SymbolKind (t);]],
+[[ return SymbolKind(t);]],
[[ /* YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX. */
immutable ]b4_int_type_for([b4_translate])[[] translate_table =
@{
@@ -848,10 +805,7 @@ m4_popdef([b4_at_dollar])])dnl
if (t <= 0)
return ]b4_symbol(0, kind)[;
else if (t <= code_max)
- {
- import std.conv : to;
- return to!SymbolKind (translate_table[t]);
- }
+ return SymbolKind(translate_table[t]);
else
return ]b4_symbol(2, kind)[;]])[
}