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57290d63fd
* cfg.mk: Disable checks where needed (e.g., we do want to check the behavior with tabs). (sc_at_parser_check): Remove. Unfortunately sincea11c144609we no longer use the './' prefix to run programs in the current directory. That was so that we could run Java programs like the other, although they are no run with the `./` prefix (see967a59d2c0). As a consequence this sc check no longer makes sense. However, since now AT_PARSER_CHECK passes the `./` prefix itself, this sc-check was superfluous. * examples/c/reccalc/scan.l: Use memcpy, not strncpy. * src/ielr.c, src/reader.c: Obfuscate "lr(0)" so that the sc-check for "space before paren" does not fire. * tests/diagnostics.at: Avoid space-tab, use tab-tab.
94 lines
1.6 KiB
Plaintext
94 lines
1.6 KiB
Plaintext
%code top {
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#include <ctype.h> /* isdigit. */
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#include <stdio.h> /* For printf, etc. */
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#include <string.h> /* strcmp. */
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int yylex (void);
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void yyerror (char const *);
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}
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%define api.header.include {"calc.h"}
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%define api.value.type union /* Generate YYSTYPE from these types: */
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%token <double> NUM "number"
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%type <double> expr term fact
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/* Generate the parser description file. */
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%verbose
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/* Enable run-time traces (yydebug). */
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%define parse.trace
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/* Formatting semantic values. */
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%printer { fprintf (yyo, "%g", $$); } <double>;
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%% /* The grammar follows. */
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input:
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%empty
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| input line
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;
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line:
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'\n'
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| expr '\n' { printf ("%.10g\n", $1); }
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| error '\n' { yyerrok; }
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;
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expr:
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expr '+' term { $$ = $1 + $3; }
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| expr '-' term { $$ = $1 - $3; }
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| term
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;
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term:
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term '*' fact { $$ = $1 * $3; }
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| term '/' fact { $$ = $1 / $3; }
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| fact
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;
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fact:
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"number"
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| '(' expr ')' { $$ = $2; }
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;
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%%
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int
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yylex (void)
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{
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int c;
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/* Ignore white space, get first nonwhite character. */
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while ((c = getchar ()) == ' ' || c == '\t')
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continue;
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if (c == EOF)
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return 0;
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/* Char starts a number => parse the number. */
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if (c == '.' || isdigit (c))
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{
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ungetc (c, stdin);
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scanf ("%lf", &yylval.NUM);
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return NUM;
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}
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/* Any other character is a token by itself. */
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return c;
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}
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/* Called by yyparse on error. */
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void
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yyerror (char const *s)
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{
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fprintf (stderr, "%s\n", s);
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}
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int
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main (int argc, char const* argv[])
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{
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/* Enable parse traces on option -p. */
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for (int i = 1; i < argc; ++i)
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if (!strcmp (argv[i], "-p"))
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yydebug = 1;
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return yyparse ();
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}
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