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-rw-r--r--contrib/seg/segscan.l115
1 files changed, 115 insertions, 0 deletions
diff --git a/contrib/seg/segscan.l b/contrib/seg/segscan.l
new file mode 100644
index 0000000..5f6595e
--- /dev/null
+++ b/contrib/seg/segscan.l
@@ -0,0 +1,115 @@
+%{
+/*
+ * A scanner for EMP-style numeric ranges
+ */
+
+/* LCOV_EXCL_START */
+
+/* No reason to constrain amount of data slurped */
+#define YY_READ_BUF_SIZE 16777216
+
+/* Avoid exit() on fatal scanner errors (a bit ugly -- see yy_fatal_error) */
+#undef fprintf
+#define fprintf(file, fmt, msg) fprintf_to_ereport(fmt, msg)
+
+static void
+fprintf_to_ereport(const char *fmt, const char *msg)
+{
+ ereport(ERROR, (errmsg_internal("%s", msg)));
+}
+
+/* Handles to the buffer that the lexer uses internally */
+static YY_BUFFER_STATE scanbufhandle;
+static char *scanbuf;
+static int scanbuflen;
+%}
+
+%option 8bit
+%option never-interactive
+%option nodefault
+%option noinput
+%option nounput
+%option noyywrap
+%option warn
+%option prefix="seg_yy"
+
+
+range (\.\.)(\.)?
+plumin (\'\+\-\')|(\(\+\-)\)
+integer [+-]?[0-9]+
+real [+-]?[0-9]+\.[0-9]+
+float ({integer}|{real})([eE]{integer})?
+
+%%
+
+{range} yylval.text = yytext; return RANGE;
+{plumin} yylval.text = yytext; return PLUMIN;
+{float} yylval.text = yytext; return SEGFLOAT;
+\< yylval.text = "<"; return EXTENSION;
+\> yylval.text = ">"; return EXTENSION;
+\~ yylval.text = "~"; return EXTENSION;
+[ \t\n\r\f]+ /* discard spaces */
+. return yytext[0]; /* alert parser of the garbage */
+
+%%
+
+/* LCOV_EXCL_STOP */
+
+void
+yyerror(SEG *result, const char *message)
+{
+ if (*yytext == YY_END_OF_BUFFER_CHAR)
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("bad seg representation"),
+ /* translator: %s is typically "syntax error" */
+ errdetail("%s at end of input", message)));
+ }
+ else
+ {
+ ereport(ERROR,
+ (errcode(ERRCODE_SYNTAX_ERROR),
+ errmsg("bad seg representation"),
+ /* translator: first %s is typically "syntax error" */
+ errdetail("%s at or near \"%s\"", message, yytext)));
+ }
+}
+
+
+/*
+ * Called before any actual parsing is done
+ */
+void
+seg_scanner_init(const char *str)
+{
+ Size slen = strlen(str);
+
+ /*
+ * Might be left over after ereport()
+ */
+ if (YY_CURRENT_BUFFER)
+ yy_delete_buffer(YY_CURRENT_BUFFER);
+
+ /*
+ * Make a scan buffer with special termination needed by flex.
+ */
+ scanbuflen = slen;
+ scanbuf = palloc(slen + 2);
+ memcpy(scanbuf, str, slen);
+ scanbuf[slen] = scanbuf[slen + 1] = YY_END_OF_BUFFER_CHAR;
+ scanbufhandle = yy_scan_buffer(scanbuf, slen + 2);
+
+ BEGIN(INITIAL);
+}
+
+
+/*
+ * Called after parsing is done to clean up after seg_scanner_init()
+ */
+void
+seg_scanner_finish(void)
+{
+ yy_delete_buffer(scanbufhandle);
+ pfree(scanbuf);
+}