1 files changed, 129 insertions, 0 deletions
diff --git a/contrib/seg/segscan.l b/contrib/seg/segscan.l
new file mode 100644
index 0000000..a1e9e99
--- /dev/null
+++ b/contrib/seg/segscan.l
@@ -0,0 +1,129 @@
+%top{
+/*
+ * A scanner for EMP-style numeric ranges
+ */
+#include "postgres.h"
+
+#include "nodes/miscnodes.h"
+
+/*
+ * NB: include segparse.h only AFTER including segdata.h, because segdata.h
+ * contains the definition for SEG.
+ */
+#include "segdata.h"
+#include "segparse.h"
+}
+
+%{
+/* 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;
+%}
+
+%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}      seg_yylval.text = yytext; return RANGE;
+{plumin}     seg_yylval.text = yytext; return PLUMIN;
+{float}      seg_yylval.text = yytext; return SEGFLOAT;
+\<           seg_yylval.text = "<"; return EXTENSION;
+\>           seg_yylval.text = ">"; return EXTENSION;
+\~           seg_yylval.text = "~"; return EXTENSION;
+[ \t\n\r\f]+ /* discard spaces */
+.            return yytext[0]; /* alert parser of the garbage */
+
+%%
+
+/* LCOV_EXCL_STOP */
+
+void
+seg_yyerror(SEG *result, struct Node *escontext, const char *message)
+{
+	/* if we already reported an error, don't overwrite it */
+	if (SOFT_ERROR_OCCURRED(escontext))
+		return;
+
+	if (*yytext == YY_END_OF_BUFFER_CHAR)
+	{
+		errsave(escontext,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("bad seg representation"),
+				 /* translator: %s is typically "syntax error" */
+				 errdetail("%s at end of input", message)));
+	}
+	else
+	{
+		errsave(escontext,
+				(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.
+	 */
+	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);
+}