From a399b382fa72cd6ca97693164a0662a135d1aa1a Mon Sep 17 00:00:00 2001
From: John Kerl <kerl.john.r@gmail.com>
Date: Mon, 5 Oct 2015 22:34:46 -0400
Subject: [PATCH] regex iterate

---
 c/mapping/mlr_val.c | 40 ++++++++++++++++++++++++++++++++++++++--
 c/todo.txt          |  2 +-
 2 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/c/mapping/mlr_val.c b/c/mapping/mlr_val.c
index db3696526..a9e622c98 100644
--- a/c/mapping/mlr_val.c
+++ b/c/mapping/mlr_val.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <math.h>
 #include <time.h>
+#include <regex.h>
 #include "lib/mlr_globals.h"
 #include "lib/mlrutil.h"
 #include "mapping/mlr_val.h"
@@ -847,8 +848,43 @@ mv_t lt_op_func(mv_t* pval1, mv_t* pval2) { return (lt_dispositions[pval1->type]
 mv_t le_op_func(mv_t* pval1, mv_t* pval2) { return (le_dispositions[pval1->type][pval2->type])(pval1, pval2); }
 
 mv_t matches_op_func(mv_t* pval1, mv_t* pval2) {
-	return (mv_t) {.type = MT_BOOL, .u.boolv = TRUE}; // xxx stub
+	char* s1 = pval1->u.strv;
+	char* s2 = pval2->u.strv;
+
+	// xxx temp -- need to regcomp once & keep it
+	regex_t reg;
+	char* sstr   = s1;
+	char* sregex = s2;
+	int cflags = REG_EXTENDED; // also support REG_ICASE somehow
+	regmatch_t pmatch[1];
+	int eflags = 0;
+	int rc;
+
+	rc = regcomp(&reg, sregex, cflags);
+	if (rc != 0) {
+		size_t nbytes = regerror(rc, &reg, NULL, 0);
+		char* errbuf = malloc(nbytes);
+		(void)regerror(rc, &reg, errbuf, nbytes);
+		fprintf(stderr, "regcomp failure: %s\n", errbuf);
+		exit(1);
+	}
+
+	rc = regexec(&reg, sstr, 1, pmatch, eflags);
+	regfree(&reg);
+	if (rc == 0) {
+		return (mv_t) {.type = MT_BOOL, .u.boolv = TRUE};
+	} else if (rc == REG_NOMATCH) {
+		return (mv_t) {.type = MT_BOOL, .u.boolv = FALSE};
+	} else {
+		size_t nbytes = regerror(rc, &reg, NULL, 0);
+		char* errbuf = malloc(nbytes);
+		(void)regerror(rc, &reg, errbuf, nbytes);
+		printf("regexec failure: %s\n", errbuf);
+		exit(1);
+	}
 }
 mv_t does_not_match_op_func(mv_t* pval1, mv_t* pval2) {
-	return (mv_t) {.type = MT_BOOL, .u.boolv = FALSE}; // xxx stub
+	mv_t rv = matches_op_func(pval1, pval2);
+	rv.u.boolv = !rv.u.boolv;
+	return rv;
 }
diff --git a/c/todo.txt b/c/todo.txt
index 06808a455..be3d316e3 100644
--- a/c/todo.txt
+++ b/c/todo.txt
@@ -19,7 +19,7 @@ MAJOR: running-mean feature ....... really for all of stats1/stats2
 ----------------------------------------------------------------
 MAJOR: regex
 
-* mlr filter '$y =~ /abc/'
+* mlr filter '$y =~ "abc"'
 * mlr put '$y = gsub(/a.*b/, "cde")'
 * having-fields
 * IOXS...