add filter(), cut(), askey()

1 files changed, 40 insertions, 8 deletions

diff --git a/it_pipe.class b/it_pipe.class
index 281ee5f..5ab7e8a 100644
--- a/it_pipe.class
+++ b/it_pipe.class
@@ -85,6 +85,16 @@ function map($expr)
 }
 
 /**
+ * Apply an expression to every line
+ */
+function filter($expr)
+{
+	$this->lines = it::filter($expr, $this->lines);
+
+	return $this;
+}
+
+/**
  * Convert pipe from utf8 to iso-latin
  */
 function latin()
@@ -101,17 +111,14 @@ function utf8()
 }
 
 /**
- * Return contents of pipe as key->val pair (key must be tab separated)
+ * Select cols from tab-separated cols in each line and tab-joins them again. Key order relevant.
  */
-function keyval()
+function cut($picks)
 {
-	foreach ($this->lines as $line)
-	{
-		list($key, $val) = explode("\t", $line, 2);
-		$result[$key] = $val;
-	}
+	foreach ($this->lines as $idx => $line)
+		$this->lines[$idx] = join("\t", it::filter_keys(explode("\t", $line), $picks, ['reorder' => true]));
 
-	return (array)$result;
+	return $this;
 }
 
 /**
@@ -128,6 +135,31 @@ function swap()
 	return $this;
 }
 
+/**
+ * Return contents of pipe as key->val pair (key must be tab separated).
+ */
+function keyval()
+{
+	foreach ($this->lines as $line)
+	{
+		list($key, $val) = explode("\t", $line, 2);
+		$result[$key] = $val;
+	}
+
+	return (array)$result;
+}
+
+/**
+ * Return contents of pipe as array keys with value true
+ */
+function askey()
+{
+	foreach ($this->lines as $line)
+		$result[$line] = true;
+
+	return (array)$result;
+}
+
 function ED()
 {
 	ED($this->lines);