fluent predicates for filtering

test/predicates_test.sh

@@ -0,0 +1,52 @@
+#! /bin/bash
+
+testIsint() {
+  assertEquals 'true' $(isint 1)
+  assertEquals 'true' $(isint -1)
+  assertEquals 'false' $(isint a)
+  assertEquals 'false' $(isint "")
+  assertEquals '1 2 3 4 5' "$(list 1 a 2 b 3 c 4 d 5 e | filter lambda x . 'isint $x' | unlist )"
+  assertEquals '1 2'       "$(list 1 a 2 b 3 c 4 d 5 e | filter lambda x . '($(isint $x) &&  [[ $x -le 2 ]] && ret true) || ret false ' | unlist )"
+
+  assertEquals 'false' $(not isint 1)
+  assertEquals 'true' $(not isint a)
+}
+
+testIsempty() {
+  assertEquals 'true' $(isempty "")
+  assertEquals 'false' $(isempty a)
+
+  assertEquals 'true' $(not isempty a)
+  assertEquals 'false' $(not isempty "")
+}
+
+testIsfile() {
+  f=$(mktemp)
+
+  assertEquals 'true' $(isfile $f)
+  assertEquals 'false' $(isfile $f.xxx)
+  assertEquals 'false' $(isfile "")
+  assertEquals 'true' $(not isfile $f.xxx)
+
+  assertEquals 'false' $(isnonzerofile $f)
+  echo hello world >$f
+  assertEquals 'true' $(isnonzerofile $f)
+
+  assertEquals 'true' $(iswritable $f)
+  chmod 400 $f
+  assertEquals 'false' $(iswritable $f)
+
+  assertEquals 'true' $(isreadable $f)
+  chmod 200 $f
+  assertEquals 'false' $(isreadable $f)
+
+  chmod 600 $f
+  rm $f
+}
+
+testIsdir() {
+  assertEquals 'true' $(isdir .)
+  assertEquals 'false' $(isdir sir_not_appearing_in_this_film)
+}
+
+. ./shunit2-init.sh