lang: Add edges to lexer and parser

This adds some initial syntax for external edges to the language.

There are still improvements which are necessary for send/recv.

examples/lang/edges0.mcl

@@ -0,0 +1,14 @@
+exec "exec0" {
+	cmd => "sleep 10s",
+	shell => "/bin/bash",
+}
+exec "exec1" {
+	cmd => "sleep 10s",
+	shell => "/bin/bash",
+}
+exec "exec2" {
+	cmd => "sleep 10s",
+	shell => "/bin/bash",
+}
+
+Exec["exec0"] -> Exec["exec1"] -> Exec["exec2"]

examples/lang/password0.mcl

@@ -0,0 +1,8 @@
+password "pass0" {
+	length => 8,
+}
+
+file "/tmp/mgmt/password" {
+}
+
+Password["pass0"].password -> File["/tmp/mgmt/password"].content

examples/lang/sendrecv0.mcl

@@ -0,0 +1,9 @@
+exec "exec0" {
+	cmd => "echo hello world && echo goodbye world 1>&2", # to stdout && stderr
+	shell => "/bin/bash",
+}
+
+print "print0" {
+}
+
+Exec["exec0"].output -> Print["print0"].msg

examples/lang/sendrecv1.mcl

@@ -0,0 +1,14 @@
+file "/tmp/mgmt/foo" {
+	content => "hello from foo\n",
+}
+
+print "print0" {
+}
+
+File["/tmp/mgmt/foo"].content -> Print["print0"].msg
+
+print "print1" {
+	msg => "hello",
+}
+
+Print["print0"] -> Print["print1"]

examples/lang/sendrecv2.mcl

@@ -0,0 +1,8 @@
+file "/tmp/mgmt/foo" {
+	content => "hello from foo\n",
+}
+
+file "/tmp/mgmt/bar" {
+}
+
+File["/tmp/mgmt/foo"].content -> File["/tmp/mgmt/bar"].content

examples/lang/sendrecv3.mcl

@@ -0,0 +1,21 @@
+$ns = "estate"
+$exchanged = kvlookup($ns)
+$state = maplookup($exchanged, $hostname, "default")
+
+exec "exec0" {
+	cmd => "echo hello world && echo goodbye world 1>&2", # to stdout && stderr
+	shell => "/bin/bash",
+}
+
+kv "kv0" {
+	key => $ns,
+	#value => "two",
+}
+
+Exec["exec0"].output -> Kv["kv0"].value
+
+if $state != "default" {
+	file "/tmp/mgmt/state" {
+		content => printf("state: %s\n", $state),
+	}
+}

examples/lang/states0.mcl

@@ -8,28 +8,43 @@ if $state == "one" || $state == "default" {
 	file "/tmp/mgmt/state" {
 		content => "state: one\n",
 	}
+
+	exec "timer" {
+		cmd => "/usr/bin/sleep 1s",
+	}
 	kv "${ns}" {
 		key => $ns,
 		value => "two",
 	}
+	Exec["timer"] -> Kv["${ns}"]
 }
 if $state == "two" {
 
 	file "/tmp/mgmt/state" {
 		content => "state: two\n",
 	}
+
+	exec "timer" {
+		cmd => "/usr/bin/sleep 1s",
+	}
 	kv "${ns}" {
 		key => $ns,
 		value => "three",
 	}
+	Exec["timer"] -> Kv["${ns}"]
 }
 if $state == "three" {
 
 	file "/tmp/mgmt/state" {
 		content => "state: three\n",
 	}
+
+	exec "timer" {
+		cmd => "/usr/bin/sleep 1s",
+	}
 	kv "${ns}" {
 		key => $ns,
 		value => "one",
 	}
+	Exec["timer"] -> Kv["${ns}"]
 }