Add scripting (tengo) support for every incoming message (#731)

TengoModifyMessage allows you to specify the location of a tengo (https://github.com/d5/tengo/) script.
This script will receive every incoming message and can be used to modify the Username and the Text of that message.
The script will have the following global variables:
to modify: msgUsername and msgText
to read: msgChannel and msgAccount

The script is reloaded on every message, so you can modify the script on the fly.

Example script can be found in https://github.com/42wim/matterbridge/tree/master/gateway/bench.tengo
and https://github.com/42wim/matterbridge/tree/master/contrib/example.tengo

The example below will check if the text contains blah and if so, it'll replace the text and the username of that message.
text := import("text")
if text.re_match("blah",msgText) {
    msgText="replaced by this"
    msgUsername="fakeuser"
}

More information about tengo on: https://github.com/d5/tengo/blob/master/docs/tutorial.md and
https://github.com/d5/tengo/blob/master/docs/stdlib.md

1 files changed, 30 insertions, 0 deletions

diff --git a/vendor/github.com/d5/tengo/objects/object.go b/vendor/github.com/d5/tengo/objects/object.go
new file mode 100644
index 00000000..4c5aa7ae
--- /dev/null
+++ b/vendor/github.com/d5/tengo/objects/object.go
@@ -0,0 +1,30 @@
+package objects
+
+import "github.com/d5/tengo/compiler/token"
+
+// Object represents an object in the VM.
+type Object interface {
+	// TypeName should return the name of the type.
+	TypeName() string
+
+	// String should return a string representation of the type's value.
+	String() string
+
+	// BinaryOp should return another object that is the result of
+	// a given binary operator and a right-hand side object.
+	// If BinaryOp returns an error, the VM will treat it as a run-time error.
+	BinaryOp(op token.Token, rhs Object) (Object, error)
+
+	// IsFalsy should return true if the value of the type
+	// should be considered as falsy.
+	IsFalsy() bool
+
+	// Equals should return true if the value of the type
+	// should be considered as equal to the value of another object.
+	Equals(another Object) bool
+
+	// Copy should return a copy of the type (and its value).
+	// Copy function will be used for copy() builtin function
+	// which is expected to deep-copy the values generally.
+	Copy() Object
+}