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, 135 insertions, 0 deletions

diff --git a/vendor/github.com/d5/tengo/objects/builtins.go b/vendor/github.com/d5/tengo/objects/builtins.go
new file mode 100644
index 00000000..67553932
--- /dev/null
+++ b/vendor/github.com/d5/tengo/objects/builtins.go
@@ -0,0 +1,135 @@
+package objects
+
+// NamedBuiltinFunc is a named builtin function.
+type NamedBuiltinFunc struct {
+	Name string
+	Func CallableFunc
+}
+
+// Builtins contains all default builtin functions.
+var Builtins = []NamedBuiltinFunc{
+	{
+		Name: "print",
+		Func: builtinPrint,
+	},
+	{
+		Name: "printf",
+		Func: builtinPrintf,
+	},
+	{
+		Name: "sprintf",
+		Func: builtinSprintf,
+	},
+	{
+		Name: "len",
+		Func: builtinLen,
+	},
+	{
+		Name: "copy",
+		Func: builtinCopy,
+	},
+	{
+		Name: "append",
+		Func: builtinAppend,
+	},
+	{
+		Name: "string",
+		Func: builtinString,
+	},
+	{
+		Name: "int",
+		Func: builtinInt,
+	},
+	{
+		Name: "bool",
+		Func: builtinBool,
+	},
+	{
+		Name: "float",
+		Func: builtinFloat,
+	},
+	{
+		Name: "char",
+		Func: builtinChar,
+	},
+	{
+		Name: "bytes",
+		Func: builtinBytes,
+	},
+	{
+		Name: "time",
+		Func: builtinTime,
+	},
+	{
+		Name: "is_int",
+		Func: builtinIsInt,
+	},
+	{
+		Name: "is_float",
+		Func: builtinIsFloat,
+	},
+	{
+		Name: "is_string",
+		Func: builtinIsString,
+	},
+	{
+		Name: "is_bool",
+		Func: builtinIsBool,
+	},
+	{
+		Name: "is_char",
+		Func: builtinIsChar,
+	},
+	{
+		Name: "is_bytes",
+		Func: builtinIsBytes,
+	},
+	{
+		Name: "is_array",
+		Func: builtinIsArray,
+	},
+	{
+		Name: "is_immutable_array",
+		Func: builtinIsImmutableArray,
+	},
+	{
+		Name: "is_map",
+		Func: builtinIsMap,
+	},
+	{
+		Name: "is_immutable_map",
+		Func: builtinIsImmutableMap,
+	},
+	{
+		Name: "is_time",
+		Func: builtinIsTime,
+	},
+	{
+		Name: "is_error",
+		Func: builtinIsError,
+	},
+	{
+		Name: "is_undefined",
+		Func: builtinIsUndefined,
+	},
+	{
+		Name: "is_function",
+		Func: builtinIsFunction,
+	},
+	{
+		Name: "is_callable",
+		Func: builtinIsCallable,
+	},
+	{
+		Name: "to_json",
+		Func: builtinToJSON,
+	},
+	{
+		Name: "from_json",
+		Func: builtinFromJSON,
+	},
+	{
+		Name: "type_name",
+		Func: builtinTypeName,
+	},
+}