Twiggy compiler fixes

[jcheron]

• [x] bug fix : no open issue
• [ ] BC break

Fixed:

These behaviors may have been voluntary choices... I don't know

raw filter

Twig raw filter is not interpreted.

Twig	Expected Latte	Actual Latte
{{foo|raw}}	{$foo|noescape}	{$foo}

see https://github.com/nette/latte-tools/commit/7aaba40e857642c503979e9b288b1d376cdea069

Twig array access

Access to the element of a Twig array is transformed into access to the member of an object.

Twig	Expected Latte	Actual Latte
{{bar['foo']}}	{$bar['foo']}	{$bar->foo}

see https://github.com/nette/latte-tools/commit/209d1fb0733902ef46b2de6f537be8962aac576a

Twig and Twiggy coexisting

pb with Twig already installed in a project (cannot redeclare Twig global functions...)

• checks with function_exists the previous declaration of the Twig global functions, see https://github.com/nette/latte-tools/commit/c1a06ed93e152dda03c61cfeda9e48480667ca72

_self replacement with toString

Replacing {{_self}} with {$_self} is problematic:

• _self with Twig refers to the template instance, using it alone in an expression calls the toString which displays the template name.
• $_self is not defined with Latte

Twig	Expected Latte	Actual Latte
{{_self}}	{$this->getName()}	{$_self}

see https://github.com/nette/latte-tools/commit/5250d9c7055531846f59058f87e1d268e0b66e0e

Unit tests

The unit tests have been modified accordingly: see https://github.com/nette/latte-tools/commit/4a2e2f5d0ae7e64af505cdedf3ce9a87f340dbc6