handle quoted template expressions and template interpolations

README.md

@@ -2,15 +2,37 @@
 
 tree-sitter grammar for the [HCL](https://github.com/hashicorp/hcl/blob/main/hclsyntax/spec.md) language
 
-## developing
+## Developing
 
 It is recommended to use `nix` to fulfill all development dependencies. To activate the development environment simply run `nix-shell` in the project root.
 
-## running tests
+## Running Tests
 
 To run tests simply run `nix-shell --run 'tree-sitter test'`. 
 
-## todo
+## Example
 
-* use [Unicode® Standard Annex #31](https://www.unicode.org/reports/tr31/) (augmented with '-')for identifiers
+Highlighting `example/example.hcl`:
+
+![Highlighting Example](/example/example.png "highlighting example")
+
+## Quoted Template Expressions
+
+In principle it is allowed to contain arbitary expressions in quoted template expressions.
+Consider for example:
+
+```hcl
+foo = "prefix-${func(\"bar\"}"
+```
+
+To make parsing a little easier, this parser only checks for valid escape sequences and template chars. 
+When using this parser one would have to take the content of a template interpolation, unescape it and parse it again to get the syntax tree. The same applies to template directives.
+
+## String Literals
+
+String literals are parsed as quoted templates. The calling application should check if the node contains any template interpolations or directives.
+
+## Todo
+
+* use [Unicode® Standard Annex #31](https://www.unicode.org/reports/tr31/) (augmented with '-') for identifiers
 * add [template expressions](https://github.com/hashicorp/hcl/blob/main/hclsyntax/spec.md#template-expressions)