Nested syntax templates

[bopjesvla]

syntax helper2 = ctx => #`
    syntax test2 = ctx => {
        return #`1`
    }`

helper2

syntax helper1 = ctx => #`(#`1`)`

syntax test1 = ctx => helper1

test1

Neither works.

[disnet]

The escape syntax for syntax templates is the same as normal templates:

#`a literal backtick \` and then we're done`

[disnet]

Oops. That's supposed to be the escape but looks like we have a bug:

syntax test = function (ctx) {
  return #`let x = \`template string\`;`
}
test

throws:

/Users/tim/dev/sweet.js/node_modules/shift-parser/dist/tokenizer.js:731
            throw this.createILLEGAL();
            ^

Error: [2:21]: Unexpected "`"
    at JsError.Error (native)
    at new JsError (/Users/tim/dev/sweet.js/node_modules/shift-parser/dist/tokenizer.js:161:81)
    at Reader.createError (/Users/tim/dev/sweet.js/node_modules/shift-parser/dist/tokenizer.js:277:14)
    at Reader.createILLEGAL (/Users/tim/dev/sweet.js/node_modules/shift-parser/dist/tokenizer.js:245:53)
    at Reader.getEscapedIdentifier (/Users/tim/dev/sweet.js/node_modules/shift-parser/dist/tokenizer.js:731:24)
    at Reader.scanIdentifier (/Users/tim/dev/sweet.js/node_modules/shift-parser/dist/tokenizer.js:795:63)
    at Reader.advance (/Users/tim/dev/sweet.js/node_modules/shift-parser/dist/tokenizer.js:1437:25)
    at Reader.advance (/Users/tim/dev/sweet.js/build/src/shift-reader.js:325:90)
    at Reader.read (/Users/tim/dev/sweet.js/build/src/shift-reader.js:227:24)
    at Reader.read (/Users/tim/dev/sweet.js/build/src/shift-reader.js:252:28)

[bopjesvla]

Yeah, I tried that too. I based the syntax for nested templates on the reader tests.

[gabejohnson]

This is still an issue. I have some ideas, but they involve changing our strategy for reading syntax templates. I'd also like to implement the ideas from #551 (comment) at the same time.