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mirror of https://github.com/janet-lang/janet synced 2024-06-29 16:43:20 +00:00
janet/tools/bars.janet
Calvin Rose 2d7df6b78e Many changes for adding dynamic (fiber-level) scope.
- Allow passing a table to fibers, which make fiber level scope easier.
- Add fiber/getenv, fiber/setenv, dyn, and setdyn
- Remove meta, *env*, and *doc-width*
- Some functions changed dignatures, and no longer take an env
2019-04-16 15:41:45 -04:00

56 lines
1.5 KiB
Clojure

# A flexible templater for janet. Compiles
# templates to janet functions that produce buffers.
(defn template
"Compile a template string into a function"
[source]
# State for compilation machine
(def p (parser/new))
(def forms @[])
(defn parse-chunk
"Parse a string and push produced values to forms."
[chunk]
(parser/consume p chunk)
(while (parser/has-more p)
(array/push forms (parser/produce p)))
(if (= :error (parser/status p))
(error (parser/error p))))
(defn code-chunk
"Parse all the forms in str and return them
in a tuple prefixed with 'do."
[str]
(parse-chunk str)
true)
(defn string-chunk
"Insert string chunk into parser"
[str]
(parser/insert p str)
(parse-chunk "")
true)
# Run peg
(def grammar
~{:code-chunk (* "{%" (drop (cmt '(any (if-not "%}" 1)) ,code-chunk)) "%}")
:main-chunk (drop (cmt '(any (if-not "{%" 1)) ,string-chunk))
:main (any (+ :code-chunk :main-chunk (error "")))})
(def parts (peg/match grammar source))
# Check errors in template and parser
(unless parts (error "invalid template syntax"))
(parse-chunk "\n")
(case (parser/status p)
:pending (error (string "unfinished parser state " (parser/state p)))
:error (error (parser/error p)))
# Make ast from forms
(def ast ~(fn [&opt params] (default params @{}) (,buffer ,;forms)))
(def ctor (compile ast (fiber/getenv (fiber/current)) source))
(if-not (function? ctor)
(error (string "could not compile template")))
(ctor))