diff options
author | Eduardo Julian | 2017-07-24 20:03:42 -0400 |
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committer | Eduardo Julian | 2017-07-24 20:03:42 -0400 |
commit | 6928bc80cfc265628215b0111751e072f6f2e640 (patch) | |
tree | 21ff37c1faeb2eb85739209ddf94c3240735f744 /stdlib/source | |
parent | 2c1a4d14de8f968ea0530ad471a1999488983c9d (diff) |
- Added models as a mechanism to encode nominal types.
Diffstat (limited to 'stdlib/source')
-rw-r--r-- | stdlib/source/lux/type/model.lux | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/stdlib/source/lux/type/model.lux b/stdlib/source/lux/type/model.lux new file mode 100644 index 000000000..757640b3c --- /dev/null +++ b/stdlib/source/lux/type/model.lux @@ -0,0 +1,188 @@ +(;module: + lux + (lux (control [applicative] + [monad #+ do Monad] + ["p" parser "p/" Monad<Parser>]) + (data [text "text/" Eq<Text>] + text/format + ["R" result] + (coll [list "L/" Functor<List> Monoid<List>])) + [macro #+ Monad<Lux>] + (macro [code] + ["s" syntax #+ syntax:] + (syntax ["cs" common] + (common ["csr" reader] + ["csw" writer]))) + type/auto)) + +(def: (get k plist) + (All [a] + (-> Text (List [Text a]) (Maybe a))) + (case plist + #;Nil + #;None + + (#;Cons [k' v] plist') + (if (text/= k k') + (#;Some v) + (get k plist')))) + +(def: (put k v plist) + (All [a] + (-> Text a (List [Text a]) (List [Text a]))) + (case plist + #;Nil + (list [k v]) + + (#;Cons [k' v'] plist') + (if (text/= k k') + (#;Cons [k' v] plist') + (#;Cons [k' v'] (put k v plist'))))) + +(def: (remove k plist) + (All [a] + (-> Text (List [Text a]) (List [Text a]))) + (case plist + #;Nil + #;Nil + + (#;Cons [k' v'] plist') + (if (text/= k k') + plist' + (#;Cons [k' v'] (remove k plist'))))) + +(def: down-cast Text "@model") +(def: up-cast Text "@repr") +(def: macro-anns Anns (list [["lux" "macro?"] (#;BoolA true)])) + +(do-template [<name> <tag>] + [(def: <name> + (-> Text Text) + (|>. (format "{" kind "@" module "}") + (let [[module kind] (ident-for <tag>)])))] + + [representation-name #;;Representation] + [down-cast-name #;;Down-Cast] + [up-cast-name #;;Up-Cast] + ) + +(def: (install-casts' this-module-name name type-vars) + (-> Text Text (List Text) (Lux Unit)) + (do Monad<Lux> + [this-module (macro;find-module this-module-name) + #let [this-module (|> this-module + (update@ #;defs (put down-cast (: Def + [Macro macro-anns + (function [tokens] + (case tokens + (^ (list value)) + (wrap (list (if (list;empty? type-vars) + (` (|> (~ value) + (: (~ (code;local-symbol (representation-name name)))) + (:! (~ (code;local-symbol name))))) + (` ((~ (code;local-symbol (down-cast-name name))) + (~ value)))))) + + _ + (macro;fail (format "Wrong syntax for " down-cast))))]))) + (update@ #;defs (put up-cast (: Def + [Macro macro-anns + (function [tokens] + (case tokens + (^ (list value)) + (wrap (list (if (list;empty? type-vars) + (` (|> (~ value) + (: (~ (code;local-symbol name))) + (:! (~ (code;local-symbol (representation-name name)))))) + (` ((~ (code;local-symbol (up-cast-name name))) + (~ value)))))) + + _ + (macro;fail (format "Wrong syntax for " up-cast))))]))))]] + (function [compiler] + (#R;Success [(update@ #;modules (put this-module-name this-module) compiler) + []])))) + +(def: (un-install-casts' this-module-name) + (-> Text (Lux Unit)) + (do Monad<Lux> + [this-module (macro;find-module this-module-name) + #let [this-module (|> this-module + (update@ #;defs (remove down-cast)) + (update@ #;defs (remove up-cast)))]] + (function [compiler] + (#R;Success [(update@ #;modules (put this-module-name this-module) compiler) + []])))) + +(syntax: #hidden (install-casts [name s;local-symbol] + [type-vars (s;tuple (p;some s;local-symbol))]) + (do @ + [this-module-name macro;current-module-name + ?down-cast (macro;find-macro [this-module-name down-cast]) + ?up-cast (macro;find-macro [this-module-name up-cast])] + (case [?down-cast ?up-cast] + [#;None #;None] + (do @ + [_ (install-casts' this-module-name name type-vars)] + (wrap (list))) + + _ + (macro;fail (format "Cannot temporarily define casting functions (" + down-cast " & " up-cast + ") because definitions like that already exist."))))) + +(syntax: #hidden (un-install-casts) + (do Monad<Lux> + [this-module-name macro;current-module-name + ?down-cast (macro;find-macro [this-module-name down-cast]) + ?up-cast (macro;find-macro [this-module-name up-cast])] + (case [?down-cast ?up-cast] + [(#;Some _) (#;Some _)] + (do @ + [_ (un-install-casts' this-module-name)] + (wrap (list))) + + _ + (macro;fail (format "Cannot un-define casting functions (" + down-cast " & " up-cast + ") because they do not exist."))))) + +(def: declaration + (s;Syntax [Text (List Text)]) + (p;either (s;form (p;seq s;local-symbol (p;some s;local-symbol))) + (p;seq s;local-symbol (::: wrap (list))))) + +(syntax: #export (model: [export csr;export] + [[name type-vars] declaration] + [annotations (p;default cs;empty-annotations csr;annotations)] + representation-type + [primitives (p;some s;any)]) + (let [hidden-name (code;local-symbol (representation-name name)) + type-varsC (L/map code;local-symbol type-vars) + model-declaration (` ((~ (code;local-symbol name)) (~@ type-varsC))) + representation-declaration (` ((~ hidden-name) (~@ type-varsC))) + conversion-functions (: (List Code) + (if (list;empty? type-vars) + (list) + (let [export' (case export + #;None #;None + (#;Some _) (#;Some #cs;Hidden))] + (list (` (def: (~@ (csw;export export')) + (~ (code;local-symbol (down-cast-name name))) + (All [(~@ type-varsC)] + (-> (~ representation-declaration) (~ model-declaration))) + (|>. :!!))) + (` (def: (~@ (csw;export export')) + (~ (code;local-symbol (up-cast-name name))) + (All [(~@ type-varsC)] + (-> (~ model-declaration) (~ representation-declaration))) + (|>. :!!)))))))] + (wrap (list& (` (type: (~@ (csw;export export)) (~ model-declaration) + (host (~ hidden-name)))) + (` (type: (~@ (csw;export export)) (~ representation-declaration) + (~ representation-type))) + ($_ L/append + conversion-functions + (list (` (install-casts (~ (code;local-symbol name)) [(~@ type-varsC)]))) + primitives + (list (` (un-install-casts)))))))) |