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| author | s-ol <s-ol@users.noreply.github.com> | 2020-08-21 13:50:59 +0000 |
|---|---|---|
| committer | s-ol <s+removethis@s-ol.nu> | 2025-03-02 14:24:49 +0000 |
| commit | 8e425d8aee01ce49d263ce401b46b83ef1a246e8 (patch) | |
| tree | 54649c182d826d816f8dae1b86bb1e1e65566645 | |
| parent | move struct ops into library (diff) | |
| download | alive-8e425d8aee01ce49d263ce401b46b83ef1a246e8.tar.gz alive-8e425d8aee01ce49d263ce401b46b83ef1a246e8.zip | |
fix if, add when
| -rw-r--r-- | alv/builtins.moon | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/alv/builtins.moon b/alv/builtins.moon index a0a319a..8a08705 100644 --- a/alv/builtins.moon +++ b/alv/builtins.moon @@ -239,7 +239,7 @@ function is invoked." scope\set name, RTNode :result super RTNode! -do_expr = Constant.meta +do_ = Constant.meta meta: name: 'do' summary: "Evaluate multiple expressions in a new scope." @@ -278,7 +278,7 @@ to `then-expr`, otherwise it is equivalent to `else-xpr` if given, or nil otherw if not xif\is_const! msg = "'if'-expression needs to be constant, did you mean 'switch'?" error Error 'argument', msg - xif = xif\result!\unwrap! + xif = xif.result\unwrap! super if xif xthen\eval scope @@ -287,6 +287,37 @@ to `then-expr`, otherwise it is equivalent to `else-xpr` if given, or nil otherw else RTNode! +when_ = Constant.meta + meta: + name: 'when' + summary: "Make an evaltime const choice with side effects" + examples: { '(when bool then-exprs…)' } + description: " +`bool` has to be an evaltime constant. If it is truthy, this expression is equivalent +to `(do then-exprs…)`, otherwise it results in nil." + + value: class extends Builtin + eval: (scope, tail) => + L\trace "evaling #{@}" + assert #tail >= 2, "'when' needs at least two parameters" + + xif = L\push tail[1]\eval, scope + if not xif\is_const! + msg = "'when'-expression needs to be constant, did you mean 'switch'?" + error Error 'argument', msg + xif = xif.result\unwrap! + + super if xif + scope = Scope scope + children = [expr\eval scope for expr in *tail[2,]] + result = if last = children[#children] then last.result + if result and result.metatype == '=' + result = result.type\mk_sig result\unwrap! + + RTNode :children, :result + else + RTNode! + switch_ = Constant.meta meta: name: 'switch' @@ -596,8 +627,9 @@ Scope.from_table { 'export*': export_star :fn, :defn - 'do': do_expr + 'do': do_ 'if': if_ + 'when': when_ 'switch': switch_ '=': to_const |