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authorMarshall Lochbaum <mwlochbaum@gmail.com>2021-11-29 20:55:22 -0500
committerMarshall Lochbaum <mwlochbaum@gmail.com>2021-11-29 20:55:22 -0500
commitfb3580660898306105c2e1f041f29bbdb9006210 (patch)
treeb704efe38eb38c0ebfdc3c7cbb8a37eba52be953 /spec/evaluate.md
parenta7148422c8f4a69134263b4d37d05499996aaa7c (diff)
Remove return (→) from the spec
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1 files changed, 1 insertions, 3 deletions
diff --git a/spec/evaluate.md b/spec/evaluate.md
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@@ -6,7 +6,7 @@ This page describes the semantics of the code constructs whose grammar is given
Here we assume that the referent of each identifier, or equivalently the connections between identifiers, have been identified according to the [scoping rules](scope.md).
-Evaluation is an ordered process, and any actions required to evaluate a node always have a specified order unless performing them in any order would have the same effect. Side effects that are relevant to ordering are setting and getting the value of a variable, causing an error, and returning (with `→`) from a block. Errors described in this page are "evaluation errors" and can be caught by the Catch (`⎊`) modifier. For caught errors and returns, evaluation halts without attempting to complete any in-progress node, and is restarted by Catch (for errors) or at the end of the appropriate block evaluation (for returns).
+Evaluation is an ordered process, and any actions required to evaluate a node always have a specified order unless performing them in any order would have the same effect. Side effects that are relevant to ordering are setting and getting the value of a variable, and causing an error. Errors described in this page are "evaluation errors" and can be caught by the Catch (`⎊`) modifier. If caught, evaluation halts without attempting to complete any in-progress node, and is restarted by Catch.
As specified, BQN programs can involve an arbitrary amount of information, but when run there will be memory and possibly other limitations. To accommodate this, any part of evaluation can cause an error, if a resource such as memory, stack memory, or limited execution time is exhausted.
@@ -38,8 +38,6 @@ The right-hand-side value, here called `v`, in destructuring assignment must be
We now give rules for evaluating an `atom`, `Func`, `_mod1` or `_mod2_` expression (the possible options for `ANY`). A literal or primitive `sl`, `Fl`, `_ml`, or `_cl_` has a fixed value defined by the specification ([literals](literal.md) and [built-ins](primitive.md)). An identifier `s`, `F`, `_m`, or `_c_`, if not preceded by `atom "."`, must have an associated variable due to the scoping rules, and returns this variable's value, or causes an error if it has not yet been set. If it is preceded by `atom "."`, then the `atom` node is evaluated first; its value must be a namespace, and the result is the value of the identifier's name in the namespace, or an error if the name is undefined. A parenthesized expression such as `"(" _modExpr ")"` simply returns the result of the interior expression. A braced construct such as `BraceFunc` is defined by the evaluation of the statements it contains after all parameters are accepted. Finally, a list `"⟨" ⋄? ( ( EXPR ⋄ )* EXPR ⋄? )? "⟩"` or `ANY ( "‿" ANY )+` consists grammatically of a list of expressions. To evaluate it, each expression is evaluated in source order and their results are placed as elements of a rank-1 array. The two forms have identical semantics but different punctuation.
-A `Return` node creates a return function. As [discussed](scope.md#returns) in the scoping rules, its identifier indicates a namespace from a particular block evaluation. When called, the function causes an error if that block has finished execution, or if the call includes a left argument `𝕨`. Otherwise, evaluation stops immediately, and resumes at the end of the block where it returns the right argument `𝕩` from that block.
-
Rules in the table below are function and modifier evaluation.
| L | Left | Called | Right | R | Types
|-----|---------------------------|----------|-----------------------|-----|-----------