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Tweak: execution instead of evaluation

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Tony Garnock-Jones 2022-02-25 14:49:24 +01:00
parent f11cacf513
commit 808b991a35
1 changed files with 9 additions and 9 deletions
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18
src/operation/scripting.md
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@ -120,7 +120,7 @@ the contents of a variable, use the `+=` form of *AssertionInstruction*.
    `<`*ValueExpr*` `*ValueExpr*...`>` |     `<`*ValueExpr*` `*ValueExpr*...`>` |
    `{`*ValueExpr*`:`*ValueExpr*` `...`}`     `{`*ValueExpr*`:`*ValueExpr*` `...`}`
The most general form of *AssertionInstruction* is "`+= `*ValueExpr*". When evaluated, the The most general form of *AssertionInstruction* is "`+= `*ValueExpr*". When executed, the
result of evaluating *ValueExpr* will be published (asserted) at the entity denoted by the result of evaluating *ValueExpr* will be published (asserted) at the entity denoted by the
active target register. active target register.
@ -131,7 +131,7 @@ As a convenient shorthand, the compiler also interprets every Preserves record o
*SendInstruction* = `! `*ValueExpr* *SendInstruction* = `! `*ValueExpr*
When evaluated, the result of evaluating *ValueExpr* will be sent as a message to the entity When executed, the result of evaluating *ValueExpr* will be sent as a message to the entity
denoted by the active target register. denoted by the active target register.
### Reacting to events ### Reacting to events
@ -183,10 +183,10 @@ facet terminates, *Instruction* is run.
    *ValueExpr*     *ValueExpr*
Values can be destructured and new variables introduced into the environment with `let`, which Values can be destructured and new variables introduced into the environment with `let`, which
is a "destructuring bind" or "pattern-match definition" statement. When evaluated, the result is a "destructuring bind" or "pattern-match definition" statement. When executed, the result of
of evaluating *ConvenienceExpr* is matched against the result of evaluating *PatternExpr*. If evaluating *ConvenienceExpr* is matched against the result of evaluating *PatternExpr*. If the
the match fails, the actor crashes. If the match succeeds, the resulting binding variables (if match fails, the actor crashes. If the match succeeds, the resulting binding variables (if any)
any) are introduced into the environment. are introduced into the environment.
The right-hand-side of a `let`, after the equals sign, is either a normal *ValueExpr* or one of The right-hand-side of a `let`, after the equals sign, is either a normal *ValueExpr* or one of
the following special "convenience" expressions: the following special "convenience" expressions:
@ -200,15 +200,15 @@ the following special "convenience" expressions:
`stop` to the entity (using e.g. the *SendInstruction* "`! stop`") triggers termination of `stop` to the entity (using e.g. the *SendInstruction* "`! stop`") triggers termination of
its associated facet. The entity does not respond to any other assertion or message. its associated facet. The entity does not respond to any other assertion or message.
### Conditional evaluation ### Conditional execution
*ConditionalInstruction* = `$`*var*` =~ `*PatternExpr*` `*Instruction*` `*Instruction* ... *ConditionalInstruction* = `$`*var*` =~ `*PatternExpr*` `*Instruction*` `*Instruction* ...
When evaluated, the value in variable *var* is matched against the result of evaluating When executed, the value in variable *var* is matched against the result of evaluating
*PatternExpr*. *PatternExpr*.
- If the match succeeds, the resulting bound variables are placed in the environment and - If the match succeeds, the resulting bound variables are placed in the environment and
evaluation continues with the first *Instruction*. The subsequent *Instruction*s are not execution continues with the first *Instruction*. The subsequent *Instruction*s are not
executed in this case. executed in this case.
- If the match fails, then the first *Instruction* is skipped, and the subsequent - If the match fails, then the first *Instruction* is skipped, and the subsequent