diff options
Diffstat (limited to 'spec/evaluate.md')
| -rw-r--r-- | spec/evaluate.md | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/spec/evaluate.md b/spec/evaluate.md index a1c4ef43..c991e3c6 100644 --- a/spec/evaluate.md +++ b/spec/evaluate.md @@ -49,12 +49,10 @@ In each case the constituent expressions are evaluated in reverse source order: Modifiers that are evaluated when they receive operands are called *immediate*. Other modifiers, including primitives and some kinds of block, simply record the operands and are called *deferred*. The result of applying a deferred modifier once is called a *derived function*. -The following rules always create *derived operations*, either 1-modifiers or derived functions. A derived operation is identified by the rule that created it, and the values of its parts. +The rules for trains create another kind of derived function. A derived function is identified by the rule that created it, and the values of its parts. | Left | Center | Right | Result |------------|-----------|-----------------------|-------------- -| | `_mod2_` | `( subject \| Func )` | `{š½ _C_ R}` -| `Operand` | `_mod2_` | | `{L _C_ š½}` | `Operand` | `Derv` | `Fork` | `{(šØLš©)C(šØRš©)}` | `nothing?` | `Derv` | `Fork` | `{ C(šØRš©)}` -As with applications, all expressions are evaluated in reverse source order before doing anything else. Then a result is formed without calling the center value. Its behavior as a function is described in the rightmost column, using `L`, `C`, and `R` for the results of the expressions in the left, center, and right columns, respectively. For the first two rules (*partial application*), the given operand is bound to the 2-modifier: the result is a 1-modifier that, when called, calls the center 2-modifier with the bound operand on the same side it appeared on and the new operand on the remaining side. A *train* is a function that, when called, calls the right-hand function on all arguments, then the left-hand function, and calls the center function with these results as arguments. +A *train* is a function that, when called, calls the right-hand function on all arguments, then the left-hand function, and calls the center function with these results as arguments. As with applications, all expressions are evaluated in reverse source order before doing anything else. Then a result is formed without calling the center value. Its behavior as a function is described in the rightmost column, using `L`, `C`, and `R` for the results of the expressions in the left, center, and right columns, respectively. |