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rewrote whileTrue:, whileFalse:, and similar methods for BlockContext in an imperative style

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hyunghwan.chung
2017-02-02 04:46:29 +00:00
parent 07d8d0ea83
commit 5c755d68f5
2 changed files with 84 additions and 56 deletions
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136
moo/kernel/Context.moo
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@ -167,108 +167,136 @@ class(#pointer) BlockContext(Context)
method ifTrue: aBlock method ifTrue: aBlock
{ {
^(self value) ifTrue: aBlock. ##^(self value) ifTrue: aBlock.
^if (self value) { aBlock value }.
} }
method ifFalse: aBlock method ifFalse: aBlock
{ {
^(self value) ifFalse: aBlock. ##^(self value) ifFalse: aBlock.
^if (self value) { (* nothing *) } else { aBlock value }.
} }
method ifTrue: trueBlock ifFalse: falseBlock method ifTrue: trueBlock ifFalse: falseBlock
{ {
^(self value) ifTrue: trueBlock ifFalse: falseBlock ##^(self value) ifTrue: trueBlock ifFalse: falseBlock
^if (self value) { trueBlock value } else { falseBlock value }.
} }
method whileTrue: aBlock method whileTrue: aBlock
{ {
## -------------------------------------------------- (* --------------------------------------------------
## Naive implementation * Naive recursive implementation
## -------------------------------------------------- * --------------------------------------------------
## (self value) ifFalse: [^nil]. (self value) ifFalse: [^nil].
## aBlock value. aBlock value.
## self whileTrue: aBlock. self whileTrue: aBlock.
## -------------------------------------------------- * -------------------------------------------------- *)
## -------------------------------------------------- (* --------------------------------------------------
## Non-recursive implementation * Non-recursive implementation
## -------------------------------------------------- * --------------------------------------------------
| pc sp | | pc sp |
pc := thisContext pcplus1. pc := thisContext pcplus1.
(self value) ifFalse: [ ^nil ]. (self value) ifFalse: [ ^nil ].
aBlock value. aBlock value.
## the pc: method leaves thisContext and pc in the stack after * the pc: method leaves thisContext and pc in the stack after
## having changes the instruction poointer. * having changes the instruction poointer.
## as a result, the stack keeps growing. the goto method * as a result, the stack keeps growing. the goto method
## clears thisContext and pc off the stack unlike normal methods. * clears thisContext and pc off the stack unlike normal methods.
##thisContext pc: pc. * thisContext pc: pc.
thisContext goto: pc. thisContext goto: pc.
## -------------------------------------------------- * -------------------------------------------------- *(
(* --------------------------------------------------
* Imperative implementation - == true or ~~ false? match the VM implementation
* -------------------------------------------------- *)
while ((self value) ~~ false) { aBlock value }.
} }
method whileTrue method whileTrue
{ {
## (self value) ifFalse: [^nil]. (* --------------------------------------------------
## self whileTrue. * Naive recursive implementation
* --------------------------------------------------
(self value) ifFalse: [^nil].
self whileTrue.
* -------------------------------------------------- */
## -------------------------------------------------- (* --------------------------------------------------
## Non-recursive implementation * Non-recursive implementation
## -------------------------------------------------- * --------------------------------------------------
| pc | | pc |
pc := thisContext pcplus1. pc := thisContext pcplus1.
(self value) ifFalse: [ ^nil ]. (self value) ifFalse: [ ^nil ].
thisContext goto: pc. thisContext goto: pc.
## -------------------------------------------------- * -------------------------------------------------- */
(* --------------------------------------------------
* Imperative implementation
* -------------------------------------------------- *)
while ((self value) ~~ false) { }.
} }
method whileFalse: aBlock method whileFalse: aBlock
{ {
## -------------------------------------------------- (* --------------------------------------------------
## Naive implementation * Naive recursive implementation
## -------------------------------------------------- * --------------------------------------------------
## (self value) ifTrue: [^nil]. (self value) ifTrue: [^nil].
## aBlock value. aBlock value.
## self whileFalse: aBlock. self whileFalse: aBlock.
## -------------------------------------------------- * -------------------------------------------------- *)
## -------------------------------------------------- (* --------------------------------------------------
## Non-recursive implementation * Non-recursive implementation
## -------------------------------------------------- * --------------------------------------------------
## The assignment to 'pc' uses the POP_INTO_TEMPVAR_1. * The assignment to 'pc' uses the POP_INTO_TEMPVAR_1.
## It pops a value off the stack top, stores it to the second * It pops a value off the stack top, stores it to the second
## temporary variable(aBlock is the first temporary variable). * temporary variable(aBlock is the first temporary variable).
## It is a single byte instruction. 'pc' returned by * It is a single byte instruction. 'pc' returned by
## 'thisContext pcplus1'' should point to the instruction after * 'thisContext pcplus1'' should point to the instruction after
## the POP_INTO_TEMPVAR_0 instruction. * the POP_INTO_TEMPVAR_0 instruction.
## *
## It would need the increment of 2 if the pair of * It would need the increment of 2 if the pair of
## STORE_INTO_TEMPVAR_1 and POP_STACKTOP were used. * STORE_INTO_TEMPVAR_1 and POP_STACKTOP were used.
## This implementation is subject to the instructions chosen * This implementation is subject to the instructions chosen
## by the compiler. * by the compiler.
## * --------------------------------------------------
| pc | | pc |
pc := thisContext pcplus1. pc := thisContext pcplus1.
(self value) ifTrue: [ ^nil "^self" ]. (self value) ifTrue: [ ^nil "^self" ].
aBlock value. aBlock value.
thisContext goto: pc. thisContext goto: pc.
## -------------------------------------------------- * -------------------------------------------------- *)
(* --------------------------------------------------
* Imperative implementation
* -------------------------------------------------- *)
while ((self value) == false) { aBlock value }.
} }
method whileFalse method whileFalse
{ {
## (self value) ifTrue: [^nil]. (* --------------------------------------------------
## self whileFalse. * Naive recursive implementation
* --------------------------------------------------
(self value) ifTrue: [^nil].
self whileFalse.
* -------------------------------------------------- *)
## -------------------------------------------------- (* --------------------------------------------------
## Non-recursive implementation * Non-recursive implementation
## -------------------------------------------------- * --------------------------------------------------
| pc | | pc |
pc := thisContext pcplus1. pc := thisContext pcplus1.
(self value) ifTrue: [ ^nil "^self" ]. (self value) ifTrue: [ ^nil "^self" ].
thisContext goto: pc. thisContext goto: pc.
## -------------------------------------------------- * -------------------------------------------------- *)
while ((self value) == false) { }.
} }
method pc method pc