Class IRRewriter

java.lang.Object

org.ek9lang.compiler.ir.support.IRRewriter

public final class IRRewriter
extends Object

THE IR rewriter: rebuilds an instruction list bottom-up. Every composite is rebuilt with its rewritten nested lists (CompositeInstr.withNestedLists(UnaryOperator)), then every instruction - composite or not - is given to the rewrite, which returns what replaces it (itself, nothing, or several). Instructions are immutable, so this is how any pass changes IR: the ownership lowering now, the IR_OPTIMISATION passes later. Nothing unchanged is copied: an untouched list comes back as the same list.

Method Summary

Modifier and Type	Method	Description
static List<IRInstr>	rewrite(List<IRInstr> instructions, Function<IRInstr, List<IRInstr>> rewrite)	Rewrite an instruction list; the same list when nothing in it (at any depth) changed.
static void	rewrite(OperationInstr operation, Function<IRInstr, List<IRInstr>> rewrite)	Rewrite an operation's body in place (the operation takes the rebuilt body, or keeps its own when nothing changed).
static List<IRInstr>	rewriteLists(List<IRInstr> instructions, UnaryOperator<List<IRInstr>> listRewrite)	Rewrite a list and every list nested in it, bottom-up; listRewrite returns its argument unchanged (the same list) when it changes nothing.
static void	rewriteLists(OperationInstr operation, UnaryOperator<List<IRInstr>> listRewrite)	Rewrite an operation's body list by list: every nested list first (bottom-up), then the list that holds it.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

rewrite

public static void rewrite(OperationInstr operation,
 Function<IRInstr, List<IRInstr>> rewrite)

Rewrite an operation's body in place (the operation takes the rebuilt body, or keeps its own when nothing changed).

rewrite

public static List<IRInstr> rewrite(List<IRInstr> instructions,
 Function<IRInstr, List<IRInstr>> rewrite)

Rewrite an instruction list; the same list when nothing in it (at any depth) changed.

rewriteLists

public static void rewriteLists(OperationInstr operation,
 UnaryOperator<List<IRInstr>> listRewrite)

Rewrite an operation's body list by list: every nested list first (bottom-up), then the list that holds it. For a pass that needs to see a whole list at once - one instruction's replacement depending on what follows it in the same list.

rewriteLists

public static List<IRInstr> rewriteLists(List<IRInstr> instructions,
 UnaryOperator<List<IRInstr>> listRewrite)

Rewrite a list and every list nested in it, bottom-up; listRewrite returns its argument unchanged (the same list) when it changes nothing.