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RequirementMachine: Rename RewriteStep::AdjustConcreteType to ::PrefixSubstitutions

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This commit is contained in:
Slava Pestov
2022-02-03 15:01:26 -05:00
parent 7464a5f139
commit d8aa79c5e5
7 changed files with 47 additions and 42 deletions
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18
lib/AST/RequirementMachine/PropertyUnification.cpp
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@@ -586,28 +586,30 @@ void PropertyMap::addConcreteTypeProperty(
//
// U.V.[concrete: G<...> with <U.X, U.Y>]
//
// Record a loop relating the two rules via a concrete type adjustment.
// Record a loop relating the two rules via a rewrite step to prefix 'U' to
// the symbol's substitutions.
//
// Since the new rule appears without context, it becomes redundant.
if (checkRulePairOnce(*props->ConcreteTypeRule, ruleID)) {
const auto &otherRule = System.getRule(*props->ConcreteTypeRule);
assert(otherRule.getRHS().size() < key.size());
unsigned adjustment = (key.size() - otherRule.getRHS().size());
unsigned prefixLength = (key.size() - otherRule.getRHS().size());
// Build a loop that rewrites U.V back into itself via the two rules,
// with a concrete type adjustment in the middle.
// with a prefix substitutions step in the middle.
RewritePath path;
// Add a rewrite step U.(V => V.[concrete: G<...> with <X, Y>]).
path.add(RewriteStep::forRewriteRule(/*startOffset=*/adjustment,
path.add(RewriteStep::forRewriteRule(/*startOffset=*/prefixLength,
/*endOffset=*/0,
*props->ConcreteTypeRule,
/*inverse=*/true));
// Add a concrete type adjustment.
path.add(RewriteStep::forAdjustment(/*startOffset=*/adjustment,
/*endOffset=*/0,
/*inverse=*/false));
// Add a rewrite step to prefix 'U' to the substitutions.
path.add(RewriteStep::forPrefixSubstitutions(/*length=*/prefixLength,
/*endOffset=*/0,
/*inverse=*/false));
// Add a rewrite step (U.V.[concrete: G<...> with <U.X, U.Y>] => U.V).
path.add(RewriteStep::forRewriteRule(/*startOffset=*/0,