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| author | dos-reis <gdr@axiomatics.org> | 2009-01-10 00:08:55 +0000 |
|---|---|---|
| committer | dos-reis <gdr@axiomatics.org> | 2009-01-10 00:08:55 +0000 |
| commit | 447540cef1c15768e7aa15679696ed4dd7b2d151 (patch) | |
| tree | 87b375611247b357f133cd934d7a4a510acc10d2 /src/interp/compiler.boot | |
| parent | 5810cb6f263679851a135691a7ee483fda959472 (diff) | |
| download | open-axiom-447540cef1c15768e7aa15679696ed4dd7b2d151.tar.gz | |
* interp/compiler.boot (compPredicate): Rename from compBoolean.
Lose second argument. Document.
Diffstat (limited to 'src/interp/compiler.boot')
| -rw-r--r-- | src/interp/compiler.boot | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/src/interp/compiler.boot b/src/interp/compiler.boot index ad1392fe..72baf917 100644 --- a/src/interp/compiler.boot +++ b/src/interp/compiler.boot @@ -1145,11 +1145,11 @@ compHasFormat (pred is ["has",olda,b]) == --% IF compIf: (%Form,%Mode,%Env) -> %Maybe %Triple -compBoolean: (%Form,%Mode,%Env) -> %List +compPredicate: (%Form,%Env) -> %List compFromIf: (%Form,%Mode,%Env) -> %Maybe %Triple compIf(["IF",a,b,c],m,E) == - [xa,ma,Ea,Einv]:= compBoolean(a,$Boolean,E) or return nil + [xa,ma,Ea,Einv]:= compPredicate(a,E) or return nil [xb,mb,Eb]:= Tb:= compFromIf(b,m,Ea) or return nil [xc,mc,Ec]:= Tc:= compFromIf(c,resolve(mb,m),Einv) or return nil xb':= coerce(Tb,mc) or return nil @@ -1199,8 +1199,19 @@ canReturn(expr,level,exitCount,ValueFlag) == --SPAD: exit and friends and/[canReturn(u,level,exitCount,ValueFlag) for u in expr] systemErrorHere ['"canReturn",expr] --for the time being -compBoolean(p,m,E) == - [p',m,E]:= comp(p,m,E) or return nil +++ We are compiling a conditional expression, type check and generate +++ code for the predicate of the branch as a Boolean expression. +compPredicate(p,E) == + -- Ideally, we should be first inferring the type of the predicate + -- `p'. That would have the virtue of pointing out possible + -- ambiguities. Then, on a second phase, implicitly coerce the + -- the result to Boolean. However, that would not quite work. The + -- being that there are cases, such as equality, that are highgly + -- ambiguous (e.g. see the various overloading of `=') for which it + -- would be unfortunate to require more type annotation. Note that + -- the problem here is many misguided overloading of some operators. + -- Consequently, we compile directly with Boolean as target. + [p',m,E] := comp(p,$Boolean,E) or return nil [p',m,getSuccessEnvironment(p,E),getInverseEnvironment(p,E)] getSuccessEnvironment(a,e) == @@ -1812,7 +1823,7 @@ compRetractAlternative(x,t,stmt,m,s,T) == -- 1.1. Try courtesy coercions first. That way we can use -- optimized versions where available. That also -- makes the scheme work for untagged unions. - if testT := compBoolean(["case",y,t],$Boolean,e) then + if testT := compPredicate(["case",y,t],e) then [caseCode,.,e,envFalse] := testT [restrictCode,.,e] := tryCourtesyCoercion([y,T.mode,e],t) or |