diff options
Diffstat (limited to 'src/interp/compiler.boot')
| -rw-r--r-- | src/interp/compiler.boot | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/src/interp/compiler.boot b/src/interp/compiler.boot index 2eb63a11..13cb5951 100644 --- a/src/interp/compiler.boot +++ b/src/interp/compiler.boot @@ -397,6 +397,8 @@ transImplementation(op,map,fn) == ["call",fn] compAtom(x,m,e) == + x = "break" => compBreak(x,m,e) + x = "iterate" => compIterate(x,m,e) T:= compAtomWithModemap(x,m,e,get(x,"modemap",e)) => T x="nil" => T:= @@ -1085,6 +1087,31 @@ compLeave(["leave",level,x],m,e) == modifyModeStack(m',index) [["TAGGEDexit",index,u],m,e] +jumpFromLoop(kind,key) == + null $exitModeStack or kind ^= $loopKind => + stackAndThrow('"You can use %1b only in %2b loop",[key,kind]) + false + true + +compBreak: (%Symbol,%Mode,%Env) -> %Maybe %Triple +compBreak(x,m,e) == + x ^= "break" or not jumpFromLoop("REPEAT",x) => nil + index:= #$exitModeStack-1-$leaveLevelStack.0 + $breakCount := $breakCount + 1 + u := coerce(["$NoValue",$Void,e],$exitModeStack.index) or return nil + u := coerce(u,m) or return nil + modifyModeStack(u.mode,index) + [["TAGGEDexit",index,u],m,e] + +compIterate: (%Symbol,%Mode,%Env) -> %Maybe %Triple +compIterate(x,m,e) == + x ^= "iterate" or not jumpFromLoop("REPEAT",x) => nil + $iterateCount := $iterateCount + 1 + -- We don't really produce a value; but we cannot adequately convey + -- that to the current 'EXIT' structure. So, pretend we have an + -- undefined value, which is a good enough approximation. + [["THROW","$loopBodyTag",nil],m,e] + --% return compReturn: (%Form,%Mode,%Env) -> %Maybe %Triple @@ -2272,6 +2299,9 @@ compRepeatOrCollect(form,m,e) == ,e) where fn(form,$exitModeStack,$leaveLevelStack,$formalArgList,e) == $until: local := nil + $loopKind: local := nil + $iterateCount: local := 0 + $breakCount: local := 0 oldEnv := e aggr := nil [repeatOrCollect,:itl,body]:= form @@ -2293,9 +2323,15 @@ compRepeatOrCollect(form,m,e) == return nil -- If we're doing a collect, and the type isn't conformable -- then we've boobed. JHD 26.July.1990 + -- ??? we hve a plain old loop; the return type should be Void + $loopKind := repeatOrCollect $NoValueMode [body',m',e']:= compOrCroak(body,bodyMode,e) or return nil + -- Massage the loop body if we have a structured jump. + if $iterateCount > 0 then + bodyTag := quoteForm GENSYM() + body' := ["CATCH",bodyTag,NSUBST(bodyTag,"$loopBodyTag",body')] if $until then [untilCode,.,e']:= comp($until,$Boolean,e') itl':= substitute(["UNTIL",untilCode],'$until,itl') |