[GHC] #10854: Remove recursive uses of `pprParendHsExpr` from `HsExpr.ppr_expr`
#10854: Remove recursive uses of `pprParendHsExpr` from `HsExpr.ppr_expr` -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: newcomer | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- An `HsExpr` should look exactly as a user wrote some Haskell code. Its pretty printer should therefore be quite dumb. Just print out the code! But a few places in GHC create `HsExpr`s and aren't scrupulous with regard to adding `HsPar` nodes where source syntax would need them. Thus, well- meaning souls have added `pprParendExpr` calls to the `HsExpr` pretty- printer to try to cover these cases. Simon and I [https://phabricator.haskell.org/D1219#34199 think] that we should remove all recursive uses of `pprParendExpr` from the `HsExpr` pretty-printer and instead add the `HsPar`s where necessary. It was recently reported that the following test cases break when simply removing `pprParendExpr`: {{{ Unexpected failures: deriving/should_fail T4846 [stderr mismatch] (normal) generics GenDerivOutput [stderr mismatch] (normal) generics GenDerivOutput1_0 [stderr mismatch] (normal) generics GenDerivOutput1_1 [stderr mismatch] (normal) ghci/scripts T10248 [bad stderr] (ghci) indexed-types/should_compile PushedInAsGivens [stderr mismatch] (normal) safeHaskell/safeLanguage SafeLang10 [stderr mismatch] (normal) safeHaskell/safeLanguage SafeLang17 [stderr mismatch] (normal) typecheck/should_fail T8603 [stderr mismatch] (normal) typecheck/should_fail tcfail177 [stderr mismatch] (normal) }}} See also considerable commentary on Phab:D1114. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10854 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10854: Remove recursive uses of `pprParendHsExpr` from `HsExpr.ppr_expr` -------------------------------------+------------------------------------- Reporter: goldfire | Owner: kseo Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by kseo): * owner: => kseo -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10854#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10854: Remove recursive uses of `pprParendHsExpr` from `HsExpr.ppr_expr` -------------------------------------+------------------------------------- Reporter: goldfire | Owner: kseo Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * cc: alanz (added) Comment: Adding alanz who has done some work in this area. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10854#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10854: Remove recursive uses of `pprParendHsExpr` from `HsExpr.ppr_expr` -------------------------------------+------------------------------------- Reporter: goldfire | Owner: kseo Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13238 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by alanz): * related: => #13238 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10854#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10854: Remove recursive uses of `pprParendHsExpr` from `HsExpr.ppr_expr` -------------------------------------+------------------------------------- Reporter: goldfire | Owner: kseo Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13238 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by sjakobi): * cc: sjakobi (added) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10854#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10854: Remove recursive uses of `pprParendHsExpr` from `HsExpr.ppr_expr` -------------------------------------+------------------------------------- Reporter: goldfire | Owner: kseo Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13238 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by monoidal): It seems to me that Phab:D3043 has completed this. Can this ticket be closed, or is there something remaining? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10854#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#10854: Remove recursive uses of `pprParendHsExpr` from `HsExpr.ppr_expr` -------------------------------------+------------------------------------- Reporter: goldfire | Owner: kseo Type: task | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: newcomer Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #13238 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Strictly speaking, I don't think this ticket's goal has been achieved yet, since it's possible to find recursive occurrences of `pprDebugParendExpr` (i.e., [http://git.haskell.org/ghc.git/blob/eb46345d37ee61575e6fed04da718c1b7ee0bb99... here]), which is just a thin wrapper around `pprParendExpr`. But then again, I am not the person who originally opened this ticket, so all I can offer is speculation. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10854#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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