the `isone` predicate throws instead of returning `false`

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#310 opened on Feb 28, 2025 1 comment 0 reactions 0 assignees View on GitHub

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Assessment

Difficulty: 2/5
Estimated time: 1-3 hours
Newbie friendliness: 76/100

Issue type: Bug
Clarity: Clearly specified
Activity status: Active
Tech stack: julia
Domain: backend

Research direction

Start with the rawone and oneunit paths in src/fixed.jl and src/FixedPointNumbers.jl, then rerun the Julia 1.11.3 reproduction from the issue. Verify the isone(0.0Q0f15) behavior against the reported expectation. Done means the predicate returns false instead of throwing an ArgumentError.

Written by the indexing model from the issue text.

Description

julia> using FixedPointNumbers

julia> isone(0.0Q0f15)
ERROR: ArgumentError: Q0f15 is a 16-bit type representing 65536 values from -1.0 to 0.99997; cannot represent 1
Stacktrace:
 [1] throw_converterror(::Type{Q0f15}, x::Int64)
   @ FixedPointNumbers ~/.julia/packages/FixedPointNumbers/Dn4hv/src/FixedPointNumbers.jl:326
 [2] rawone(::Type{Q0f15})
   @ FixedPointNumbers ~/.julia/packages/FixedPointNumbers/Dn4hv/src/fixed.jl:41
 [3] oneunit(::Type{Q0f15})
   @ FixedPointNumbers ~/.julia/packages/FixedPointNumbers/Dn4hv/src/FixedPointNumbers.jl:108
 [4] one(::Type{Q0f15})
   @ FixedPointNumbers ~/.julia/packages/FixedPointNumbers/Dn4hv/src/FixedPointNumbers.jl:109
 [5] one(x::Q0f15)
   @ FixedPointNumbers ~/.julia/packages/FixedPointNumbers/Dn4hv/src/FixedPointNumbers.jl:222
 [6] isone(x::Q0f15)
   @ Base ./number.jl:62
 [7] top-level scope
   @ REPL[2]:1

julia> versioninfo()
Julia Version 1.11.3
Commit d63adeda50d (2025-01-21 19:42 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 8 × AMD Ryzen 3 5300U with Radeon Graphics
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, znver2)
Threads: 1 default, 0 interactive, 1 GC (on 8 virtual cores)
Environment:
  JULIA_NUM_PRECOMPILE_TASKS = 4
  JULIA_PKG_PRECOMPILE_AUTO = 0

(@v1.11) pkg> st FixedPointNumbers
Status `~/.julia/environments/v1.11/Project.toml`
  [53c48c17] FixedPointNumbers v0.8.5

Dominant language: Julia
Stars: 95
Forks: 38
Avg merge: 13m
Merged PRs (30d): 2

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