make --version printing compatible with juliac (#103)

src/juliac.jl

@@ -70,6 +70,25 @@ function sprint_showerror_juliac(err::Exception)
     end
 end
 
+# juliac-compatible print(::IO, ::VersionNumber) with explicitly `@inline`d `join` calls...
+function print_vnum_juliac(io::IO, v::VersionNumber)
+    v == typemax(VersionNumber) && return print(io, "∞")
+    print(io, v.major)
+    print(io, '.')
+    print(io, v.minor)
+    print(io, '.')
+    print(io, v.patch)
+    if !isempty(v.prerelease)
+        print(io, '-')
+        @inline join(io, v.prerelease, '.')
+    end
+    if !isempty(v.build)
+        print(io, '+')
+        @inline join(io, v.build, '.')
+    end
+    return
+end
+
 # juliac-compatible `Base.tempdir` and `Base.mktempdir` without logging and deferred cleanup
 function tempdir_juliac()
     buf = Base.StringVector(Base.Filesystem.AVG_PATH - 1)

src/main.jl

@@ -16,6 +16,7 @@ const juliac = @load_preference("juliac", false)
     const printstyled = printstyled_juliac
     const mktempdir = mktempdir_juliac
     const sprint_showerror = sprint_showerror_juliac
+    const print_vnum = print_vnum_juliac
 else
     # const stdin = Base.stdin
     # const stdout = Base.stdout
@@ -24,6 +25,7 @@ else
     const printstyled = Base.printstyled
     const mktempdir = Base.mktempdir
     sprint_showerror(err::Exception) = sprint(showerror, err)
+    const print_vnum = Base.print
 end
 
 supports_color(io) = get(io, :color, false)
@@ -149,7 +151,11 @@ function print_help()
 end
 
 function print_version()
-    println(stdout, "runic version $(RUNIC_VERSION), julia version $(VERSION)")
+    print(stdout, "runic version ")
+    print_vnum(stdout, RUNIC_VERSION)
+    print(stdout, ", julia version ")
+    print_vnum(stdout, VERSION)
+    println(stdout)
     return
 end