add syntax highlighting (#66)

* add syntax highlighting

Author: KristofferC

Manifest.toml

@@ -9,10 +9,33 @@ git-tree-sha1 = "983f5f7a57c604322917ab8bc5b86ba914d3c345"
 uuid = "da1fd8a2-8d9e-5ec2-8556-3022fb5608a2"
 version = "0.3.2"
 
+[[Crayons]]
+git-tree-sha1 = "416737eea5c50ee5a08c588ea73d77d5eebc94e7"
+repo-rev = "master"
+repo-url = "https://github.com/KristofferC/Crayons.jl.git"
+uuid = "a8cc5b0e-0ffa-5ad4-8c14-923d3ee1735f"
+version = "3.0.0"
+
+[[Dates]]
+deps = ["Printf"]
+uuid = "ade2ca70-3891-5945-98fb-dc099432e06a"
+
 [[Distributed]]
 deps = ["Random", "Serialization", "Sockets"]
 uuid = "8ba89e20-285c-5b6f-9357-94700520ee1b"
 
+[[DocStringExtensions]]
+deps = ["LibGit2", "Markdown", "Pkg", "Test"]
+git-tree-sha1 = "4d30e889c9f106a51ffa4791a88ffd4765bf20c3"
+uuid = "ffbed154-4ef7-542d-bbb7-c09d3a79fcae"
+version = "0.7.0"
+
+[[Highlights]]
+deps = ["DocStringExtensions", "InteractiveUtils", "REPL", "Test"]
+git-tree-sha1 = "286ff83d696dd92748e603a3219618d9e407e872"
+uuid = "eafb193a-b7ab-5a9e-9068-77385905fa72"
+version = "0.3.1"
+
 [[InteractiveUtils]]
 deps = ["Markdown"]
 uuid = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
@@ -25,13 +48,24 @@ repo-url = "https://github.com/JuliaDebug/JuliaInterpreter.jl"
 uuid = "aa1ae85d-cabe-5617-a682-6adf51b2e16a"
 version = "0.1.1"
 
+[[LibGit2]]
+uuid = "76f85450-5226-5b5a-8eaa-529ad045b433"
+
 [[Logging]]
 uuid = "56ddb016-857b-54e1-b83d-db4d58db5568"
 
 [[Markdown]]
 deps = ["Base64"]
 uuid = "d6f4376e-aef5-505a-96c1-9c027394607a"
 
+[[Pkg]]
+deps = ["Dates", "LibGit2", "Markdown", "Printf", "REPL", "Random", "SHA", "UUIDs"]
+uuid = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+
+[[Printf]]
+deps = ["Unicode"]
+uuid = "de0858da-6303-5e67-8744-51eddeeeb8d7"
+
 [[REPL]]
 deps = ["InteractiveUtils", "Markdown", "Sockets"]
 uuid = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
@@ -56,3 +90,6 @@ uuid = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 [[UUIDs]]
 deps = ["Random", "SHA"]
 uuid = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
+
+[[Unicode]]
+uuid = "4ec0a83e-493e-50e2-b9ac-8f72acf5a8f5"

Project.toml

@@ -5,6 +5,8 @@ version = "0.1.0"
 
 [deps]
 CodeTracking = "da1fd8a2-8d9e-5ec2-8556-3022fb5608a2"
+Crayons = "a8cc5b0e-0ffa-5ad4-8c14-923d3ee1735f"
+Highlights = "eafb193a-b7ab-5a9e-9068-77385905fa72"
 JuliaInterpreter = "aa1ae85d-cabe-5617-a682-6adf51b2e16a"
 Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"

README.md

@@ -50,7 +50,7 @@ Advanced commands:
 - `si`: same as `se` but step into a call if a call is the next expression
 - `sg`: step into a generated function
 
-## Breakpoints
+### Breakpoints
 
 There are currently no designated commands in the debug mode for adding and removing breakpoints, instead they are manipulated using the API from the package JuliaInterpreter (which need to be installed). The different ways of manipulating breakpoints are documented [here](https://juliadebug.github.io/JuliaInterpreter.jl/latest/dev_reference/#Breakpoints-1).
 
@@ -78,7 +78,7 @@ About to run: (abs_float)(2.0)
   | T::DataType = Float64
 ```
 
-### Breakpoint on error
+#### Breakpoint on error
 
 It is possible to halt execution when an error is thrown. This is done by calling the exported function `break_on_error(true)`.
 
@@ -114,6 +114,15 @@ About to run: (throw)(StringIndexError("αβ", 2))
 [4] f() at REPL[17]:1
 ```
 
+### Syntax highlighting
+
+The source code preview is syntax highlighted and this highlighting has some options.
+The theme can be set by calling `Debugger.set_theme(theme)` where `theme` is a [Highlights.jl theme](https://juliadocs.github.io/Highlights.jl/stable/demo/themes.html).
+It can be completely turned off or alternatively, different quality settings for the colors might be chosen by calling `Debugger.set_highlight(opt)` where `opt` is a `Debugger.HighlightOption` enum.
+The choices are `HIGHLIGHT_OFF` `HIGHLIGHT_SYSTEM_COLORS`, `HIGHLIGHT_256_COLORS`, `HIGHLIGHT_24_BIT`. System colors works in pretty much all terminals, 256 in most terminals (with the exception of Windows)
+and 24 bit in some terminals.
+
+
 [travis-img]: https://travis-ci.org/JuliaDebug/Debugger.jl.svg?branch=master
 [travis-url]: https://travis-ci.org/JuliaDebug/Debugger.jl
 

src/Debugger.jl

@@ -1,5 +1,8 @@
 module Debugger
 
+using Highlights
+using Crayons
+
 using Markdown
 using Base.Meta: isexpr
 using REPL

src/printing.jl

@@ -16,7 +16,7 @@ function print_var(io::IO, var::JuliaInterpreter.Variable)
     catch
         val = Suppressed("printing error")
     end
-    println(io, var.name, "::", T, " = ", val)
+    println(io, highlight_code(string(var.name, "::", T, " = ", val); context=io))
 end
 
 print_locdesc(io::IO, frame::Frame) = println(io, locdesc(frame))
@@ -69,7 +69,7 @@ function print_next_expr(io::IO, frame::Frame)
             end
         end
     end
-    print(io, expr)
+    print(io, highlight_code(string(expr); context=io))
     println(io)
 end
 
@@ -85,8 +85,7 @@ function print_status(io::IO, frame::Frame)
             else
                 read(loc.filepath, String)
             end
-        print_sourcecode(outbuf, data,
-            loc.line, loc.defline)
+        print_sourcecode(outbuf, data, loc.line, loc.defline)
     else
         print_codeinfo(outbuf, frame)
     end
@@ -134,7 +133,7 @@ function compute_source_offsets(code::String, offset::Integer, startline::Intege
     if offsetline - NUM_SOURCE_LINES_UP_DOWN[] > length(file.offsets) || startline > length(file.offsets)
         return -1, -1
     end
-    startoffset = max(file.offsets[max(offsetline - NUM_SOURCE_LINES_UP_DOWN[], 1)], file.offsets[startline])
+    startoffset = max(file.offsets[max(offsetline - NUM_SOURCE_LINES_UP_DOWN[], 1)], startline == 0 ? 0 : file.offsets[startline])
     stopoffset = lastindex(code)-1
     if offsetline + NUM_SOURCE_LINES_UP_DOWN[] < lastindex(file.offsets)
         stopoffset = min(stopoffset, file.offsets[offsetline + NUM_SOURCE_LINES_UP_DOWN[]] - 1)
@@ -145,7 +144,53 @@ function compute_source_offsets(code::String, offset::Integer, startline::Intege
     startoffset, stopoffset
 end
 
-function print_sourcecode(io::IO, code::String, line::Integer, defline::Integer; file::SourceFile = SourceFile(code))
+@enum HighlightOption begin
+    HIGHLIGHT_OFF
+    HIGHLIGHT_SYSTEM_COLORS
+    HIGHLIGHT_256_COLORS
+    HIGHLIGHT_24_BIT
+end
+
+const _syntax_highlighting = Ref(Sys.iswindows() ? HIGHLIGHT_SYSTEM_COLORS : HIGHLIGHT_256_COLORS)
+const _current_theme = Ref{Type{<:Highlights.AbstractTheme}}(Highlights.Themes.MonokaiTheme)
+
+set_theme(theme::Type{<:Highlights.AbstractTheme}) = _current_theme[] = theme
+set_highlight(opt::HighlightOption) = _syntax_highlighting[] = opt
+
+function Format.render(io::IO, ::MIME"text/ansi-debugger", tokens::Format.TokenIterator)
+    for (str, id, style) in tokens
+        fg = style.fg.active ? map(Int, (style.fg.r, style.fg.g, style.fg.b)) : :nothing
+        bg = style.bg.active ? map(Int, (style.bg.r, style.bg.g, style.bg.b)) : :nothing
+        crayon = Crayon(
+            foreground = fg,
+            background = bg,
+            bold       = style.bold ? true : :nothing,
+            italics    = style.italic ? true : :nothing,
+            underline  = style.underline ? true : :nothing,
+        )
+        if _syntax_highlighting[] == HIGHLIGHT_256_COLORS
+            crayon = Crayons.to_256_colors(crayon)
+        elseif _syntax_highlighting[] == HIGHLIGHT_SYSTEM_COLORS
+            crayon = Crayons.to_system_colors(crayon)
+        end
+        print(io, crayon, str, inv(crayon))
+    end
+end
+
+function highlight_code(code; context=nothing)
+    if _syntax_highlighting[] != HIGHLIGHT_OFF
+        return sprint(highlight, MIME("text/ansi-debugger"), code, Lexers.JuliaLexer, _current_theme[]; context=context)
+    else
+        return code
+    end
+end
+
+
+const RESET = Crayon(reset = true)
+
+function print_sourcecode(io::IO, code::String, line::Integer, defline::Integer)
+    code = highlight_code(code; context=io)
+    file = SourceFile(code)
     startoffset, stopoffset = compute_source_offsets(code, file.offsets[line], defline, line+NUM_SOURCE_LINES_UP_DOWN[]; file=file)
 
     if startoffset == -1
@@ -173,5 +218,6 @@ function print_sourcecode(io::IO, code::String, line::Integer, defline::Integer;
         println(io, textline)
         lineno += 1
     end
+    _syntax_highlighting[] == HIGHLIGHT_OFF || print(io, RESET)
     println(io)
 end

test/misc.jl

@@ -59,6 +59,16 @@ loc = Debugger.locinfo(state.frame)
 @test isfile(loc.filepath)
 @test occursin("logging.jl", loc.filepath)
 
+try
+    Debugger.set_highlight(Debugger.HIGHLIGHT_SYSTEM_COLORS)
+    frame = Debugger.@make_frame f()
+    st = chomp(sprint(Debugger.print_status, frame; context = :color => true))
+    x_1_plus_1_colored = "\e[39m\e[97mx\e[39m\e[97m \e[39m\e[91m=\e[39m\e[97m \e[39m1\e[97m \e[39m\e[91m+\e[39m\e[97m \e[39m1\e[97m"
+    @test occursin(x_1_plus_1_colored, st)
+finally 
+    Debugger.set_highlight(Debugger.HIGHLIGHT_OFF)
+end
+
 frame = @make_frame Test.eval(1)
 desc = Debugger.locdesc(frame)
 @test occursin(Sys.STDLIB, desc)

test/runtests.jl

@@ -9,6 +9,8 @@ if !isdefined(Main, :isnothing)
     isnothing(x) = x === nothing
 end
 
+Debugger.set_highlight(Debugger.HIGHLIGHT_OFF)
+
 #@testset "Main tests" begin
     include("utils.jl")
     include("misc.jl")