Record tag error message includes record name instead of only "userdata"

[Vipul-Cariappa]

Fixes: #151

Code:

-- main.lua

Mod = require "Shapes"

C1 = Mod.Circle_New(3.0)
R1 = Mod.Rectangle_New(3.0, 4.0)

print(Mod.Circle_Area(R1))
print(Mod.Circle_Area(1)) 

-- Shapes.pln

local Shapes: module = {}

record Circle
    radius: float
end

record Rectangle
    length: float
    width: float
end

function Shapes.Circle_New(r: float): Circle
    local c: Circle = {radius = r}
    return c
end

function Shapes.Circle_Area(c: Circle): float
    return c.radius * c.radius * 3.1415
end

function Shapes.Rectangle_New(l: float, w: float): Rectangle
    local c: Rectangle = {length = l, width = w}
    return c
end

function Shapes.Rectangle_Area(c: Rectangle): float
    return c.length * c.width
end

return Shapes

Old behaviour

❯ lua main.lua                                  
lua: main.lua:8: file Shapes.pln: line 17: wrong type for argument 'c', expected userdata but found userdata
stack traceback:
        [C]: in function 'Shapes.Circle_Area'
        main.lua:8: in main chunk
        [C]: in ?

❯ lua main.lua
lua: main.lua:9: file Shapes.pln: line 17: wrong type for argument 'c', expected userdata but found integer
stack traceback:
        [C]: in function 'Shapes.Circle_Area'
        main.lua:9: in main chunk
        [C]: in ?

New behaviour

❯ lua main.lua
lua: main.lua:8: file Shapes.pln: line 17: wrong type for argument 'c', expected Circle but found Rectangle
stack traceback:
        [C]: in function 'Shapes.Circle_Area'
        main.lua:8: in main chunk
        [C]: in ?

❯ lua main.lua
lua: main.lua:9: file Shapes.pln: line 17: wrong type for argument 'c', expected Circle but found integer
stack traceback:
        [C]: in function 'Shapes.Circle_Area'
        main.lua:9: in main chunk
        [C]: in ?

[hugomg]

Thanks, Vipul! Looks like the PR is not passing the test suite. Can you please look into that?

[hugomg]

Do we still need pallene_tag_name, now that we have pallene_type_name?

[Vipul-Cariappa]

We would require both pallene_tag_name and pallene_type_name. They are different in two ways.

1. Difference in the function signature const char *pallene_tag_name(int raw_tag) and const char *pallene_type_name(lua_State *L, const TValue *v)
2. expected_type is known at the compile time (and uses pallene_tag_name) i.e. the argument's expected type. Whereas the argument const TValue *v passed to pallene_type_name cannot be known at compile time. v is the type of the actual argument passed at runtime.

[hugomg]

1. IIRC, there aren't any other places that call pallene_tag_name. The tag name function was there only for the error messages and pallene_type_name now does that job. Notice how both functions are currently quite similar.

2. If your goal was that the expected_type be known at compile time, then calling pallene_tag_name is not the way to do that. That C function call will only happen at run-time.

3. One last thing: In the coder.lua, please use different variable names for the type tag returned by pallene_type_tag and for the type name that you compute inside the if statement.

[Vipul-Cariappa]

Please have a look at the recent changes. Hope the latest commit resolves the issues/suggestions you mentioned.

[hugomg]

Hmm, why is our CI failing? 🤔
The tests are passing on my machine. Is that also the case for you, Vipul?

[hugomg]

Looks like it's passing now, go figure...
Thanks again!