Recipe: trim

created by LociOiling

Profile

• Name: trim
• ID: 108773
• Shared with: Public
• Parent: None
• Children: None
• Created on: July 19, 2024 at 15:53 PM UTC
• Updated on: July 19, 2024 at 15:54 PM UTC
• Description:

  Quick demo of structure.TrimPose function. The function can throw errors, so the demo uses pcall () to catch them.

Code

--[[

    trim - quick demo of structure.TrimPose

    use pcall to catch errors which otherwise end the recipe

    LociOiling 20240719

]]--

--
--  ParseError -- common routine used by safe functions
--
function ParseError ( errmsg )
    local reason
    local start, stop, line, msg
    start, stop, line, msg = errmsg:find ( ":(%d+):%s()" )
    if msg ~= nil then
        errmsg = errmsg:sub ( msg, #errmsg )
    end
    return errmsg    
end
--
--  SafeTrim uses pcall
--  to call structure.TrimPose, returning
--  a numeric return code and an error message.
--
--  The return codes are:
--
--     0 - successful, error message is nil
--    -1 - pose was already trimmed 
--    -2 - nothing selected
--  -999 - other error
--
function SafeTrim ()
--
    local BADTRIM = "Cannot trim already trimmed pose."
    local NOSEL = "Cannot trim pose with no residues selected."
--
    local good, errmsg = pcall ( structure.TrimPose )
    if good then
        return 0, nil
    else
        local err2 = ParseError ( errmsg )
        local errp = err2:find ( BADTRIM )
        if errp ~= nil then
            return -1, err2
        end
        local errp = err2:find ( NOSEL )
        if errp ~= nil then
            return -2, err2
        end
        return -999, err2
    end
end

print ( "trim demo" )

startsegs = structure.GetCount ()
print ( "before trim, segment count = " .. startsegs )

selcnt = selection.GetCount ()
print ( "selected segments = " .. selcnt ) 

local rc,trimerr = SafeTrim ()
if rc ~= 0 then 
    print ( "trim error: \"" .. trimerr .. "\"" ) 
end

trimsegs = structure.GetCount ()
print ( "after trim, segment count = " .. trimsegs )

if trimsegs == startsegs then
    print ( "nothing trimmed" )
    if rc == -1 then
        print ( "pose was already trimmed" )
    elseif rc == -2 then
        print ( "nothing was selected" )
    elseif rc ~= 0 then
        print ( "unknown error" )
    end
end