premake_argmatcher.lua - demonstrates Adaptive Argmatchers

[chrisant996]

This script demonstrates the use of the new Adaptive Argmatcher capabilities in v1.3.10.

It is a fully functional argmatcher for Premake.

Since Premake's flags and arguments depend on premake.lua scripts in the current directory tree, an argmatcher for Premake needs to rebuilt itself the next time it's used after the current directory changes.

premake_argmatcher.lua

--------------------------------------------------------------------------------
-- Clink argmatcher for Premake5.
--
-- Uses argmatcher:setdelayinit() to dynamically (re-)initialize the argmatcher
-- based on the current directory.

if (clink.version_encoded or 0) < 10030010 then
    -- This script requires Clink v1.3.10 or higher.
    return
end

local prev_cwd = ""

local function delayinit(argmatcher)
    -- If the current directory is the same, the argmatcher is already
    -- initialized.
    local cwd = os.getcwd()
    if prev_cwd == cwd then
        return
    end

    -- Reset the argmatcher and update the current directory.
    argmatcher:reset()
    prev_cwd = cwd

    -- Invoke 'premake5 --help' and parse its output to collect the available
    -- flags and arguments.
    local actions
    local flags = {}
    local descriptions = {}
    local pending_link
    local values
    local placeholder
    local r = io.popen('premake5.exe --help 2>nul')

    -- The output from premake5 follows this layout:
    --
    --      ... ignore lines until ...
    --      OPTIONS ...
    --       --flag         Description
    --       --etc ...
    --      ACTIONS
    --       action         Description
    --       etc ...
    --      ... stop once a non-indented line is reached.
    --
    -- Additionally, some flags follow this layout:
    --
    --       --flag=value   Description of flag
    --          value        Description of value
    --          etc ...
    --      ... until another --flag line, or ACTIONS.
    --
    for line in r:lines() do
        if actions then
            -- A non-blank, non-indented line ends the actions.
            if #line > 0 and line:sub(1,1) ~= ' ' then
                break
            end
            -- Parsing an action.
            local action, description = line:match('^ ([^ ]+) +(.+)$')
            if action then
                table.insert(actions, { match=action, type="arg", description=description })
            end
        elseif line:find('^ACTIONS') then
            -- An 'ACTIONS' line starts the actions section.
            actions = {}
        elseif values and line:match('^     ') then
            -- Add a value to the values table for the pending_link.
            local value, description = line:match('^     ([^ ]+) +(.+)$')
            if value then
                table.insert(values, { match=value, type="arg", description=description })
            end
        else
            -- Not a value line, so if there's a pending_link then it's
            -- finished; add the pending values to it.
            if pending_link then
                pending_link:addarg(#values > 0 and values or placeholder)
                pending_link = nil
                values = nil
                placeholder = nil
            end
            -- Parse a flag line.
            local flag, value, description
            flag, description = line:match('^[ ]+(%-%-[^ =]+) +(.+)$')
            if not flag then
                flag, value, description = line:match('^[ ]+(%-%-[^ =]+=)([^ ]+) +(.+)$')
            end
            -- If the line defines a flag, process the flag.
            if flag then
                if description then
                    description = description:gsub('; one of:$', '')
                end
                -- Add the flag.
                if value then
                    pending_link = clink.argmatcher()
                    table.insert(flags, flag..pending_link)
                    descriptions[flag] = { value, description }
                    -- Prepare placeholder value.
                    values = {}
                    placeholder = { match=value, type="arg", description=description }
                else
                    descriptions[flag] = description
                    table.insert(flags, flag)
                end
            end
        end
    end

    r:close()

    argmatcher:addarg(actions or {})
    argmatcher:addflags(flags)
    argmatcher:adddescriptions(descriptions)
end

local matcher = clink.argmatcher('premake5')
if matcher.setdelayinit then
    matcher:setdelayinit(delayinit)
end

[chrisant996]

The premake_argmatcher.lua script is now part of clink-gizmos, and is renamed to completions\premake5.lua.