Merge remote-tracking branch 'myk002/myk_printall_nontable' into develop

docs/changelog.txt

@@ -50,6 +50,9 @@ changelog.txt uses a syntax similar to RST, with a few special sequences:
 ## API
 - The ``Items`` module ``moveTo*`` and ``remove`` functions now handle projectiles
 
+## Lua
+- new global function: ``safe_pairs(iterable[, iterator_fn])`` will iterate over the ``iterable`` (a table or iterable userdata)  with the ``iterator_fn`` (``pairs`` if not otherwise specified) if iteration is possible. If iteration is not possible or would throw an error, for example if ``nil`` is passed as the ``iterable``, the iteration is just silently skipped.
+
 ## Documentation
 - `quickfort-library-guide`: updated dreamfort documentation and added screenshots
 - `dfhack-examples-guide`: documentation for all of `dreamfort`'s supporting files (useful for all forts, not just Dreamfort!)

library/lua/dfhack.lua

@@ -162,22 +162,47 @@ NEWLINE = "\n"
 COMMA = ","
 PERIOD = "."
 
-function printall(table)
-    local ok,f,t,k = pcall(pairs,table)
+local function _wrap_iterator(next_fn, ...)
+    local wrapped_iter = function(...)
+        local ret = {pcall(next_fn, ...)}
+        local ok = table.remove(ret, 1)
         if ok then
-        for k,v in f,t,k do
-            print(string.format("%-23s\t = %s",tostring(k),tostring(v)))
+            return table.unpack(ret)
         end
     end
+    return wrapped_iter, ...
 end
 
-function printall_ipairs(table)
-    local ok,f,t,k = pcall(ipairs,table)
-    if ok then
-        for k,v in f,t,k do
-            print(string.format("%-23s\t = %s",tostring(k),tostring(v)))
+function safe_pairs(t, iterator_fn)
+    iterator_fn = iterator_fn or pairs
+    if (pcall(iterator_fn, t)) then
+        return _wrap_iterator(iterator_fn(t))
+    else
+        return function() end
     end
+end
+
+-- calls elem_cb(k, v) for each element of the table
+-- returns true if we iterated successfully, false if not
+-- this differs from safe_pairs() above in that it only calls pcall() once per
+-- full iteration and it returns whether iteration succeeded or failed.
+local function safe_iterate(table, iterator_fn, elem_cb)
+    local function iterate()
+        for k,v in iterator_fn(table) do elem_cb(k, v) end
     end
+    return pcall(iterate)
+end
+
+local function print_element(k, v)
+    dfhack.println(string.format("%-23s\t = %s", tostring(k), tostring(v)))
+end
+
+function printall(table)
+    safe_iterate(table, pairs, print_element)
+end
+
+function printall_ipairs(table)
+    safe_iterate(table, ipairs, print_element)
 end
 
 local do_print_recurse
@@ -199,15 +224,9 @@ local fill_chars = {
 setmetatable(fill_chars, fill_chars)
 
 local function print_fields(value, seen, indent, prefix)
-    local ok,f,t,k = pcall(pairs,value)
-    if not ok then
-        dfhack.print(prefix)
-        dfhack.println('<Type doesn\'t support iteration with pairs>')
-        return 0
-    end
     local prev_value = "not a value"
     local repeated = 0
-    for k, v in f,t,k do
+    local print_field = function(k, v)
         -- Only show set values of bitfields
         if value._kind ~= "bitfield" or v then
             local continue = false
@@ -233,7 +252,10 @@ local function print_fields(value, seen, indent, prefix)
             end
         end
     end
-    if repeated > 0 then
+    if not safe_iterate(value, pairs, print_field) then
+        dfhack.print(prefix)
+        dfhack.println('<Type doesn\'t support iteration with pairs>')
+    elseif repeated > 0 then
         dfhack.println(prefix .. "<Repeated " .. repeated .. " times>")
     end
     return 0

test/library/misc.lua

@@ -0,0 +1,40 @@
+-- tests misc functions added by dfhack.lua
+
+function test.safe_pairs()
+    for k,v in safe_pairs(nil) do
+        expect.fail('nil should not be iterable')
+    end
+    for k,v in safe_pairs('a') do
+        expect.fail('a string should not be iterable')
+    end
+    for k,v in safe_pairs({}) do
+        expect.fail('an empty table should not be iterable')
+    end
+    for k,v in safe_pairs(df.item._identity) do
+        expect.fail('a non-iterable light userdata var should not be iterable')
+    end
+
+    local iterated = 0
+    local t = {a='hello', b='world', [1]='extra'}
+    for k,v in safe_pairs(t) do
+        expect.eq(t[k], v)
+        iterated = iterated + 1
+    end
+    expect.eq(3, iterated)
+end
+
+function test.safe_pairs_ipairs()
+    local t = {1, 2}
+    setmetatable(t, {
+        __pairs = function()
+            expect.fail('pairs() should not be called')
+        end,
+    })
+
+    local iterated = 0
+    for k,v in safe_pairs(t, ipairs) do
+        expect.eq(k, v)
+        iterated = iterated + 1
+    end
+    expect.eq(#t, iterated)
+end

test/library/print.lua

@@ -0,0 +1,205 @@
+-- tests print-related functions added by dfhack.lua
+
+local dfhack = dfhack
+
+local mock_print = mock.func()
+local function test_wrapper(test_fn)
+    mock.patch({{dfhack, 'print', mock_print},
+                {dfhack, 'println', mock_print}},
+               test_fn)
+    mock_print = mock.func()
+end
+config.wrapper = test_wrapper
+
+function test.printall_table()
+    printall({a='b'})
+    expect.eq(1, mock_print.call_count)
+    expect.true_(mock_print.call_args[1][1]:find('a%s+= b'))
+end
+
+function test.printall_string()
+    printall('a')
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_number()
+    printall(10)
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_nil()
+    printall(nil)
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_boolean()
+    printall(false)
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_function()
+    printall(function() end)
+    expect.eq(0, mock_print.call_count)
+end
+
+local function new_int_vector()
+    -- create a vector of integers by cloning one from world. we do it this way
+    -- because we can't allocate typed vectors from lua directly.
+    local vector = df.global.world.busy_buildings:new()
+    vector:resize(0)
+    return vector
+end
+
+function test.printall_userdata()
+    local utable = new_int_vector()
+    dfhack.with_temp_object(utable, function()
+            utable:insert(0, 10)
+            utable:insert(1, 20)
+            printall(utable)
+            expect.eq(2, mock_print.call_count)
+            expect.true_(mock_print.call_args[1][1]:find('0%s+= 10'))
+            expect.true_(mock_print.call_args[2][1]:find('1%s+= 20'))
+        end)
+end
+
+function test.printall_noniterable_userdata()
+    printall(df.item._identity)
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_ipairs_table()
+    printall_ipairs({'a', 'b'})
+    expect.eq(2, mock_print.call_count)
+    expect.true_(mock_print.call_args[1][1]:find('1%s+= a'))
+    expect.true_(mock_print.call_args[2][1]:find('2%s+= b'))
+end
+
+function test.printall_ipairs_string()
+    printall_ipairs('a')
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_ipairs_number()
+    printall_ipairs(10)
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_ipairs_nil()
+    printall_ipairs(nil)
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_ipairs_boolean()
+    printall_ipairs(false)
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_ipairs_function()
+    printall_ipairs(function() end)
+    expect.eq(0, mock_print.call_count)
+end
+
+function test.printall_ipairs_userdata()
+    local utable = new_int_vector()
+    dfhack.with_temp_object(utable, function()
+            utable:insert(0, 10)
+            utable:insert(1, 20)
+            printall_ipairs(utable)
+            expect.eq(2, mock_print.call_count)
+            expect.true_(mock_print.call_args[1][1]:find('0%s+= 10'))
+            expect.true_(mock_print.call_args[2][1]:find('1%s+= 20'))
+        end)
+end
+
+function test.printall_ipairs_noniterable_userdata()
+    printall_ipairs(df.item._identity)
+    expect.eq(0, mock_print.call_count)
+end
+
+local function validate_patterns(start_idx, patterns)
+    for i,pattern in ipairs(patterns) do
+        expect.true_(mock_print.call_args[start_idx+i-1][1]:find(pattern))
+    end
+    return start_idx + #patterns
+end
+
+function test.printall_recurse()
+    local udatatable = new_int_vector()
+    dfhack.with_temp_object(udatatable, function()
+        local udataint = df.new('uint32_t')
+        dfhack.with_temp_object(udataint, function ()
+            udatatable:insert(0, 10)
+            udatatable:insert(1, 20)
+            udatatable:insert(2, 20)
+            udatatable:insert(3, 20)
+            udatatable:insert(4, 0)
+            udatatable:insert(5, 0)
+            local t2 = {}
+            local t = {num=5,
+                    bool=false,
+                    fn=function() end,
+                    udatatable=udatatable,
+                    udataint=udataint,
+                    lightudata=df.item._identity,
+                    table=t2}
+            t2.cyclic = t
+            printall_recurse(t)
+            expect.eq(55, mock_print.call_count)
+            expect.true_(mock_print.call_args[1][1]:find('^table: '))
+            local idx = 2
+            local EQ = '^%s+= $'
+            while idx <= 55 do
+                expect.eq('', mock_print.call_args[idx][1])
+                idx = idx + 1
+                local str = mock_print.call_args[idx][1]
+                if str:startswith('num') then
+                    idx = validate_patterns(idx, {'^num$', EQ, '^5$'})
+                elseif str:startswith('bool') then
+                    idx = validate_patterns(idx, {'^bool$', EQ, '^false$'})
+                elseif str:startswith('fn') then
+                    idx = validate_patterns(idx, {'^fn$', EQ, '^function: '})
+                elseif str:startswith('udatatable') then
+                    idx = validate_patterns(idx,
+                            {'^udatatable$', EQ, '^<vector<int32_t>%[6%]: ',
+                             '%s+', '^0$', EQ, '^10$',
+                             '%s+', '^1$', EQ, '^20$',
+                             'Repeated 2 times',
+                             '%s+', '^4$', EQ, '^0$',
+                             'Repeated 1 times'}) -- [sic]
+                elseif str:startswith('udataint') then
+                    idx = validate_patterns(idx,
+                            {'^udataint$', EQ, '^<uint32_t: ',
+                             '%s+', '^value$', EQ, '^0$'})
+                elseif str:startswith('lightudata') then
+                    idx = validate_patterns(idx,
+                            {'^lightudata$', EQ, '',
+                             '', 'iteration with pairs>$'})
+                elseif str:startswith('table') then
+                    idx = validate_patterns(idx,
+                            {'^table$', EQ, '^table: ',
+                             '%s+', '^cyclic$', EQ, '^table: ',
+                             '%s+', '^<Cyclic reference'})
+                else
+                    expect.fail('unhandled print output')
+                    break
+                end
+            end
+        end)
+    end)
+end
+
+function test.printall_recurse_cyclic_userdata()
+    local t = df.job_list_link:new()
+    dfhack.with_temp_object(t, function()
+        t.next = t
+        printall_recurse(t)
+        expect.eq(15, mock_print.call_count)
+        -- conveniently, field order is deterministic
+        validate_patterns(1,
+            {'^<job_list_link: ',
+             '', '^item$', EQ, 'nil',
+             '', '^prev$', EQ, 'nil',
+             '', '^next$', EQ, '^<job_list_link: ',
+             ' +', '^<Cyclic reference'})
+    end)
+end