diff options
Diffstat (limited to 'lib/control_flow.nom')
| -rw-r--r-- | lib/control_flow.nom | 468 |
1 files changed, 241 insertions, 227 deletions
diff --git a/lib/control_flow.nom b/lib/control_flow.nom index b05862c..7347a29 100644 --- a/lib/control_flow.nom +++ b/lib/control_flow.nom @@ -40,10 +40,9 @@ immediately %when_false_expr unless %condition else %when_true_expr %when_false_expr unless %condition then %when_true_expr ..to - local %safe #.. If %when_true_expr is guaranteed to be truthy, we can use Lua's idiomatic equivalent of a conditional expression: (cond and if_true or if_false) - if: {Text:yes, List:yes, Dict:yes, Number:yes}->(%when_true_expr's "type") + if: (%when_true_expr's "type") in {Text:yes, List:yes, Dict:yes, Number:yes} return "(\(%condition as lua) and \(%when_true_expr as lua) or \(%when_false_expr as lua))" ..else #.. Otherwise, need to do an anonymous inline function (yuck, too bad lua @@ -58,9 +57,10 @@ immediately end end)() + # GOTOs immediately - compile [-> %label] to code ".." + compile [=== %label ===, --- %label ---] to code ".." ::label_\(nomsu "var_to_lua_identifier" [%label])::; compile [go to %label] to code ".." goto label_\(nomsu "var_to_lua_identifier" [%label]); @@ -72,46 +72,77 @@ immediately # Helper function immediately - action [tree %tree has function call %call] - lua> ".." - local target = (\%call).stub; - for subtree,depth in coroutine.wrap(function() nomsu:walk_tree(\%tree); end) do - if type(subtree) == 'table' and subtree.type == "FunctionCall" - and subtree.stub == target then - return true; + compile [for subtree %subtree where %condition in %tree %body] to code ".." + for \(%subtree as lua) in coroutine.wrap(function() nomsu:walk_tree(\(%tree as lua)) end) do + if type(\(%subtree as lua)) == 'table' and \(%subtree as lua).type then + if \(%condition as lua) then + \(%body as lua statements) end end - return false; + end # While loops immediately - compile [do next repeat-loop] to code "goto continue_repeat;" - compile [stop repeat-loop] to code "goto stop_repeat;" + compile [do next repetition] to code "goto continue_repeat;" + compile [stop repeating] to code "goto stop_repeat;" compile [repeat while %condition %body] to code - set %continue_labels = - "\n::continue_repeat::;" - ..if (tree %body has function call \(do next repeat-loop)) else "" - set %code = ".." + %continue_labels <- "" + for subtree % where + ((%'s "type") = "FunctionCall") and ((%'s "stub") == "do next repetition") + ..in %body + %continue_labels <- "\n::continue_repeat::;" + stop + %code <- ".." while \(%condition as lua) do \(%body as lua statements)\ ..\%continue_labels end --while-loop - if: tree %body has function call \(stop repeat-loop) - return ".." - do --while-loop label scope + for subtree % where + ((%'s "type") = "FunctionCall") and ((%'s "stub") == "stop repeating") + ..in %body + %code <- ".." + do -- scope of "stop repeating" label \%code ::stop_repeat::; - end --while-loop label scope + end -- end of "stop repeating" label scope + %continue_labels <- "\n::continue_repeat::;" + stop return %code parse [repeat %body] as: repeat while (yes) %body parse [repeat until %condition %body] as: repeat while (not %condition) %body + compile [..] + repeat %n times %body + ..to code + %continue_labels <- "" + for subtree % where + ((%'s "type") = "FunctionCall") and ((%'s "stub") == "do next repetition") + ..in %body + %continue_labels <- "\n::continue_repeat::;" + stop + # This trashes the loop variables, just like in Python. + %code <- ".." + for i=1,\(%n as lua) do + \(%body as lua statements)\ + ..\%continue_labels + end --numeric for-loop + %stop_labels <- "" + for subtree % where + ((%'s "type") = "FunctionCall") and ((%'s "stub") == "stop repeating") + ..in %body + %code <- ".." + do -- scope of "stop repeating" label + \%code + ::stop_repeat::; + end -- end of "stop repeating" label scope + %continue_labels <- "\n::continue_repeat::;" + stop + return %code + # For loop control flow: immediately - compile [stop for-loop] to code "goto stop_for;" compile [stop %var] to code ".." goto stop_\(nomsu "var_to_lua_identifier" [%var]); - compile [do next for-loop] to code "goto continue_for;" compile [do next %var] to code ".." goto continue_\(nomsu "var_to_lua_identifier" [%var]); @@ -121,37 +152,42 @@ immediately for %var from %start to %stop by %step %body for %var from %start to %stop via %step %body ..to code - local [%continue_labels, %code, %stop_labels, %loop_var, %loop_var_shim] - set %continue_labels = "" - if: tree %body has function call \(do next for-loop) - %continue_labels join= "\n::continue_for::;" - if: tree %body has function call (tree \(do next %) with {"":%var}) - %continue_labels join= "\n::continue_\(nomsu "var_to_lua_identifier" [%var])::;" + %continue_labels <- "" + for subtree % where + ((%'s "type") = "FunctionCall") and + ((%'s "stub") == "do next %") and + ((3rd in (%'s "value"))'s "src") == (%var's "src") + ..in %body + %continue_labels <- "\n::continue_\(nomsu "var_to_lua_identifier" [%var])::;" + stop + if: (%var's "type") is "Var" - set %loop_var = (%var as lua) - set %loop_var_shim = "" + %loop_var <- (%var as lua) + %loop_var_shim <- "" ..else - set %loop_var = "i" - set %loop_var_shim = "\n\(%var as lua) = i;" + %loop_var <- "i" + %loop_var_shim <- "\n\(%var as lua) = i;" # This trashes the loop variables, just like in Python. - set %code = ".." + %code <- ".." for \(%loop_var)=\(%start as lua),\(%stop as lua),\(%step as lua) do\ ..\%loop_var_shim \(%body as lua statements)\ ..\%continue_labels end --numeric for-loop - set %stop_labels = "" - if: tree %body has function call \(stop for-loop) - %stop_labels join= "\n::stop_for::;" - if: tree %body has function call (tree \(stop %) with {"":%var}) - %stop_labels join= "\n::stop_\(nomsu "var_to_lua_identifier" [%var])::;" - return - ".." - do --for-loop label scope - \%code\ - ..\%stop_labels - end --for-loop label scope - ..if (%stop_labels is not "") else %code + + for subtree % where + ((%'s "type") = "FunctionCall") and + ((%'s "stub") == "stop %") and + ((2nd in (%'s "value"))'s "src") == (%var's "src") + ..in %body + %code <- ".." + do -- scope for stopping for-loop + \%code + ::stop_\(nomsu "var_to_lua_identifier" [%var])::; + end -- end of scope for stopping for-loop + stop + + return %code immediately parse [for %var from %start to %stop %body] as: for %var from %start to %stop via 1 %body @@ -161,207 +197,209 @@ immediately ..as: for % from %start to %stop via %step %body parse [for all %start to %stop %body] as: for all %start to %stop via 1 %body +# For-each loop immediately compile [for %var in %iterable %body] to code - local [%continue_labels, %code, %stop_labels, %loop_var, %loop_var_shim] - set %continue_labels = "" - if: tree %body has function call \(do next for-loop) - %continue_labels join= "\n::continue_for::;" - if: tree %body has function call (tree \(do next %) with {"":%var}) - %continue_labels join= "\n::continue_\(nomsu "var_to_lua_identifier" [%var])::;" + %continue_labels <- "" + for subtree % where + ((%'s "type") = "FunctionCall") and + ((%'s "stub") == "do next %") and + ((3rd in (%'s "value"))'s "src") == (%var's "src") + ..in %body + %continue_labels <- "\n::continue_\(nomsu "var_to_lua_identifier" [%var])::;" + stop if: (%var's "type") is "Var" - set %loop_var = (%var as lua) - set %loop_var_shim = "" + %loop_var <- (%var as lua) + %loop_var_shim <- "" ..else - set %loop_var = "value" - set %loop_var_shim = "\n\(%var as lua) = value;" + %loop_var <- "value" + %loop_var_shim <- "\n\(%var as lua) = value;" # This trashes the loop variables, just like in Python. - set %code = ".." + %code <- ".." for i,\%loop_var in ipairs(\(%iterable as lua)) do\ ..\%loop_var_shim \(%body as lua statements)\ ..\%continue_labels end --foreach-loop - set %stop_labels = "" - if: tree %body has function call \(stop for-loop) - %stop_labels join= "\n::stop_for::;" - if: tree %body has function call (tree \(stop %) with {"":%var}) - %stop_labels join= "\n::stop_\(nomsu "var_to_lua_identifier" [%var])::;" - if: %stop_labels is not "" - set %code = ".." - do --for-loop label scope - \%code\%stop_labels - end --for-loop label scope + for subtree % where + ((%'s "type") = "FunctionCall") and + ((%'s "stub") == "stop %") and + ((2nd in (%'s "value"))'s "src") == (%var's "src") + ..in %body + %code <- ".." + do -- scope for stopping for-loop + \%code + ::stop_\(nomsu "var_to_lua_identifier" [%var])::; + end -- end of scope for stopping for-loop + stop return %code parse [for all %iterable %body] as: for % in %iterable %body -immediately - compile [..] - repeat %n times %body, repeat %n x %body - ..to code - local [%continue_labels, %code, %stop_labels] - set %continue_labels = "" - if: tree %body has function call \(do next repeat-loop) - %continue_labels join= "\n::continue_repeat::;" - # This trashes the loop variables, just like in Python. - set %code = ".." - for i=1,\(%n as lua) do - \(%body as lua statements)\ - ..\%continue_labels - end --numeric for-loop - set %stop_labels = "" - if: tree %body has function call \(stop repeat-loop) - %stop_labels join= "\n::stop_repeat::;" - return - ".." - do --repeat-loop label scope - \%code\ - ..\%stop_labels - end --repeat-loop label scope - ..if (%stop_labels is not "") else %code - # Dict iteration (lua's "pairs()") immediately compile [for %key = %value in %iterable %body] to code - local [..] - %continue_labels, %code, %stop_labels, %key_loop_var, %key_loop_var_shim, - %value_loop_var, %value_loop_var_shim - set %continue_labels = "" - if: tree %body has function call \(do next for-loop) - %continue_labels join= "\n::continue_for::;" - if: tree %body has function call (tree \(do next %) with {"":%key}) - %continue_labels join= "\n::continue_\(nomsu "var_to_lua_identifier" [%key])::;" - if: tree %body has function call (tree \(do next %) with {"":%value}) - %continue_labels join= "\n::continue_\(nomsu "var_to_lua_identifier" [%value])::;" + %continue_labels <- "" + for subtree % where + ((%'s "type") = "FunctionCall") and + ((%'s "stub") == "do next %") and + ((3rd in (%'s "value"))'s "src") == (%key's "src") + ..in %body + <- %continue_labels + "\n::continue_\(nomsu "var_to_lua_identifier" [%key])::;" + stop + + for subtree % where + ((%'s "type") = "FunctionCall") and + ((%'s "stub") == "do next %") and + ((3rd in (%'s "value"))'s "src") == (%value's "src") + ..in %body + <- %continue_labels + "\n::continue_\(nomsu "var_to_lua_identifier" [%value])::;" + stop + if: (%key's "type") is "Var" - set %key_loop_var = (%key as lua) - set %key_loop_var_shim = "" + %key_loop_var <- (%key as lua) + %key_loop_var_shim <- "" ..else - set %key_loop_var = "key" - set %key_loop_var_shim = "\n\(%key as lua) = key;" + %key_loop_var <- "key" + %key_loop_var_shim <- "\n\(%key as lua) = key;" if: (%value's "type") is "Var" - set %value_loop_var = (%value as lua) - set %value_loop_var_shim = "" + %value_loop_var <- (%value as lua) + %value_loop_var_shim <- "" ..else - set %value_loop_var = "value" - set %value_loop_var_shim = "\n\(%value as lua) = value;" + %value_loop_var <- "value" + %value_loop_var_shim <- "\n\(%value as lua) = value;" # This trashes the loop variables, just like in Python. - set %code = ".." + %code <- ".." for \%key_loop_var,\%value_loop_var in pairs(\(%iterable as lua)) do\ ..\%key_loop_var_shim\%value_loop_var_shim \(%body as lua statements)\ ..\%continue_labels end --foreach-loop - set %stop_labels = "" - if: tree %body has function call \(stop for-loop) - %stop_labels join= "\n::stop_for::;" - if: tree %body has function call (tree \(stop %) with {"":%key}) - %stop_labels join= "\n::stop_\(nomsu "var_to_lua_identifier" [%key])::;" - if: tree %body has function call (tree \(stop %) with {"":%value}) - %stop_labels join= "\n::stop_\(nomsu "var_to_lua_identifier" [%value])::;" - return - ".." - do --for-loop label scope - \%code\ - ..\%stop_labels - end --for-loop label scope - ..if (%stop_labels is not "") else %code + %stop_labels <- "" + for subtree % where + ((%'s "type") = "FunctionCall") and + ((%'s "stub") == "stop %") and + ((2nd in (%'s "value"))'s "src") == (%key's "src") + ..in %body + <- %stop_labels + "\n::stop_\(nomsu "var_to_lua_identifier" [%key])::;" + stop + + for subtree % where + ((%'s "type") = "FunctionCall") and + ((%'s "stub") == "stop %") and + ((2nd in (%'s "value"))'s "src") == (%value's "src") + ..in %body + <- %stop_labels + "\n::stop_\(nomsu "var_to_lua_identifier" [%value])::;" + stop + + if: %stop_labels is not "" + %code <- ".." + do -- scope for stopping for % = % loop + \%code\%stop_labels + end + return %code # Switch statement/multi-branch if immediately compile [when %body] to code - local [%result, %fallthroughs, %first] - set %result = "" - set %fallthroughs = [] - set %first = (yes) + %result <- "" + %fallthroughs <- [] + %is_first <- (yes) for %func_call in (%body's "value") - local [%tokens, %star, %condition, %action] assume ((%func_call's "type") is "FunctionCall") or barf ".." Invalid format for 'when' statement. Only '*' blocks are allowed. - set %tokens = (%func_call's "value") - set %star = (%tokens -> 1) - assume (=lua "\%star and \%star.type == 'Word' and \%star.value == '*'") or barf ".." - Invalid format for 'when' statement. Lines must begin with '*' - - set %condition = (%tokens -> 2) - assume %condition or barf ".." - Invalid format for 'when' statement. Lines must begin with '*' and have a condition or the word "else" - - set %action = (%tokens -> 3) - if: %action is (nil) - lua do> "table.insert(\%fallthroughs, \%condition)" - do next %func_call - - if: =lua "\%condition.type == 'Word' and \%condition.value == 'else'" - %result join= ".." - - else - \(%action as lua statements) - stop for-loop - ..else - set %condition = (%condition as lua) - for all %fallthroughs - %condition join= " or \(% as lua)" - %result join= ".." - - \("if" if %first else "elseif") \%condition then - \(%action as lua statements) - - set %fallthroughs = [] - set %first = (no) + with [..] + %tokens <- (%func_call's "value") + %star <- (1st in %tokens) + %condition <- (2nd in %tokens) + %action <- (3rd in %tokens) + .. + assume (=lua "\%star and \%star.type == 'Word' and \%star.value == '*'") or barf ".." + Invalid format for 'when' statement. Lines must begin with '*' + assume %condition or barf ".." + Invalid format for 'when' statement. Lines must begin with '*' and have a condition or the word "else" + if: %action is (nil) + lua do> "table.insert(\%fallthroughs, \%condition)" + do next %func_call + + if: =lua "\%condition.type == 'Word' and \%condition.value == 'else'" + + <- %result + ".." + + else + \(%action as lua statements) + stop + ..else + %condition <- (%condition as lua) + for all %fallthroughs + <- %condition + " or \(% as lua)" + <- %result + ".." + + \("if" if %is_first else "elseif") \%condition then + \(%action as lua statements) + + %fallthroughs <- [] + %is_first <- (no) if: %result is not "" - %result join= "\nend" + <- %result + "\nend" return %result # Switch statement immediately compile [when %branch_value = ? %body, when %branch_value is ? %body] to code - set %result = "" - set %fallthroughs = [] - set %first = (yes) + %result <- "" + %fallthroughs <- [] + %is_first <- (yes) + %seen_else <- (no) for %func_call in (%body's "value") assume ((%func_call's "type") is "FunctionCall") or barf ".." Invalid format for 'when' statement. Only '*' blocks are allowed. - set %tokens = (%func_call's "value") - set %star = (%tokens -> 1) - assume (=lua "\%star and \%star.type == 'Word' and \%star.value == '*'") or barf ".." - Invalid format for 'when' statement. Lines must begin with '*' - - set %condition = (%tokens -> 2) - assume %condition or barf ".." - Invalid format for 'when' statement. Lines must begin with '*' and have a condition or the word "else" - - set %action = (%tokens -> 3) - if: %action is (nil) - lua> "table.insert(\%fallthroughs, \%condition)" - do next %func_call - - if: =lua "\%condition.type == 'Word' and \%condition.value == 'else'" - %result join= ".." - - else - \(%action as lua statements) - stop for-loop - ..else - set %condition = "branch_value == (\(%condition as lua))" - for all %fallthroughs - %condition join= " or (branch_value == \(% as lua))" - %result join= ".." - - \("if" if %first else "elseif") \%condition then - \(%action as lua statements) - - set %fallthroughs = [] - set %first = (no) + %tokens <- (%func_call's "value") + with [%star<-(1st in %tokens), %condition<-(2nd in %tokens), %action<-(3rd in %tokens)] + assume (=lua "\%star and \%star.type == 'Word' and \%star.value == '*'") or barf ".." + Invalid format for 'when' statement. Lines must begin with '*' + assume %condition or barf ".." + Invalid format for 'when' statement. Lines must begin with '*' and have a condition or the word "else" + if: %action is (nil) + lua> "table.insert(\%fallthroughs, \%condition)" + do next %func_call + + if: =lua "\%condition.type == 'Word' and \%condition.value == 'else'" + assume (not %is_first) or barf "'else' clause cannot be first in 'when % = ?' block" + <- %result + ".." + + else + \(%action as lua statements) + end + %seen_else <- (yes) + ..else + assume (not %seen_else) or barf "'else' clause needs to be last in 'when % = ?' block" + %clause <- "" + if: ((%condition's "type") is "Text") or ((%condition's "type") is "Number") + %clause <- "branch_value == (\(%condition as lua))" + ..else + %clause <- "utils.equivalent(branch_value, \(%condition as lua))" + for all %fallthroughs + if: ((%'s "type") is "Text") or ((%'s "type") is "Number") + <- %clause + " or branch_value == (\(%condition as lua))" + ..else + <- %clause + " or utils.equivalent(branch_value, \(%condition as lua))" + <- %result + ".." + + \("if" if %is_first else "elseif") \%clause then + \(%action as lua statements) - if: %result is not "" - set %result = ".." - do --when % = ? - local branch_value = \(%branch_value as lua);\ - ..\%result - end - end --when % = ? + %fallthroughs <- [] + %is_first <- (no) + + assume (%result is not "") or barf "No body for 'when % = ?' block!" + unless %seen_else + <- %result + "\nend" + %result <- ".." + do --when % = ? + local branch_value = \(%branch_value as lua);\ + ..\%result + end --when % = ? return %result # Try/except @@ -417,27 +455,3 @@ immediately end end -immediately - compile [with %assignments %action] to code - local [%lua, %olds, %old_vals, %new_vals] - set {%temp_vars:[], %old_vals:[], %new_vals:[]} - for %i=%assignment in (%assignments' "value") - set (%temp_vars->%i) = "temp\%i" - set (%old_vals->%i) = ((%assignment's "dict_key") as lua) - set (%new_vals->%i) = ((%assignment's "dict_value") as lua) - return ".." - do - local \(join %temp_vars with ", ") = \(join %old_vals with ", "); - \(join %old_vals with ", ") = \(join %new_vals with ", "); - local fell_through = false; - local ok, ret = pcall(function() - do - \(%action as lua statements) - end - fell_through = true; - end); - \(join %old_vals with ", ") = \(join %temp_vars with ", "); - if not ok then error(ret, 0); end - if not fell_through then return ret end - end - |