diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/core/control_flow.nom | 138 |
1 files changed, 68 insertions, 70 deletions
diff --git a/lib/core/control_flow.nom b/lib/core/control_flow.nom index ca67394..a1fdeee 100644 --- a/lib/core/control_flow.nom +++ b/lib/core/control_flow.nom @@ -161,31 +161,71 @@ test: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # For-each loop (lua's "ipairs()") -(for $var in $iterable at $i $body) compiles to: +(for $var in $iterable $body) compiles to: + unless $var: + at (this tree) fail "No var here" # This uses Lua's approach of only allowing loop-scoped variables in a loop + if (($var.type == "Action") and ($var.stub == "1 =")): + [$key, $value] = [$var.1, $var.3] + go to (vars set) + if (($var.type == "Action") and ($var.stub == "1 at")): + [$key, $value] = [$var.3, $var.1] + ..else: + [$key, $value] = [nil, $var] + + --- (vars set) --- + unless $value: + at (this tree) fail "No value here" + + # Numeric loop: if (($iterable.type == "Action") and (($iterable, get stub) == "1 to")): [$start, $stop] = [$iterable.1, $iterable.3] $loop = Lua (" local _start = \($start as lua expr) - for \($var as lua identifier)=_start,\($stop as lua expr) do - \($i as lua identifier) = \($var as lua identifier) - _start + 1 + for \($value as lua identifier)=_start,\($stop as lua expr) do + ") + if $key: + $loop, add (" + + local \($key as lua identifier) = \($value as lua identifier) - _start + 1; ") + go to (loop set) + + # Numeric loop with step: if (($iterable.type == "Action") and (($iterable, get stub) == "1 to 2 by")): [$start, $stop, $step] = [$iterable.1, $iterable.3, $iterable.5] $loop = Lua (" - local _start, _step = \($start as lua expr), \($step as lua expr) - for \($var as lua identifier)=_start,\($stop as lua expr),_step do - \($i as lua identifier) = (\($var as lua identifier) - _start)/_step + 1 + local _start, _step = \($start as lua expr), \($step as lua expr); + for \($value as lua identifier)=_start,\($stop as lua expr),_step do + ") + if $key: + $loop, add (" + + local \($key as lua identifier) = (\($value as lua identifier) - _start)/_step + 1 + ") + go to (loop set) + + # for $ in (...): + if $key: + $loop = + Lua (" + local _iterating = \($iterable as lua expr); + local _next = getmetatable(_iterating).__next or next; + for \($key as lua identifier),\($value as lua identifier) in _next,_iterating,nil do + if \($value as lua identifier) == nil and _1_is_a_dead_coroutine(_iterating) then break end ") - unless $loop: + ..else: $loop = Lua (" - local _iterating = _1_as_list(\($iterable as lua expr)) - for \($i as lua identifier)=1,#_iterating do - \($var as lua identifier) = _iterating[\($i as lua identifier)] + local _iterating = _1_as_an_iterable(\($iterable as lua expr)) + for _i=1,#_iterating do + local \($value as lua identifier) = _iterating[_i] + if \($value as lua identifier) == nil and _1_is_a_dead_coroutine(_iterating) then break end ") + + --- (loop set) --- $lua = Lua (" do -- for-loop @@ -196,17 +236,27 @@ test: if ($body has subtree \(do next)): $lua, add "\n ::continue::" - if ($body has subtree \(do next $var)): - $lua, add "\n " (\(---next $var ---) as lua) + if ($key and ($body has subtree \(do next $key))): + $lua, add "\n " (\(---next $key ---) as lua) + + if ($body has subtree \(do next $value)): + $lua, add "\n " (\(---next $value ---) as lua) $lua, add "\n end" - if ($body has subtree \(stop $var)): - $lua, add "\n " (\(---stop $var ---) as lua) + if ($key and ($body has subtree \(stop $key))): + $lua, add "\n " (\(---stop $key ---) as lua) + if ($body has subtree \(stop $value)): + $lua, add "\n " (\(---stop $value ---) as lua) $lua, add "\nend -- for-loop" + $lua, remove free vars [($value as lua identifier, text), $key and ($key as lua identifier, text)] return $lua -(for $var in $iterable $body) parses as - for $var in $iterable at (=lua "_i") $body +# TODO: remove these shims: +(for $var in $iterable at $i $body) parses as + for ($i = $var) in $iterable $body + +(for $k = $v in $iterable $body) parses as + for ($k = $v) in $iterable $body test: $d = {.a = 10, .b = 20, .c = 30, .d = 40, .e = 50} @@ -237,7 +287,7 @@ test: stop $outer assume ($nums == [1, -2, 3, -2, 3, 4, 3, 4, 5]) -# These are shims, and should be phased out: +# TODO: These are shims, and should be phased out: [ for $var in $start to $stop by $step $body for $var in $start to $stop via $step $body @@ -253,59 +303,7 @@ test: $x += 1 assume $x == 5 -(repeat $n times $body) parses as (for (=lua "_XXX_") in (1 to $n by 1) $body) - -# Dict iteration (lua's "pairs()") -test: - $a = [10, 20, 30, 40, 50] - $b = [] - for $x in $a: - $b, add $x - assume ($a == $b) - $b = [] - for $x in $a: - if ($x == 10): - do next $x - - if ($x == 50): - stop $x - - $b, add $x - assume ($b == [20, 30, 40]) - # Small memory footprint: - assume (1 to (1 << 31)) - -[for $key = $value in $iterable $body, for $key $value in $iterable $body] -..all compile to: - $lua = - Lua (" - for \($key as lua identifier),\($value as lua identifier) in pairs(\ - ..\($iterable as lua expr)) do - ") - $lua, add "\n " ($body as lua) - if ($body has subtree \(do next)): - $lua, add "\n ::continue::" - - if ($body has subtree \(do next $key)): - $lua, add "\n " (\(---next $key ---) as lua) - - if ($body has subtree \(do next $value)): - $lua, add "\n " (\(---next $value ---) as lua) - - $lua, add "\nend --foreach-loop" - $stop_labels = (Lua "") - if ($body has subtree \(stop $key)): - $stop_labels, add "\n" (\(---stop $key ---) as lua) - - if ($body has subtree \(stop $value)): - $stop_labels, add "\n" (\(---stop $value ---) as lua) - - if ((size of "\$stop_labels") > 0): - $inner_lua = $lua - $lua = (Lua "do -- scope for stopping for $ = $ loop\n ") - $lua, add $inner_lua $stop_labels "\nend" - - return $lua +(repeat $n times $body) parses as (for (=lua "_i") in (1 to $n by 1) $body) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |