ranger - mirror of ranger - a simple, vim-like file manager

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1 files changed, 1 insertions, 1 deletions

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Mu - 040brace.cc</title> <meta name="Generator" content="Vim/7.4"> <meta name="plugin-version" content="vim7.4_v1"> <meta name="syntax" content="cpp"> <meta name="settings" content="use_css,pre_wrap,no_foldcolumn,expand_tabs,prevent_copy="> <meta name="colorscheme" content="minimal"> <style type="text/css">  </style> <script type='text/javascript'>  </script> </head> <body> <pre id='vimCodeElement'> //: Structured programming //: //: Our jump recipes are quite inconvenient to use, so mu provides a //: lightweight tool called 'transform_braces' to work in a slightly more //: convenient format with nested braces: //: //: { //: some instructions //: { //: more instructions //: } //: } //: //: Braces are just labels, they require no special parsing. The pseudo //: recipes 'loop' and 'break' jump to just after the enclosing '{' and '}' //: respectively. //: //: Conditional and unconditional 'loop' and 'break' should give us 80% of the //: benefits of the control-flow primitives we're used to in other languages, //: like 'if', 'while', 'for', etc. :(scenarios transform) :(scenario brace_conversion) recipe main [ { break 1:number <- copy 0 } ] +after-brace: recipe main +after-brace: jump 1:offset +after-brace: copy ... //: one-time setup :(after "int main") Transform.push_back(transform_braces); :(code) void transform_braces(const recipe_ordinal r) { //? cout << "AAA transform_braces\n"; //? 1 //? exit(0); //? 1 const int OPEN = 0, CLOSE = 1; // use signed integer for step index because we'll be doing arithmetic on it list<pair<int/*OPEN/CLOSE*/, /*step*/long long int> > braces; for (long long int index = 0; index < SIZE(Recipe[r].steps); ++index) { const instruction& inst = Recipe[r].steps.at(index); if (inst.label == "{") { trace("brace") << r << ": push (open, " << index << ")" << end(); braces.push_back(pair<int,long long int>(OPEN, index)); } if (inst.label == "}") { trace("brace") << "push (close, " << index << ")" << end(); braces.push_back(pair<int,long long int>(CLOSE, index)); } } stack</*step*/long long int> open_braces; trace("after-brace") << "recipe " << Recipe[r].name << end(); for (long long int index = 0; index < SIZE(Recipe[r].steps); ++index) { instruction& inst = Recipe[r].steps.at(index); if (inst.label == "{") { open_braces.push(index); continue; } if (inst.label == "}") { open_braces.pop(); continue; } if (inst.is_label) continue; if (inst.operation != Recipe_ordinal["loop"] && inst.operation != Recipe_ordinal["loop-if"] && inst.operation != Recipe_ordinal["loop-unless"] && inst.operation != Recipe_ordinal["break"] && inst.operation != Recipe_ordinal["break-if"] && inst.operation != Recipe_ordinal["break-unless"]) { trace("after-brace") << inst.name << " ..." << end(); continue; } // update instruction operation if (inst.name.find("-if") != string::npos) inst.operation = Recipe_ordinal["jump-if"]; else if (inst.name.find("-unless") != string::npos) inst.operation = Recipe_ordinal["jump-unless"]; else inst.operation = Recipe_ordinal["jump"]; // check for explicitly provided targets if (inst.name.find("-if") != string::npos || inst.name.find("-unless") != string::npos) { // conditional branches check arg 1 if (SIZE(inst.ingredients) > 1 && is_literal(inst.ingredients.at(1))) { trace("after-brace") << "jump " << inst.ingredients.at(1).name << ":offset" << end(); continue; } } else { // unconditional branches check arg 0 if (!inst.ingredients.empty() && is_literal(inst.ingredients.at(0))) { trace("after-brace") << "jump " << inst.ingredients.at(0).name << ":offset" << end(); continue; } } // if implicit, compute target reagent target; target.types.push_back(Type_ordinal["offset"]); target.set_value(0); if (open_braces.empty()) raise << inst.name << " needs a '{' before\n" << end(); else if (inst.name.find("loop") != string::npos) target.set_value(open_braces.top()-index); else // break instruction target.set_value(matching_brace(open_braces.top(), braces, r) - index - 1); inst.ingredients.push_back(target); // log computed target if (inst.name.find("-if") != string::npos) trace("after-brace") << "jump-if " << inst.ingredients.at(0).name << ", " << target.value << ":offset" << end(); else if (inst.name.find("-unless") != string::npos) trace("after-brace") << "jump-unless " << inst.ingredients.at(0).name << ", " << target.value << ":offset" << end(); else trace("after-brace") << "jump " << target.value << ":offset" << end(); } } // returns a signed integer not just so that we can return -1 but also to // enable future signed arithmetic long long int matching_brace(long long int index, const list<pair<int, long long int> >& braces, recipe_ordinal r) { int stacksize = 0; for (list<pair<int, long long int> >::const_iterator p = braces.begin(); p != braces.end(); ++p) { if (p->second < index) continue; stacksize += (p->first ? 1 : -1); if (stacksize == 0) return p->second; } raise << Recipe[r].name << ": unbalanced '{'\n" << end(); return SIZE(Recipe[r].steps); // exit current routine } // temporarily suppress run void transform(string form) { load(form); transform_all(); } //: Make sure these pseudo recipes get consistent numbers in all tests, even //: though they aren't implemented. :(before "End Primitive Recipe Declarations") BREAK, BREAK_IF, BREAK_UNLESS, LOOP, LOOP_IF, LOOP_UNLESS, :(before "End Primitive Recipe Numbers") Recipe_ordinal["break"] = BREAK; Recipe_ordinal["break-if"] = BREAK_IF; Recipe_ordinal["break-unless"] = BREAK_UNLESS; Recipe_ordinal["loop"] = LOOP; Recipe_ordinal["loop-if"] = LOOP_IF; Recipe_ordinal["loop-unless"] = LOOP_UNLESS; :(scenario loop) recipe main [ 1:number <- copy 0 2:number <- copy 0 { 3:number <- copy 0 loop } ] +after-brace: recipe main +after-brace: copy ... +after-brace: copy ... +after-brace: copy ... +after-brace: jump -2:offset :(scenario break_empty_block) recipe main [ 1:number <- copy 0 { break } ] +after-brace: recipe main +after-brace: copy ... +after-brace: jump 0:offset :(scenario break_cascading) recipe main [ 1:number <- copy 0 { break } { break } ] +after-brace: recipe main +after-brace: copy ... +after-brace: jump 0:offset +after-brace: jump 0:offset :(scenario break_cascading2) recipe main [ 1:number <- copy 0 2:number <- copy 0 { break 3:number <- copy 0 } { break } ] +after-brace: recipe main +after-brace: copy ... +after-brace: copy ... +after-brace: jump 1:offset +after-brace: copy ... +after-brace: jump 0:offset :(scenario break_if) recipe main [ 1:number <- copy 0 2:number <- copy 0 { break-if 2:number 3:number <- copy 0 } { break } ] +after-brace: recipe main +after-brace: copy ... +after-brace: copy ... +after-brace: jump-if 2, 1:offset +after-brace: copy ... +after-brace: jump 0:offset :(scenario break_nested) recipe main [ 1:number <- copy 0 { 2:number <- copy 0 break { 3:number <- copy 0 } 4:number <- copy 0 } ] +after-brace: jump 4:offset :(scenario break_nested_degenerate) recipe main [ 1:number <- copy 0 { 2:number <- copy 0 break { } 4:number <- copy 0 } ] +after-brace: jump 3:offset :(scenario break_nested_degenerate2) recipe main [ 1:number <- copy 0 { 2:number <- copy 0 break { } } ] +after-brace: jump 2:offset :(scenario break_label) % Hide_warnings = true; recipe main [ 1:number <- copy 0 { break +foo:offset } ] +after-brace: jump +foo:offset :(scenario break_unless) recipe main [ 1:number <- copy 0 2:number <- copy 0 { break-unless 2:number 3:number <- copy 0 } ] +after-brace: recipe main +after-brace: copy ... +after-brace: copy ... +after-brace: jump-unless 2, 1:offset +after-brace: copy ... :(scenario loop_unless) recipe main [ 1:number <- copy 0 2:number <- copy 0 { loop-unless 2:number 3:number <- copy 0 } ] +after-brace: recipe main +after-brace: copy ... +after-brace: copy ... +after-brace: jump-unless 2, -1:offset +after-brace: copy ... :(scenario loop_nested) recipe main [ 1:number <- copy 0 { 2:number <- copy 0 { 3:number <- copy 0 } loop-if 4:boolean 5:number <- copy 0 } ] +after-brace: recipe main +after-brace: jump-if 4, -5:offset :(scenario loop_label) recipe main [ 1:number <- copy 0 +foo 2:number <- copy 0 ] +after-brace: recipe main +after-brace: copy ... +after-brace: copy ... //: test how things actually run :(scenarios run) :(scenario brace_conversion_and_run) #? % Trace_stream->dump_layer = "run"; recipe test-factorial [ 1:number <- copy 5 2:number <- copy 1 { 3:boolean <- equal 1:number, 1 break-if 3:boolean # $print 1:number 2:number <- multiply 2:number, 1:number 1:number <- subtract 1:number, 1 loop } 4:number <- copy 2:number # trigger a read ] +mem: location 2 is 120 :(scenario break_outside_braces_warns) % Hide_warnings = true; recipe main [ break ] +warn: break needs a '{' before </pre> </body> </html>


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