//: Phase 1 of running Mu code: load it from a textual representation.
//:
//: The process of running Mu code:
//: load -> transform -> run
:(scenarios load) // use 'load' instead of 'run' in all scenarios in this layer
:(scenario first_recipe)
def main [
1:number <- copy 23
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: product: {1: "number"}
:(code)
vector<recipe_ordinal> load(string form) {
istringstream in(form);
in >> std::noskipws;
return load(in);
}
vector<recipe_ordinal> load(istream& in) {
in >> std::noskipws;
vector<recipe_ordinal> result;
while (has_data(in)) {
skip_whitespace_and_comments(in);
if (!has_data(in)) break;
string command = next_word(in);
if (command.empty()) {
assert(!has_data(in));
break;
}
// Command Handlers
if (command == "recipe" || command == "def") {
recipe_ordinal r = slurp_recipe(in);
if (r > 0) result.push_back(r);
}
else if (command == "recipe!" || command == "def!") {
Disable_redefine_checks = true;
recipe_ordinal r = slurp_recipe(in);
if (r > 0) result.push_back(r);
Disable_redefine_checks = false;
}
// End Command Handlers
else {
raise << "unknown top-level command: " << command << '\n' << end();
}
}
return result;
}
// return the recipe ordinal slurped, or -1 if it failed
// (later layers will cause failures)
int slurp_recipe(istream& in) {
recipe result;
result.name = next_word(in);
if (result.name.empty()) {
assert(!has_data(in));
raise << "file ended with 'recipe'\n" << end();
return -1;
}
// End Load Recipe Name
skip_whitespace_but_not_newline(in);
// End Recipe Refinements
if (result.name.empty())
raise << "empty result.name\n" << end();
trace(9991, "parse") << "--- defining " << result.name << end();
if (!contains_key(Recipe_ordinal, result.name))
put(Recipe_ordinal, result.name, Next_recipe_ordinal++);
if (Recipe.find(get(Recipe_ordinal, result.name)) != Recipe.end()) {
trace(9991, "parse") << "already exists" << end();
if (should_check_for_redefine(result.name))
raise << "redefining recipe " << result.name << "\n" << end();
Recipe.erase(get(Recipe_ordinal, result.name));
}
slurp_body(in, result);
// End Recipe Body(result)
put(Recipe, get(Recipe_ordinal, result.name), result);
return get(Recipe_ordinal, result.name);
}
void slurp_body(istream& in, recipe& result) {
in >> std::noskipws;
skip_whitespace_but_not_newline(in);
if (in.get() != '[')
raise << result.name << ": recipe body must begin with '['\n" << end();
skip_whitespace_and_comments(in); // permit trailing comment after '['
instruction curr;
while (next_instruction(in, &curr)) {
curr.original_string = to_original_string(curr);
// End Rewrite Instruction(curr, recipe result)
trace(9992, "load") << "after rewriting: " << to_string(curr) << end();
if (!curr.is_empty()) result.steps.push_back(curr);
}
}
bool next_instruction(istream& in, instruction* curr) {
curr->clear();
skip_whitespace_and_comments(in);
if (!has_data(in)) {
raise << "incomplete recipe at end of file (0)\n" << end();
return false;
}
vector<string> words;
while (has_data(in) && in.peek() != '\n') {
skip_whitespace_but_not_newline(in);
if (!has_data(in)) {
raise << "incomplete recipe at end of file (1)\n" << end();
return false;
}
string word = next_word(in);
if (word.empty()) {
assert(!has_data(in));
raise << "incomplete recipe at end of file (2)\n" << end();
return false;
}
words.push_back(word);
skip_whitespace_but_not_newline(in);
}
skip_whitespace_and_comments(in);
if (SIZE(words) == 1 && words.at(0) == "]")
return false; // end of recipe
if (SIZE(words) == 1 && is_label_word(words.at(0))) {
curr->is_label = true;
curr->label = words.at(0);
trace(9993, "parse") << "label: " << curr->label << end();
if (!has_data(in)) {
raise << "incomplete recipe at end of file (3)\n" << end();
return false;
}
return true;
}
vector<string>::iterator p = words.begin();
if (find(words.begin(), words.end(), "<-") != words.end()) {
for (; *p != "<-"; ++p)
curr->products.push_back(reagent(*p));
++p; // skip <-
}
if (p == words.end()) {
raise << "instruction prematurely ended with '<-'\n" << end();
return false;
}
curr->old_name = curr->name = *p; ++p;
// curr->operation will be set in a later layer
for (; p != words.end(); ++p)
curr->ingredients.push_back(reagent(*p));
trace(9993, "parse") << "instruction: " << curr->name << end();
trace(9993, "parse") << " number of ingredients: " << SIZE(curr->ingredients) << end();
for (vector<reagent>::iterator p = curr->ingredients.begin(); p != curr->ingredients.end(); ++p)
trace(9993, "parse") << " ingredient: " << to_string(*p) << end();
for (vector<reagent>::iterator p = curr->products.begin(); p != curr->products.end(); ++p)
trace(9993, "parse") << " product: " << to_string(*p) << end();
if (!has_data(in)) {
raise << "9: unbalanced '[' for recipe\n" << end();
return false;
}
return true;
}
// can return empty string -- only if `in` has no more data
string next_word(istream& in) {
skip_whitespace_but_not_newline(in);
// End next_word Special-cases
ostringstream out;
slurp_word(in, out);
skip_whitespace_and_comments_but_not_newline(in);
string result = out.str();
if (result != "[" && ends_with(result, '['))
raise << "insert a space before '[' in '" << result << "'\n" << end();
return result;
}
bool is_label_word(const string& word) {
if (word.empty()) return false; // error raised elsewhere
return !isalnum(word.at(0)) && string("$_*@&,=-[]()").find(word.at(0)) == string::npos;
}
bool ends_with(const string& s, const char c) {
if (s.empty()) return false;
return *s.rbegin() == c;
}
:(before "End Globals")
// word boundaries
extern const string Terminators("(){}");
:(code)
void slurp_word(istream& in, ostream& out) {
char c;
if (has_data(in) && Terminators.find(in.peek()) != string::npos) {
in >> c;
out << c;
return;
}
while (in >> c) {
if (isspace(c) || Terminators.find(c) != string::npos || Ignore.find(c) != string::npos) {
in.putback(c);
break;
}
out << c;
}
}
void skip_whitespace_and_comments(istream& in) {
while (true) {
if (!has_data(in)) break;
if (isspace(in.peek())) in.get();
else if (Ignore.find(in.peek()) != string::npos) in.get();
else if (in.peek() == '#') skip_comment(in);
else break;
}
}
// confusing; move to the next line only to skip a comment, but never otherwise
void skip_whitespace_and_comments_but_not_newline(istream& in) {
while (true) {
if (!has_data(in)) break;
if (in.peek() == '\n') break;
if (isspace(in.peek())) in.get();
else if (Ignore.find(in.peek()) != string::npos) in.get();
else if (in.peek() == '#') skip_comment(in);
else break;
}
}
void skip_comment(istream& in) {
if (has_data(in) && in.peek() == '#') {
in.get();
while (has_data(in) && in.peek() != '\n') in.get();
}
}
:(scenario recipe_instead_of_def)
recipe main [
1:number <- copy 23
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: product: {1: "number"}
:(scenario parse_comment_outside_recipe)
# this comment will be dropped by the tangler, so we need a dummy recipe to stop that
def f1 [
]
# this comment will go through to 'load'
def main [
1:number <- copy 23
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: product: {1: "number"}
:(scenario parse_comment_amongst_instruction)
def main [
# comment
1:number <- copy 23
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: product: {1: "number"}
:(scenario parse_comment_amongst_instruction_2)
def main [
# comment
1:number <- copy 23
# comment
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: product: {1: "number"}
:(scenario parse_comment_amongst_instruction_3)
def main [
1:number <- copy 23
# comment
2:number <- copy 23
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: product: {1: "number"}
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: product: {2: "number"}
:(scenario parse_comment_after_instruction)
def main [
1:number <- copy 23 # comment
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: product: {1: "number"}
:(scenario parse_label)
def main [
+foo
]
+parse: label: +foo
:(scenario parse_dollar_as_recipe_name)
def main [
$foo
]
+parse: instruction: $foo
:(scenario parse_multiple_properties)
def main [
1:number <- copy 23/foo:bar:baz
]
+parse: instruction: copy
+parse: ingredient: {23: "literal", "foo": ("bar" "baz")}
+parse: product: {1: "number"}
:(scenario parse_multiple_products)
def main [
1:number, 2:number <- copy 23
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: product: {1: "number"}
+parse: product: {2: "number"}
:(scenario parse_multiple_ingredients)
def main [
1:number, 2:number <- copy 23, 4:number
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: ingredient: {4: "number"}
+parse: product: {1: "number"}
+parse: product: {2: "number"}
:(scenario parse_multiple_types)
def main [
1:number, 2:address:number <- copy 23, 4:number
]
+parse: instruction: copy
+parse: ingredient: {23: "literal"}
+parse: ingredient: {4: "number"}
+parse: product: {1: "number"}
+parse: product: {2: ("address" "number")}
:(scenario parse_properties)
def main [
1:address:number/lookup <- copy 23
]
+parse: product: {1: ("address" "number"), "lookup": ()}
//: this test we can't represent with a scenario
:(code)
void test_parse_comment_terminated_by_eof() {
load("recipe main [\n"
" a:number <- copy 34\n"
"]\n"
"# abc"); // no newline after comment
cerr << "."; // termination = success
}
:(scenario warn_on_missing_space_before_bracket)
% Hide_errors = true;
def main[
1:number <- copy 23
]
+error: insert a space before '[' in 'main['
//: Warn if a recipe gets redefined, because large codebases can accidentally
//: step on their own toes. But there'll be many occasions later where
//: we'll want to disable the errors.
:(before "End Globals")
bool Disable_redefine_checks = false;
:(before "End Setup")
Disable_redefine_checks = false;
:(code)
bool should_check_for_redefine(const string& recipe_name) {
if (Disable_redefine_checks) return false;
return true;
}
:(scenario forbid_redefining_recipes)
% Hide_errors = true;
def main [
1:number <- copy 23
]
def main [
1:number <- copy 24
]
+error: redefining recipe main
:(scenario permit_forcibly_redefining_recipes)
def main [
1:number <- copy 23
]
def! main [
1:number <- copy 24
]
-error: redefining recipe main
$error: 0
:(code)
// for debugging
void show_rest_of_stream(istream& in) {
cerr << '^';
char c;
while (in >> c)
cerr << c;
cerr << "$\n";
exit(0);
}