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|
require "lib/metaprogramming.nom"
require "lib/operators.nom"
require "lib/utils.nom"
# Conditionals
compile [if %condition %if_body] to code: ".."
|if \(%condition as lua) then;
| \(%if_body as lua statements)
|end;
compile [if %condition %if_body else %else_body] to code: ".."
|if \(%condition as lua) then;
| \(%if_body as lua statements)
|else;
| \(%else_body as lua statements)
|end;
# Return
compile [return] to code: "do; return; end;"
compile [return %return-value] to code: "do; return \(%return-value as lua); end;"
# GOTOs
compile [-> %label] to code: ".."
|::label_\(nomsu "var_to_lua_identifier" [%label])::;
compile [go to %label] to code: ".."
|goto label_\(nomsu "var_to_lua_identifier" [%label]);
# Loop control flow
compile [stop, stop loop, break] to code: "break"
compile [stop for, stop for-loop, break for] to code: "goto break_for"
compile [stop repeat, stop repeat-loop, break repeat] to code: "goto break_repeat"
compile [stop %var, break %var] to code: ".."
|goto break_\(nomsu "var_to_lua_identifier" [%var]);
compile [continue, continue loop] to code: "continue"
compile [continue for, continue for-loop] to code: "goto continue_for"
compile [continue repeat, continue repeat-loop] to code: "goto continue_repeat"
compile [continue %var, go to next %var, on to the next %var] to code: ".."
|goto continue_\(nomsu "var_to_lua_identifier" [%var]);
# While loops
compile [repeat while %condition %body] to code: ".."
|do;
| while \(%condition as lua) do;
| \(%body as lua statements)
| ::continue_repeat::;
| end;
| ::break_repeat::;
|end;
parse [repeat %body] as: repeat while (true) %body
parse [repeat until %condition %body] as: repeat while (not %condition) %body
# Numeric range for loops
compile [..]
for %var from %start to %stop by %step %body
for %var from %start to %stop via %step %body
..to code: ".."
|do;
| for i=\(%start as lua),\(%stop as lua),\(%step as lua) do;
# This trashes the loop variables, just like in Python.
| \(%var as lua) = i;
| \(%body as lua statements)
| ::continue_for::;
| ::continue_\(nomsu "var_to_lua_identifier" [%var])::;
| end;
| ::break_for::;
| ::break_\(nomsu "var_to_lua_identifier" [%var])::;
|end;
parse [for %var from %start to %stop %body] as: for %var from %start to %stop via 1 %body
parse [..]
for all %start to %stop by %step %body
for all %start to %stop via %step %body
..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
compile [for %var in %iterable %body] to code:
".."
|do;
| for i,value in ipairs(\(%iterable as lua)) do;
# This trashes the loop variables, just like in Python.
| \(%var as lua) = value;
| \(%body as lua statements)
| ::continue_for::;
| ::continue_\(nomsu "var_to_lua_identifier" [%var])::;
| end;
| ::break_for::;
| ::break_\(nomsu "var_to_lua_identifier" [%var])::;
|end;
parse [for all %iterable %body] as: for % in %iterable %body
# Switch statement/multi-branch if
compile [when %body] to code:
%result = "do;\n"
%fallthroughs = []
for %func-call in (%body's "value"):
assert ((%func-call's "type") == "FunctionCall") ".."
|Invalid format for 'when' statement. Only '*' blocks are allowed.
%tokens = (%func-call's "value")
%star = (%tokens -> 1)
assert (lua expr "vars.star and vars.star.type == 'Word' and vars.star.value == '*'") ".."
|Invalid format for 'when' statement. Lines must begin with '*'
%condition = (%tokens -> 2)
assert %condition ".."
|Invalid format for 'when' statement. Lines must begin with '*' and have a condition or the word "else"
%action = (%tokens -> 3)
if (%action == (nil)):
lua block "table.insert(vars.fallthroughs, vars.condition)"
go to next %func-call
if (lua expr "vars.condition.type == 'Word' and vars.condition.value == 'else'"):
%result join= ".."
|
|do;
..else:
%condition = (%condition as lua)
for all %fallthroughs:
%condition join= " or \(% as lua)"
%result join= ".."
|
|if \(%condition) then;
%result join= ".."
|
| \(%action as lua statements)
| goto finished_when;
|end;
%fallthroughs = []
%result join= "\n::finished_when::;\nend;"
%result
# Switch statement
compile [when %branch-value == ? %body] to code:
%result = "do;\nlocal branch_value = \(%branch-value as lua)"
%fallthroughs = []
for %func-call in (%body's "value"):
assert ((%func-call's "type") == "FunctionCall") ".."
|Invalid format for 'when' statement. Only '*' blocks are allowed.
%tokens = (%func-call's "value")
%star = (%tokens -> 1)
assert (lua expr "vars.star and vars.star.type == 'Word' and vars.star.value == '*'") ".."
|Invalid format for 'when' statement. Lines must begin with '*'
%condition = (%tokens -> 2)
assert %condition ".."
|Invalid format for 'when' statement. Lines must begin with '*' and have a condition or the word "else"
%action = (%tokens -> 3)
if (%action == (nil)):
lua block "table.insert(vars.fallthroughs, vars.condition)"
go to next %func-call
if (lua expr "vars.condition.type == 'Word' and vars.condition.value == 'else'"):
%result join= ".."
|
|do;
..else:
%condition = "branch_value == (\(%condition as lua))"
for all %fallthroughs:
%condition join= " or (branch_value == \(% as lua))"
%result join= ".."
|
|if \(%condition) then;
%result join= ".."
|
| \(%action as lua statements)
| goto finished_when;
|end;
%fallthroughs = []
%result join= "\n::finished_when::;\nend;"
%result
|
