nomsu/lib/collections.nom

require "lib/metaprogramming.nom"
require "lib/utils.nom"
require "lib/control_flow.nom"
require "lib/operators.nom"

# List/dict functions:

# Indexing
parse [..]
    %index st in %list, %index nd in %list, %index rd in %list
    %index th in %list, %index in %list
..as: %list -> %index
compile [..]
    %index st to last in %list, %index nd to last in %list, %index rd to last in %list
    %index th to last in %list
..to: "nomsu.utils.nth_to_last(\(%list as lua), \(%index as lua))"

parse [first in %list, first %list] as: 1 st in %list
parse [last in %list, last %list] as: 1 st to last in %list

# Dict iteration convenience function. This could also be accomplished with: for all (entries in %dict): ...
compile [for %key -> %value in %dict %body] to code: ".."
    |do;
    |    for k, v in pairs(\(%dict as lua)) do;
    |        \(%key as lua), \(%value as lua) = k, v;
    |        \(%body as lua statements)
    |    end;
    |end;

# Membership testing
rule [%item is in %list, %list contains %item, %list has %item] =:
    for %key -> %value in %list:
        if (%key == %item): return (yes)
    return (no)

rule [..]
    %item isn't in %list, %item is not in %list
    %list doesn't contain %item, %list does not contain %item
    %list doesn't have %item, %list does not have %item
..=:
    for %key -> %value in %list:
        if (%key == %item): return (no)
    return (yes)

compile [%list has key %index, %list has index %index] to: ".."
    |((\(%list as lua))[\(%index as lua)] ~= nil)

compile [..]
    %list doesn't have key %index, %list does not have key %index
    %list doesn't have index %index, %list does not have index %index
..to: "((\(%list as lua))[\(%index as lua)] ~= nil)"

compile [length of %list, size of %list, size %list, number of %list, len %list] to:
    "nomsu.utils.size(\(%list as lua))"

# Chained lookup
compile [%list ->* %indices] to:
    assert ((%indices's "type") == "List") ".."
        |Expected List for chained lookup, not \(%indices's "type")
    %ret = "\(%list as lua)"
    for %index in (%indices's "value"):
        %ret join= "[\(%index as lua)]"
    "\(%ret)"

# Assignment
compile [..]
    %list's %index = %new_value, %index st in %list = %new_value, %index nd in %list = %new_value
    %index rd in %list = %new_value, %index th in %list = %new_value, %index in %list = %new_value
    %list -> %index = %new_value
..to code:
    "(\(%list as lua))[\(%index as lua)] = \(%new_value as lua);"

compile [append %item to %list, add %item to %list] to:
    "table.insert(\(%list as lua), \(%item as lua))"

rule [flatten %lists] =:
    %flat = []
    for %list in %lists:
        for %item in %list:
            add %item to %flat
    %flat

rule [dict %items] =:
    %dict = []
    for %pair in %items:
        %dict -> (%pair -> 1) = (%pair -> 2)
    %dict

rule [entries in %dict] =:
    %entries = []
    for %k -> %v in %dict:
        add (dict [["key",%k],["value",%v]]) to %entries
    %entries

rule [keys in %dict] =:
    %keys = []
    for %k -> %v in %dict: add %k to %keys
    %keys

rule [values in %dict] =:
    %values = []
    for %k -> %v in %dict: add %v to %values
    %values

# List Comprehension
compile [%expression for %var in %iterable] to:
    assert ((%var's "type") == "Var") ".."
        |List comprehension has the wrong type for the loop variable. Expected Var, but got: \(%var's "type")
    ".."
        |(function(game, vars);
        |    local comprehension = {};
        |    for i,value in ipairs(\(%iterable as lua)) do;
        |        \(%var as lua) = value;
        |        comprehension[i] = \(%expression as lua);
        |    end;
        |    return comprehension;
        |end)(game, setmetatable({}, {__index=vars}))
parse [%expression for all %iterable] as: %expression for % in %iterable

rule [%items sorted] =:
    %copy = (% for all %items)
    sort %copy
    %copy
rule [%items sorted by %key] =:
    %copy = (% for all %items)
    sort %copy by %key
    %copy

# TODO: maybe make a generator/coroutine?

#.. Dict comprehensions can be accomplished okay by doing:
    dict ([new_key using (%'s "key"), new_value using (%'s "value")] for all (entries in %dict))
    or something similar
# TODO: fix compiler bugs
pass