1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
#..
This file contains definitions of operators like "+" and "and".
use "lib/metaprogramming.nom"
# Indexing:
immediately
#.. NOTE!!! It's critical that there are spaces around %key if it's a string,
otherwise, Lua will get confused and interpret %obj[[[foo]]] as %obj("[foo]")
instead of %obj[ "foo" ].
It's also critical to have parens around %obj, otherwise Lua is too dumb to
realize that {x=1}["x"] is the same as ({x=1})["x"] or that
{x=1}.x is the same as ({x=1}).x
compile [..]
%obj' %key, %obj's %key, %key in %obj, %key'th in %obj, %key of %obj,
%key st in %obj, %key nd in %obj, %key rd in %obj, %key th in %obj,
..to
lua> ".."
local obj_lua = \(%obj as lua);
if not obj_lua:sub(-1,-1):match("[a-zA-Z)]") then
obj_lua = "("..obj_lua..")";
end
local key_lua = \(%key as lua);
local key_attr = (key_lua:match("'([a-zA-Z][a-zA-Z0-9]*)'")
or key_lua:match('"([a-zA-Z][a-zA-Z0-9]*)"'));
if key_attr then
return obj_lua.."."..key_attr;
elseif key_lua:sub(1,1) == "[" then
key_lua = " "..key_lua.." ";
end
return obj_lua.."["..key_lua.."]";
# Comparison Operators
immediately
compile [%x < %y] to "(\(%x as lua) < \(%y as lua))"
compile [%x > %y] to "(\(%x as lua) > \(%y as lua))"
compile [%x <= %y] to "(\(%x as lua) <= \(%y as lua))"
compile [%x >= %y] to "(\(%x as lua) >= \(%y as lua))"
compile [%a is %b, %a = %b, %a == %b] to
lua> ".."
local safe = {Text=true, Number=true};
local a_lua, b_lua = nomsu:tree_to_lua(\%a).expr, nomsu:tree_to_lua(\%b).expr;
if safe[\%a.type] or safe[\%b.type] then
return "("..a_lua.." == "..b_lua..")";
else
return "utils.equivalent("..a_lua..", "..b_lua..")";
end
compile [%a isn't %b, %a is not %b, %a not= %b, %a != %b] to
lua> ".."
local safe = {Text=true, Number=true};
local a_lua, b_lua = nomsu:tree_to_lua(\%a).expr, nomsu:tree_to_lua(\%b).expr;
if safe[\%a.type] or safe[\%b.type] then
return "("..a_lua.." ~= "..b_lua..")";
else
return "(not utils.equivalent("..a_lua..", "..b_lua.."))";
end
# For strict identity checking, use (%x's id) is (%y's id)
compile [%'s id, id of %] to "nomsu.ids[\(% as lua)]"
# Variable assignment operator
immediately
lua> ".."
nomsu:define_compile_action("%var <- %value", \(__line_no__), function(\%var, \%value)
local lua = {};
lua.statements = ("%s = %s;"):format(
assert(nomsu:tree_to_lua(\%var).expr, "Invalid target for assignment: "..\%var.src),
assert(nomsu:tree_to_lua(\%value).expr, "Invalid value for assignment: "..\%value.src));
if \%var.type == "Var" then
lua.locals = {nomsu:tree_to_lua(\%var).expr};
end
return lua;
end, \(__src__ 1));
lua> ".."
nomsu:define_compile_action("export %var <- %value", \(__line_no__), function(\%var, \%value)
local lua = {};
lua.statements = ("%s = %s;"):format(
assert(nomsu:tree_to_lua(\%var).expr, "Invalid target for assignment: "..\%var.src),
assert(nomsu:tree_to_lua(\%value).expr, "Invalid value for assignment: "..\%value.src));
return lua;
end, \(__src__ 1));
lua> ".."
nomsu:define_compile_action("with %assignments %body", \(__line_no__), function(\%assignments, \%body)
local body_lua = nomsu:tree_to_lua(\%body);
local declarations = "";
local leftover_locals = {};
for _, body_local in ipairs(body_lua.locals or {}) do
leftover_locals[body_local] = true;
end
assert(\%assignments.type == "List",
"Expected a List for the assignments part of 'with' statement, not "..\%assignments.src);
for i, item in ipairs(\%assignments.value) do
if item.type == "Var" then
local var = nomsu:tree_to_lua(item).expr;
leftover_locals[var] = nil;
declarations = declarations.."local "..var..";\\n ";
else
assert(item.type == "FunctionCall" and #item.value == 3 and item.value[2].src == "<-",
"'with' statement expects entries of the form: '%var <- %value', not: "..item.src);
local target, value = item.value[1], item.value[3];
if target.type == "Var" then
local var = nomsu:tree_to_lua(target).expr;
leftover_locals[var] = nil;
declarations = declarations..(("local %s = %s;\\n "):format(
var, assert(nomsu:tree_to_lua(value).expr, "Invalid value for assignment: "..value.src)));
else
declarations = declarations..(("%s = %s;\\n "):format(
assert(nomsu:tree_to_lua(target).expr, "Invalid target for assignment: "..target.src),
assert(nomsu:tree_to_lua(value).expr, "Invalid value for assignment: "..value.src)));
end
end
end
local code = ([[
do
%s%s
end]]):format(declarations, body_lua.statements or (body_lua.expr..";"));
return {statements=code, locals=utils.keys(leftover_locals)};
end, \(__src__ 1));
lua> ".."
nomsu:define_compile_action("exporting %exported %body", \(__line_no__), function(\%exported, \%body)
local body_lua = nomsu:tree_to_lua(\%body);
local declarations = "";
local leftover_locals = {};
for _, body_local in ipairs(body_lua.locals or {}) do
leftover_locals[body_local] = true;
end
assert(\%exported.type == "List",
"Expected a List for the export part of 'exporting' statement, not "..\%exported.src);
for i, item in ipairs(\%exported.value) do
assert(item.type == "Var", "exporting statement expects Vars, not: "..item.src);
local var = nomsu:tree_to_lua(item).expr;
leftover_locals[var] = nil;
end
local code = ([[
do
%s%s
end]]):format(declarations, body_lua.statements or (body_lua.expr..";"));
return {statements=code, locals=utils.keys(leftover_locals)};
end, \(__src__ 1));
immediately
# Math Operators
compile [%x + %y] to "(\(%x as lua) + \(%y as lua))"
compile [%x - %y] to "(\(%x as lua) - \(%y as lua))"
compile [%x * %y] to "(\(%x as lua) * \(%y as lua))"
compile [%x / %y] to "(\(%x as lua) / \(%y as lua))"
compile [%x ^ %y] to "(\(%x as lua) ^ \(%y as lua))"
compile [%x wrapped around %y, %x mod %y] to "(\(%x as lua) % \(%y as lua))"
# 3-part chained comparisons
# (uses a lambda to avoid re-evaluating middle value, while still being an expression)
parse [%x < %y < %z] as: =lua "(function(x,y,z) return x < y and y < z; end)(\%x,\%y,\%z)"
parse [%x <= %y < %z] as: =lua "(function(x,y,z) return x <= y and y < z; end)(\%x,\%y,\%z)"
parse [%x < %y <= %z] as: =lua "(function(x,y,z) return x < y and y <= z; end)(\%x,\%y,\%z)"
parse [%x <= %y <= %z] as: =lua "(function(x,y,z) return x <= y and y <= z; end)(\%x,\%y,\%z)"
parse [%x > %y > %z] as: =lua "(function(x,y,z) return x > y and y > z; end)(\%x,\%y,\%z)"
parse [%x >= %y > %z] as: =lua "(function(x,y,z) return x >= y and y > z; end)(\%x,\%y,\%z)"
parse [%x > %y >= %z] as: =lua "(function(x,y,z) return x > y and y >= z; end)(\%x,\%y,\%z)"
parse [%x >= %y >= %z] as: =lua "(function(x,y,z) return x >= y and y >= z; end)(\%x,\%y,\%z)"
# TODO: optimize for common case where x,y,z are all either variables or number literals
# Boolean Operators
compile [%x and %y] to "(\(%x as lua) and \(%y as lua))"
compile [%x or %y] to "(\(%x as lua) or \(%y as lua))"
# Bitwise Operators
compile [%a OR %b, %a | %b] to "bit32.bor(\(%a as lua), \(%b as lua))"
compile [%a XOR %b] to "bit32.bxor(\(%a as lua), \(%b as lua))"
compile [%a AND %b, %a & %b] to "bit32.band(\(%a as lua), \(%b as lua))"
compile [NOT %, ~ %] to "bit32.bnot(\(% as lua))"
compile [%x LSHIFT %shift, %x << %shift] to "bit32.lshift(\(%x as lua), \(%shift as lua))"
compile [%x RSHIFT %shift, %x >>> %shift] to "bit32.rshift(\(%x as lua), \(%shift as lua))"
compile [%x ARSHIFT %shift, %x >> %shift] to "bit32.arshift(\(%x as lua), \(%shift as lua))"
# TODO: implement OR, XOR, AND for multiple operands?
# Unary operators
compile [- %] to "(- \(% as lua))"
compile [not %] to "(not \(% as lua))"
# Update operators
immediately
parse [<- %var + %] as: %var <- (%var + %)
parse [<- %var - %] as: %var <- (%var - %)
parse [<- %var * %] as: %var <- (%var * %)
parse [<- %var / %] as: %var <- (%var / %)
parse [<- %var ^ %] as: %var <- (%var ^ %)
parse [<- %var and %] as: %var <- (%var and %)
parse [<- %var or %] as: %var <- (%var or %)
parse [wrap %var around %] as: "\(%var as lua) = \(%var as lua) % \(% as lua);"
|
