Class: Opal::Nodes::IfNode
- Inherits:
-
Base
- Object
- Base
- Opal::Nodes::IfNode
show all
- Defined in:
- opal/lib/opal/nodes/if.rb
Constant Summary
collapse
- SWITCH_TEST_MATCH =
Matches: case some_value_or_expression; when 123
Captures: [s(:int, 123), "$ret_or_1", s(:send, nil, :some_value_or_expression))]
AST::Matcher.new do
s(:send,
cap(s(%i[float int sym str true false nil], :*)),
:===,
s(:lvasgn, cap(:*), cap(:*))
)
end
- SWITCH_TEST_MATCH_CONTINUED =
Matches: case some_value_or_expression; when 123, 456; end
Captures: [
s(:int, 123),
"$ret_or_1",
s(:send, nil, :some_value_or_expression)),
…here we delegate to either SWITCH_BRANCH_TEST_MATCH or SWITCH_BRANCH_TEST_MATCH_CONTINUED
]
AST::Matcher.new do
s(:if,
s(:send,
cap(s(%i[float int sym str true false nil], :*)),
:===,
s(:lvasgn, cap(:*), cap(:*))
),
s(:true),
cap(:*)
)
end
- SWITCH_BRANCH_TEST_MATCH =
Matches: when 456
(from case foo; when 123; when 456; end
)
Captures: [s(:int, 456), "$ret_or_1"]
AST::Matcher.new do
s(:send,
cap(s(%i[float int sym str true false nil], :*)),
:===,
s(:js_tmp, cap(:*))
)
end
- SWITCH_BRANCH_TEST_MATCH_CONTINUED =
Matches: when 456
Captures: [
s(:int, 789),
"$ret_or_1",
…here we delegate to either SWITCH_BRANCH_TEST_MATCH or SWITCH_BRANCH_TEST_MATCH_CONTINUED
]
AST::Matcher.new do
s(:if,
s(:send,
cap(s(%i[float int sym str true false nil], :*)),
:===,
s(:js_tmp, cap(:*))
),
s(:true),
cap(:*)
)
end
Instance Attribute Summary
Attributes inherited from Base
#compiler, #sexp, #type
#closure
Instance Method Summary
collapse
Methods inherited from Base
#add_gvar, #add_ivar, #add_local, #add_temp, #children, children, #class_variable_owner, #class_variable_owner_nesting_level, #comments, #compile_to_fragments, #error, #expr, #expr?, #expr_or_empty, #expr_or_nil, #fragment, handle, handlers, #has_rescue_else?, #helper, #in_ensure, #in_ensure?, #in_resbody, #in_resbody?, #in_rescue, #in_while?, #initialize, #process, #push, #recv, #recv?, #s, #scope, #source_location, #stmt, #stmt?, #top_scope, truthy_optimize?, #unshift, #while_loop, #with_temp, #wrap
#closure_is?, #compile_catcher, #generate_thrower, #generate_thrower_without_catcher, #in_closure, #pop_closure, #push_closure, #select_closure, #thrower
Methods included from Helpers
#current_indent, #empty_line, #indent, #js_truthy, #js_truthy_optimize, #line, #mid_to_jsid, #property, #valid_name?
Instance Method Details
#compile ⇒ Object
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
|
# File 'opal/lib/opal/nodes/if.rb', line 13
def compile
if should_compile_as_simple_expression?
if true_body == s(:true)
compile_with_binary_or
elsif false_body == s(:false)
compile_with_binary_and
else
compile_with_ternary
end
elsif could_become_switch?
compile_with_switch
else
compile_with_if
end
end
|
#compile_switch_case(test) ⇒ Object
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
|
# File 'opal/lib/opal/nodes/if.rb', line 365
def compile_switch_case(test)
line "case ", expr(test), ":"
if @switch_additional_rules
@switch_additional_rules.each do |rule|
line "case ", expr(rule), ":"
end
end
indent do
line stmt(true_body)
line "break;" if !true_body || !returning?(true_body)
end
if false_body
if false_body.meta[:switch_default]
compile_switch_default
elsif false_body.meta[:switch_child]
push stmt(false_body)
end
else
push stmt(s(:nil))
end
end
|
#compile_switch_default ⇒ Object
387
388
389
390
391
392
|
# File 'opal/lib/opal/nodes/if.rb', line 387
def compile_switch_default
line "default:"
indent do
line stmt(false_body)
end
end
|
#compile_with_binary_and ⇒ Object
130
131
132
133
134
135
136
137
138
139
140
141
|
# File 'opal/lib/opal/nodes/if.rb', line 130
def compile_with_binary_and
if sexp.meta[:do_js_truthy_on_true_body]
truthy = js_truthy(true_body || s(:nil))
else
truthy = expr(true_body || s(:nil))
end
push '('
push js_truthy(test), ' && '
push '(', truthy, ')'
push ')'
end
|
#compile_with_binary_or ⇒ Object
143
144
145
146
147
148
149
150
151
152
153
154
|
# File 'opal/lib/opal/nodes/if.rb', line 143
def compile_with_binary_or
if sexp.meta[:do_js_truthy_on_false_body]
falsy = js_truthy(false_body || s(:nil))
else
falsy = expr(false_body || s(:nil))
end
push '('
push js_truthy(test), ' || '
push '(', falsy, ')'
push ')'
end
|
#compile_with_if ⇒ Object
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
|
# File 'opal/lib/opal/nodes/if.rb', line 29
def compile_with_if
push_closure if expects_expression?
truthy = self.truthy
falsy = self.falsy
if falsy && !truthy
push 'if (!', js_truthy(test), ') {'
falsy, truthy = truthy, falsy
else
push 'if (', js_truthy(test), ') {'
end
indent { line stmt(truthy) } if truthy
if falsy
if falsy.type == :if
line '} else ', stmt(falsy)
else
line '} else {'
indent do
line stmt(falsy)
end
line '}'
end
else
line '}'
line 'return nil;' if expects_expression?
end
pop_closure if expects_expression?
if expects_expression?
return_kw = 'return ' if returning_if?
if scope.await_encountered
wrap "#{return_kw}(await (async function() {", '})())'
else
wrap "#{return_kw}(function() {", '})()'
end
end
end
|
#compile_with_switch ⇒ Object
346
347
348
349
350
351
352
353
354
355
356
357
358
|
# File 'opal/lib/opal/nodes/if.rb', line 346
def compile_with_switch
if sexp.meta[:switch_child]
@switch_variable = sexp.meta[:switch_variable]
@switch_additional_rules = sexp.meta[:switch_additional_rules]
compile_switch_case(sexp.meta[:switch_test])
else
line "switch (", expr(@switch_first_test), ") {"
indent do
compile_switch_case(@switch_test)
end
line "}"
end
end
|
#compile_with_ternary ⇒ Object
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
# File 'opal/lib/opal/nodes/if.rb', line 112
def compile_with_ternary
truthy = true_body
falsy = false_body
push '('
push js_truthy(test), ' ? '
push '(', expr(truthy || s(:nil)), ') : '
if !falsy || falsy.type == :if
push expr(falsy || s(:nil))
else
push '(', expr(falsy || s(:nil)), ')'
end
push ')'
end
|
#could_become_switch? ⇒ Boolean
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
|
# File 'opal/lib/opal/nodes/if.rb', line 254
def could_become_switch?
return false if expects_expression?
return true if sexp.meta[:switch_child]
test_match = SWITCH_TEST_MATCH.match(test) || SWITCH_TEST_MATCH_CONTINUED.match(test)
return false unless test_match
@switch_test, @switch_variable, @switch_first_test, additional_rules = *test_match
additional_rules = handle_additional_switch_rules(additional_rules)
return false unless additional_rules @switch_additional_rules = additional_rules
return false unless valid_switch_body?(true_body)
could_become_switch_branch?(false_body)
end
|
#could_become_switch_branch?(body) ⇒ Boolean
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
|
# File 'opal/lib/opal/nodes/if.rb', line 286
def could_become_switch_branch?(body)
if !body
return true
elsif body.type != :if
if valid_switch_body?(body)
body.meta[:switch_default] = true
return true
end
return false
end
test, true_body, false_body = *body
test_match = SWITCH_BRANCH_TEST_MATCH.match(test) || SWITCH_BRANCH_TEST_MATCH_CONTINUED.match(test)
unless test_match
if valid_switch_body?(body, true)
body.meta[:switch_default] = true
return true
end
end
switch_test, switch_variable, additional_rules = *test_match
switch_additional_rules = handle_additional_switch_rules(additional_rules)
return false unless switch_additional_rules
return false unless switch_variable == @switch_variable
return false unless valid_switch_body?(true_body)
return false unless could_become_switch_branch?(false_body)
body.meta.merge!(switch_child: true,
switch_test: switch_test,
switch_variable: @switch_variable,
switch_additional_rules: switch_additional_rules
)
true
end
|
#expects_expression? ⇒ Boolean
98
99
100
|
# File 'opal/lib/opal/nodes/if.rb', line 98
def expects_expression?
expr? || recv?
end
|
#falsy ⇒ Object
86
87
88
|
# File 'opal/lib/opal/nodes/if.rb', line 86
def falsy
returnify(false_body)
end
|
#handle_additional_switch_rules(additional_rules) ⇒ Object
272
273
274
275
276
277
278
279
280
281
282
283
284
|
# File 'opal/lib/opal/nodes/if.rb', line 272
def handle_additional_switch_rules(additional_rules)
switch_additional_rules = []
while additional_rules
match = SWITCH_BRANCH_TEST_MATCH.match(additional_rules) || SWITCH_BRANCH_TEST_MATCH_CONTINUED.match(additional_rules)
return false unless match
switch_test, switch_variable, additional_rules = *match
return false unless switch_variable == @switch_variable
switch_additional_rules << switch_test
end
switch_additional_rules
end
|
#returnify(body) ⇒ Object
90
91
92
93
94
95
96
|
# File 'opal/lib/opal/nodes/if.rb', line 90
def returnify(body)
if expects_expression? && body
compiler.returns(body)
else
body
end
end
|
#returning?(body) ⇒ Boolean
360
361
362
363
|
# File 'opal/lib/opal/nodes/if.rb', line 360
def returning?(body)
%i[return js_return next].include?(body.type) ||
(body.type == :begin && %i[return js_return next].include?(body.children.last.type))
end
|
#returning_if? ⇒ Boolean
78
79
80
|
# File 'opal/lib/opal/nodes/if.rb', line 78
def returning_if?
@sexp.meta[:returning]
end
|
#should_compile_as_simple_expression? ⇒ Boolean
There was a particular case in the past, that when we
expected an expression from if, we always had to closure
it. This produced an ugly code that was hard to minify.
This addition tries to make a few cases compiled with
a ternary operator instead and possibly a binary operator
even?
108
109
110
|
# File 'opal/lib/opal/nodes/if.rb', line 108
def should_compile_as_simple_expression?
expects_expression? && simple?(true_body) && simple?(false_body)
end
|
#simple?(body) ⇒ Boolean
Let's ensure there are no control flow statements inside.
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
# File 'opal/lib/opal/nodes/if.rb', line 157
def simple?(body)
case body
when AST::Node
case body.type
when :return, :js_return, :break, :next, :redo, :retry
false
when :xstr
XStringNode.single_line?(
XStringNode.strip_empty_children(body.children)
)
else
body.children.all? { |i| simple?(i) }
end
else
true
end
end
|
#truthy ⇒ Object
82
83
84
|
# File 'opal/lib/opal/nodes/if.rb', line 82
def truthy
returnify(true_body)
end
|
#valid_switch_body?(body, check_variable = false) ⇒ Boolean
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
|
# File 'opal/lib/opal/nodes/if.rb', line 325
def valid_switch_body?(body, check_variable = false)
case body
when AST::Node
case body.type
when :break, :redo, :retry
false
when :iter, :while
true
else
body.children.all? { |i| valid_switch_body?(i, check_variable) }
end
when @switch_variable
!check_variable
else
true
end
end
|