1	# Hay Metaprogramming
2
3	#### Conditional Inside Blocks
4	shopt --set oil:all
5
6	hay define Rule
7
8	const DEBUG = true
9
10	Rule one {
11	if (DEBUG) {
12	deps = 'foo'
13	} else {
14	deps = 'bar'
15	}
16	}
17
18	json write (_hay()) | jq '.children[0]' > actual.txt
19
20	diff -u - actual.txt <<EOF
21	{
22	"type": "Rule",
23	"args": [
24	"one"
25	],
26	"children": [],
27	"attrs": {
28	"deps": "foo"
29	}
30	}
31	EOF
32
33	## STDOUT:
34	## END
35
36
37	#### Conditional Outside Block
38	shopt --set oil:all
39
40	hay define Rule
41
42	const DEBUG = true
43
44	if (DEBUG) {
45	Rule two {
46	deps = 'spam'
47	}
48	} else {
49	Rule two {
50	deps = 'bar'
51	}
52	}
53
54	json write (_hay()) | jq '.children[0].attrs' > actual.txt
55
56	diff -u - actual.txt <<EOF
57	{
58	"deps": "spam"
59	}
60	EOF
61
62	## STDOUT:
63	## END
64
65
66	#### Iteration Inside Block
67	shopt --set oil:all
68
69	hay define Rule
70
71	Rule foo {
72	var d = {}
73	# private var with _
74	for name_ in spam eggs ham {
75	setvar d[name_] = true
76	}
77	}
78
79	json write (_hay()) | jq '.children[0].attrs' > actual.txt
80
81	# For loop name leaks! Might want to make it "name_" instead!
82
83	#cat actual.txt
84
85	diff -u - actual.txt <<EOF
86	{
87	"d": {
88	"spam": true,
89	"eggs": true,
90	"ham": true
91	}
92	}
93	EOF
94
95
96	## STDOUT:
97	## END
98
99
100	#### Iteration Outside Block
101	shopt --set oil:all
102
103	hay define Rule
104
105	for name in spam eggs ham {
106	Rule $name {
107	path = "/usr/bin/$name"
108	}
109	}
110
111	json write (_hay()) | jq '.children[].attrs' > actual.txt
112
113	diff -u - actual.txt <<EOF
114	{
115	"path": "/usr/bin/spam"
116	}
117	{
118	"path": "/usr/bin/eggs"
119	}
120	{
121	"path": "/usr/bin/ham"
122	}
123	EOF
124
125	## STDOUT:
126	## END
127
128
129	#### Proc Inside Block
130	shopt --set oil:all
131
132	hay define rule # lower case allowed
133
134	proc p(name, :out) {
135	echo 'p'
136	setref out = name
137	}
138
139	rule hello {
140	var eggs = ''
141	var bar = ''
142
143	p spam :eggs
144	p foo :bar
145	}
146
147	json write (_hay()) | jq '.children[0].attrs' > actual.txt
148
149	diff -u - actual.txt <<EOF
150	{
151	"eggs": "spam",
152	"bar": "foo"
153	}
154	EOF
155
156	## STDOUT:
157	p
158	p
159	## END
160
161
162
163	#### Proc That Defines Block
164	shopt --set oil:all
165
166	hay define Rule
167
168	proc myrule(name) {
169
170	# Each haynode has its own scope. But then it can't see the args! Oops.
171	# Is there a better way to do this?
172
173	shopt --set dynamic_scope {
174	Rule $name {
175	path = "/usr/bin/$name"
176	}
177	}
178	}
179
180	myrule spam
181	myrule eggs
182	myrule ham
183
184	json write (_hay()) | jq '.children[].attrs' > actual.txt
185
186	diff -u - actual.txt <<EOF
187	{
188	"path": "/usr/bin/spam"
189	}
190	{
191	"path": "/usr/bin/eggs"
192	}
193	{
194	"path": "/usr/bin/ham"
195	}
196	EOF
197
198	## STDOUT:
199	## END
200