OILS / ysh / testdata / expr-sub.ysh View on Github | oilshell.org

94 lines, 59 significant
1#!/usr/bin/env bash
2#
3# Usage:
4# ysh/testdata/inline-function-calls.sh <function name>
5
6shopt -s ysh:upgrade
7
8source $LIB_YSH/list.ysh
9
10simple-demo() {
11 var myarray = %(spam eggs ham)
12
13 echo '+ Call in expression context:'
14 var length = len(myarray)
15 echo $length
16 echo
17
18 echo '+ Inline call that coerces to string:'
19 write -- $[len(myarray)] $[len("abc")] ''
20 echo
21
22 echo '+ Inline calls can be part of a word:'
23 write -- --length=$[len(myarray)] $[len("abc")]$[len("xyz")]
24 echo
25
26 echo "+ Caveat: can't double quote. It would break programs."
27 echo " Should we add an option 'shopt -s parse_dparen'?"
28 echo
29
30 # NOTE: Oil's echo builtin takes --, and requires it here
31 write -- "--length=$[len(myarray)]"
32 echo
33
34 echo '+ Just as you can splice @myarray'
35 write -- @myarray
36 echo
37
38 var mydict = { 'hello': 0, 'world': 1 }
39
40 echo '+ You can also splice the result of a function returning a sequence:'
41 echo ' Notes:'
42 echo ' - the Dict->reverse() method is from Python.'
43 echo
44 write -- @[mydict=>keys()]
45 echo
46
47 # But this is a syntax error
48 #echo @sorted(myarray)@invalid
49}
50
51split-join-demo() {
52 var parts = %(aaa BB c)
53 write -- 'Parts:' @parts
54 echo
55
56 write 'join(parts):' $[join(parts)]
57 echo
58
59 echo '+ Another way of doing it, without creating another variable:'
60 write --sep '' -- @parts
61 echo
62
63 var j = join(parts, ":")
64 #var a = split(j)
65 #repr j a
66
67 write --sep '' "j => " $j
68 write --sep '' 'When IFS is the default, split(j) => '
69 write @[split(j)]
70 echo
71
72 # NOTE: Can't use setvar IFS = ':' here because of static check
73 # declare or declare -g makes sense
74 declare IFS=':'
75 echo 'When IFS is :, split(j) => '
76 write @[split(j)]
77 echo
78
79 unset IFS
80
81 echo '+ Since there is no word splitting of unquoted $(ls), here is an idiom:'
82 write @[split( $(write bin/ lib/ | grep b) )]
83}
84
85types-demo() {
86 echo 'TODO: bool, int, etc.'
87}
88
89all() {
90 simple-demo
91 split-join-demo
92}
93
94"$@"