| 1 | # spec/ysh-case
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| 2 | 
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| 3 | ## our_shell: ysh
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| 4 | ## oils_failures_allowed: 0
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| 5 | 
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| 6 | #### case syntax, one line
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| 7 | const x = "header.h"
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| 8 | case (x) {
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| 9 |   *.h | *.cc { echo C++ }
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| 10 |   *.py       { echo Python }
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| 11 | }
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| 12 | 
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| 13 | # not recommended, but it works
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| 14 | case (x) { header.h { echo header.h } * { echo other } }
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| 15 | 
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| 16 | ## status: 0
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| 17 | ## STDOUT:
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| 18 | C++
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| 19 | header.h
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| 20 | ## END
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| 21 | 
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| 22 | #### case syntax, multiline
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| 23 | const x = "hello.py"
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| 24 | case (x) {
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| 25 |   *.h | *.cc {
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| 26 |     echo C++
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| 27 |     echo 2; echo 3
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| 28 |   }
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| 29 |   *.py {
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| 30 |     echo \
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| 31 |       Python
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| 32 |   }
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| 33 | }
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| 34 | ## status: 0
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| 35 | ## STDOUT:
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| 36 | Python
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| 37 | ## END
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| 38 | 
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| 39 | #### case syntax, simple expressions
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| 40 | const x = 3
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| 41 | case (x) {
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| 42 |   (3) { echo three }
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| 43 |   (4) { echo four }
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| 44 | }
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| 45 | ## status: 0
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| 46 | ## STDOUT:
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| 47 | three
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| 48 | ## END
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| 49 | 
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| 50 | #### case syntax, complex expressions
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| 51 | const x = 3
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| 52 | case (x) {
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| 53 |   (1 + 2) { echo three }
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| 54 |   (2 + 2) { echo four }
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| 55 | }
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| 56 | ## STDOUT:
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| 57 | three
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| 58 | ## END
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| 59 | 
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| 60 | #### case semantics, no match
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| 61 | const x = 2
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| 62 | case (x) {
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| 63 |   (3) { echo three }
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| 64 |   (4) { echo four }
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| 65 | }
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| 66 | ## status: 0
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| 67 | ## STDOUT:
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| 68 | ## END
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| 69 | 
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| 70 | #### eggex as case arm
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| 71 | const x = "main.cc"
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| 72 | case (x) {
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| 73 |   / dot* '.py' / {
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| 74 |     echo Python
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| 75 |   }
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| 76 |   / dot* ('.cc' | '.h') / {
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| 77 |    echo C++
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| 78 |   }
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| 79 | }
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| 80 | ## STDOUT:
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| 81 | C++
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| 82 | ## END
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| 83 | 
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| 84 | #### eggex respects flags
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| 85 | const x = 'MAIN.PY'
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| 86 | case (x) {
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| 87 |   / dot* '.py' ; i / {
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| 88 |     echo Python
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| 89 |   }
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| 90 |   / dot* ('.cc' | '.h') / {
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| 91 |    echo C++
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| 92 |   }
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| 93 | }
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| 94 | ## STDOUT:
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| 95 | Python
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| 96 | ## END
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| 97 | 
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| 98 | #### empty case statement
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| 99 | const x = ""
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| 100 | case (x) { }
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| 101 | ## status: 0
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| 102 | ## STDOUT:
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| 103 | ## END
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| 104 | 
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| 105 | #### typed args
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| 106 | const x = "0"
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| 107 | case (x) {
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| 108 |   (0) { echo int }
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| 109 |   ("0") { echo string }
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| 110 | }
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| 111 | 
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| 112 | ## status: 0
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| 113 | ## STDOUT:
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| 114 | string
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| 115 | ## END
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| 116 | 
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| 117 | #### eggex capture
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| 118 | for name in foo/foo.py bar/bar.cc zz {
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| 119 |   case (name) {
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| 120 |     / '/f' <capture dot*> '.' / { echo "g0=$[_group(0)] g1=$[_group(1)]" }
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| 121 |     / '/b' <capture dot*> '.' / { echo "g0=$[_group(1)] g1=$[_group(1)]" }
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| 122 |     (else) { echo 'no match' }
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| 123 |   }
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| 124 | }
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| 125 | ## status: 0
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| 126 | ## STDOUT:
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| 127 | g0=/foo. g1=oo
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| 128 | g0=ar g1=ar
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| 129 | no match
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| 130 | ## END
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| 131 | 
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| 132 | #### else case pattern
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| 133 | var x = 123
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| 134 | case (x) {
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| 135 |   (else) { echo else matches all }
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| 136 |   (123) { echo unreachable }
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| 137 | }
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| 138 | ## status: 0
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| 139 | ## STDOUT:
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| 140 | else matches all
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| 141 | ## END
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| 142 | 
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| 143 | #### expression evaluation shortcuts
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| 144 | var x = 123
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| 145 | case (x) {
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| 146 |   (x) | (y) { echo no error }
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| 147 | }
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| 148 | ## status: 0
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| 149 | ## STDOUT:
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| 150 | no error
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| 151 | ## END
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| 152 | 
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| 153 | #### expression evaluation order
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| 154 | var x = 123
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| 155 | case (x) {
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| 156 |   (y) | (x) { echo no error }
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| 157 | }
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| 158 | ## status: 1
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| 159 | ## STDOUT:
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| 160 | ## END
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| 161 | 
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| 162 | #### word evaluation shortcuts
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| 163 | var x = "abc"
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| 164 | case (x) {
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| 165 |   $x | $y { echo no error }
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| 166 | }
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| 167 | ## status: 0
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| 168 | ## STDOUT:
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| 169 | no error
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| 170 | ## END
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| 171 | 
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| 172 | #### word evaluation order
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| 173 | var x = "abc"
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| 174 | case (x) {
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| 175 |   $y | $x { echo no error }
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| 176 | }
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| 177 | ## status: 1
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| 178 | ## STDOUT:
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| 179 | ## END
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| 180 | 
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| 181 | #### only one branch is evaluated
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| 182 | var x = "42"
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| 183 | case (x) {
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| 184 |   ('42') { echo a }
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| 185 |   42 { echo b }
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| 186 |   / '42' / { echo c }
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| 187 |   (Str(40 + 2)) { echo d }
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| 188 | 
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| 189 |   # even errors are ignored
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| 190 |   (42 / 0) { echo no error }
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| 191 | }
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| 192 | ## status: 0
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| 193 | ## STDOUT:
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| 194 | a
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| 195 | ## END
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| 196 | 
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| 197 | #### stop on errors
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| 198 | var x = "42"
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| 199 | case (x) {
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| 200 |   (42 / 0) { echo no error }
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| 201 | 
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| 202 |   ('42') { echo a }
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| 203 |   42 { echo b }
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| 204 |   / '42' / { echo c }
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| 205 |   (Str(40 + 2)) { echo d }
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| 206 | }
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| 207 | ## status: 3
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| 208 | ## STDOUT:
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| 209 | ## END
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| 210 | 
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| 211 | #### old and new case statements
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| 212 | 
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| 213 | for flag in -f -x {
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| 214 | 
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| 215 |   # We can disallow this with shopt --unset parse_old_case, because the new
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| 216 |   # case statement does everything the old one does
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| 217 |   #
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| 218 |   # bin/osh and shopt --set ysh:upgrade let you use both styles, but bin/ysh
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| 219 |   # only lets you use the new style
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| 220 | 
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| 221 |   case $flag in
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| 222 |     -f|-d)
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| 223 |       echo 'file'
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| 224 |       ;;
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| 225 |     *)
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| 226 |       echo 'other'
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| 227 |       ;;
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| 228 |   esac
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| 229 | 
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| 230 |   case (flag) {
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| 231 |     -f|-d { echo 'file' }
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| 232 |     *     { echo 'other' }
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| 233 |   }
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| 234 | 
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| 235 |   echo --
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| 236 | }
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| 237 | 
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| 238 | ## STDOUT:
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| 239 | file
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| 240 | file
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| 241 | --
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| 242 | other
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| 243 | other
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| 244 | --
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| 245 | ## END
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