1 | # YSH specific features of eval
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2 |
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3 | ## our_shell: ysh
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4 | ## oils_failures_allowed: 6
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5 |
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6 | #### Eval does not take a literal block - can restore this later
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7 |
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8 | var b = ^(echo obj)
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9 | eval (b)
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10 |
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11 | eval (^(echo command literal))
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12 |
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13 | # Doesn't work because it's a positional arg
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14 | eval { echo block }
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15 |
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16 | ## status: 3
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17 | ## STDOUT:
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18 | obj
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19 | command literal
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20 | ## END
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21 |
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22 |
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23 | #### Eval a block within a proc
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24 | proc run (;;; block) {
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25 | eval (block)
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26 | }
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27 |
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28 | run {
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29 | echo 'In a block!'
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30 | }
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31 | ## STDOUT:
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32 | In a block!
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33 | ## END
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34 |
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35 | #### Eval block created by calling a proc
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36 | proc lazy-block ( ; out; ; block) {
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37 | call out->setValue(block)
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38 | }
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39 |
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40 | var myglobal = 0
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41 |
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42 | lazy-block (&my_block) {
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43 | json write (myglobal)
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44 | }
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45 |
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46 | eval (my_block)
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47 | setvar myglobal = 1
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48 | eval (my_block)
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49 | ## STDOUT:
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50 | 0
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51 | 1
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52 | ## END
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53 |
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54 | #### eval (block) can read variables like eval ''
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55 |
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56 | proc p2(code_str) {
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57 | var mylocal = 42
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58 | eval $code_str
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59 | }
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60 |
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61 | p2 'echo mylocal=$mylocal'
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62 |
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63 | proc p (;;; block) {
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64 | var mylocal = 99
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65 | eval (block)
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66 | }
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67 |
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68 | p {
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69 | echo mylocal=$mylocal
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70 | }
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71 |
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72 |
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73 | ## STDOUT:
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74 | mylocal=42
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75 | mylocal=99
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76 | ## END
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77 |
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78 | #### eval should have a sandboxed mode
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79 |
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80 | proc p (;;; block) {
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81 | var this = 42
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82 |
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83 | # like push-registers? Not sure
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84 | # We could use state.ctx_Temp ? There's also ctx_FuncCall etc.
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85 | #
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86 | # I think we want to provide full control over the stack.
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87 | push-frame {
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88 | eval (block)
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89 | }
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90 | }
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91 |
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92 | p {
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93 | echo $this
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94 | }
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95 |
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96 | ## status: 1
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97 | ## STDOUT:
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98 | TODO
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99 | ## END
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100 |
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101 | #### eval with argv bindings
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102 | eval ^[echo "$@"] (argv=:| foo bar baz |)
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103 | eval ^[pp line (:| $1 $2 $3 |)] (argv=:| foo bar baz |)
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104 |
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105 | ## status: 0
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106 | ## STDOUT:
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107 | foo bar baz
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108 | (List) ["foo","bar","baz"]
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109 | ## END
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110 |
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111 | #### eval with vars bindings
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112 | var myVar = "abc"
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113 | eval (^(pp line (myVar)))
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114 | eval (^(pp line (myVar)), vars={ 'myVar': '123' })
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115 |
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116 | # eval doesn't modify it's environment
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117 | eval (^(pp line (myVar)))
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118 |
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119 | ## status: 0
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120 | ## STDOUT:
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121 | abc
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122 | 123
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123 | ## END
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124 |
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125 | #### dynamic binding names and mutation
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126 | proc foreach (binding, in_; list ;; block) {
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127 | if (in_ !== "in") {
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128 | error 'Must use the "syntax" `foreach <binding> in (<expr>) { ... }`'
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129 | }
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130 |
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131 | for _ in (list) {
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132 | eval (block, vars={ binding: _ })
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133 | }
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134 | }
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135 |
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136 | var mydicts = [{'a': 1}, {'b': 2}, {'c': 3}]
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137 | foreach mydict in (mydicts) {
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138 | pp line (mydict)
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139 | setvar mydict.d = 0
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140 | }
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141 |
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142 | pp line (mydicts)
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143 |
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144 | ## status: 0
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145 | ## STDOUT:
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146 | (Dict) {"a":1}
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147 | (Dict) {"b":2}
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148 | (Dict) {"c":3}
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149 | (List) [{"a":1,"d":0},{"b":2,"d":0},{"c":3,"d":0}]
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150 | ## END
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151 |
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152 | #### binding procs in the eval-ed namespace
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153 | proc __flag (short, long) {
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154 | echo "flag $short $long"
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155 | }
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156 |
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157 | proc __arg (name) {
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158 | echo "arg $name"
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159 | }
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160 |
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161 | proc parser (; spec ;; block) {
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162 | eval (block, vars={ 'flag': __flag, 'arg': __arg })
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163 | }
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164 |
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165 | parser (&spec) {
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166 | flag -h --help
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167 | arg file
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168 | }
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169 |
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170 | # but flag/arg are unavailable outside of `parser`
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171 | # _error.code = 127 is set on "command not found" errors
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172 |
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173 | try { flag }
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174 | if (_error.code !== 127) { error 'expected failure' }
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175 |
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176 | try { arg }
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177 | if (_error.code !== 127) { error 'expected failure' }
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178 |
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179 | ## status: 0
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180 | ## STDOUT:
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181 | flag -h --help
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182 | arg file
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183 | ## END
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184 |
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185 | #### vars initializes the variable frame, but does not remember it
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186 | var vars = { 'foo': 123 }
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187 | eval (^(var bar = 321), vars=vars)
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188 | pp line (vars)
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189 |
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190 | ## status: 0
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191 | ## STDOUT:
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192 | (Dict) {"foo":123}
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193 | ## END
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