RosettaCodeData/Task/JSON/Tcl/json-2.tcl

57 lines
1.4 KiB
Tcl

package require Tcl 8.6
proc tcl2json value {
# Guess the type of the value; deep *UNSUPPORTED* magic!
regexp {^value is a (.*?) with a refcount} \
[::tcl::unsupported::representation $value] -> type
switch $type {
string {
# Skip to the mapping code at the bottom
}
dict {
set result "{"
set pfx ""
dict for {k v} $value {
append result $pfx [tcl2json $k] ": " [tcl2json $v]
set pfx ", "
}
return [append result "}"]
}
list {
set result "\["
set pfx ""
foreach v $value {
append result $pfx [tcl2json $v]
set pfx ", "
}
return [append result "\]"]
}
int - double {
return [expr {$value}]
}
booleanString {
return [expr {$value ? "true" : "false"}]
}
default {
# Some other type; do some guessing...
if {$value eq "null"} {
# Tcl has *no* null value at all; empty strings are semantically
# different and absent variables aren't values. So cheat!
return $value
} elseif {[string is integer -strict $value]} {
return [expr {$value}]
} elseif {[string is double -strict $value]} {
return [expr {$value}]
} elseif {[string is boolean -strict $value]} {
return [expr {$value ? "true" : "false"}]
}
}
}
# For simplicity, all "bad" characters are mapped to \u... substitutions
set mapped [subst -novariables [regsub -all {[][\u0000-\u001f\\""]} \
$value {[format "\\\\u%04x" [scan {& } %c]]}]]
return "\"$mapped\""
}