jim.c: make lindex work as identity function.

[jimtcl.git] / stdlib.tcl

# Implements script-based standard commands for Jim Tcl

# Creates an anonymous procedure
proc lambda {arglist args} {
        tailcall proc [ref {} function lambda.finalizer] $arglist {*}$args
}

proc lambda.finalizer {name val} {
        rename $name {}
}

# Like alias, but creates and returns an anonyous procedure
proc curry {args} {
        alias [ref {} function lambda.finalizer] {*}$args
}

# Returns the given argument.
# Useful with 'local' as follows:
#   proc a {} {...}
#   local function a
#
#   set x [lambda ...]
#   local function $x
#
proc function {value} {
        return $value
}

# Returns a live stack trace as a list of proc filename line ...
# with 3 entries for each stack frame (proc),
# (deepest level first)
proc stacktrace {{skip 0}} {
        set trace {}
        incr skip
        foreach level [range $skip [info level]] {
                lappend trace {*}[info frame -$level]
        }
        return $trace
}

# Returns a human-readable version of a stack trace
proc stackdump {stacktrace} {
        set lines {}
        foreach {l f p} [lreverse $stacktrace] {
                set line {}
                if {$p ne ""} {
                        append line "in procedure '$p' "
                        if {$f ne ""} {
                                append line "called "
                        }
                }
                if {$f ne ""} {
                        append line "at file \"$f\", line $l"
                }
                if {$line ne ""} {
                        lappend lines $line
                }
        }
        join $lines \n
}

# Sort of replacement for $::errorInfo
# Usage: errorInfo error ?stacktrace?
proc errorInfo {msg {stacktrace ""}} {
        if {$stacktrace eq ""} {
                # By default add the stack backtrace and the live stacktrace
                set stacktrace [info stacktrace]
                # omit the procedure 'errorInfo' from the stack
                lappend stacktrace {*}[stacktrace 1]
        }
        lassign $stacktrace p f l
        if {$f ne ""} {
                set result "Runtime Error: $f:$l: "
        }
        append result "$msg\n"
        append result [stackdump $stacktrace]

        # Remove the trailing newline
        string trim $result
}

# Finds the current executable by searching along the path
# Returns the empty string if not found.
proc {info nameofexecutable} {} {
        if {[info exists ::jim_argv0]} {
                if {[string match "*/*" $::jim_argv0]} {
                        return [file join [pwd] $::jim_argv0]
                }
                foreach path [split [env PATH ""] $::tcl_platform(pathSeparator)] {
                        set exec [file join [pwd] [string map {\\ /} $path] $::jim_argv0]
                        if {[file executable $exec]} {
                                return $exec
                        }
                }
        }
        return ""
}

# Script-based implementation of 'dict with'
proc {dict with} {&dictVar {args key} script} {
        set keys {}
        foreach {n v} [dict get $dictVar {*}$key] {
                upvar $n var_$n
                set var_$n $v
                lappend keys $n
        }
        catch {uplevel 1 $script} msg opts
        if {[info exists dictVar] && ([llength $key] == 0 || [dict exists $dictVar {*}$key])} {
                foreach n $keys {
                        if {[info exists var_$n]} {
                                dict set dictVar {*}$key $n [set var_$n]
                        } else {
                                dict unset dictVar {*}$key $n
                        }
                }
        }
        return {*}$opts $msg
}

# Script-based implementation of 'dict update'
proc {dict update} {&varName args script} {
        set keys {}
        foreach {n v} $args {
                upvar $v var_$v
                if {[dict exists $varName $n]} {
                        set var_$v [dict get $varName $n]
                }
        }
        catch {uplevel 1 $script} msg opts
        if {[info exists varName]} {
                foreach {n v} $args {
                        if {[info exists var_$v]} {
                                dict set varName $n [set var_$v]
                        } else {
                                dict unset varName $n
                        }
                }
        }
        return {*}$opts $msg
}

# Script-based implementation of 'dict merge'
# This won't get called in the trivial case of no args
proc {dict merge} {dict args} {
        foreach d $args {
                # Check for a valid dict
                dict size $d
                foreach {k v} $d {
                        dict set dict $k $v
                }
        }
        return $dict
}

proc {dict replace} {dictionary {args {key value}}} {
        if {[llength ${key value}] % 2} {
                tailcall {dict replace}
        }
        tailcall dict merge $dictionary ${key value}
}

# Script-based implementation of 'dict lappend'
proc {dict lappend} {varName key {args value}} {
        upvar $varName dict
        if {[exists dict] && [dict exists $dict $key]} {
                set list [dict get $dict $key]
        }
        lappend list {*}$value
        dict set dict $key $list
}

# Script-based implementation of 'dict append'
proc {dict append} {varName key {args value}} {
        upvar $varName dict
        if {[exists dict] && [dict exists $dict $key]} {
                set str [dict get $dict $key]
        }
        append str {*}$value
        dict set dict $key $str
}

# Script-based implementation of 'dict incr'
proc {dict incr} {varName key {increment 1}} {
        upvar $varName dict
        if {[exists dict] && [dict exists $dict $key]} {
                set value [dict get $dict $key]
        }
        incr value $increment
        dict set dict $key $value
}

# Script-based implementation of 'dict remove'
proc {dict remove} {dictionary {args key}} {
        foreach k $key {
                dict unset dictionary $k
        }
        return $dictionary
}

# Script-based implementation of 'dict values'
proc {dict values} {dictionary {pattern *}} {
        dict keys [lreverse $dictionary] $pattern
}

# Script-based implementation of 'dict for'
proc {dict for} {vars dictionary script} {
        if {[llength $vars] != 2} {
                return -code error "must have exactly two variable names"
        }
        dict size $dictionary
        tailcall foreach $vars $dictionary $script
}