Software of the Month Club 1996 September/Software of the Month Club 1996 September.iso/mac/Software Research Institute-SRI/Business/Alpha ƒ/Tcl/SystemCode/latexEngine.tcl

Text File | 1995-12-03 | 31.1 KB | 1,005 lines | [TEXT/ALFA]

#############################################################################
#############################################################################
#
# latexEngine.tcl (called from latex.tcl)
#
# The LaTeX engine
#
#############################################################################
#
# Author:  Tom Scavo <[e-mail]>
#
#############################################################################
#############################################################################


#--------------------------------------------------------------------------
# Mark Menu:
#--------------------------------------------------------------------------

# proc TeXMarkFile {} {
#     set end [maxPos]
#     set pos 0
#     set l {}
#
#     # Remove all previous marks in this file?
#     set exp {\\((sub)*section|chapter)(\[.*\]|\*)?{([^{}]*)}}
#     while {![catch {search -s -f 1 -r 1 -m 0 -i 0 $exp $pos} res]} {
#         set start [lindex $res 0]
#         set end [lindex $res 1]
#         set text [getText $start $end]
#         if {[regexp {\{(.*)\}} $text dummy mtch]} {
#             set lab ""
#             if {[regexp {(sub)*section} $text title]} then {
#                 append lab $l [format "%[expr [string length $title] - 7]\s" ""]
#             } else {
#                 set l {   }
#             }
#             # WTP
#             regsub -all "\[\ \r\t\]\+" $mtch { } mtch
#             if {[string length $mtch] > 30} { set mtch "[string range $mtch 0 26]..." }
#             #
#             append lab $mtch
#             regsub -all {[<(]} $lab {} lab
#             regsub -all {[)>]} $lab {╚} lab
#             regsub -all {[!^/]} $lab {|} lab
#             setNamedMark $lab [lineStart [expr $start - 1]] $start $start
#         }
#         set pos [expr $end+1]
#     }
# }

# Bug:  won't add a section (in a different chapter) with the same name.
# Bug:  should ignore comments, but doesn't.
proc TeXMarkFile {} {
    set end [maxPos]
    set pos 0
    set l {}

    # Remove all previous marks in this file?
#     set exp {^[^%]*\\((sub)*section|chapter)(\[.*\]|\*)?{(.*)}}
    set exp {^\\((sub)*section|chapter)(\[.*\]|\*)?{(.*)}}
    while {![catch {search -s -f 1 -r 1 -m 0 -i 0 $exp $pos} res]} {
        set start [lindex $res 0]
        set end [lindex $res 1]
        set text [getText $start $end]
        if {[regexp {\{(.*)\}} $text dummy mtch]} {
            set lab ""
            if {[regexp {(sub)*section} $text title]} then {
                append lab $l [format "%[expr [string length $title] - 7]\s" ""]
            } else {
                set l {   }
            }
            # WTP
            regsub -all "\[\ \r\t\]\+" $mtch { } mtch
            if {[string length $mtch] > 30} { set mtch "[string range $mtch 0 26]..." }
            #
            append lab $mtch
            regsub -all {[<(]} $lab {} lab
            regsub -all {[)>]} $lab {╚} lab
            regsub -all {[!^/]} $lab {|} lab
            setNamedMark $lab [lineStart [expr $start - 1]] $start $start
        }
        set pos [expr $end+1]
    }
}

#--------------------------------------------------------------------------
# Command-double-clicking:
#--------------------------------------------------------------------------
# In TeX mode, use Cmd-double-clicks to follow references and citations,
# or open input files.
#
# (written by Tom Pollard and Andreas Amann)
#
# Remaining bugs:
#   - searches are successful even if the pattern is commented out

proc TeXDblClick {from to} {
    global TeXmodeVars TeXSearchPath

    # Reset the search path list, forcing it to be rebuilt.
    # (It would improve responsiveness if the searchPath were only
    # rebuilt as needed, perhaps at startup and when requested by the user.)
    #
    set TeXSearchPath {}

    set bibPat "\\bibliography\{"
    set theBibPat "\\begin\{thebibliography"
    set bibitemPat {\bibitem(\[[^\]*\])?\{}
    set labelPat "\\label\{"
     set bibTopPat {@([a-zA-Z]+)[\{\(][     ]*}

    # Extend selection to largest string delimited by commas or curly-braces
    set text [string trim [eval getText [TeXExtendArg $from $to]]]

    # Quote regexp-active characters in case we use $text in a regexp search
    set qtext [quoteExpr $text]

    # Set $cmd to TeX command for which the selection is an argument, but
    # only if user clicked on a valid command argument.
    set cmd {}
    if {[set mtch [findCommandWithParts $from 0]] != ""} {
        set beg [lindex $mtch 0]
        set arg [lindex $mtch 2]
        set end [lindex $mtch 3]
        # Make sure the user clicked within a TeX argument and not
        # on the command name itself
        if {$from > $arg && $to < $end} {
            set cmd [extractCommandName [getText $beg $arg]]
        }
    }

    # \cite, \nocite, etc.
    #
    if {[lsearch -exact $TeXmodeVars(citeCommands) $cmd] >= 0} {

        # Check first for a \thebibliography environment:
        if {![catch {search -f 0 -r 0 -m 0 -s $theBibPat [maxPos]} mtch]} {
            set bibPos [lindex $mtch 1]
            if {![catch {search -f 1 -r 1 -m 0 -s "$bibitemPat$qtext\}" $bibPos} mtch]} {
                pushMark
                eval select $mtch
                message "press <Ctl .> to return to original cursor position"
                return
            }
        }

        # ...otherwise get the bib file name(s) from a \bibliography command
        if {![catch {search -f 0 -r 0 -s -m 0 $bibPat [maxPos]} mtch]} {
            # Get ALL the bib file names:
            set beg [lindex $mtch 1]
            set end [matchIt "\{" $beg]
            set fnames "[split [getText $beg $end] ,]"
            # Check every file:
            foreach fname $fnames {
                set filename [absolutePath "$fname.bib"]
                set searchResult [searchInFile $filename $bibTopPat$qtext 1]
                if {[lindex $searchResult 0] >= 0} {
                    openFileQuietly $filename
                    eval select $searchResult
                    return
                }
            }
            # Build the TeX search path:
            if {[llength $TeXSearchPath] == 0} {
                set TeXSearchPath [buildTeXSearchPath]
            }
            # Check every file in the TeX search path:
            foreach fname $fnames {
                foreach folder $TeXSearchPath {
                    set filename "$folder$fname.bib"
                    set searchResult [searchInFile $filename $bibTopPat$qtext 1]
                    if {[lindex $searchResult 0] >= 0} {
                        openFileQuietly $filename
                        eval select $searchResult
                        return
                    }
                }
            }
            beep
            message "can't find \"$text\" in the .bib file(s)"

        } else {
            beep
            message "can't find a \\bibliography"
        }

    # \ref, \pageref, etc.
    } elseif {[lsearch -exact $TeXmodeVars(refCommands) $cmd] >= 0} {
        if {![catch {search -f 1 -r 0 -m 0 -s "$labelPat$text\}" 0} mtch]} {
            pushMark
            eval select $mtch
            message "press <Ctl .> to return to original cursor position"
        } else {
            message {No matching \label found}
        }

    #    \input
    } elseif { $cmd == "input" } {
        openTeXFile $text ".tex"

    #    \include
    } elseif { $cmd == "include" } {
        openTeXFile "${text}.tex"

    # \documentclass or \LoadClass
    } elseif { $cmd == "documentclass" || $cmd == "LoadClass" } {
        openTeXFile "${text}.cls"

    # \usepackage or \RequirePackage
    } elseif { $cmd == "usepackage" || $cmd == "RequirePackage" } {
        openTeXFile "${text}.sty"

    # \bibliography
    } elseif {$cmd == "bibliography"} {
        openTeXFile "${text}.bib"

    # \bibliographystyle
    } elseif {$cmd == "bibliographystyle"} {
        openTeXFile "${text}.bst"

    # box-making macro ($boxMacroName)
    } elseif {$cmd == $TeXmodeVars(boxMacroName)} {
        openTeXFile $text

    # Other
    } else {
        select $from $to
        message {Command-double-click on the required argument of an underlined LaTeX command}
    }
}

# Open a TeX source file.
#
proc openTeXFile {file {ext ""}} {
    global TeXSearchPath
    # Determine absolute file specification
    # Ignore $ext if $file already has an extension
    if {[string length [file extension $file]] == 0} {
        set file $file$ext
    }
    set filename [absolutePath $file]
    if {![catch {openFileQuietly $filename}]} {
        message $filename
        return
    }
    if {[llength $TeXSearchPath] == 0} {
        set TeXSearchPath [buildTeXSearchPath]
    }
    foreach folder $TeXSearchPath {
#         set filename "$folder$file$ext"
        set filename "$folder$file"
        if {![catch {openFileQuietly $filename}]} {
            message $filename
            return
        }
    }
    beep
    message "can't find TeX input file \"$file\""
}

# Return a list of folders in which to search for TeX input files,
# including the TeXInputs folder (if it exists) and any folders of
# the form "*input*" in the TeX application directory.  The current
# folder is not included in the list.
#
# (The TeXInputs folder is assigned from the AppPaths submenu.)
#
proc buildTeXSearchPath {} {
    global TeXInputs texPath
    message "building TeX search path╔"
    set folders {}

    # The local 'TeXInputs' folder:
    if {[info exists TeXInputs] && [string length $TeXInputs] > 0} {
        set folders [concat $folders [list $TeXInputs]]
        # Search subfolders one level deep:
        set folders [concat $folders [listSubfolders $TeXInputs 1]]
    }

    # Any "*inputs*" folders in the TeX application folder:
    if {[info exists texPath] && [string length $texPath] > 0} {
        set TeXDir [file dirname $texPath]
        set folders [concat $folders [list $TeXDir]]
        # Bug:  'glob' is case sensitive!
        foreach folder [glob "$TeXDir:*\[Ii\]nputs*"] {
            set folders [concat $folders [list $folder]]
            # Search subfolders one level deep:
            set folders [concat $folders [listSubfolders $folder 1]]
        }
    }

    # Make sure each folder ends with a colon:
    set result {}
    foreach folder $folders {
        set folder "[string trimright $folder {:}]:"
        set result [concat $result [list $folder]]
    }
    return $result
}


# Extend the argument around the position $from.
# (Args are delimited by commas or curly-braces.)
proc TeXExtendArg {from {to 0}} {
    if {$to == 0} { set to $from }
    set result [list $from $to]
    if {![catch {search -f 0 -r 1 -s -m 0 "\[,\{\]" $from} mtch0]} {
        if {![catch {search -f 1 -r 1 -s -m 0 "\[,\}\]" $to} mtch1]} {
            set from [lindex $mtch0 1]
            set to [lindex $mtch1 0]
            ## Embedded braces in the arg probably mean that the user
            ## clicked outside a valid command argument
            if {[regexp "\[\{\}\]" [getText $from $to]] == 0} {
                set result [list $from $to]
            }
        }
    }
    return $result
}

# Find a LaTeX command with arguments in either direction.
# (see findCommandWithArgs in latexMacros.tcl)
# This version returns the positions at which the command options
# and arguments start, as well.
proc findCommandWithParts {pos direction} {
    set searchString {\\([^a-zA-Z\t\r]|[a-zA-Z]+\*?)(\[.*\])*({[^{}]*})?}
    if {![catch {search -s -f $direction -r 1 $searchString $pos} mtch]} {
        set beg [lindex $mtch 0]
        set end [lindex $mtch 1]
        regexp -indices $searchString [getText $beg $end] all cmd opt arg
        set opt [expr $beg + [lindex $opt 0]]
        set arg [expr $beg + [lindex $arg 0]]
        return [list $beg $opt $arg $end]
    } else {
        return ""
    }
}

#--------------------------------------------------------------------------
# Insertion routines:
#--------------------------------------------------------------------------

# Returns a modified text string if the string $text is non-null,
# and the null string otherwise.  The argument 'operation' is a
# string directing 'doPrefixText' to either "insert" or "remove"
# $prefixString to/from each line of $text.  (This routine is
# adapted from strings.tcl.)
proc doPrefixText {operation prefixString text} {
    if {$text == ""} {return ""}
    set pref [quoteExpr $prefixString]
    if {$operation == "insert"} then {
        set trailChar ""
        set textLen [string length $text]
        if {[string index $text [expr $textLen-1]] == "\r"} then {
            set text [string range $text 0 [expr $textLen-2]]
            set trailChar "\r"
        }
        set str \r$prefixString
        regsub -all \r $text $str text
        return $prefixString$text$trailChar
    } elseif {$operation == "remove"} then {
        regsub -all \r$pref $text \r text
        regsub ^$pref $text "" text
        return $text
    }
}

# Shift each line of $text to the right by inserting a string of
# $whitespace characters at the beginning of each line, returning
# the resulting string.
proc shiftTextRight {text whitespace} {
    return [doPrefixText "insert" $whitespace $text]
}

# Return a string of whitespace characters from the beginning
# of the line containing $pos up to the first non-whitespace
# character.
proc getIndentation {pos} {
    set text [getText [lineStart $pos] [nextLineStart $pos]]
    regexp {^[ \t]*} $text theIndentation
    return $theIndentation
}

# Return an "indented carriage return" if any character preceding
# the insertion point (on the same line) is a non-whitespace
# character.  Otherwise, return the null string.
proc openingCarriageReturn {} {
    set pos [getPos]
    set end $pos
    set start [lineStart $pos]
    set text [getText $start $end]
    if {[isWhitespace $text]} then {
        if {$start == $end} {return [getIndentation $pos]} {return ""}
    } else {
        return "\r[getIndentation $pos]"
    }
}
# Return an "indented carriage return" if any character following
# the insertion point (on the same line) is a non-whitespace
# character.  Otherwise, return the null string.
proc closingCarriageReturn {} {
    set pos [selEnd]
    if {[isSelection] && ($pos == [lineStart $pos])} then {
        return "\r"
    } else {
        set start $pos
        set end [nextLineStart $start]
        set text [getText $start $end]
        if {[isWhitespace $text]} then {
            return ""
        } else {
            return "\r[getIndentation $pos]"
        }
    }
}

# Insert an object at the insertion point. If there is a selection and the
# global variable 'deleteObjectNoisily' is false, quietly delete the selection
# (like 'paste'). Otherwise, prompt the user for the appropriate action.
# Returns true if the object is ultimately inserted, and false if the
# user cancels the operation.
proc insertObject {objectName} {
    global TeXmodeVars
#     if {$TeXmodeVars(expertMode) == 0} then {
#         if {![isInDocument]} then {
#             if {$TeXmodeVars(searchNoisily)} {beep}
#             case [askyesno "The cursor is not in the document environment.\
#                             \rContinue the operation?"] in {
#                 "yes" {}
#                 "no" {error "insertObject:  out of context"}
#             }
#         }
#     }
    if {[isSelection]} then {
        if {$TeXmodeVars(deleteObjectNoisily)} then {
            case [askyesno -c "Delete selection?"] in {
                "yes" {deleteText [getPos] [selEnd]}
                "no" {backwardChar}
                "cancel" {return 0}
            }
        } else {
            deleteText [getPos] [selEnd]
        }
    }
    insertText $objectName
    return 1
}

# Insert an object at the insertion point. If there is a selection, wrap
# it inside the parameters $left and $right. Returns true if there is a
# selection (in which case it will wrap), and false otherwise.
proc wrapObject {left right} {
#     global TeXmodeVars
#     if {$TeXmodeVars(expertMode) == 0} then {
#         if {![isInDocument]} then {
#             if {$TeXmodeVars(searchNoisily)} {beep}
#             case [askyesno "The cursor is not in the document environment.\
#                             \rContinue the operation?"] in {
#                 "yes" {}
#                 "no" {error "wrapObject:  out of context"}
#             }
#         }
#     }
    set currentPos [getPos]
    set selected [isSelection]
    if {$selected} then {
        replaceText $currentPos [selEnd] $left [getSelect] $right
    } else {
        insertText $left "Ñ" $right
    }
    goto $currentPos
    nextTabStop
    return $selected
}

# Builds and returns a LaTeX environment, that is, a \begin...\end
# pair, given the name of the environment, an argument string,
# and the environment body.  The body should be passed to this
# procedure fully formatted, including indentation.
proc buildEnvironment {envName envArg envBody trailingComment} {
    set indent [getIndentation [getPos]]
    set envStr [openingCarriageReturn]
    append envStr "\\begin{" $envName "}"
    append envStr $envArg "\r"
    append envStr $envBody
    append envStr $indent "\\end{" $envName "}$trailingComment"
    append envStr [closingCarriageReturn]
    return $envStr
}

# Inserts a LaTeX environment with the specified name, argument,
# and body at the insertion point.  Positions the cursor at the
# beginning of the environment, leaving any subsequent action to the
# calling procedure.  Deletes the current selection quietly if the
# global variable 'deleteEnvironmentNoisily' is false; otherwise
# the user is prompted for directions.  Returns true if the
# environment is ultimately inserted, and false if the user cancels
# the operation.
proc insertEnvironment {envName envArg envBody} {
    global TeXmodeVars
#     if {$TeXmodeVars(expertMode) == 0} then {
#         if {![isInDocument]} then {
#             if {$TeXmodeVars(searchNoisily)} {beep}
#             case [askyesno "The cursor is not in the document environment.\
#                             \rContinue the operation?"] in {
#                 "yes" {}
#                 "no" {error "insertEnvironment:  out of context"}
#             }
#         }
#     }
    if {[isSelection]} then {
        if {$TeXmodeVars(deleteEnvironmentNoisily)} then {
            case [askyesno -c "Delete selection?"] in {
                "yes" {}
                "no" {backwardChar}
                "cancel" {return 0}
            }
        }
    }
    set start [getPos]
    set end [selEnd]
    set body [shiftTextRight $envBody [getIndentation $start]]
    replaceText $start $end [buildEnvironment $envName $envArg $body "Ñ"]
    goto $start
    return 1
}

# Inserts an environment with the given name, argument, and body at
# the insertion point.  Positions the cursor at the beginning of
# the environment, leaving any subsequent action to the calling
# procedure.  If there is currently a selection, cut and paste it
# into the body of the new environment, maintaining proper
# indentation; otherwise, insert a tab stop into the body of the
# environment.  Returns true if there is a selection, and false
# otherwise.
proc wrapEnvironment {envName envArg envBody} {
#     global TeXmodeVars
#     if {$TeXmodeVars(expertMode) == 0} then {
#         if {![isInDocument]} then {
#             if {$TeXmodeVars(searchNoisily)} {beep}
#             case [askyesno "The cursor is not in the document environment.\
#                             \rContinue the operation?"] in {
#                 "yes" {}
#                 "no" {error "wrapEnvironment:  out of context"}
#             }
#         }
#     }
    set start [getPos]
    set end [selEnd]
    set indent [getIndentation $start]
    if {[isSelection]} then {
        set text [getSelect]
        set textLen [string length $text]
        if {[string index $text [expr $textLen-1]] != "\r"} then {
            append text "\r"
        }
        if {$start == [lineStart $start]} then {
            set body [shiftTextRight $text \t]
        } else {
            set body "$indent[shiftTextRight $text \t]"
        }
        append body [shiftTextRight $envBody $indent]
        set environment [buildEnvironment $envName $envArg $body "Ñ"]
        set returnFlag 1
    } else {
        append body "$indent\tÑ\r" [shiftTextRight $envBody $indent]
        set environment [buildEnvironment $envName $envArg $body "Ñ"]
        set returnFlag 0
    }
    replaceText $start $end $environment
    goto $start
    return $returnFlag
}

# A generic call to 'wrapEnvironment' used throughout latex.tcl:
proc doWrapEnvironment {envName} {
    if {[wrapEnvironment $envName "" ""]} then {
        set msgText "selection wrapped"
    } else {
        set msgText "enter body of $envName environment"
    }
    nextTabStop
    message $msgText
}

# Inserts a structured document template at the insertion point.
# Three arguments are required:  the class name of the document, a
# preamble string, and a string containing the body of the document.
# If the preamble is null, a generic \usepackage statement is
# inserted; otherwise, the preamble is inserted as is.  This routine
# does absolutely no error-checking (this is totally left up to the
# calling procedure) and returns nothing.
proc insertDocument {className preamble docBody} {
    set docStr "\\documentclass\[Ñ\]{$className}\r"
    if {$preamble == ""} then {
        append docStr "\\usepackage\[Ñ\]{Ñ}\r\rÑ\r\r"
    } else {
        append docStr $preamble
    }
    append docStr [buildEnvironment "document" "" $docBody "\r"]
    set start [getPos]
    set end [selEnd]
    replaceText $start $end $docStr
    goto $start
    return
}

# Inserts a document template at the insertion point given the
# class name of the document to be inserted.  If ALL of the current
# document is selected, then the routine wraps the text inside a
# generic document template.  If the file is empty, a bullet is
# inserted in place of the document body.  If neither of these
# conditions is true, an alert is displayed, and no action is taken.
# Returns true if wrapping occurs, and false otherwise.
proc wrapDocument {className} {
    if {[isEmptyFile]} then {
        append body "\rÑ\r\r"
        set returnFlag 0
    } else {
        if {[isDocumentSelected]} then {
            set text [getSelect]
            append body "\r$text\r"
            set returnFlag 1
        } else {
            alertnote "nonempty file:  delete text or \'Select All\'\
                from the Edit menu"
            return 0
        }
    }
    set docStr "\\documentclass\[Ñ\]{$className}\r"
    append docStr "\\usepackage\[Ñ\]{Ñ}\r\rÑ\r\r"
    append docStr [buildEnvironment "document" "" $body "\r"]
    set start [getPos]
    set end [selEnd]
    replaceText $start $end $docStr
    goto $start
    return $returnFlag
}

#--------------------------------------------------------------------------
# Booleans to determine the location of the insertion point
#--------------------------------------------------------------------------

# Return true if the insertion point is before the preamble, and
# false otherwise.   Define "before the preamble" to be all text to
# the left of "\" in "\documentclass".
proc isBeforePreamble {} {
    set searchString "\\documentclass"
    set searchResult [search -s -f 1 -r 0 -n $searchString [getPos]]
    if {[llength $searchResult]} {
        return 1
    } else {
        return 0
    }
}

# Return true if the insertion point is in the preamble, and false
# otherwise.  Define "preamble" to be all text to the left of "\"
# in "\begin{document}", but not before the "\" in "\documentclass".
proc isInPreamble {} {
    set searchString "\\begin\{document\}"
    set searchResult [search -s -f 1 -r 0 -n $searchString [getPos]]
    if {[llength $searchResult]} {
        return 1
    } else {
        return 0
    }
}

# Return true if the insertion point is in the document environment,
# and false otherwise.  Define "document" to be all text between
# "\begin{document}" and "\end{document}", exclusive.
proc isInDocument {} {
    set pos [getPos]
    set searchString "\\begin\{document\}"
    # adjust for the length of the search string:
    set len [string length $searchString]
    if {$pos < $len} then {return 0}
    set searchResult [search -s -f 0 -r 0 -n $searchString [expr $pos - $len]]
    if {[llength $searchResult]} then {
        set searchString "\\end\{document\}"
        set searchResult [search -s -f 1 -r 0 -n $searchString $pos]
        if {[llength $searchResult]} then {
            return 1
        } else {
            return 0
        }
    } else {
        return 0
    }
}

# Return true if the insertion point is after the document
# environment, and false otherwise.  Define "after the document
# environment" to be all text to the right of "}" in "\end{document}".
proc isAfterDocument {} {
    set pos [getPos]
    set searchString "\\end\{document\}"
    set searchResult [search -s -f 0 -r 0 -n $searchString $pos]
    if {[llength $searchResult]} {
        set pos1 [lindex $searchResult 0]
        set pos2 [lindex $searchResult 1]
        if {$pos1 <= $pos && $pos < $pos2} then {
            return 0
        } else {
            return 1
        }
    } else {
        return 0
    }
}

proc isInMathMode {} {
    set pos [getPos]
    # Check to see if in LaTeX math mode:
    set searchString {\\[()]}
    set searchResult1 [search -s -f 0 -r 1 -n $searchString [expr $pos - 1]]
    if {[llength $searchResult1]} then {
        set delim1 [eval getText $searchResult1]
    } else {
        set delim1 "none"
    }
    set searchResult2 [search -s -f 1 -r 1 -n $searchString $pos]
    if {[llength $searchResult2]} then {
        set delim2 [eval getText $searchResult2]
    } else {
        set delim2 "none"
    }
    set flag1 [expr [string match {none} $delim1] && [string match {\\)} $delim2]]
    set flag2 [expr [string match {\\(} $delim1] && [string match {none} $delim2]]
    set flag3 [expr [string match {\\(} $delim1] && [string match {\\)} $delim2]]
    set flag4 [expr [string match {\\(} $delim1] && [string match {\\(} $delim2]]
    set flag5 [expr [string match {\\)} $delim1] && [string match {\\)} $delim2]]
    if {$flag3} then {
        return 1
    } elseif {$flag1 || $flag2 || $flag4 || $flag5} then {
        set messageString "unbalanced math mode delimiters"
        beep
        alertnote $messageString
        error "isInMathMode:  $messageString"
    }
    # Check to see if in LaTeX displaymath mode:
    set searchString {[^\\]\\\[|\\\]}
    set searchResult1 [search -s -f 0 -r 1 -n $searchString [expr $pos - 1]]
    if {[llength $searchResult1]} then {
        set begPos [lindex $searchResult1 0]
        set endPos [lindex $searchResult1 1]
        if {[lookAt [expr $endPos - 1]] == "\["} then {
            set delim1 [getText [expr $begPos + 1] $endPos]
        } else {
            set delim1 [eval getText $searchResult1]
        }
    } else {
        set delim1 "none"
    }
    set searchResult2 [search -s -f 1 -r 1 -n $searchString $pos]
    if {[llength $searchResult2]} then {
        set begPos [lindex $searchResult2 0]
        set endPos [lindex $searchResult2 1]
        if {[lookAt [expr $endPos - 1]] == "\["} then {
            set delim2 [getText [expr $begPos + 1] $endPos]
        } else {
            set delim2 [eval getText $searchResult2]
        }
    } else {
        set delim2 "none"
    }
    set flag1 [expr [string match {none} $delim1] && [string match {\\\]} $delim2]]
    set flag2 [expr [string match {\\\[} $delim1] && [string match {none} $delim2]]
    set flag3 [expr [string match {\\\[} $delim1] && [string match {\\\]} $delim2]]
    set flag4 [expr [string match {\\\[} $delim1] && [string match {\\\[} $delim2]]
    set flag5 [expr [string match {\\\]} $delim1] && [string match {\\\]} $delim2]]
    if {$flag3} then {
        return 1
    } elseif {$flag1 || $flag2 || $flag4 || $flag5} then {
        set messageString "unbalanced math mode delimiters"
        beep
        alertnote $messageString
        error "isInMathMode:  $messageString"
    }
    # Check to see if in math environment:
    set envName [extractCommandArg [eval getText [searchEnvironment]]]
    set envList [list "math" "displaymath" "equation" "eqnarray" "eqnarray*" "array"]
    if {[lsearch -exact $envList $envName] == -1} {return 0} {return 1}
}

#--------------------------------------------------------------------------
# Routines to dissect LaTeX commands
#--------------------------------------------------------------------------

# Given a LaTeX command string, extract and return the command name.
proc extractCommandName {commandStr} {
    if {[regexp {\\([^a-zA-Z\t\r]|[a-zA-Z]+\*?)} $commandStr dummy commandName]} then {
        return $commandName
    } else {
        return ""
    }
}

# Given a LaTeX command string with at most one required argument and
# no embedded carriage returns, extract and return the argument.
# (Note:  this proc needs more testing.)
proc extractCommandArg {commandStr} {
    if {[regexp {\{(.*)\}} $commandStr dummy arg]} then {
        return $arg
    } else {
        return ""
    }
}

#--------------------------------------------------------------------------
# An environment search routine
#--------------------------------------------------------------------------

# Search for the closest surrounding environment and return a list
# of two positions if the environment is found; otherwise return the
# empty list.  Assumes the LaTeX document is syntactically correct.
# The command 'eval select [searchEnvironment]' selects the "\begin"
# statement (with argument) of the surrounding environment.
proc searchEnvironment {} {
    watchCursor
    set pos [getPos]
    if {$pos == 0} {
        return [list]
    }
    # adjust position if insertion point is contained in "\end{...}"
    set searchPos [expr $pos - 1]
    set searchString {\\end\{[^\{\}]*\}}
    set searchResult [search -s -f 0 -r 1 -n $searchString $searchPos]
    if {[llength $searchResult]} {
        set pos1 [lindex $searchResult 0]
        set pos2 [lindex $searchResult 1]
        if {$pos1 < $pos && $pos < $pos2} then {
            set searchPos [expr $pos1 - 1]
        }
    }
    # begin reverse search:
    set searchString {\\(begin|end)\{[^\{\}]*\}}
    set searchResult [search -s -f 0 -r 1 -n $searchString $searchPos]
    if {[llength $searchResult]} {
#         set text [getText [lindex $searchResult 0] [lindex $searchResult 1]]
        set text [eval getText $searchResult]
    } else {
        return [list]
    }
    set depthCounter 0
    set commandName [extractCommandName $text]
    while {$commandName == "end" || $depthCounter > 0} {
        if {$commandName == "end"} {
            set depthCounter [expr $depthCounter + 1]
        } else {
            set depthCounter [expr $depthCounter - 1]
        }
        set searchPos [expr [lindex $searchResult 0] - 1]
        set searchResult [search -s -f 0 -r 1 -n $searchString $searchPos]
        if {[llength $searchResult]} {
#             set text [getText [lindex $searchResult 0] [lindex $searchResult 1]]
            set text [eval getText $searchResult]
        } else {
            return [list]
        }
        set commandName [extractCommandName $text]
    }
    return $searchResult
}

#--------------------------------------------------------------------------
# Misc:
#--------------------------------------------------------------------------

proc isInteger {str1} {
#     if { [regexp {^(\+|-)?[0-9]+$} [string trim $str1]] } then {
#         return 1
#     } else {
#         return 0
#     }
    return [regexp {^(\+|-)?[0-9]+$} [string trim $str1]]
}

proc isUnsignedInteger {str1} {
#     if { [regexp {^[0-9]+$} [string trim $str1]] } then {
#         return 1
#     } else {
#         return 0
#     }
    return [regexp {^[0-9]+$} [string trim $str1]]
}

proc isPositiveInteger {str1} {
    if { [isUnsignedInteger $str1] } then {
        if { ![regexp {^0+$} [string trim $str1]] } {
            return 1
        }
    }
    return 0
}

# Checks to see if there is a current selection.
#
# This seems to be bugged:
# proc isSelection {} {
#     return [expr [getPos] == [selEnd]]
# }
proc isSelection {} {
    return [string length [getSelect]]
}

# Checks to see if the current window is empty, except for whitespace.
proc isEmptyFile {} {
    return [isWhitespace [getText 0 [maxPos]]]
}

# If there is a selection, make sure it's uppercase.  Otherwise,
# check to see if the character after the insertion point is uppercase.
proc isUppercase {} {
    if {[isSelection]} then {
        set text [getSelect]
    } else {
        set text [lookAt [getPos]]
    }
    return [expr {[string toupper $text] == $text}]
}

# Returns true if the entire window is selected, and false otherwise.
proc isDocumentSelected {} {
    return [expr {([getPos] == 0) && ([selEnd] == [maxPos])}]
}

# Takes any string and tests whether or not that string contains all
# whitespace characters.  Carriage returns are considered whitespace,
# as are spaces and tabs.  Also returns true for the null string.
proc isWhitespace {anyString} {
    set len [string length $anyString]
    for {set i 0} {$i < $len} {incr i} {
        set c [string index $anyString $i]
        if {($c != "\ ") && ($c != "\t") && ($c != "\r")} then {return 0}
    }
    return 1
}

# Select the line containing the insertion point.
proc lineSelect {} {
    goto [lineStart [getPos]]
    nextLineSelect
}

proc checkMathMode {procName mathModeFlag} {
#     global TeXmodeVars
#     if {$TeXmodeVars(expertMode) == 0} then {
#         if {[isInDocument] && [isInMathMode] != $mathModeFlag} then {
#             if {$TeXmodeVars(searchNoisily)} {beep}
#             if {$mathModeFlag} then {
#                 set messageString "You are not in math mode"
#             } else {
#                 set messageString "You are already in math mode"
#             }
#             case [askyesno "$messageString.\rContinue the operation?"] in {
#                 "yes" {}
#                 "no" {error "$procName:  out of context"}
#             }
#         }
#     }
}

# Check to see if the LaTeX symbol package has been loaded; if not, ask
# the user for directions.  Returns false if the package is not loaded
# AND the user cancels the operation; otherwise, returns true.
proc isSymbolPackageLoaded {} {
    global searchNoisily
    set begPos [getPos]
    set endPos [selEnd]
    set searchString {\\usepackage\{.*latexsym.*\}}
    set searchResult [search -s -n -f 0 -m 0 -i 1 -r 1 $searchString $begPos]
    if {[llength $searchResult] == 0} then {
        case [askyesno -c "Insert the LaTeX symbol package?"] in {
            "yes" {
                set searchString {\\documentclass(\[.*\])?\{.*\}}
                set searchResult [search -s -n -f 0 -m 0 -i 1 -r 1 $searchString $begPos]
                if {[llength $searchResult] == 0} then {
                    set returnVal 0
                    if {$searchNoisily} {beep}
                    message "can't find \\documentclass"
                } else {
                    goto [lindex $searchResult 1]
                    set txt "\r\\usepackage\{latexsym\}"
                    set offset [string length $txt]
                    set begPos [expr $begPos + $offset]
                    set endPos [expr $endPos + $offset]
                    insertText $txt
                    set returnVal 1
                }
            }
            "no" {set returnVal 1}
            "cancel" {set returnVal 0}
        }
    } else {
        set returnVal 1
    }
    select $begPos $endPos
    return $returnVal
}