The following is a list of all the different Tcl_Obj types defined in 8.4, with docco culled from the source, and the names of functions which implement the four operations defined on all Tcl_Obj instances. [CMcC]

APN Also see Tcl_Obj types list for a script that generates a list of the different types.

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Types in 8.4 edit

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array search

Tcl_ObjType: tclArraySearchType

Type of Tcl_Objs used to speed up array searches.

• twoPtrValue.ptr1 = searchIdNumber as offset from (char*)NULL
• twoPtrValue.ptr2 = variableNameStartInString as offset from (char*)NULL

Note that the value stored in ptr2 is the offset into the string of the start of the variable name and not the address of the variable name itself, as this can be safely copied.

Free Internal

NULL

Dup Internal

NULL

Update String

NULL

Set Internal

SetArraySearchObj

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boolean

Tcl_ObjType: tclBooleanType

Free Internal

NULL

Dup Internal

NULL

Update String

UpdateStringOfBoolean

Set Internal

SetBooleanFromAny

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bytearray

Tcl_ObjType: tclByteArrayType

This object type represents an array of bytes. An array of bytes is not equivalent to an internationalized string. Conceptually, a string is an array of 16-bit quantities organized as a sequence of properly formed UTF-8 characters, while a ByteArray is an array of 8-bit quantities. Accessor functions are provided to convert a ByteArray to a String or a String to a ByteArray. Two or more consecutive bytes in an array of bytes may look like a single UTF-8 character if the array is casually treated as a string. But obtaining the String from a ByteArray is guaranteed to produced properly formed UTF-8 sequences so that there is a one-to-one map between bytes and characters.

Converting a ByteArray to a String proceeds by casting each byte in the array to a 16-bit quantity, treating that number as a Unicode character, and storing the UTF-8 version of that Unicode character in the String. For ByteArrays consisting entirely of values 1..127, the corresponding String representation is the same as the ByteArray representation.

Converting a String to a ByteArray proceeds by getting the Unicode representation of each character in the String, casting it to a byte by truncating the upper 8 bits, and then storing the byte in the ByteArray. Converting from ByteArray to String and back to ByteArray is not lossy, but converting an arbitrary String to a ByteArray may be.

Free Internal

FreeByteArrayInternalRep

Dup Internal

DupByteArrayInternalRep

Update String

UpdateStringOfByteArray

Set Internal

SetByteArrayFromAny

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bytecode

Tcl_ObjType: tclByteCodeType

defines the bytecode Tcl object type by means of procedures that can be invoked by generic object code.

Free Internal

FreeByteCodeInternalRep

Dup Internal

DupByteCodeInternalRep

Update String

NULL

Set Internal

SetByteCodeFromAny - Attempts to generate an byte code internal form for the Tcl object "objPtr" by compiling its string representation.

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cmdName

Tcl_ObjType: tclCmdNameType

Objects of this type cache the Command pointer that results from looking up command names in the command hashtable. Such objects appear as the zeroth ("command name") argument in a Tcl command.

Free Internal

FreeCmdNameInternalRep

Dup Internal

DupCmdNameInternalRep

Update String

NULL

Set Internal

SetCmdNameFromAny

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double

Tcl_ObjType: tclDoubleType

Free Internal

NULL

Dup Internal

NULL

Update String

UpdateStringOfDouble

Set Internal

SetDoubleFromAny

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end-offset

Tcl_ObjType: tclEndOffsetType

A Tcl object type definition for an object that represents a list index in the form, "end-offset". It is used as a performance optimization in TclGetIntForIndex. The internal rep is an integer, so no memory management is required for it.

Free Internal

NULL

Dup Internal

NULL

Update String

UpdateStringOfEndOffset

Set Internal

SetEndOffsetFromAny

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index

Tcl_ObjType: tclIndexType

Free Internal

FreeIndex

Dup Internal

DupIndex

Update String

UpdateStringOfIndex

Set Internal

SetIndexFromAny

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int

Tcl_ObjType: tclIntType

Free Internal

NULL

Dup Internal

NULL

Update String

UpdateStringOfInt

Set Internal

SetIntFromAny

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list

Tcl_ObjType: tclListType

The internal representation of a list object is a two-pointer representation. The first pointer designates a List structure that contains an array of pointers to the element objects, together with integers that represent the current element count and the allocated size of the array. The second pointer is normally NULL; during execution of functions in this file that operate on nested sublists, it is occasionally used as working storage to avoid an auxiliary stack.

Free Internal

FreeListInternalRep - Frees listPtr's List* internal representation and sets listPtr's internalRep.twoPtrValue.ptr1 to NULL. Decrements the ref counts of all element objects, which may free them.

Dup Internal

DupListInternalRep

Update String

UpdateStringOfList

Set Internal

SetListFromAny

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localVarName

Tcl_ObjType: tclLocalVarNameType

Types of Tcl_Objs used to cache variable lookups.

• twoPtrValue.ptr1 = pointer to the corresponding Proc
• twoPtrValue.ptr2 = index into locals table

Free Internal

FreeLocalVarName

Dup Internal

DupLocalVarName

Update String

UpdateLocalVarName

Set Internal

NULL

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namespaceVarName

Tcl_ObjType: tclNsVarNameType

• twoPtrValue.ptr1: pointer to the namespace containing the reference
• twoPtrValue.ptr2: pointer to the corresponding Var

Free Internal

FreeNsVarName

Dup Internal

DupNsVarName

Update String

NULL

Set Internal

NULL

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nsName

Tcl_ObjType: tclNsNameType

Defines a Tcl object type that contains a namespace reference. It is used in commands that take the name of a namespace as an argument. The namespace reference is resolved, and the result in cached in the object.

Free Internal

FreeNsNameInternalRep

Dup Internal

DupNsNameInternalRep

Update String

UpdateStringOfNsName

Set Internal

SetNsNameFromAny

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parsedVarName

Tcl_ObjType: tclParsedVarNameType

• twoPtrValue.ptr1 = pointer to the array name Tcl_Obj, or NULL if it is a scalar variable
• twoPtrValue.ptr2 = pointer to the element name string (owned by this Tcl_Obj), or NULL if it is a scalar variable

Free Internal

FreeParsedVarName

Dup Internal

DupParsedVarName

Update String

UpdateParsedVarName

Set Internal

NULL

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path

Tcl_ObjType: tclFsPathType

Define the 'path' object type, which Tcl uses to represent file paths internally.

Free Internal

FreeFsPathInternalRep

Dup Internal

DupFsPathInternalRep

Update String

NULL

Set Internal

SetFsPathFromAny

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procbody

Tcl_ObjType: tclProcBodyType

Free Internal

ProcBodyFree

Dup Internal

ProcBodyDup

Update String

ProcBodyUpdateString

Set Internal

ProcBodySetFromAny - Calls panic, since we can't set the value of the object from a string representation (or any other internal ones).

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regexp

Tcl_ObjType: tclRegexpType

The regular expression Tcl object type. This serves as a cache of the compiled form of the regular expression.

Free Internal

FreeRegexpInternalRep

Dup Internal

DupRegexpInternalRep

Update String

NULL

Set Internal

SetRegexpFromAny

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string

Tcl_ObjType: tclStringType

Some string operations work with UTF strings and others require Unicode format. Functions that require knowledge of the width of each character, such as indexing, operate on Unicode data.

A Unicode string is an internationalized string. Conceptually, a Unicode string is an array of 16-bit quantities organized as a sequence of properly formed UTF-8 characters. There is a one-to-one map between Unicode and UTF characters. Because Unicode characters have a fixed width, operations such as indexing operate on Unicode data. The String ojbect is opitmized for the case where each UTF char in a string is only one byte. In this case, we store the value of numChars, but we don't store the Unicode data (unless Tcl_GetUnicode is explicitly called).

The String object type stores one or both formats. The default behavior is to store UTF. Once Unicode is calculated by a function, it is stored in the internal rep for future access (without an additional O(n) cost).

To allow many appends to be done to an object without constantly reallocating the space for the string or Unicode representation, we allocate double the space for the string or Unicode and use the internal representation to keep track of how much space is used vs. allocated.

Free Internal

FreeStringInternalRep

Dup Internal

DupStringInternalRep

Update String

UpdateStringOfString - The object's string may be set by converting its Unicode represention to UTF format.

Set Internal

SetStringFromAny - Any old internal reputation for objPtr is freed and the internal representation is set to "String".

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wideInt

Tcl_ObjType: tclWideIntType

Integer value (at least) 64-bits long. On 64-bit platforms, this is identical to the normal integer type.

Free Internal

NULL

Dup Internal

NULL

Update String

UpdateStringOfWideInt

Set Internal

SetWideIntFromAny

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Types in 8.5 edit

[todo]

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Types in 8.6 edit

[todo]

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