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Diffstat (limited to 'doc/context/sources/general/manuals/luametatex/luametatex-enhancements.tex')
| -rw-r--r-- | doc/context/sources/general/manuals/luametatex/luametatex-enhancements.tex | 72 |
1 files changed, 70 insertions, 2 deletions
diff --git a/doc/context/sources/general/manuals/luametatex/luametatex-enhancements.tex b/doc/context/sources/general/manuals/luametatex/luametatex-enhancements.tex index 8a1466301..4b4156d5d 100644 --- a/doc/context/sources/general/manuals/luametatex/luametatex-enhancements.tex +++ b/doc/context/sources/general/manuals/luametatex/luametatex-enhancements.tex @@ -821,6 +821,21 @@ This can be a bit nicer than using the uppercase tricks (using the property of \stopsubsection +\startsubsection[title={\lpr {lettonothing} and \lpr {glettonothing}}] + +This primitive is equivalent to: + +\starttyping +\protected\def\lettonothing#1{\def#1{}} +\stoptyping + +and although it might feel faster (only measurable with millions of calls) it's +mostly there because it is easier on tracing (less clutter). An advantage over +letting to an empty predefined macro is also that in tracing we keep seeing the +name (relaxing would show the relax equivalent). + +\stopsubsection + \startsubsection[title={\lpr {glet}}] This primitive is similar to: @@ -1541,13 +1556,42 @@ related primitives. \topicindex {tracing} If \prm {tracingonline} is larger than~2, the node list display will also print -the node number of the nodes. +the node number of the nodes as well as set attributes (these can be made verbose +by a callback). We have only a generic whatsit but again a callback can be used +to provide detail. So, when a box is shown in \CONTEXT\ you will see quite a lot +more than in other engines. Because nodes have more fields, more is shown anyway, +and for nodes that have sublists (like discretionaries) these are also shown. All +that could have been delegated to \LUA\ but it felt wrong to not made that a core +engine feature. When bit~1 of \lpr {tracinglevels} is set the current level is prepended to tracing lines in the log and when bit~2 is set the input level is prepended. You can set both bits and get both numbers prepended. In \CONTEXT\ we default to the value~3, so you get prefixes like \type {3:4:} followed by a space. +When \type {\tracingcommands} is larger than 3 the mode switch will be not be +prefixed to the \type {{command}} but get its own \type {[line]}. + +When \type {\tracinglevels} variable is set to 3 the group and input level are +shown, a value of 1 or 2 shows only one of them (in \CONTEXT\ we default to 3). + +When \type {\tracinghyphenation} is set to 1 duplicate patterns are reported (in +\CONTEXT\ we default to that) and higher values will also show details about the +\LUA\ hyphenation (exception) feedback loop discussed elsewhere. + +When set to 1 the \type {\tracingmath} variable triggers the reporting of the +mode (inline or display) an mlist is processed. + +Because in \LUATEX\ the saving and restoring of locally redefined macros and set +variables is optimized a bit in order to prevent redundant stack usage, there +will be less tracing visible. + +Also, because we have a more extensive macro argument parser, a fast path (and +less storage demands) for macros with no arguments, and flags that can be set for +macros the way macros are traced can be different in details (we therefore have +for instance \type {\meaningfull} and \type {\meaningless} as variants of \type +{\meaning}). + \stopsubsection % \startsubsection[title={\lpr {lastnodetype}, \lpr {lastnodesubtype}, \lpr @@ -2071,6 +2115,9 @@ more parsing options: \NC 0 \NC discard but count the argument \NC \NR \ML \NC * \NC ignore spaces \NC \NR +\NC . \NC ignore pars and spaces \NC \NR +\NC , \NC push back space when no match \NC \NR +\ML \NC : \NC pick up scanning here \NC \NR \NC ; \NC quit scanning \NC \NR \LL @@ -2222,7 +2269,7 @@ users redefine instances but there a warning or error is kind of welcome. \stopsection -\startsection[title=Constants] +\startsection[title={Constants with \lpr{integerdef} and \lpr {dimendef}}] It is rather common to store constant values in a register or character definition. @@ -2250,6 +2297,27 @@ in a previous section. \stopsection +\startsection[title={Serialization with \lpr {todimension}, \lpr {toscaled} and \lpr {tointeger}}] + +These three serializers take a verbose or symbolic quantity: + +\starttyping +\todimension 10pt \todimension \scratchdimen % with unit +\toscaled 10pt \toscaled \scratchdimen % without unit +\tointeger 10 \tointeger \scratchcounter +\stoptyping + +This is particularly handy in cases where you don't know what you deal with, for instance +when a value is stored in a macro. Using \type {\the} could fail there while: + +\starttyping +\the\dimexpr10pt\relax +\stoptyping + +is often overkill and gives more noise in a trace. + +\stopsection + \startsection[title=Nodes] The \ETEX\ primitive \type {\lastnodetype} is not honest in reporting the |