Debugging 'Tex Capacity Exceeded' Errors Caused By Spaces

TeX memory capacity errors can occur when too many spaces build up in the source code, using up all available memory. This article will cover methods for locating problematic spaces, explain why spaces consume memory, suggest strategies to reduce space usage, provide example code adjustments, and show how to permanently increase TeX's memory limit.

Locating Spaces Causing Capacity Issues

The first step in debugging capacity exceeded errors is to identify sections in the TeX source code containing a high density of spaces. Typically these occur in:

Lengthy text paragraphs
Indented code or poetry blocks
Tables with space-separated columns
Documents with extensive commented passages

Scan through the full source code manually checking the above areas. Also use search functions to locate common space delimiter patterns like:

Table of Contents

5+ spaces between words or tokens
30+ consecutive spaces on a line
Trailing spaces after punctuation

When examining code comments and text paragraphs, pay attention to both horizontal spacing from line indents and vertical spacing from stacked empty lines. Identify the specific locations contributing the most spaces.

Why Spaces Use TeX Memory

To understand solutions for reducing space usage, you need to know how TeX handles spaces in its memory. Here are key reasons spaces take up capacity:

Each space token requires storing character data
Consecutive spaces generate additional space tokens
Line breaks count as space tokens too
Alignment and indentation add more spaces

As the TeX compiler parses source code into tokens, every encountered space character consumes 1 byte in memory. While tiny individually, collectively they add up. 1MB could store 8 million space tokens!

TeX also inserts implicit space tokens automatically at line breaks and around punctuation. Manually coded alignment through indentation or spacing further inflates totals. Reducing spaces lowers required capacity.

Strategies for Reducing Memory Use from Spaces

With problem space locations identified and reasons for high capacity understood, next employ targeted strategies to reduce space numbers. Common techniques include:

Removing Unnecessary Spaces

Eliminate all extraneous spaces possible without affecting document structure:

Delete excess spaces between tokens
Remove unused lines causing implicit line break spaces
Trim trailing spaces after punctuation

Balance space removal with readability though. Some spaces aid code clarity and alignment.

Shortening Lengthy Text Sections

Long text paragraphs likely contain high space totals from word spacing and line breaks. Reduce their length by:

Separating into multiple smaller paragraphs
Converting prose to concise bullet points
Distilling key info into tables or diagrams

Generating the same content with fewer total words directly decreases spaces needed in memory.

Adjusting Space Tokens with Commands

Rather than manually inserting spaces, utilize TeX commands to define spacing rules:

\spaceskip - Fixed spacewidth
\linebreak - Break lines without space
\indent - Indent without spaces

Commands insert standardized space tokens only as required by arguments rather than every occurrence.

Example Codes

Below are examples demonstrating practical applications of the space reduction strategies:

Removing Trailing Spaces

Before:
Hello World! This sentence has trailing spaces  
After: 
Hello World! This sentence has trailing spaces

Simply delete extraneous trailing spaces manually or via find/replace.

Using Comments Instead of Spaces

Before:

                    This text is indented 

After:

%[[[[[[[[[[[[[[[[[[[
This text is indented 
]]]]]]]]]]]]]]]]]]]]

For alignment spacing, substitute comments markers. Remove spaces and achieve the same formatting without consuming capacity.

Setting Fixed Space Width

Before:
The     quick brown fox jumps over the lazy dog
After: 
\spaceskip=10pt
The\spaceskip quick\spaceskip brown\spaceskip fox\spaceskip jumps\spaceskip over\spaceskip the\spaceskip lazy\spaceskip dog

Using \spaceskip applies a consistent spacing rule instead of variable spaces.

Permanently Increasing TeX Memory Capacity

If space optimizations are insufficient, allocate more total memory for TeX processes by:

Using the \extramem command
Increasing pool size for multi-instance TeX engines like pdfTeX
Adding more RAM to the system

This permits a larger number of space tokens before hitting the capacity limit.

Debugging ‘Tex Capacity Exceeded’ Errors Caused By Spaces