lettersPattern — Create a pattern matching letter characters.
lettersPattern creates a greedy pattern for one or more Unicode letters by default, or for an exact or inclusive bounded count.
Syntax
pat = lettersPattern
pat = lettersPattern(N)
pat = lettersPattern(minCharacters, maxCharacters)Inputs
| Name | Type | Required | Default | Description |
|---|---|---|---|---|
N | NumericScalar | Yes | — | Exact nonnegative number of characters to match. |
minCharacters | NumericScalar | Yes | — | Minimum nonnegative number of characters to match. |
maxCharacters | NumericScalar | Yes | — | Maximum nonnegative count, or positive infinity for no upper bound. |
Returns
| Name | Type | Description |
|---|---|---|
pat | Any | Host pattern object. |
Errors
| Identifier | When | Message |
|---|---|---|
RunMat:lettersPattern:ArgumentCount | More than two count arguments are supplied. | lettersPattern: expected zero, one, or two input arguments |
RunMat:lettersPattern:InvalidCount | A count is not a host or automatically resident nonnegative numeric integer scalar, or positive infinity in the maximum position. | lettersPattern: invalid character count |
RunMat:lettersPattern:InvalidRange | minCharacters exceeds maxCharacters. | lettersPattern: minCharacters must not exceed maxCharacters |
How lettersPattern works
- Without a count, the greedy pattern matches one or more Unicode alphabetic characters.
- Exact and bounded counts accept single, double, and all eight integer classes without routing typed values through floating compatibility storage.
- The bounded form accepts positive infinity as the maximum and rejects negative, fractional, nonscalar, reversed, or platform-oversized counts.
Example
Using lettersPattern with coding agents
Open a RunMat example with live inputs, then ask the agent to explain how lettersPattern changes the result.
Run a small lettersPattern example, explain the result, then change one input and compare the output.
Related Strings functions
Pattern
digitsPattern · pattern · regexpPattern · textBoundary · wildcardPattern
Text Analytics
addDependencyDetails · addEntityDetails · addLemmaDetails · addPartOfSpeechDetails · addSentenceDetails · addTypeDetails · bagOfNgrams · bagOfWords · cosineSimilarity · doc2sequence · encode · extractFileText · extractHTMLText · fastTextWordEmbedding · findElement · getAttribute · htmlTree · ind2word · isVocabularyWord · normalizeWords · readWordEmbedding · removeLongWords · removeShortWords · removeStopWords · removeWords · stopWords · tokenDetails · tokenizedDocument · trainWordEmbedding · vaderSentimentScores · vec2word · word2ind · word2vec · wordEncoding · writeWordEmbedding
Transform
append · deblank · erase · eraseBetween · erasePunctuation · eraseURLs · extractAfter · extractBefore · extractBetween · insertAfter · insertBefore · join · lower · pad · replace · replaceBetween · reverse · split · splitlines · strcat · strip · strjoin · strjust · strrep · strsplit · strtrim · upper
Core
blanks · char · compose · convertCharsToStrings · convertContainedStringsToChars · convertStringsToChars · genvarname · int2str · isletter · isspace · isStringScalar · isstrprop · mat2str · native2unicode · newline · num2str · sprintf · sscanf · str2double · str2num · strcmp · strcmpi · string · string.empty · strings · strlength · strncmp · strncmpi · strtok · unicode2native
Search
contains · endsWith · matches · startsWith · strfind
Open-source implementation
Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how lettersPattern is executed, line by line, in Rust.
- View the source for lettersPattern in Rust on GitHub
- Learn how the RunMat runtime works
- Found a bug? Open an issue with a minimal reproduction.
About RunMat
RunMat is an open-source runtime that executes MATLAB-syntax code blazing on any GPU. It is licensed under the Apache 2.0 license.
- RunMat automatically optimizes your math for GPU execution on Apple, Nvidia, and AMD hardware. No code changes needed. Simulations that took hours now take minutes.
- Start running code in seconds. RunMat runs in the browser, on the desktop, or from the CLI. No license server, no IT ticket.