Function Reference

Comprehensive cross-reference catalog of all 400+ functions available in the Rexx interpreter, organized by category with implementation status and availability.

Function Resolution Order

When a function is called, the interpreter resolves it using this priority order:

  1. Built-in REXX functions (LENGTH, SUBSTR, POS, etc.) - Always available regardless of ADDRESS context
  2. External functions from REQUIRE’d libraries
  3. ADDRESS handler custom methods - Only checked if not a built-in function
  4. Browser functions (executeBrowserStringFunction)
  5. RPC/fallback handler

This ensures:

  • Standard REXX functions like LENGTH(), SUBSTR(), POS() always work, even when inside an ADDRESS context
  • ADDRESS handlers can define custom methods without conflicting with built-in functions
  • DOM functions use DOM_ prefix (DOM_QUERY, DOM_CLICK, etc.) to avoid naming conflicts with ADDRESS handler methods

Operations vs Functions

RexxJS distinguishes between two types of callable code:

Operations (Imperative Commands)

Operations are side-effect actions called without parentheses:

  • ❌ No parentheses in call syntax
  • ✅ Named parameters only (passed as params object)
  • ✅ Used for state changes and side effects
  • ❌ Cannot be used in expressions or pipes
  • ✅ Loaded via REQUIRE alongside functions

Example:

REQUIRE "cwd:libs/bathhouse.js"
SERVE_GUEST guest="river_spirit" bath="herbal"
CLEAN_BATHHOUSE area="main_hall" intensity="deep"

Functions (Expressions)

Functions are pure/query operations called with parentheses:

  • ✅ Always use parentheses (even if no parameters)
  • ✅ Support both positional AND named parameters
  • ✅ Can be used in expressions, assignments, pipes
  • ✅ Parameters converted via parameter-converter
  • ✅ Work with pipe operator: data |> FUNC(param=val)

Example:

-- Positional parameters
LET upper = UPPER("hello")
LET sub = SUBSTR("hello world", 7, 5)  -- "world"

-- Named parameters
LET spirit = IDENTIFY_SPIRIT(description="muddy")
LET sub2 = SUBSTR(start=7, length=5)  -- Works with piped data

-- Named parameters in pipe operator
LET result = "hello world" |> SUBSTR(start=7, length=5)  -- "world"
LET cleaned = "  text  " |> STRIP() |> SUBSTR(start=2, length=3)  -- "ext"

Named Parameters Support

All functions support both positional and named parameters interchangeably:

-- Traditional positional style
LET result1 = SUBSTR("hello world", 7, 5)       -- "world"
LET index1 = POS("world", "hello world")        -- 7
LET word1 = WORDPOS("brown", "the quick brown") -- 3

-- Modern named style (data-first design for pipes)
LET result2 = "hello world" |> SUBSTR(start=7, length=5)       -- "world"
LET index2 = "hello world" |> POS(needle="world")              -- 7
LET word2 = "the quick brown" |> WORDPOS(phrase="brown")       -- 3

How It Works:

  1. Parser accepts both positional and named syntax
  2. Parameter-converter translates named params to positional args
  3. Functions receive clean positional arguments
  4. Pipe operator integrates seamlessly with named params

Data-First Functions: Many functions are designed for pipe compatibility where the data flows first:

  • String functions: SUBSTR, POS, WORDPOS, LASTPOS, STRIP, TRIM
  • Array functions: ARRAY_LENGTH, ARRAY_MAP, ARRAY_FILTER, ARRAY_SLICE
  • Validation: IS_EMAIL, IS_URL, IS_NUMBER
  • Encoding: BASE64_ENCODE, URL_ENCODE

See Basic Syntax for complete documentation.

Legend

Status

  • ✅ Pure JS: Works anywhere JavaScript runs
  • 🟡 Environment-dependent: Works in specific environments or has limitations
  • 🔴 External required: Needs RPC, APIs, file system, or external services

Execution Mode

  • Autonomous Web: Direct browser execution, self-contained
  • Controlled Web: Director/Worker iframe architecture with postMessage
  • Command-line: Server or desktop command-line execution with file system access (Node.js dependency)
  • All modes: Language is the same but not all features and integrations available everywhere
  • External: Requires external services or RPC connections

Function Categories

Core Language Functions

String Functions - 60+ functions

  • Basic operations: LENGTH, UPPER, LOWER, SUBSTRING, INDEXOF
  • Advanced processing: SPLIT, JOIN, REPLACE, TRIM, PADLEFT
  • Text manipulation: CAPITALIZE, TITLECASE, SWAPCASE, REVERSE
  • Text processing: HEAD, TAIL, WC, CUT, PASTE, SORT, UNIQ, GREP
  • Line operations: NL, TAC, REV - Number lines, reverse line order, reverse each line
  • Text formatting: FOLD, FMT, EXPAND - Wrap lines, format paragraphs, tabs to spaces
  • Line endings: DOS2UNIX, UNIX2DOS - Convert between Windows/Unix line endings
  • String extraction: STRINGS - Extract printable strings from data
  • Stream editing: SED, TRANSLATE (tr) - Stream editor and character translation
  • File splitting: FILESPLIT, TEE - Split files into chunks, duplicate output
  • Status: ✅ Pure JS, All modes

Mathematical Functions - 25+ functions

  • Basic arithmetic: ABS, SQRT, POWER, MAX, MIN
  • Trigonometry: SIN, COS, TAN, ASIN, ACOS, ATAN, ATAN2
  • Logarithms: LOG, LOG10, EXP
  • Rounding: FLOOR, CEIL, ROUND, TRUNC, SIGN
  • Statistics: REGRESSION, FORECAST
  • Status: ✅ Pure JS, All modes

Array Functions - 18+ functions

  • Creation/modification: ARRAY_CREATE, ARRAY_PUSH, ARRAY_POP, ARRAY_SHIFT
  • Processing: ARRAY_MAP, ARRAY_FILTER, ARRAY_REDUCE, ARRAY_SORT
  • Searching: ARRAY_INCLUDES, ARRAY_INDEXOF, ARRAY_FIND, ARRAY_UNIQUE
  • Utilities: ARRAY_FLATTEN
  • Status: ✅ Pure JS, Both environments

JSON Functions - 21+ functions

  • Core operations: JSON_PARSE, JSON_STRINGIFY, JSON_GET, JSON_SET
  • Advanced processing: JSON_PATH, JSON_FLATTEN, JSON_MERGE, JSON_CLONE
  • Validation: JSON_VALIDATE, JSON_SCHEMA_VALIDATE, JSON_DIFF, JSON_PATCH
  • Status: ✅ Pure JS, Both environments

Data Processing Functions

Date/Time Functions - 17+ functions

  • Current values: DATE, TIME, NOW, TIMESTAMP
  • Formatting: DATEFORMAT, DATEPARSE, DAYNAME, MONTHNAME
  • Calculations: DATEADD, DATEDIFF, QUARTER, WEEKOFYEAR
  • Status: ✅ Pure JS, Both environments

Validation Functions - 29+ functions

  • Format validation: IS_EMAIL, IS_URL, IS_PHONE, IS_CREDIT_CARD
  • Type checking: IS_NUMBER, IS_INTEGER, IS_BOOLEAN, IS_DATE
  • Network validation: IS_IP, IS_MAC, IS_UUID
  • Content validation: IS_ALPHA, IS_ALPHANUMERIC, IS_EMPTY, IS_JSON
  • Advanced validation: VALIDATE_SCHEMA, CHECK_TYPES
  • Status: ✅ Pure JS, Both environments

Regular Expression Functions - 4+ functions

  • Pattern matching: REGEX_MATCH, REGEX_EXTRACT, REGEX_REPLACE, REGEX_SPLIT
  • Full JavaScript regex engine support with flags and capture groups
  • Status: ✅ Pure JS, Both environments

Statistical and Scientific Functions

R-Language Functions - 150+ functions

  • Summary functions: R_MAX, R_MIN, R_SUM, R_MEAN, R_MEDIAN, R_VAR, R_SD
  • Mathematical functions: R_SQRT, R_LOG, R_EXP, R_SIN, R_COS, R_TAN
  • Matrix operations: R_MATRIX, R_CBIND, R_RBIND, R_T, R_DET, R_SOLVE, R_EIGEN
  • Data manipulation: R_C, R_REP, R_SEQ, R_SORT, R_UNIQUE, R_WHICH
  • Apply functions: R_APPLY, R_LAPPLY, R_SAPPLY, R_MAPPLY
  • String functions: R_PASTE, R_NCHAR, R_SUBSTR, R_STRSPLIT
  • Factor functions: R_FACTOR, R_LEVELS, R_NLEVELS
  • DataFrame functions: R_DATA_FRAME, R_HEAD, R_TAIL, R_SUMMARY
  • Time series: R_TS, R_LAG, R_DIFF, R_ACF, R_DECOMPOSE
  • Graphics: R_HIST, R_BOXPLOT, R_SCATTER, R_LINE, R_DENSITY
  • Machine learning: R_LM, R_PREDICT, R_KMEANS, R_PCA
  • Status: ✅ Pure JS (data), 🟡 Canvas dependent (rendering), Both environments

SciPy Interpolation Functions - 16+ functions

  • 1D interpolation: SP_INTERP1D, SP_PCHIP, SP_AKIMA1D
  • 2D interpolation: SP_INTERP2D, SP_GRIDDATA, SP_REGULARGRID
  • Spline functions: SP_SPLREP, SP_SPLEV, SP_CUBIC_SPLINE, SP_LSQ_SPLINE
  • Scattered data: SP_RBF, SP_BARYCENTRIC, SP_KROGH
  • Advanced methods: SP_UNISPLINE, SP_SPLPREP, SP_PPOLY
  • Status: ✅ Pure JS, Both environments

Probability Functions - 22+ functions

  • Distributions: PROB_NORMAL, PROB_BINOMIAL, PROB_POISSON, PROB_EXPONENTIAL
  • Random generation: RANDOM_NORMAL, RANDOM_BINOMIAL, RANDOM_UNIFORM
  • Statistical tests: PROB_CHI_SQUARED, PROB_T, PROB_F
  • Status: ✅ Pure JS, Both environments

Statistical Functions - 5+ functions

  • Descriptive stats: MEAN, MEDIAN, MODE, STDEV, VARIANCE
  • Status: ✅ Pure JS, Both environments

Excel-Compatible Functions

Excel Functions - 18+ functions

  • Lookup functions: VLOOKUP, HLOOKUP, INDEX, MATCH
  • Logical functions: IF, AND, OR, NOT
  • Text functions: CONCATENATE, LEFT, RIGHT, MID, FIND, SUBSTITUTE
  • Conversion functions: TEXT, VALUE
  • Testing functions: ISBLANK, ISERROR
  • Status: ✅ Pure JS, Both environments

Web and Networking Functions

URL Functions - 3+ functions

  • Encoding: URL_ENCODE, URL_DECODE, URL_PARSE
  • Status: ✅ Pure JS, Both environments

Security Functions - 25+ functions

  • Hash functions: HASH_MD5, HASH_SHA1, HASH_SHA256, HASH_SHA384, HASH_SHA512
  • Checksums: CKSUM, CRC32, SUM_BSD - POSIX and BSD checksums
  • Encoding: BASE64_ENCODE, BASE64_DECODE, BASE32, HEX_ENCODE, HEX_DECODE
  • Unix encoding: UUENCODE, UUDECODE - Classic Unix encoding/decoding
  • Hex utilities: XXD, HEXDUMP, OD - Hex/octal dumps with encode/decode
  • Encryption: ENCRYPT_AES, DECRYPT_AES
  • Password hashing: MKPASSWD - bcrypt-compatible password hashing
  • Status: 🟡 Web Cryptography API dependent, Both environments

ID Generation Functions - 4+ functions

  • Identifiers: UUID, MCOOKIE - Generate UUIDs and random hex cookies
  • Random data: SECURE_RANDOM
  • Temporary files: MKTEMP - Generate temp file paths
  • Status: ✅ Built-in crypto (UUID), 🟡 Web Cryptography API dependent (SECURE_RANDOM), Both environments

Compression Functions - 4+ functions

  • Gzip: GZIP, GUNZIP, ZCAT - Compress/decompress gzip data
  • Status: ✅ Pure JS (Node.js zlib built-in), Node.js only

Network Functions - 2+ functions

  • DNS: HOST - DNS lookup, returns IP addresses
  • Network info: IFCONFIG - Network interface information
  • Status: 🟡 Node.js dependent (uses dns and os modules)

System and Environment Functions

File System Functions - 60+ functions

  • File operations: CAT, CP, MV, RM, TOUCH, TRUNCATE, UNLINK, LINK, LN
  • File info: FILE_EXISTS, FILE_SIZE, FILE_MODIFIED, STAT, READLINK
  • Directory operations: MKDIR, RMDIR, LS, FIND, DU
  • Path operations: BASENAME, DIRNAME, PATH_RESOLVE, PATH_EXTNAME
  • Permissions: CHMOD, CHOWN, CHGRP, INSTALL
  • File comparison: CMP, COMM - Compare files byte-by-byte or line-by-line
  • Disk usage: DU - Calculate directory sizes
  • File synchronization: FSYNC, SYNC - Flush data to disk
  • Status: 🟡 Environment dependent (localStorage/OPFS browser, fs Node.js), Both environments

System Information Functions - 15+ functions

  • User info: WHOAMI, USERINFO, LOGNAME, GROUPS - Current user and group information
  • System info: HOSTNAME, UNAME, ARCH, NPROC, UPTIME, DNSDOMAINNAME - System details
  • Environment: ENV(varname), GETENV(varname) - Environment variable access
  • Configuration: GETCONF(name) - System configuration values
  • Terminal: TTY - Check if running in a terminal
  • Status: 🟡 Node.js dependent (uses os module)
  • Examples:
    • SAY "User: " || WHOAMI()
    • SAY "CPUs: " || NPROC()
    • SAY "System: " || UNAME()

Runtime Detection Variables - 6 built-in variables

  • Execution environment: RUNTIME.TYPE - “nodejs”, “browser”, or “pkg”
  • Version info: RUNTIME.NODE_VERSION - Node.js version string
  • Package detection: RUNTIME.IS_PKG - “1” if running as pkg executable, “0” otherwise
  • Capability flags:
    • RUNTIME.HAS_NODEJS_REQUIRE - “1” if require() available
    • RUNTIME.HAS_WINDOW - “1” if window object available
    • RUNTIME.HAS_DOM - “1” if DOM manipulation available
  • Status: ✅ Pure JS, All modes (automatically set by interpreter at startup)
  • Example: IF RUNTIME.TYPE = "nodejs" THEN SAY "Running in Node.js"

DOM Functions - 11+ functions

  • Element interaction: DOM_ELEMENT_CLICK, DOM_ELEMENT_TYPE, DOM_ELEMENT_TEXT
  • Element queries: DOM_GET, DOM_ELEMENT_QUERY, DOM_ELEMENT_VISIBLE
  • Page operations: DOM_WAIT_FOR, DOM_SCREENSHOT, DOM_SCROLL
  • State management: DOM_ELEMENT_STALE, DOM_ELEMENT_ATTRIBUTE
  • Utilities: SLEEP
  • Status: 🔴 Autonomous Web Mode, or remote browser via JSON-RPC

Advanced Processing Functions

Data Functions - 6+ functions

  • Transformation: TRANSPOSE, PIVOT, UNPIVOT, GROUPBY, AGGREGATE, CROSSTAB
  • Status: ✅ Pure JS, Both environments

Logic Functions - 4+ functions

  • Boolean operations: LOGIC_AND, LOGIC_OR, LOGIC_NOT, LOGIC_XOR
  • Status: ✅ Pure JS, Both environments

Utility Functions - 12+ functions

  • Random generation: RANDOM, RANDOM_INT, RANDOM_CHOICE
  • Sequences: SEQ - Generate numeric sequences
  • Shuffling: SHUF - Shuffle lines or arrays randomly
  • Prime factorization: FACTOR - Factor numbers into primes
  • Calendar: CAL - Generate calendar for month/year
  • Command location: WHICH - Search PATH for command
  • Option parsing: GETOPT - Parse command-line options
  • Command building: XARGS - Build and execute commands from input
  • ASCII table: ASCII - ASCII character information and table
  • Timing: TIMEOUT - Run command with time limit
  • Delays: SLEEP, USLEEP - Busy-wait delays
  • Boolean utilities: TRUE, FALSE, YES - Return constants or repeat text
  • Status: ✅ Pure JS, Both environments

Process Management Functions - 2+ functions

  • Signals: KILL - Send signals to processes
  • Timing: TIME - Measure command execution time
  • Status: 🟡 Node.js dependent (uses process module)

Function Availability Summary

By Implementation Status

Status Count Percentage Categories
✅ Pure JS ~400+ ~85% String, Math, Array, JSON, Date/Time, Validation, Regex, Statistical, R-functions (data), SciPy, Probability, Excel, Data, Logic, Utilities, Text Processing
🟡 Environment-dependent ~60 ~13% File operations, System info, Network, Compression, Process management, Crypto functions, R-graphics (rendering)
🔴 External required ~11 ~2% DOM functions

By Environment Support

Environment Function Count Key Categories
Both (Browser + Node.js) ~400+ All core functions, R-functions, SciPy, Statistical analysis, Text processing
Browser only ~11 DOM manipulation and browser automation
Node.js preferred ~60 File system, System info, Network, Compression, Process management

By Functional Domain

Domain Function Count Completeness
Text Processing ~85+ Complete - Unix text tools, string manipulation, regex, validation
Mathematical Computing ~70+ Complete - basic math, advanced statistics, linear algebra
Statistical Analysis ~150+ Comprehensive - R-language compatibility, ML, time series
Data Manipulation ~80+ Complete - JSON, arrays, transformations, Excel compatibility
Scientific Computing ~20+ Specialized - SciPy interpolation, probability distributions
File Operations ~60+ Comprehensive - Unix file tools, permissions, disk usage
System Information ~25+ Complete - user info, system details, environment variables
Security & Encoding ~25+ Complete - hashing, checksums, encoding, encryption
Web Development ~25+ Partial - URL handling, validation, limited DOM access
Utilities ~20+ Complete - sequences, random, calendar, command tools

Cross-Reference by Use Case

Data Analysis Workflows

  • Data loading: JSON functions, File operations, Array creation
  • Data cleaning: Regex functions, String functions, Validation functions
  • Statistical analysis: R-functions (summary, mathematical, statistical)
  • Visualization: R-graphics functions (histogram, scatter, boxplot, etc.)
  • Modeling: R-functions (linear models, clustering, PCA)

Text Processing Pipelines

  • Pattern matching: Regex functions (match, extract, replace, split)
  • String manipulation: String functions (transform, format, analyze)
  • Validation: Validation functions (format checking, type verification)
  • Data extraction: Regex + JSON functions for structured data

Scientific Computing

  • Interpolation: SciPy functions (1D/2D, splines, scattered data)
  • Statistical distributions: Probability functions (generation, analysis)
  • Linear algebra: R-matrix functions (operations, decomposition)
  • Signal processing: R-signal functions (FFT, filtering, analysis)

Web Applications

  • Input validation: Validation + Regex functions
  • Data processing: JSON + Array functions
  • User interface: DOM functions (browser automation)
  • Security: Security functions (hashing, encryption)

Implementation Coverage

This Rexx interpreter provides exceptional functional coverage across domains:

  • ~470+ total functions spanning 35+ categories
  • ~85% pure JavaScript implementation - works offline without dependencies
  • Complete Unix command-line toolset - 85+ text processing and file operations
  • Complete R-language statistical suite - 150+ functions for data science
  • Advanced interpolation library - 16 methods including scattered data and splines
  • Comprehensive security toolkit - 25+ hashing, checksum, and encoding functions
  • System integration layer - 25+ OS info, process, and network functions
  • Excel compatibility layer - familiar spreadsheet functions
  • Modern web capabilities - JSON, validation, security, DOM interaction

The interpreter achieves near-complete Unix shell equivalence for text processing while providing research-grade statistical computing and production-ready data manipulation capabilities in a single JavaScript environment.