Lumesh Parse Module

Lumesh Parsing Functions Documentation

Function Overview

Function Category	Function Name	Call Format	Description
Data Parsing	`json`	`parse.json json_str`	Parse a JSON string into Lumesh data structure
Data Parsing	`toml`	`parse.toml toml_str`	Parse a TOML string into Lumesh data structure
Data Parsing	`csv`	`parse.csv csv_str`	Parse a CSV string into Lumesh data structure
Code Parsing	`expr`	`parse.expr lumesh_code`	Parse a Lumesh code string into an executable expression
Command Parsing	`cmd`	`parse.cmd [headers...] output`	Parse command line output into structured data
Data Serialization	`to_json`	`parse.to_json expr`	Serialize Lumesh data structure into a JSON string
Data Serialization	`to_toml`	`parse.to_toml expr`	Serialize Lumesh data structure into a TOML string
Data Serialization	`to_csv`	`parse.to_csv expr`	Serialize Lumesh data structure into a CSV string
JSON Query	`jq`	`parse.jq json_str`	Perform common JSON queries, supporting pipes, attributes, indices, and select

Detailed Descriptions and Examples

1. `parse.toml`

Parameters:

toml_str: String type, containing valid TOML content

Output Example:

parse.toml "name = 'Alice'\nage = 30"

#   Returns:
   +---------------------+
   | KEY    VALUE        |
   +=====================+
   | name   "Alice"      |
   | age    30           |
   +---------------------+

To convert back to a string, use parse.to_toml on the expression.

2. `parse.json`

Parameters:

json_str: String type, containing valid JSON content

Nested Structure Output:

parse.json '{"name":"Alice","hobbies":["reading","swimming"]}'
# or
parse.json "{\"name\":\"Alice\",\"hobbies\":[\"reading\",\"swimming\"]}"

#   Returns:
   +---------------------------------+
   | KEY      VALUE                  |
   +=================================+
   | age      30                     |
   | hobbies  ┌─────────┬──────────┐ |
   |          │ reading │ swimming │ |
   |          └─────────┴──────────┘ |
   | name     "Alice"                |
   +---------------------------------+

To convert back to a string, use parse.to_json on the expression.

3. `parse.csv`

Parameters:

csv_str: String type, containing valid CSV content

Nested Structure Output:

parse.csv "Product Name,Category,Price,Stock
Laptop,Electronics,999.99,50
Smartphone,Electronics,499.99,150
Desk Chair,Furniture,89.99,75
Coffee Maker,Appliances,29.99,200
Notebook,Stationery,2.99,500
"

# Output
+------------------------------------------+
| CATEGORY     PRICE   PRODUCT NAME  STOCK |
+==========================================+
| Electronics  999.99  Laptop        50    |
| Electronics  499.99  Smartphone    150   |
| Furniture    89.99   Desk Chair    75    |
| Appliances   29.99   Coffee Maker  200   |
| Stationery   2.99    Notebook      500   |
+------------------------------------------+

To convert back to a string, use parse.to_csv on the expression.

4. `parse.expr`

Parameters:

lumesh_code: String type, containing valid Lumesh syntax

Dynamic Code Execution:

let code = "x -> math.max(x, 5)"
let action = parse.expr(code)
action(2)                #=> 5

5. `parse.cmd`

Parameter Modes:

Mode	Example	Description
Auto Detection	`parse.cmd output`	Smartly detects headers and data rows
List Headers	`parse.cmd [h1, h2] output`	Specify a list of headers
Multiple Parameters	`parse.cmd h1 h2 ... output`	Directly specify multiple headers

Table Output Example:

parse.cmd(["ID", "NAME", "AGE"], "1 Alice 30\n2 Bob 25")

#  Returns:
   +------------------------------+
   | ID  NAME    AGE              |
   +==============================+
   | 1   "Alice" 30               |
   | 2   "Bob"   25               |
   +------------------------------+

Complex Structure Output:

parse.cmd "ITEM  QTY  PRICE
Apple  10   2.5
Banana 5    1.8"

#   Returns:
   +---------------------------------+
   | ITEM    QTY   PRICE             |
   +=================================+
   | Apple   10    2.5               |
   | Banana  5     1.8               |
   +---------------------------------+

6. `parse.jq`

Parameters:

query_str: String type, containing valid JSON queries, supporting pipes, attributes, indices, and select
Pipe: |
Attribute Access: .name
Wildcard: .[] returns the entire array
Select statements support basic comparison operators: >, <, >=, <=, ==, !=
json_str: String type, containing valid JSON content

let a = '[{"name": "Alice", "age": 30}, {"name": "Bob", "age": 25}]'

parse.jq '[0]|.name' a         # Output: "Alice"
parse.jq 'select(.age>28)' a   # Output: [{"name":"Alice","age":30}]

Special Case Handling

Pre-structured Data Recognition

parse.cmd "1, 2, 3"
# Directly returns a list:
  +-------------+
  | C0   C1  C2 |
  +=============+
  | 1,   2,  3  |
  +-------------+

Header Auto-conversion

parse.cmd "CPU%  MEM(MB) MAJ:MIN\n50    1024   259:0"
# After header conversion:
  +-----------------------+
  | CPU%  MAJ_MIN  MEM_MB |
  +=======================+
  | 50    259:0    1024   |
  +-----------------------+

Empty Input Handling

parse.toml ""   ; => none
parse.cmd ""    ; => [] (empty list)

# Output:
  +------------+
  | KEY  VALUE |
  +============+
  +------------+

Best Practices

parse.cmd is generally used to convert the results of system commands from strings to structured tables.

ps aux | head -n4 | parse.cmd()

# Output:
+-------------------------------------------------------------------------------------+
| %CPU  %MEM  COMMAND                   PID  RSS   START  STAT  TIME  TTY  USER  VSZ  |
+=====================================================================================+
| 0.0   0.0   /sbin/init                1    1932  09:05  S     0:00  ?    root  2608 |
| 0.0   0.0   [kthreadd]                2    0     09:05  S     0:00  ?    root  0    |
| 0.0   0.0   [pool_workqueue_release]  3    0     09:05  S     0:00  ?    root  0    |
+-------------------------------------------------------------------------------------+

parse.cmd is often used in conjunction with where and select statements.

ps aux | parse.cmd() | where(COMMAND ~: "lume") | select "%CPU" COMMAND RSS

# Output:
+----------------------------------+
| %CPU  COMMAND              RSS   |
+==================================+
| 0.0   ./target/debug/lume  10476 |
| 0.0   ./target/debug/lume  12148 |
+----------------------------------+

Lumesh’s built-in module commands do not require parse.cmd conversion and can directly use where and select.

fs.ls -l -k | where(size > 8)

# Output
+---------------------------------------------------------------+
| MODE  MODIFIED                       NAME          SIZE  TYPE |
+===============================================================+
| 420   2025-06-01 06:12:18.911115732  Cargo.lock    47    file |
| 420   2025-05-30 10:26:40.122231239  CHANGELOG.md  10    file |
+---------------------------------------------------------------+

updated at 2025-06-12

# libs # parse # json # toml # csv # jq

Lumesh Parse Module

Lumesh Parsing Functions Documentation

Function Overview

Detailed Descriptions and Examples

1. parse.toml

2. parse.json

3. parse.csv

4. parse.expr

5. parse.cmd

6. parse.jq

Special Case Handling

Pre-structured Data Recognition

Header Auto-conversion

Empty Input Handling

Best Practices

1. `parse.toml`

2. `parse.json`

3. `parse.csv`

4. `parse.expr`

5. `parse.cmd`

6. `parse.jq`