scrappy-file

File system utilities for the scrappy web scraping library, plus pgrep - a grep-like CLI that uses Parsec parsers instead of regex.

pgrep

Search files using Parsec parser patterns instead of regular expressions.

Installation

cabal build pgrep
cabal install pgrep

Make sure ~/.local/bin is in your PATH:

export PATH="$HOME/.local/bin:$PATH"

Usage

pgrep PATTERN FILE...
pgrep [OPTIONS] PATTERN FILE...

DSL Primitives

Primitive	Example	Description
char	char 'x'	Single character
string	string "abc"	Literal string
anyChar	anyChar	Any character
digit	digit	0-9
letter	letter	a-z, A-Z
alphaNum	alphaNum	Letter or digit
space	space	Single whitespace
spaces	spaces	Zero or more whitespace
newline	newline	Newline character
oneOf	oneOf "abc"	Match one of chars
noneOf	noneOf "xyz"	Match none of chars

DSL Combinators

Combinator	Syntax	Description
Sequence	p1 >> p2	Run p1 then p2, return p2's result
Concat	p1 <+> p2	Run both, concatenate results
Alternative	p1 <|> p2	Try p1, else p2
Many	many p	Zero or more
Some	some p	One or more
Optional	optional p	Zero or one
Try	try p	Backtracking
Between	between '(' ')' p	Parse between delimiters
Count	count 3 p	Exactly n repetitions
ManyTill	manyTill p end	Non-greedy: match p until end

Examples

# Find digits
pgrep 'some digit' file.txt

# Find email patterns
pgrep 'some alphaNum <+> char '\''@'\'' <+> some alphaNum <+> char '\''.'\'' <+> some letter' contacts.txt

# Find TODO comments
pgrep 'string "TODO"' -r ./src/

# Search recursively with extension filter
pgrep -r -e .hs 'string "import"' ./src/

# Count matches
pgrep -c 'digit' data.txt

# JSON output
pgrep --json 'some digit' file.txt

# Non-greedy matching: find everything between X and Y
pgrep 'string "START" <+> manyTill anyChar (string "END")' file.txt

Options

-r, --recursive      Search directories recursively
-e, --extension EXT  Only search files with extension (e.g., .hs, .txt)
-v, --verbose        Verbose output with full match text
-c, --count          Only print count of matches
-q, --quiet          Quiet mode (exit code only)
-m, --max-results N  Maximum number of results to show
--json               Output results as JSON

Output Format

Default output is grep-like:

file.txt:1:28:123
file.txt:2:5:test@example.com

Format: filepath:line:column:matched_text

Library API

The Scrappy.Grep.* modules expose:

• Scrappy.Grep.DSL - AST types (ParserExpr, MatchResult)
• Scrappy.Grep.DSL.Parser - Parse DSL strings to AST
• Scrappy.Grep.DSL.Interpreter - Convert AST to Parsec parsers
• Scrappy.Grep.Search - File/directory search functions
• Scrappy.Grep.Output - Result formatting