The pratt command is a stripped-down expression parser based on the
Pratt parser. To help understand Pratt parsing, the command also
provides a naive, recursive, right-associative expression parser and a naive,
iterative, left-associative expression parser.
Try it with:
go run ./main.go '1 + 2 * 3'
pratt is intended for demonstration and education purposes only. It is
purposefully thin on error handling. The input expression is expected to be a
valid, using known operators only: <, +, -, *, /. Operators and
operands must be separated by a single space, e.g. 1 + 2 * 3.
The svg command is meant to be used with the pratt command. It generates
and opens an SVG image of the expression tree in the default SVG viewer.
Try it with:
go install ./...
pratt '1 * 2 + 3 * 4' | svg -o
You can install the pratt command without cloning and rebuilding this repo.
Download the latest release for your platform, unzip it and add pratt
to your path.
Use Homebrew to install pratt.
brew install evylang/tap/pratt