From 8fa41a15f184660ab5bda5f86d645ba9b2582389 Mon Sep 17 00:00:00 2001 From: Sean Whitton Date: Thu, 16 Mar 2023 11:56:31 -0700 Subject: support indented heredocs, add new "Reader macros" manual section Signed-off-by: Sean Whitton --- src/reader.lisp | 72 ++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 58 insertions(+), 14 deletions(-) (limited to 'src/reader.lisp') diff --git a/src/reader.lisp b/src/reader.lisp index e4f15b9..f744fa4 100644 --- a/src/reader.lisp +++ b/src/reader.lisp @@ -1,6 +1,6 @@ ;;; Consfigurator -- Lisp declarative configuration management system -;;; Copyright (C) 2021 Sean Whitton +;;; Copyright (C) 2021, 2023 Sean Whitton ;;; This file is free software; you can redistribute it and/or modify ;;; it under the terms of the GNU General Public License as published by @@ -17,20 +17,64 @@ (in-package :consfigurator) +(defun lines (text &optional trimfun (trimchars '(#\Space #\Tab))) + (with-input-from-string (stream text) + (let (bolp buffer) + (flet ((trim (line) + (if trimfun (funcall trimfun trimchars line) line)) + (reset () + (setq bolp t + buffer (make-array 0 :fill-pointer 0 + :element-type 'character)))) + ;; Split on either , or ; would mean split + ;; with a blank line in between. Drop a single trailing blank line. + (loop initially (reset) + for char = (read-char stream nil nil) + if char + if (member char '(#\Return #\Newline) :test #'char=) + collect (trim buffer) + and do (reset) + (when (char= char #\Return) + (when-let ((next (peek-char nil stream nil nil))) + (when (char= next #\Newline) + (read-char stream)))) + else do (setq bolp nil) + (vector-push-extend char buffer) + end + else + unless bolp collect (trim buffer) end + and do (loop-finish)))))) + +(defun unlines (lines) + (format nil "~{~A~%~}" lines)) + (defun read-heredoc (stream char arg) - "Like CL-HEREDOC:READ-HEREDOC but treat #>EOF> and #>>EOF>> differently: -#>>EOF>> skips over the remainder of the current line and its newline. -For the sake of future extension, the remainder of the line after the #>>EOF>> -should not contain anything other than a single-line comment." - (if (char= (peek-char nil stream t :eof t) char) - ;; #>>EOF>> -- ignore the rest of the line. - (progn (read-char stream t :eof t) - (let* ((delim (make-string 2 :initial-element char)) - (ender (cl-heredoc:read-until-match stream delim))) - (read-line stream t :eof t) - (cl-heredoc:read-until-match stream ender))) - ;; #>EOF> -- just use the normal READ-HEREDOC. - (cl-heredoc:read-heredoc stream char arg))) + "Like CL-HEREDOC:READ-HEREDOC, with some additional features. + +Treat #>EOF> and #>>EOF>> differently: #>>EOF>> skips over the remainder of +the current line and its newline. For the sake of future extension, the +remainder of the line after the #>>EOF>> must not contain anything other than +a single-line comment. + +Preceding the specification of the terminating string with a tilde means an +indented heredoc; see perlop(1)." + (declare (ignore arg)) + (let* ((>> (and (char= char (peek-char nil stream t :eof t)) + (read-char stream t :eof t))) + (indented (and (char= #\~ (peek-char nil stream t :eof t)) + (read-char stream t :eof t))) + (delim (if >> (make-string 2 :initial-element char) (string char))) + (ender (cl-heredoc:read-until-match stream delim))) + (when >> + (read-line stream t :eof t)) + (let ((heredoc (cl-heredoc:read-until-match stream ender))) + (if indented + (loop with lines = (lines heredoc) + with indent = (length (lastcar lines)) + for (line . rest) on lines while rest + collect (subseq line (min indent (length line))) into accum + finally (return (unlines accum))) + heredoc)))) (named-readtables:defreadtable :consfigurator (:merge :standard) -- cgit v1.2.3