Added optional Lua lexer support.

This support is disabled by default and must be enabled via compile-time option.

1 files changed, 48 insertions, 0 deletions

diff --git a/lexlua/ledger.lua b/lexlua/ledger.lua
new file mode 100644
index 000000000..a697a6d8b
--- /dev/null
+++ b/lexlua/ledger.lua
@@ -0,0 +1,48 @@
+-- Copyright 2015-2018 Charles Lehner. See License.txt.
+-- ledger journal LPeg lexer, see http://www.ledger-cli.org/
+
+local lexer = require('lexer')
+local token, word_match = lexer.token, lexer.word_match
+local P, R, S = lpeg.P, lpeg.R, lpeg.S
+
+local lex = lexer.new('ledger', {lex_by_line = true})
+
+local delim = P('\t') + P('  ')
+
+-- Account.
+lex:add_rule('account', token(lexer.VARIABLE,
+                              lexer.starts_line(S(' \t')^1 *
+                                                (lexer.print - delim)^1)))
+
+-- Amount.
+lex:add_rule('amount', token(lexer.NUMBER, delim * (1 - S(';\r\n'))^1))
+
+-- Comments.
+lex:add_rule('comment', token(lexer.COMMENT, S(';#') * lexer.nonnewline^0))
+
+-- Whitespace.
+lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
+
+-- Strings.
+local sq_str = lexer.delimited_range("'")
+local dq_str = lexer.delimited_range('"')
+local label = lexer.delimited_range('[]', true, true)
+lex:add_rule('string', token(lexer.STRING, sq_str + dq_str + label))
+
+-- Date.
+lex:add_rule('date', token(lexer.CONSTANT,
+                           lexer.starts_line((lexer.digit + S('/-'))^1)))
+
+-- Automated transactions.
+lex:add_rule('auto_tx', token(lexer.PREPROCESSOR,
+                              lexer.starts_line(S('=~') * lexer.nonnewline^0)))
+
+-- Directives.
+local directive_word = word_match[[
+	account alias assert bucket capture check comment commodity define end fixed
+  endfixed include payee apply tag test year
+]] + S('AYNDCIiOobh')
+lex:add_rule('directive', token(lexer.KEYWORD,
+                                lexer.starts_line(S('!@')^-1 * directive_word)))
+
+return lex