gsl-shell.git - gsl-shell

diff --git a/expr-lexer.lua b/expr-lexer.lua
index c13b1c38..f464cff1 100644
--- a/expr-lexer.lua
+++ b/expr-lexer.lua

@@ -8,10 +8,25 @@ local lexer_mt = {

local literal_chars = {['('] = 1, [')'] = 1, ['~'] = 1, [','] = 1, ['|'] = 1, [':'] = 1}

-local oper_table = {['+'] = 0, ['-'] = 0, ['*'] = 1, ['/'] = 1, ['^'] = 2, ['='] = 3, ['>'] = 3, ['<'] = 3, ['%'] = -1}

+local oper_table = {['+'] = 2, ['-'] = 2, ['*'] = 3, ['/'] = 3, ['^'] = 4, ['!='] = 1, ['='] = 1, ['>'] = 1, ['>='] = 1, ['<'] = 1, ['<='] = 1, ['AND'] = 0, ['OR'] = 0, ['%'] = -1}

expr_lexer.operators = oper_table

-expr_lexer.max_oper_prio = 3

+expr_lexer.max_oper_prio = 4

+

+local oper_start_sym

+local function compile_oper_pattern()

+ local oper_start_set = {}

+ for k in pairs(oper_table) do

+ oper_start_set[k:sub(1,1)] = true

+ end

+

+ oper_start_sym = '['

+ for k in pairs(oper_start_set) do

+ local str = (k == '-' or k == '%' or k == '^') and ('%' .. k) or k

+ oper_start_sym = oper_start_sym .. str

+ end

+ oper_start_sym = oper_start_sym .. ']'

+end

function expr_lexer.new(src)

local lexer = {n = 1, src= src}

@@ -48,6 +63,35 @@ function expr_lexer.skip(lexer, pattern)

if m then lexer.n = lexer.n + len(m) end

end

+local function consume_oper(lexer, c)

+ local op

+ if lexer:match('AND[^%l%u_]') then

+ lexer:consume('AND')

+ op = 'AND'

+ elseif lexer:match('OR[^%l%u_]') then

+ lexer:consume('OR')

+ op = 'OR'

+ elseif lexer:match('>=') then

+ lexer:consume('>=')

+ op = '>='

+ elseif lexer:match('<=') then

+ lexer:consume('<=')

+ op = '<='

+ elseif lexer:match('!=') then

+ lexer:consume('!=')

+ op = '!='

+ else

+ op = oper_table[c] and c

+ if op then

+ lexer:incr()

+ end

+ end

+ if op then

+ local prio = oper_table[op]

+ return {type= 'operator', symbol= op, priority = prio}

+ end

+end

+

function expr_lexer.next_token(lexer)

lexer:skip('%s*')

if lexer.n > len(lexer.src) then return {type= 'EOF'} end

@@ -60,10 +104,9 @@ function expr_lexer.next_token(lexer)

local str = lexer:consume('%b[]')

return {type= 'ident', value= str:sub(2,-2)}

end

- if oper_table[c] then

- local prio = oper_table[c]

- lexer:incr()

- return {type= 'operator', symbol= c, priority = prio}

+ if lexer:match(oper_start_sym) then

+ local elt = consume_oper(lexer, c)

+ if elt then return elt end

end

if literal_chars[c] then

lexer:incr()

@@ -94,4 +137,6 @@ function expr_lexer.local_error(lexer, msg, n_pos)

error(string.format("%s\n%s\n%s", msg, line, pos))

end

+compile_oper_pattern()

+

return expr_lexer

diff --git a/expr-print.lua b/expr-print.lua
index 4c73f44d..543ee58a 100644
--- a/expr-print.lua
+++ b/expr-print.lua

@@ -66,6 +66,11 @@ local function eval_operator(op, a, b)

elseif op == '=' then return (a == b and 1 or 0)

elseif op == '>' then return (a > b and 1 or 0)

elseif op == '<' then return (a < b and 1 or 0)

+ elseif op == '!=' then return (a ~= b and 1 or 0)

+ elseif op == '>=' then return (a >= b and 1 or 0)

+ elseif op == '<=' then return (a <= b and 1 or 0)

+ elseif op == 'AND' then return ((a ~= 0 and b ~= 0) and 1 or 0)

+ elseif op == 'OR' then return ((a ~= 0 or b ~= 0) and 1 or 0)

else error('unkown operation: ' .. op) end

end