o 8Va@sldZddlmZddlmZefddZddZefd d Zd d Zd dZ ddZ efddZ ddZ dS)zP Generic Rules for SymPy This file assumes knowledge of Basic and little else. )sift)newcfdd}|S)a Create a rule to remove identities. isid - fn :: x -> Bool --- whether or not this element is an identity. Examples ======== >>> from sympy.strategies import rm_id >>> from sympy import Basic >>> remove_zeros = rm_id(lambda x: x==0) >>> remove_zeros(Basic(1, 0, 2)) Basic(1, 2) >>> remove_zeros(Basic(0, 0)) # If only identites then we keep one Basic(0) See Also: unpack csftt|j}t|dkr|St|t|kr*|jgddt|j|DRS|j|jdS)z Remove identities rcSsg|]\}}|s|qSr).0argxrr5/usr/lib/python3/dist-packages/sympy/strategies/rl.py $sz/rm_id..ident_remove..)listmapargssumlen __class__zip)exprZidsisidrrr ident_removes zrm_id..ident_remover)rrrrrr rm_id s rcsfdd}|S)a6 Create a rule to conglomerate identical args. Examples ======== >>> from sympy.strategies import glom >>> from sympy import Add >>> from sympy.abc import x >>> key = lambda x: x.as_coeff_Mul()[1] >>> count = lambda x: x.as_coeff_Mul()[0] >>> combine = lambda cnt, arg: cnt * arg >>> rl = glom(key, count, combine) >>> rl(Add(x, -x, 3*x, 2, 3, evaluate=False)) 3*x + 5 Wait, how are key, count and combine supposed to work? >>> key(2*x) x >>> count(2*x) 2 >>> combine(2, x) 2*x csbt|j}fdd|D}fdd|D}t|t|jkr/tt|g|RS|S)z2 Conglomerate together identical args x + x -> 2x cs i|] \}}|tt|qSr)rr )rkr)countrr Hs z.glom..conglomerate..csg|] \}}||qSrr)rZmatZcnt)combinerr r Isz.glom..conglomerate..)rritemssetrtype)rgroupsZcountsZnewargsrrkeyrr conglomerateEs zglom..conglomerater)r!rrr"rr r glom*s r#cr)z Create a rule to sort by a key function. Examples ======== >>> from sympy.strategies import sort >>> from sympy import Basic >>> sort_rl = sort(str) >>> sort_rl(Basic(3, 1, 2)) Basic(1, 2, 3) cs|jgt|jdRS)N)r!)rsortedrrr!rrr sort_rl^szsort..sort_rlr)r!rr'rr&r sortQs r(cr)aW Turns an A containing Bs into a B of As where A, B are container types >>> from sympy.strategies import distribute >>> from sympy import Add, Mul, symbols >>> x, y = symbols('x,y') >>> dist = distribute(Mul, Add) >>> expr = Mul(2, x+y, evaluate=False) >>> expr 2*(x + y) >>> dist(expr) 2*x + 2*y cspt|jD]0\}}t|r5|jd||j||j|dd}fdd|jDSq|S)Nrcsg|] }|fqSrr)rr)Afirsttailrr r vsz5distribute..distribute_rl..) enumerater isinstance)rirbr)B)r*r+r distribute_rlrs  . z!distribute..distribute_rlr)r)r1r2rr0r distributebsr3cr)z Replace expressions exactly cs|krS|S)Nrr%ar/rr subs_rl|szsubs..subs_rlr)r5r/r6rr4r subszsr7cCst|jdkr |jdS|S)z Rule to unpack singleton args >>> from sympy.strategies import unpack >>> from sympy import Basic >>> unpack(Basic(2)) 2 rr)rrr%rrr unpacks r8cCsJ|j}g}|jD]}|j|kr||jq||q||jg|RS)z9 Flatten T(a, b, T(c, d), T2(e)) to T(a, b, c, d, T2(e)) )rrextendappend)rrclsrrrrr flattens   r<cCs |jr|S|jttt|jS)z Rebuild a SymPy tree. Explanation =========== This function recursively calls constructors in the expression tree. This forces canonicalization and removes ugliness introduced by the use of Basic.__new__ )Zis_Atomfuncr r rebuildrr%rrr r>s r>N) __doc__Zsympy.utilities.iterablesrutilrrr#r(r3r7r8r<r>rrrr s    '