com.google.template.soy.soytree

Class MsgSubstUnitBaseVarNameUtils

java.lang.Object

com.google.template.soy.soytree.MsgSubstUnitBaseVarNameUtils

public final class MsgSubstUnitBaseVarNameUtils
extends Object

Static helpers for generating base names for msg substitution units (i.e. placeholder names and plural/select vars).

Important: Do not use outside of Soy code (treat as superpackage-private).

Method Summary

Modifier and Type	Method and Description
static String	genNaiveBaseNameForExpr(ExprNode exprNode, String fallbackBaseName) Helper function to generate a base placeholder (or plural/select var) name from an expression, using the naive algorithm.
static List<String>	genNoncollidingBaseNamesForExprs(List<ExprNode> exprNodes, String fallbackBaseName, ErrorReporter errorReporter) Generates base names for all the expressions in a list, where for each expression, we use the shortest candidate base name that does not collide with any of the candidate base names generated from other expressions in the list.
static String	genShortestBaseNameForExpr(ExprNode exprNode, String fallbackBaseName) The equivalent of genNaiveBaseNameForExpr() in our new algorithm for generating base name.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

genNaiveBaseNameForExpr

public static String genNaiveBaseNameForExpr(ExprNode exprNode,
                                             String fallbackBaseName)

Helper function to generate a base placeholder (or plural/select var) name from an expression, using the naive algorithm.

If the expression is a data ref or global, then the last key (if any) is used as the base placeholder name. Otherwise, the fallback name is used.

Examples:

• $aaaBbb -> AAA_BBB
• $aaa_bbb -> AAA_BBB
• $aaa.bbb -> BBB
• $ij.aaa -> AAA
• aaa.BBB -> BBB
• $aaa.0 -> fallback
• $aaa[0] -> fallback
• $aaa[0].bbb -> BBB
• length($aaa) -> fallback
• $aaa + 1 -> fallback

Parameters:

exprNode - The root node for an expression.

fallbackBaseName - The fallback base name.

Returns:

The base placeholder (or plural/select var) name for the given expression.

genShortestBaseNameForExpr

public static String genShortestBaseNameForExpr(ExprNode exprNode,
                                                String fallbackBaseName)

The equivalent of genNaiveBaseNameForExpr() in our new algorithm for generating base name.

Examples:

• $aaaBbb -> AAA_BBB
• $aaa_bbb -> AAA_BBB
• $aaa.bbb -> BBB
• $ij.aaa -> AAA
• aaa.BBB -> BBB
• $aaa.0 -> AAA_0
• $aaa[0] -> AAA_0
• $aaa[0].bbb -> BBB
• length($aaa) -> fallback
• $aaa + 1 -> fallback

Parameters:

exprNode - The expr root of the expression to generate the shortest base name for.

fallbackBaseName - The fallback base name to use if the given expression doesn't generate any base names.

Returns:

The generated base name.

genNoncollidingBaseNamesForExprs

public static List<String> genNoncollidingBaseNamesForExprs(List<ExprNode> exprNodes,
                                                            String fallbackBaseName,
                                                            ErrorReporter errorReporter)

Generates base names for all the expressions in a list, where for each expression, we use the shortest candidate base name that does not collide with any of the candidate base names generated from other expressions in the list. Two candidate base names are considered to collide if they are identical or if one is a suffix of the other beginning after an underscore character.

For example, given the expressions $userGender and $target.gender, the generated base names would be USER_GENDER and TARGET_GENDER. (Even though the shortest candidate base names are USER_GENDER and GENDER, the latter one is not used since it collides with the former one.)

Note: We prefer the shorter candidate base names when possible, because the translator usually doesn't care about all the names. E.g. $data.actionTargets[0].personInfo.gender turns into GENDER as opposed to DATA_ACTION_TARGETS_0_PERSON_INFO_GENDER, which is overkill and probably more confusing. Another reason is that refactorings that change higher-level names should not change messages unnecessarily. E.g. a refactoring that changes $data.actionTargets[0].personInfo.gender -> $userData.actionTargets[0].personInfo.gender should not change the placeholder name.

Parameters:

exprNodes - The expr nodes of the expressions to generate noncolliding base names for.

fallbackBaseName - The fallback base name.

errorReporter - For reporting collision errors.

Returns:

The list of generated noncolliding base names.